-
Yukon Research Centre 1 / 52
Michel Duteau, Cold Climate Innovation Centre
Yukon College | 500 College Drive, PO Box 2799, Whitehorse,
Yukon Y1A 5K4
Fish Silage Project: Experimental protocol and Annotated
Bibliography
MICHEL DUTEAU Yukon Research Centre, Yukon College, 500 College
Drive, Whitehorse YT Y1A 5K4 Phone: (867) 689-8490, Fax: (867)
456-8672, email: [email protected]
Oct 27, 2015
Yukon Cold Climate Innovation Centre at Yukon College
-
Michel Duteau, Cold Climate Innovation Centre
Yukon College | 500 College Drive, PO Box 2799, Whitehorse,
Yukon Y1A 5K4
-
Michel Duteau and Amlie Janin, NSERC Industrial Research Chair
in Mine Life Cycle
Yukon College | 500 College Drive, PO Box 2799, Whitehorse,
Yukon Y1A 5K4
PROJECT INVESTIGATORS AND PARTNERS
This project was prepared in agreement with and in partnership
with:
_________________________________
_______________________________
Michel Duteau Ziad Sahid
Yukon Research Centre Yukon Research Center
_________________________________
Jonathan Lucas
Grizzly Pigs Farm
Yukon Cold Climate Innovation Centre is providing the funding
for this project, through its funding partnerships and
agreements.
-
Michel Duteau and Amlie Janin, NSERC Industrial Research Chair
in Mine Life Cycle
Yukon College | 500 College Drive, PO Box 2799, Whitehorse,
Yukon Y1A 5K4
INTRODUCTION
Fish silage definition
Fish silage can be defined as a liquid product made from whole
fish or parts of fish that are liquefied by the action of enzymes
in the fish in the presence of an added acid (Tatterson and
Windsor, 2001).
Current situation
It is estimated that fish processing for human consumption
yields around 40% of edible meat, while the remnant 60% composed of
bones, skin, head, viscera, meat scraps and scales, is fishery
by-products (Gildberg 1993 in Ramirez, 2013).
The technology required to produce fish silage is much simpler
than that needed for fish meal. Fish silage thus has a net
advantage in areas where the tonnage of waste material is
insufficient to justify the production of fish meal and it is
estimated that fish silage is most likely to be successful in areas
where fish offal or waste fish is regularly available, but the cost
of sending it to the nearest meal plant is prohibitive, and where
there are farms, particularly pig farms, close by (Tatterson and
Windsor, 2001).
According to estimates by Bimbo (2012), cold crude fish silage
sold for USD 70-173/metric ton on the Alaska market during
1998-2007. For the purpose of the present analysis, a conservative
estimate would be that farmers would have to pay CAD 200/metric ton
for fish silage on the Yukon market in 2015.
Aim and objectives
The objectives of fish silage production in the Yukon are
to:
- lower the cost of animal production in the Yukon (pigs,
broiler chickens and laying hens),
through the production of a local feed option
- unlock the value of fish waste (Icy Waters Ltd. fish offal and
casualties)
- make use of available fish resource (chum salmon)
The vision is that fish silage can be manufactured at a
commercial scale and distributed as a wet mash to animal husbandry
operations in the Yukon
An introductory experiment was conducted during summer 2014 at
Icy Waters Ltd., where it was established that it is possible to
transformed fish offal into fish silage using formic acid.
With this project, we intend in developing guidelines as to fish
silage production in the Yukon from two main sources: Icy Waters
fish waste, and chum salmon. We also want to assess the
bioequivalence of fish silage when compared to feed stuff that is
conventionally used in the Yukon i.e. we want to prove that
replacing conventional (imported) protein with locally-sourced fish
silage does not have a negative impact on animal productions. Thus,
a comparative experiment is designed to test the fish silage diet
on a sample of pigs, broiler chickens and laying hens, and infer
conclusions onto all such animals in Yukon conditions.
-
Michel Duteau and Amlie Janin, NSERC Industrial Research Chair
in Mine Life Cycle
Yukon College | 500 College Drive, PO Box 2799, Whitehorse,
Yukon Y1A 5K4
EXPERIMENTAL PROTOCOL
Setup
The feeding trials were designed to be conducted in the fall
(October-December) of 2015 at Grizzly Pigs farm, situated North of
Whitehorse Yukon, on the Mayo Road. Grizzly Pigs Farm produced pig,
broiler chickens, and eggs. Following dismantlement of Grizzly Pigs
Farm in the fall of 2015, the feeding trials can be conducted where
the animals now are hosted, contingent on conditions
suitability.
Grizzly Pigs Farm rears two kinds of pig, with hybrids and back
crossings: English Large Black (Figure 3) and Landrac-Durac (pink;
Figure 4 ). The pigs range in outdoor wind-protected (low bush)
paddocks, and have access to sheltered wood hutches. All piglets
are weaned (separated from the mother) at 1 month. Male piglets are
castrated at 4-5 days (barrows). All pigs are vaccinated for
Parvovirus and Legionella twice a year. The pigs are butchered
(market weight) at 100 kg (220 lb), which is attained at
approximately 4 months of age.
In the fall (Sept-Oct) of 2015, 6 litters are expected, with 4-6
piglets each. 3 pink and 1 black sows were bred with a same pink
boar. 1 black and 1 hybrid black/pink sows were bred with a same
black boar. All in all, this is 3 litters of pure pink, 1 hybrid, 1
pure black, and 1 hybrid backcrossing to a black. Overall, 24
piglets are expected. According to the owners experience, these
piglets in all likelihood should be similar enough for the purpose
of this experiment.
Water is provided 1-2 times a day in one bucket per paddock.
Feed is provided once a day in individual bowls for each pig
(Figure 4). Pigs at Grizzly Pigs Farm are usually fed a commercial
pig grower in the form of pellets containing oat, barley, wheat,
corn, protein supplement, and canola oil (manufactured by Federated
Co-operatives Ltd, Saskatoon, SK; Figure 5). This grower is
certified FeedAssure, a feed safety management and certification
program developed by the Animal Nutrition Association of Canada
(ANAC). This grower is imported from Southern Canada and is bought
from C&D Feed (Whitehorse, YT). Yukon Grain Farm (Steve
Mackenzie-Grieve) also has pig grower available, which would likely
not be as standardized and slightly more expensive (approximately
6$ extra per bag).
The broiler chickens stay in a heated building (garage). In the
fall of 2015, 30 chicks of a .. mix are expected, which should all
be similar enough for the purpose of this experiment. Broiler
chickens are usually fed a commercial feed also available at
C&D Feed.
The laying hens are housed in two heated temporary buildings
(tarp sheds). One is insulated with straw, and the other one is
insulated with foam. One is facing South, and the other one is
facing North. The individual space area is approximately 1 sq ft,
which amounts to 25 animals per building. In the fall of 2015, a
new hatch is expected. Water is provided once a day. The water
troughs are cleaned every 2-3 days. Feed is provided ad libitum.
Light is provided 6 am to 10 pm. The hens usually lay eggs for 10
weeks. They will have been laying for 2 weeks prior to the
experiment. The hens are expected to start laying mid-September.
Two types of laying hens are available: Brown Hybrid Leghorn and
Columbine Rock. Typical productivity at Grizzly Pigs Farm is 2 eggs
per 3 days and 1 egg per 2 days for Brown Hybrid Leghorn and
Columbine Rock, respectively. Typical overall productivity at
Grizzly Pigs Farm is 5-6 eggs per week per hen for the first 8
months. Potentially, the buildings could be inverted
mid-experiment, so as to account for the difference in living
conditions. Another way to circumvent this would be to assign
-
Michel Duteau and Amlie Janin, NSERC Industrial Research Chair
in Mine Life Cycle
Yukon College | 500 College Drive, PO Box 2799, Whitehorse,
Yukon Y1A 5K4
the hens to cages and feed them accordingly, providing for a
Complete Block Design. Laying hens are usually fed a commercial
feed also available at C&D Feed.
The animals are cared for according to guidelines of the
Canadian Council on Animal Care (1993).
Experimental plan
Testing
The objective of this experiment is to test the bioequivalence
of a recommended fish silage dosage (test diet) as an alternative
to conventional feed (control diet) for pigs, broiler chickens and
laying hens. For more complex trials (e.g. comparison of different
levels of inclusion of fish silage), more sophisticated
experimental setup would be necessary, along with finer statistical
tools.
This experiment is thus designed as a simple comparison of the
means of the two diets for a series of response variables.
Bioequivalence is granted if no statistically significant
difference is found between the means. The hypothesis of there
being a difference between the group means is tested with a series
of univariate t-tests, and a Bonferroni correction (Kuehl, 2001) is
applied to adjust () and minimize the experiment-wise error rate
(i.e. take into account the fact that a series of statistical tests
are performed on the same individuals). The results depend on the
size of the difference between the means, divided by the standard
error of the difference. Alternatively, a multivariate analysis
could be performed, considering all response variables at once.
The null hypothesis is stated as H0: d d0, where d0 is the
minimum difference between the groups that is to be detected. The
alternate hypothesis is: H1: d > d0.
Experimental design
Ideally, all individuals are the same (age, sex, ancestry), and
all conditions are the same (environmental exposure -wind, sun,
snow, rain, temperature-, floor space per individual, type of
watering system, type of feeding through, type of faeces management
system). When such an ideal situation is unattainable, the
differences become nuisance factors, and can potentially become
sources of variability. Randomization is essential to reduce the
contaminating effect of nuisance factors (e.g. sex and ancestry)
and reduce variability: subjects are randomly assigned to one
treatment or the other (control diet vs. test diet). When needed,
blocking can be used to reduce the effect of a specific nuisance
factor (e.g. exposure to wind): creating homogeneous blocks in
which the nuisance factors are held constant. However, a simple
t-test will not suffice in analyzing results for a Randomized Block
Design; an ANOVA would be called for and the F-test would become
the initial statistic of importance.
Confidence interval
In this experiment, bioequivalence is granted with a confidence
interval of 95%, i.e. the null hypothesis of no difference between
the means is rejected when p < 0.05. The probability of making a
Type I error (rejecting the null hypothesis when it should not be
rejected) is thus 5%.
Power of the test
A test's power is the probability of rejecting the null
hypothesis when it should be rejected. The power of a statistical
test is calculated as 1-, where is the probability of making a Type
II error (accepting a
-
Michel Duteau and Amlie Janin, NSERC Industrial Research Chair
in Mine Life Cycle
Yukon College | 500 College Drive, PO Box 2799, Whitehorse,
Yukon Y1A 5K4
null hypothesis when it should be rejected). A test's power is
influenced by the choice of confidence interval (1- ), and depends
on the sample size and the magnitude of the effect (the degree of
departure in the population from the null hypothesis). It is
conventional to set 80% as the target value for statistical power.
This convention implies a four-to-one trade off between -risk and
-risk. ( is the probability of a Type II error; is the probability
of a Type I error, 0.2 and 0.05 are conventional values for and ).
When a test shows that a significant difference is present, then
usually there is no need to further consider the statistical power
of the study. However, if no significant differences are detected,
then questions may arise as to whether detection of significant
differences in the means would have been made had there been more
replications in the experiment. In a bioequivalence experiment, it
is thus paramount to make sure that the power of the test be
sufficient (80%) and thus insure validity of the conclusions, by
using the proper minimum amount of replicates.
Number of replicates
It is tempting to declare that for a specific experiment, a
critical minimum quantity of replicates (n) is necessary to detect
a statistically valid difference (assess bioequivalence); however,
the interaction of specific breed, type of feed, environmental
conditions etc. makes it impossible to make concrete declarations
of sample size or levels of significance (Roush, 2004). In order to
approximate the minimum number of replicates, it is helpful to
conduct an a priori power analysis. The website of R. V. Lenth
(www.stat.uiowa.edu/rlenth/Power/) provides links to several power
analysis calculators. When the coefficient of variation (CV) and
the magnitude of the effect is known for a specific trait, a table
such as that presented in Roush (2004) or Reese (2010) can be used
to estimate the minimum number of replicates. A trait with a small
CV needs fewer samples for detection than a trait with a large CV.
In the same way, a trait with a large magnitude of the effect (e.g.
0.8) needs fewer samples for detection than a trait with a medium
(e.g. 0.4) or small (e.g. 0.1) magnitude of the effect.
Because the total number of replicates that are required depends
both on the variability of the trait (response variable) under
scrutiny and the magnitude of the effect that is expected, the
number of replicates is specific to each trait. In order for the
power to reach 80% throughout all the traits for a specific animal
(pigs, broiler chickens, laying hens), it is important to calculate
n using the trait that has the highest CV, and lowest magnitude of
the effect.
As a guidance, Reese (2010) determined that for two-sample diet
experiments with pigs, 4 pens per diet is necessary to detect a
potential difference of 15% or higher, assuming a CV of 5% - hence
a total of 8 pens is necessary. In this case, the pen (group of
pigs) is the replicate (hence, 3 degrees of freedom). The number of
pigs per pen should be as high as possible (in order to have
averages with minimum standard error, and to be able to account for
dead pigs), taking into account the comfort of the animals and the
total number of pigs available for the experiment. Based on Reese
(2010)s recommendations, three pigs per pen should be used for this
experiment, for a total number of 24 animals. Floor space should be
equal for every individual.
For two-sample diet experiments with broiler chickens and laying
hens, MacMillan suggested that 60 individuals be used per diet. In
this case, the individual is the replicate.
-
Michel Duteau and Amlie Janin, NSERC Industrial Research Chair
in Mine Life Cycle
Yukon College | 500 College Drive, PO Box 2799, Whitehorse,
Yukon Y1A 5K4
Time frame
For pigs, the experiment takes place over the growing-finishing
cycle. During this period of approximatively 3 months, the pigs
grow from 25 kg (55 lb) to 100 kg (220 lb, market weight).
Alternatively, the experiment could take place during the growing
period only (25 kg to 60 kg liveweight). Additionally, 7 days
should be allocated for adaptation to the feed, and 10 days for
adaptation to the cage.
The feeding trial on broiler chickens should be carried out
through a normal production range (6-8 weeks).
For laying hens, the experiment should take place through the
first half of the laying period (point of lay to 22 weeks).
Fish silage production
Fat in the silage may increase poly-unsaturated fatty acids
(PUFA) content, including the long-chain omega-3 fatty acids C22:6
(DHA), C22:5 (DPA) and C20:5 (EPA). This may be beneficial for
human nutrition, since the consumption of long-chain omega-3 fatty
acid may strength immune and nervous systems, as well as prevention
of the cardiovascular diseases and some types of cancer (Ramirez,
2013). However, this may have an adverse effect on the sensory
quality of meat, leading to the development of a rancid or fishy
taste (Raa and Gildberg 1982; Krogdahl 1985). Hence, fish silage
fed to pigs, broiler chickens or laying hens needs to be
defatted.
In this experiment, defatted fish silage is produced following
Jangaard (1987; Figure 1 and Figure 2):
- The raw material is first minced; suitably small particles can
be obtained by using a hammer mill grinder fitted with a screen
containing 10 mm diameter holes (Tatterson and Windsor, 2001).
- Immediately after mincing, formic acid is added at a level of
1525 g kg1 (1.5-2.5 %) wet weight depending on the ash content in
the raw. The more bone the higher rate of acid is required to bring
pH down -high calcium content will neutralize the acid and
therefore the product requirement will be higher. When making large
batches, acidity should be monitored and adjusted empirically to
stay within the 3.6-4 range; if it is above 4 more acid should be
added; if it is below 3.8 less acid could probably have been used,
with a saving in cost. It is important to mix thoroughly so that
all the fish comes into contact with acid, because pockets of
untreated material will putrefy.
- Ethoxyquin is added as an anti-oxidant at 200300 ppm wet
weight (200-300 mg/kg wet weight) - The fish silage is let to cure
for liquefaction to operate, and occasional stirring helps to
ensure
uniformity. The rate of liquefaction highly depends on the
temperature of the process. For instance, white fish offal can take
about two days to liquefy at 20C, but takes 5-10 days at 10C, and
much longer at lower temperatures. Thus in winter it would be
necessary to heat the mixture initially, or to keep it in a warm
area until liquid (Tatterson and Windsor, 2001).
- In a subsequent step, fish silage is heated to 95C, and passed
through a decanter and a centrifuge to separate the fat from the
rest. Fish fat could potentially be valued through routes such as
energy production (e.g. biodiesel), compost, dog food, etc.
-
Michel Duteau and Amlie Janin, NSERC Industrial Research Chair
in Mine Life Cycle
Yukon College | 500 College Drive, PO Box 2799, Whitehorse,
Yukon Y1A 5K4
Fish silage of the correct acidity keeps at room temperature for
at least two years without putrefaction. The protein becomes more
soluble, and the amount of free fatty acid increases in any fish
oil present during storage, but these changes are unlikely to be
significant nutritionally (Tatterson and Windsor, 2001).
According to Tatterson and Windsor (2001), the fish silage can
be blended with cereals to make a semidry feed or wet mash.
Pre-experiment measurements
Variability of farm-specific production performance
Variability of production performance is measured before the
experiment, in order to determine the minimum number of replicates
needed to assess bioequivalence of the test diet when compared to
the control diet. Variability is specific to the farm where the
experiment takes place. Variability expresses chance variation i.e.
the difference that exists between individuals, despite the best
effort to feed and treat a group alike. For instance, variability
of weight gain is a measure of weight gain difference that exists
between individuals because of factors that cannot be explained or
anticipated. Metrics used to assess production performance are
detailed in the Response Variables section. Variability should be
assessed over a whole production cycle (e.g. weaning to slaughter
for pigs). Variability is expressed in terms of Coefficient of
Variation: CV = SD/X * 100% where CV = Coefficient of Variation SD
= Standard Deviation X = Treatment Mean
Weight at time zero of the experiment
Weight of each individual animal used in the experiment is
measured at the time of inception of the experiment.
Pig weight is determined using heart girth as a proxy (Groesbeck
et al., 2002): Pig weight (lb) = 10.1709 heart girth (in) -
205.7492
Quality of the feed
Quality of the feed ingredients and quality of the feed is
determined prior to the experiment (Table 1). Dry matter content
should equate to the addition of Protein, Fat, and Ash content.
Similar to Kjos (2001, 2000, 1999), all analyses are conducted
according to standard procedures described by the Association of
Official Analytical Chemists (1990). Protein content is calculated
as the Nitrogen content (Kjedahl) multiplied by 6.25. Fat is
measured as HCl-ether extract; fatty acid composition is analyzed
by GLC procedures. Metabolizable energy is determined according to
procedures described in Krogdahl (1985), following Just (1982)s
method and using the Rostock equation described by Schiemann et al.
(1971). Quality is determined for the crude fish matter, crude fish
silage, fresh de-fatted fish silage, aged (e.g. 3 months) de-fatted
fish silage, the wet mash, and the control feed.
-
Michel Duteau and Amlie Janin, NSERC Industrial Research Chair
in Mine Life Cycle
Yukon College | 500 College Drive, PO Box 2799, Whitehorse,
Yukon Y1A 5K4
pH
Dry matter content (% of diet)
Protein content (g kg Dry Matter-1)
Fat content (g kg Dry Matter-1)
Ash content (g kg Dry Matter-1)
Crude fiber (g kg Dry Matter-1)
Nitrogen free extracts (g kg Dry Matter-1)
Fatty acid composition (g kg Dry Matter-1)
Calcium (g kg Dry Matter-1)
Phosphorus (g kg Dry Matter-1)
Magnesium (g kg Dry Matter-1)
Metabolizable energy (MJ kg Dry Matter-1)
Table 1: Quality parameters for the feed and feed
ingredients
Feeding and Diets
If not otherwise stated, feeding and diets follow Kjos (2001,
2000 and 1999)s recommendations. In order to be able to draw valid
conclusions on the bioequivalence of fish silage as a protein
source, the test and control diets are isoenergetic, i.e. balanced
on a metabolizable energy basis.
Feeding scheme
Contingent on the farm habits, pig rations are provided once or
twice a day. The pigs are fed individually. Feed quantity is
adjusted daily following a standard feeding/growth chart (e.g.
Thomke et al., 1995). From Kjos (1999)s observations, the average
daily feed intake can be assumed to be approximately 1.89-1.99 kg
day-1. Following Kjos (1999)s recommendation for the prevention of
adverse effect on sensory quality of the meat, the experimental
diet is fed until slaughter only if the de-fatted fish silages fat
level is lower than 3.4 g kg1 DM; if the fat level is up to 5.7 g
kg1 DM, the experimental diet can be fed until 60 kg liveweight,
and control feed is fed for the remainder of the finishing period
(until 100 kg).
For broiler chickens, feed and water are provided ad libitum.
From Kjos (2000)s observations, the average net feed intake can be
assumed to be approximatively 79.1-82.9 g kg-1. Following Kjos
(2000)s recommendation for the prevention of adverse effect on
sensory quality of the meat, the experimental diet can be fed until
slaughter if the de-fatted fish silages fat level is lower than 10
g kg-1 DM;
For laying hens, feed and water are provided ad libitum.
Test diet
Test diet compositions for pigs, broiler chickens and laying
hens are presented in Table 2. All test diets are a compound feed
based on a non-protein commercial mix (e.g. barley, oat, wheat,
corn, canola), and protein is supplied by fish silage and soybean
meal; fish silage is supplied at the maximum proportion recommended
in the literature to prevent adverse effect on production
performance, and the remainder of necessary protein supply is
provided by soybean meal. Rendered animal fat is used to adjust the
metabolizable energy with that of the control diet; for instance,
Kjos (2001, 2000, 1999)
-
Michel Duteau and Amlie Janin, NSERC Industrial Research Chair
in Mine Life Cycle
Yukon College | 500 College Drive, PO Box 2799, Whitehorse,
Yukon Y1A 5K4
utilized rendered fat consisting of approximately 70% lard and
30% tallow. Vitamin E is added to prevent lipid oxidation in meat
tissues and prevent adverse effect on sensory quality of the meat.
Lysine, methionine and tryptophan are added in order to meet or
exceed the National Research Council requirements for amino acids
for poultry (1994) and for swine (1998). In the same way, vitamins
are added in order to supply surplus amounts according to
requirements (ref), and to equalize diets. Diet compositions are
provided here on a relative basis, and final individual ingredient
weights will need to be determined from the fish silage quality
data (starting with protein content).
For pigs, the fish silage is provided in a proportion of 9% of
the total dietary protein; in Kjos(1999)s experiment, for instance,
9% of the total dietary protein content corresponded to 50 g fish
silage / kg diet (circa 5% of the total diet on a weight basis).
The remainder of the protein need is supplied by soybean meal; in
Kjos(1999)s experiment, for instance, 162 g kg-1 was necessary to
complete protein requirements. From Kjos (1999)s experiment, it can
be approximated that 25% of the soybean meal that would be
necessary to complete dietary protein requirements (circa 210 g
kg-1) can be replaced by fish silage. For illustrative purpose, the
metabolizable energy level in Kjos (1999)s diets was 14.4-14.8 MJ
kg-1 DM).
For broiler chickens, the fish silage is provided in a
proportion of 21% of the total dietary protein; in Kjos (2000)s
experiment, for instance, 21% of the total dietary protein content
corresponded to 100 g fish silage / kg diet (circa 10% of the total
diet on a weight basis). For illustrative purpose, the
metabolizable energy level in Kjos (2000)s diets was 11.32-11.77 MJ
kg-1 DM).
For laying hens, the fish silage is provided in a proportion of
12% of the total dietary protein; in Kjos (2001)s experiment, for
instance, 12% of the total dietary protein content corresponded to
50 g fish silage / kg diet (circa 5% of the total diet on a weight
basis). For illustrative purpose, the metabolizable energy level in
Kjos (2001)s diets was 10.6-10.7 MJ kg-1 DM).
Pigs Broiler Chickens Laying Hens
Commercial non-protein feed Basis Basis Basis
De-fatted fish silage 9% of the total dietary protein
content
21% of the total dietary protein
content
12% of the total dietary protein
content
Soybean meal To complete protein needs
To complete protein needs
To complete protein needs
Rendered Animal fat To adjust metabolizable
energy
To adjust metabolizable
energy
To adjust metabolizable
energy
Vitamin E Yes ? ?
Lysine Yes ? ?
Methionine Yes ? ?
-
Michel Duteau and Amlie Janin, NSERC Industrial Research Chair
in Mine Life Cycle
Yukon College | 500 College Drive, PO Box 2799, Whitehorse,
Yukon Y1A 5K4
Tryptophan ? ? ?
Vitamin premix Yes1 Yes2 Yes3
Table 2: Test diet composition for pigs, broiler chickens, and
laying hens. The relative proportion of each ingredient is
indicated in the column for the specific animal production.
Control diet
Control diet compositions for pigs, broiler chickens and laying
hens are presented in Table 3. All control diets are a compound
feed based on a non-protein commercial mix (e.g. barley, oat,
wheat, corn, canola), and protein needs are supplied by soybean
meal entirely. Rendered animal fat is used to adjust the
metabolizable energy with that of the test diets. Vitamin E,
essential amino acids, and Vitamin premix are also added, in the
same way as for the test diets. Control diets compositions are
provided here on a relative basis, and final individual ingredient
weights will need to be determined from the ingredients quality
data.
Pigs Broiler Chickens Laying Hens
Commercial non-protein feed Basis Basis Basis
De-fatted fish silage None None None
Soybean meal Entire protein needs
Entire protein needs
Entire protein needs
Rendered Animal fat To adjust metabolizable
energy
To adjust metabolizable
energy
To adjust metabolizable
energy
Vitamin E Yes ? ?
Lysine Yes ? ?
Methionine Yes ? ?
Tryptophan ? ? ?
Vitamin premix Yes4 Yes5 Yes6
Table 3: Control diet composition for pigs, broiler chickens,
and laying hens. The relative proportion of each ingredient is
indicated in the column for the specific animal production.
1 Trace elements and vitamins included to provide the following
amounts per kg of diet: 70 mg of Zn; 50 mg of Fe; 40 mg of Mn; 10
mg of Cu; 0.5 mg of I; 0.2 mg of Se; 6000 IU of vitamin A; 400 IU
of cholecalciferol; 40 mg of dl- -tocopheryl acetate; 3 mg of
riboflavin; 10 mg of d-pantothenic acid; 20 g of cyanocobolamine;
20 mg of niacin; 0.2 mg of biotin; 1.5 mg of folic acid; 2 mg of
thiamin; 3 mg of pyridoxine. 2 Trace elements and vitamins provide
the following amounts per kg diet: 70 mg of Zn; 50 mg of Fe; 40 mg
of Mn; 10 mg of Cu; 0.5 mg of I; 0.2 mg of Se;6000 IU of vitamin A;
400 IU of cholecalciferol; 40 mg of d1-a-tocopheryl acetate; 8 mg
of riboflavin; 15 mg of d-pantothenic acid; 20 mg of
cyanocobolamine; 60 mg of nicacin; 0.2 mg of biotin; 2 mg of folic
acid; 4 mg of thiamin; 6 mg of pyridoxine. 3 Trace elements and
vitamins to provide the following amounts per kg of diet: 60 mg of
Zn; 25 mg of Fe; 100 mg of Mn; 5 mg of Cu; 0.5 mg of I; 0.2 mg of
Se; 12,000 IU of vitamin A; 3000 IU of cholecalciferol; 40 mg of
d1-a-tocopheryl acetate; 8 mg of riboflavin; 15 mg of d-pantothenic
acid; 30 mg of cyanocobalamine; 40 mg of niacin; 0.1 mg of biotin;
1 mg of folic acid; 4 mg of thiamin; 6 mg of pyridoxine 4 Same as
in experimental diet 5 idem 6 idem
-
Michel Duteau and Amlie Janin, NSERC Industrial Research Chair
in Mine Life Cycle
Yukon College | 500 College Drive, PO Box 2799, Whitehorse,
Yukon Y1A 5K4
Response variables
Measurements are taken throughout the experiment to assess
bioequivalence of the experimental diet and the control diet.
Response variables can be categorized in terms of production
performance, economics, metabolism data, physical characteristics
of the end product, sensory quality of the end product, and
nutritive quality of the end product. If not indicated otherwise,
all response variables are measured same as in Kjos (2001, 2000 and
1999). According to budget, logistics, and technical feasibility,
measurements of some response variables might be prioritized,
modified, or eliminated.
Production performance
Production performance metrics for pigs, broiler chickens, and
laying hens are presented in Table 4. Weight of each individual is
measured at the beginning and at the end of the experiment, and net
weight gain is calculated from these observations. The number of
days necessary to fatten up to market weight (circa 100 kg for pig
and circa 2.5 kg for broiler chickens) is recorded, and average
daily gain is calculated from these observations. For pigs, weight
is also recorded every 14th day; for broiler chickens, weight is
also recorded every 7th day. For pigs, feed intake is recorded
daily; if any feed is rejected, it is measured and subtracted from
the ration weight. For broiler chickens and laying hens, feed
consumption is recorded every 7th day. Net feed intake is
calculated using this observation and the average daily feed intake
is calculated, integrating the number of days the experiment
unfolded. Feed efficiency equates to a feed-to-gain ratio, and is
calculated as net feed intake over net weight gain. Net energy
intake and average daily energy intake are calculated by
integrating the metabolizable energy value of the feed. Energy
efficiency (energy-to-gain ratio) is calculated as energy intake
over weight gain. For laying hens, eggs are collected and counted
daily, and an average daily egg quantity and egg weight production
is calculated once a week. Hen-day production represents the
average quantity of eggs that is produced per hen per day and is
calculated as:
-
Michel Duteau and Amlie Janin, NSERC Industrial Research Chair
in Mine Life Cycle
Yukon College | 500 College Drive, PO Box 2799, Whitehorse,
Yukon Y1A 5K4
Pigs Broiler Chickens Laying Hens
Initial weight (kg) X X X
Final weight (kg) X X X
Net Weight gain (kg) X X X
Number of days to market X X
Average daily gain (kg day-1) X X X
Net feed intake (kg) X X X
Average daily feed intake (kg day-1) X X X
Feed efficiency (kg kg-1 gain) X X X
Average daily energy intake (MJ day-1) X X X
Energy efficiency (MJ kg-1 gain) X X X
Average daily egg production (quantity day-1) X
Average daily egg weight production (g day-1)
X
Average hen-day egg production (%) X
Table 4: Production performance metrics for pigs, broiler
chickens, and laying hens. Those metrics marked with an X in the
column are suggested for the specific animal production.
Economics
Economical metrics for pigs, broiler chickens, and laying hens
are presented in Table 5. All economical metrics are calculated
considering a fish silage cost of CAD 200/metric ton.
Economical metric Pigs Broiler Chickens Laying Hens
Cost per weight gain (S/kg) X X X
Cost per egg produced ($/egg) X
Cost per energy intake ($/MJ) X X X
Return on investment ($/$) X X X
Table 5: Economical metrics for pigs, broiler chickens, and
laying hens. Those metrics marked with an X in the column are
suggested for the specific animal production.
Metabolism data
Metabolism metrics for pigs and broiler chickens are presented
in Table 6 (no metabolism data for laying hens). For pigs, blood
samples are taken at start of the experiment (circa 25 kg), at 60
kg live weight, and immediately before slaughter (circa 100 kg);
the blood samples are taken from the jugular vein, approximately 1
h after the morning feeding, using heparinized vacutainers for the
plasma samples and polyethylene tubes (TT tubes) for whole blood.
For broiler chickens, blood samples are taken from the jugular vein
of all chicks immediately after slaughter, using heparinized
vacutainers for the plasma samples and polyethylene tubes (TT
tubes) for the whole blood samples. Vitamin E is determined in
blood plasma using the method of McMurray and Rice (1982) with
modifications indicated in Kjos (2000
-
Michel Duteau and Amlie Janin, NSERC Industrial Research Chair
in Mine Life Cycle
Yukon College | 500 College Drive, PO Box 2799, Whitehorse,
Yukon Y1A 5K4
and 1999). Ceruloplasmin is determined in blood plasma according
to Schosinsky et al. (1974). Glutathione peroxidase is analyzed in
whole blood following the method of Paglia and Valentine
(1967).
Pigs Broiler Chickens
Vitamin E X X
Ceruloplasmin X X
Glutathione peroxidase X X
Table 6: Metabolism metrics for pigs and broiler chickens. Those
metrics marked with an X in the column are suggested for the
specific animal production. No metabolism metrics are suggested for
laying hens.
Physical characteristics of the end product
Physical characteristic metrics for pigs, broiler chickens and
laying hens are presented in Table 7. For pigs, carcass
characteristics are measured 1 d after slaughter. Lean percentage
is determined using a GP2Q pistol (Hennessy System), measuring the
diameter of the loin muscle (longissimus thoracis et lumborum) and
backfat thickness at two sites (between the last 3rd and 4th rib, 6
cm from the midline, and behind the last rib, 8 cm from the
midline). A tracing of a cross section of the cutlet, behind the
last rib, is made using tracer paper. Meat area in the cutlet is
determined with a planimeter (Coradi AG, Zrich, Switzerland). The
P2 backfat thickness is measured 8 cm from the midline behind the
last rib using tracer paper and a ruler. Subjective evaluation of
subcutaneous fat firmness using a scale from 1 to 15, in which 15
is the firmest score. Subjective evaluation of fat colour using a
scale from 1 to 15, in which 15 is the most favorable colour. For
broiler chickens, carcass weight and weight of the abdominal fat
pad are registered at the time of slaughter. For laying hens, egg
characteristics are taken on all eggs from two randomly chosen days
within the first and the second half of the experimental period,
respectively. The eggs are stored at 4oC and the analyses must take
place within 10 days. Thickness of albumen is determined on cracked
eggs using a micrometer. Haugh unit is calculated on the basis of
thickness of albumen and egg weight. Yolk color index is evaluated
by Roche Yolk Colour Fan (F. Hoffmann La Roche Ltd., Basel,
Switzerland), on a scale of 114 (1 = very pale yellow; 14 = very
dark orange).
-
Michel Duteau and Amlie Janin, NSERC Industrial Research Chair
in Mine Life Cycle
Yukon College | 500 College Drive, PO Box 2799, Whitehorse,
Yukon Y1A 5K4
Pigs Broiler Chickens Laying Hens
Slaughter weight (kg) X X
Carcass weight (kg) X X
Dressing percentage (%) X X
Lean (%) X
Meat area in the cutlet (cm2) X
P2 backfat thickness, P2 (mm) X
Subcutaneous fat firmness (1-15) X
Fat colour (1-15) X
Weight of the abdominal fat pad X
Thickness of albumen X
Yolk color index X
Table 7: Physical characteristics of the end product for pigs,
broiler chickens, and laying hens. Those metrics marked with an X
in the column are suggested for the specific animal production.
Sensory/organoleptic quality
Organoleptic quality (meat and egg acceptability) metrics for
pigs, broiler chickens, and laying hens are presented in Table 8.
For pigs, sensory quality analysis is conducted on samples of loin,
flank, and belly that have been stored in a freezer at 16C, for 1
mo (short time storage) or for 6 mo (long time storage). The
samples of belly are processed (cured and smoked) to make bacon.
Meat for sensory analysis is vacuum-packaged prior to storage. The
sensory analysis is conducted according to international standards
(ISO 3972 Sensory analysis Methodology Method of investigating
sensitivity of taste); a trained panel of eight members evaluate
the samples, using a scale from 1 to 9, where 1 is the lowest and 9
the highest intensity, for all parameters. The sensory analysis can
be conducted at the Norwegian Meat Research Laboratory, Oslo,
Norway.
For broiler chickens, sensory quality is analyzed on thigh meat
taken from 15 chicks of each dietary treatment, randomly chosen
from each of the replicate pens. The samples are taken 1 h
post-mortem, and are frozen immediately. Sensory quality analysis
is conducted on pieces of meat that have been frozen for 1 mo and 6
mo and with the same method as described for pigs (see
hereinabove).
For laying hens, sensory analysis is conducted on two sets of 12
eggs, collected from two randomly chosen days. The eggs are stored
at 4oC and analyzed for sensory evaluation after 7 days and after
35 days, respectively. The sensory analysis is conducted according
to international standards (ISO 3972 Sensory analysis Methodology
Method of investigating sensitivity of taste). Similar to Kjos
(2001), sensory analysis can be conducted at the Norwegian Food
Research Institute, s, Norway, using a computerized system for
recording of data (Compusense Five, Compusense, Guelph, ON). The
eggs are boiled for 10 min and then cooled in cold water for 5 s
before sensory evaluation. A trained panel of 11 members evaluate
both albumen and yolk for the parameters odor, off-odor, taste,
off-taste, whiteness and hardness. Each assessor evaluates the
samples on the computerized system, using a continuous
-
Michel Duteau and Amlie Janin, NSERC Industrial Research Chair
in Mine Life Cycle
Yukon College | 500 College Drive, PO Box 2799, Whitehorse,
Yukon Y1A 5K4
scale. The computer translates the responses into numbers
between 1 to 9, where 1 equals no intensity and 9 equals high
intensity of the parameter.
Pigs Broiler Chickens Laying Hens
Loin [odour, off-odour, taste, off-taste, juiciness, tenderness]
(1-9)
X
Flank [odour, off-odour, taste, off-taste] (1-9)
X
Belly [odour, off-odour, smoke odour, taste, off-taste, smoke
taste, salt taste] (1-9)
X
Thigh meat [odour, off-odour, taste, off-taste, rancid taste,
juiciness, tenderness] (1-9)
X
Albumen [odor, off-odor, taste, off-taste, whiteness,
hardness]
X
Yolk [odor, off-odor, taste, off-taste, yellowness,
hardness]
X
Table 8: Sensory quality of the end product for pigs, broiler
chickens, and laying hens. Those metrics marked with an X in the
column are suggested for the specific animal production.
Nutritive quality of the end product -contents of fatty
acids
Nutritive quality metrics for pigs, broiler chickens, and laying
hens are presented in Table 9. Fatty acid results are presented as
relative distribution of the individual fatty acids (g 100 g1 of
total fatty acids). Total poly unsaturated fatty acids (PUFA)
include the long-chain omega-3 fatty acids C22:6 (DHA), C22:5 (DPA)
and C20:5 (EPA). Fatty acids composition is analyzed by GLC
procedures according to the methods described by Ulbreth and
Henninger (1992) for extracted/methylated samples. The fatty acid
methyl esters are determined on a Perkin Elmer Autosystem gas
chromatograph (Perkin Elmer Corp., Norwalk, CT) with a SGE
capillary column no. 5QC3/bpx70, 0.25, 25 + 25 m (SGE International
Pty. LTD, Ringwood, Victoria, Australia). For pigs, the content of
fatty acids is measured in subcutaneous fat. For broiler chickens,
fatty acids composition is analyzed on (samples of) the abdominal
fat pad of all the chicks and (of) the breast meat of five chicks
of each treatment randomly chosen. For laying hens, nutritive
quality (cholesterol and fatty acid content) is measured on 4 eggs
collected randomly throughout the experiment period. The eggs are
stored at 4oC and analyzed within 10 days. Cholesterol in egg yolk
is determined spectrophotometrically in Encore Chemistry System
(Baker Instruments, UK), using Cholesterol Enzumatique PAP 100,
kit. Ref. 61 224 from bioMeriedux (France).
-
Michel Duteau and Amlie Janin, NSERC Industrial Research Chair
in Mine Life Cycle
Yukon College | 500 College Drive, PO Box 2799, Whitehorse,
Yukon Y1A 5K4
Pigs Broiler Chickens Laying Hens
Proportion of individual fatty acids (in meat/in yolk) (g 100 g
total fatty acids-1) C14:0 C16:0 C16:1 C18:0 C18:1 C18:2 (n-6)
C18:3 (n-3) C20:1 C20:4 C20:5 (n-3) C22-1 C22:5 (n-3) C22:6
(n-3)
X X X
Proportion of poly unsaturated fatty acids (PUFA) (g 100 g total
fatty acids-1)
X X X
Cholesterol in egg yolk X
Table 9: Nutritive quality of the end product for pigs, broiler
chickens, and laying hens. Those metrics marked with an X in the
column are suggested for the specific animal production.
-
Michel Duteau and Amlie Janin, NSERC Industrial Research Chair
in Mine Life Cycle
Yukon College | 500 College Drive, PO Box 2799, Whitehorse,
Yukon Y1A 5K4
PHOTOS AND FIGURES
Figure 1: Typical fish silage installation (adapted from
Jangaard, 2007)
Figure 2: Processing method for concentrated, defatted fish
silage (adapted from Kjos, 1999).
-
Michel Duteau and Amlie Janin, NSERC Industrial Research Chair
in Mine Life Cycle
Yukon College | 500 College Drive, PO Box 2799, Whitehorse,
Yukon Y1A 5K4
Figure 3: English Large Black sow and her 6 piglets at Grizzly
Pigs Farm (July 2015)
Figure 4: Pink sow at Grizzly Pigs Farm (July 2015)
-
Michel Duteau and Amlie Janin, NSERC Industrial Research Chair
in Mine Life Cycle
Yukon College | 500 College Drive, PO Box 2799, Whitehorse,
Yukon Y1A 5K4
Figure 3: Example of a small pig hutch at Grizzly Pigs Farm
(July 2015
)
Figure 4: Feed bowls for individual pigs
Figure 5: Commercial Grower Feed utilized for pigs, broiler
chickens and laying hens at Grizzly Pigs Farm
-
Michel Duteau and Amlie Janin, NSERC Industrial Research Chair
in Mine Life Cycle
Yukon College | 500 College Drive, PO Box 2799, Whitehorse,
Yukon Y1A 5K4
-
Michel Duteau and Amlie Janin, NSERC Industrial Research Chair
in Mine Life Cycle
Yukon College | 500 College Drive, PO Box 2799, Whitehorse,
Yukon Y1A 5K4
ANNOTATED BIBLIOGRAPHY
Addcon, 2015. The principle of making fish silage to preserve
by-products for the feed industry. Webpage.
Notes This document presents how to use ENSILOXR, a product that
can be used for making fish silage. This product consists of formic
acid and an antioxidant, the latter helping in protecting the oil
content. Addcon is based in Germany.
Al-Marzooqi, W., Al-Farsi, M., Kadim, I., Mahgoub, O., Goddard,
J., 2010. The effect of feeding different levels of sardine fish
silage on broiler performance, meat quality and sensory
characteristics under closed and open-sided housing systems.
Asian-Australasian Journal of Animal Sciences. 23 (12),
1614-1625.
Abstract Two experiments were conducted to evaluate the use of
fish silage prepared from Indian oil sardines, Sardinella
longiceps, as partial replacement of soybean meal as a sole source
of protein for growing broiler chickens. The main objective of
Experiment 1, an ileal digestibility assay, was to assess the
nutritional value of fish silage compared with soybean meal for
feeding broiler chickens. The two test ingredients, soybean meal
and dried fish silage, were incorporated into semi-synthetic diets,
as the only component containing protein. The ileal digestibility
coefficients of amino acids of fish silage were considerably higher
than those of soybean meal (p
-
Michel Duteau and Amlie Janin, NSERC Industrial Research Chair
in Mine Life Cycle
Yukon College | 500 College Drive, PO Box 2799, Whitehorse,
Yukon Y1A 5K4
Association of Official Analytical Chemists 1990. Official
methods of analysis. 15th ed. AOAC, Washington, DC.
Methods for analysis the quality of the fish silage can be found
in there (Kjos, 1999).
Balios, J., 2003. Nutritional value of fish by-products, and
their utilization as fish silage in the nutrition of poultry.
Proceedings of the 8th International Conference on Environmental
Science and Technology8-10.
Abstract It can be concluded from the experiments that fish
silage is a very good alternative source of protein when partly
replacing other more expensive sources of protein. In our days,
with consumers being more and more sensitive in matter related to
the pollution of the environment, fish silage provides the means of
utilizing fish waste from the canning industry, instead of being
thrown away. Among the advantages of making fish silage are: Fairly
low capital cost, can be made by unskilled workers, there is no
smell of the final product and can be stored, under favourably
conditions, for up to two years. Disadvantages are, the high
transportation cost and also that high inclusions in the diet of
the farm animals can affect negatively the flavor of meat and eggs
(fishy taint).
Bimbo, A., 2012. Alaska seafood byproducts: potential products,
markets and competing products. Anchorage, Alaska: Alaska Fisheries
Development Foundation. 277.
Summary
Composts, hydrolyzates, digests and silage must be market driven
since they are either very high in water content (silage) or bulky
thus making transportation costs a key factor. There is a tendency
to interchange hydrolyzates, silage and digest nomenclature. For
our purposes, fish solubles is the concentrated stickwater from
fishmeal production. Silage is the autolysate or fish digest using
the internal enzymes in the fish plus acid for stability. The acid
inhibits and destroys the bacteria allowing the internal fish
enzymes to digest the fish mass. Cold silage is the product that
represents the fish material in liquid form without removal of
water or oil. Hot or concentrated or advanced silage involves oil
and water removal and evaporation and results in a more
concentrated product. If the raw material is low in fat, no oil
removal is needed. Fish solubles are sometimes marketed as
hydrolyzates or something similar. []A recent headline from Alaska
indicates that fertilizers are in short supply and the prices have
increased 400% so there could be a market for fish waste in
agriculture now. Liquid silages, fish solubles etc. are used as
organic fertilizers and have found niche markets for golf courses,
the growing of cranberries etc. [] (Table 103-11- present the
composition of branded fish silages (e.g. ash content, proteins,
energy, amino acidsetc.)) []About 40,000 tons of raw silage is
processed with finished products shipped to Norway, Finland,
Denmark, France and Holland. A similar co-op set up could be put in
place in Alaska as well but this must be market driven. [] SCANBIO
SCOTLAND LTD ENSILER EQUIPMENT: manufactures off the shelf silage
plants of all sizes and shapes that can be moved from place to
place. [] As already mentioned, there is a shortage of fertilizer
in Alaska so perhaps silage production could fill that need.
[]There is very little information available on the price structure
for Fish Silage, Hydrolyzates And Fish Solubles. The only
information is on the internet and this only reflects retail sales
of products in pint and quart
http://seafood.oregonstate.edu/.pdf%20Links/Alaska-Seafood-By-Products-Potential-Products-Markets-and-Competing-Products.pdfhttp://www.norfab.co.uk/enciliers.asphttp://www.norfab.co.uk/enciliers.asp
-
Michel Duteau and Amlie Janin, NSERC Industrial Research Chair
in Mine Life Cycle
Yukon College | 500 College Drive, PO Box 2799, Whitehorse,
Yukon Y1A 5K4
bottles and 5 gallon pails. Some of the hydrolyzates from France
have sold in the US$900+/ton range for early weaned pig and milk
replacer diets. However, the early weaned pig market is only 8
weeks out of the life of the pig. Omega Protein is the only company
that sells fish solubles as a separate product. Based on their SEC
filing, during the period 1998-2007 as shown in the following
figure, fish solubles sold in the US$175 $432/metric ton over that
period. If we assume that the fish solubles are 50% solids and that
conventional cold silage is 20% solids and that the nutrient
composition is comparable, we could estimate that over that same
period of time, cold crude fish silage would have sold in the $70 -
$173/metric ton. []
Coates, J.W., Holbek, N.E., Beames, R.M., Puls, R., O'Brien,
W.P., 1998. Gastric ulceration and suspected vitamin A toxicosis in
grower pigs fed fish silage. The Canadian Veterinary Journal. 39
(3), 167.
Abstract In 3 feeding trials, gastric ulceration was diagnosed
in 2 of 12 lame and recumbent grower pigs fed a diet of 50% fish
silage produced from the offal of farmed Atlantic salmon. Premature
femoral physeal closure and elevated serum retinyl palmitate
levels, features of vitamin A toxicosis, were also observed.
Cameron, C. D. T. Acid fish offal silage as a source of protein
in growing and finishing rations for bacon pigs. Canadian Journal
of Animal Science 42.1 (1962): 41-48. Abstract
Three factorially designed experiments, involving 136
growing-finishing Yorkshire pigs, were carried out to determine the
feeding value of acid-ensiled cod and haddock offal. Rate of gain,
feed efficiency and carcass characteristics indicated that this
product was a satisfactory source of supplementary protein.
However, a moderate off-flavor was detected in the meat from pigs
fedfish silage to market weight. The intensity of the off-flavor
was not affected by removal of fish silage from the ration of pigs
at approximately 170 pounds body weight when slaughtered at 200
pounds. The results from discontinuing the feeding of fish silage
when the pigs reached body weights of 100 and 150 pounds on
off-flavor in the meat were not conclusive.
Canadian Council on Animal Care 1993. Guide to the care and use
of experimental animals. Vol. 1, 2nd ed. Canadian Council on Animal
Care, Ottawa, ON.
Collazos, H., Guio, C., 2007. The effects of dietary biological
fish silage on performance and egg quality of laying Japanese
quails (Coturnix coturnix japonica). World Poultry Science
Association, Proceedings of the 16th European Symposium on Poultry
Nutrition, Strasbourg, France, 26-30 August, 2007: World's Poultry
Science Association (WPSA). 37-40.
Abstract An 8 week experiment was conducted to evaluate the
effects of biological fish silage supplementation in laying
Japanese quails diets on performance and egg quality. A total of
120, 60 d-old laying japanese quails were allotted in a randomized
experimental design with four treatments (Controls, 2, 4 and 6% of
biological fish silage), with five replicates and 6 birds per
replicate. Diets were formulated to meet or exceed NRC
recommendations. Feed and water were supplied ad libitum and light
was scheduled for 16 hours of light and 8 hours of dark each day.
Feed consumption was measured weekly and feed conversion was
calculated. Laying percentage,
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1539927/pdf/canvetj00149-0041.pdfhttp://www.ncbi.nlm.nih.gov/pmc/articles/PMC1539927/pdf/canvetj00149-0041.pdfhttp://pubs.aic.ca/doi/pdf/10.4141/cjas62-006http://pubs.aic.ca/doi/pdf/10.4141/cjas62-006http://www.cabi.org/Uploads/animal-science/worlds-poultry-science-association/WPSA-france-2007/82.pdfhttp://www.cabi.org/Uploads/animal-science/worlds-poultry-science-association/WPSA-france-2007/82.pdf
-
Michel Duteau and Amlie Janin, NSERC Industrial Research Chair
in Mine Life Cycle
Yukon College | 500 College Drive, PO Box 2799, Whitehorse,
Yukon Y1A 5K4
egg weight, and egg mass were recorded daily during 8 to 16 wk
of age. Random samples of 8 eggs from each treatment were collected
weekly to measure egg quality: such as, eggshell thickness, Haugh
units, egg specific gravity, and yolk percentage. Productive
parameters such as feed intake, egg weight, feed efficiency, body
weight variation, and egg mass were not affected (P>0.05), only
laying percentage was affected (P0.05) by dietary treatments.
Results obtained indicate that biological fish silage can be
included in laying diets of Japanese quails up to 6% without
adverse effects. Introduction A particular problem in animal
nutrition is the lack of quality protein sources with a good amino
acid profile, due to availability and relative high cost. Objective
Determine the effects of (biological) fish silage supplementation
in laying Japanese quails diets on performance and egg quality when
supplemented over standard corn and soymeal diet. Materials and
Methods Experiment with biological fish silage. Experiment
performed on Japanese qualis. Completely Randomized experimental
design. 4 treatment groups. 120 quails used. 6 quails per
(replicate) cage. 5 (replicate) cages. Each cage was the
experimental unit. Metallic cages were used. Initial age of 60
days. The (biologica) fish silage was prepared following FAO
procedures (FAO, 1992), from slaughter by-products (heads, guts,
remains after deboning) of tilapia (oreochromis spp). Wastes were
washed, ,cooked for 15 minutes to reach 91oC, in order to avoid
contamination problem, drained and fine grounded (2mm), and added
15% molasses. The fish silage was preserved by mean of lactic acid
bacteria (Lactobacillus bulgaricus and Streptococcus thermophilus),
the microbial culture was previously prepared, to be added to the
substract and molass (5% W:W).The culture microorganisms
concentration was of 10 x 108 cfu. The mixture was placed in a
incubator at 40oC for 96 hours, in anaerobic conditions. The
biological fish silage had 29.10% crude protein and 48.90% Dry
Matter. Base ration was based on corn and soybean meal as main
ingredients. Diets were formulated to meet or exceed NRC
recommendations (NRC 1994) and contained 20% of Crude protein and
2605 Kcal/kg of ME. Control diet (CO): No fish silage Diet 1: 2%
biological fish silage Diet 2: 4% biological fish silage Diet 3: 6%
biological fish silage Metrics (Performance): Weight gain (Average
daily gain); Feed intake (Average ME intake); Feed efficiency (Egg
Production): Laying percentage (hen-day egg production (%)?); Egg
weight; Egg mass (Egg Characteristics): Eggshell thickness; Haugh
units; Egg specific gravity; Yolk percentage
-
Michel Duteau and Amlie Janin, NSERC Industrial Research Chair
in Mine Life Cycle
Yukon College | 500 College Drive, PO Box 2799, Whitehorse,
Yukon Y1A 5K4
Results (Performance and Egg production): Productive parameters
such as feed intake, egg weight, feed efficiency, body weight
variation, and egg mass were not affected (P>0.05). The level of
fish silage affected egg production (laying percentage), which was
higher (77.03%) in controls, and lower in T2 (67.84%). Egg weight,
Weight gain, and eggshell thickness, and yolk percentage increased
linearly as level of silage increased. (Egg Characteristics): Egg
quality parameters were no affected (P>0.05) by dietary
treatments Conclusion The results obtained in this experiment
showed that biological fish silage supplementation to the diet
tended to improve egg weight, weight gain, eggshell thickness, and
yolk percentage. Fish silage can be included in laying diets of
Japanese quails up to 6% without adverse effects.
National Research Council, 1994. Nutrient requirements of
poultry. National Research Council. National Academy Press
Washington USA. National Research Council, 1998. Nutrient
requirements of swine. National Academic Press, Washington, DC.
Dapkevicius, M.L.E., Nout, M.R., Rombouts, F.M., Houben, J.H.,
Wymenga, W., 2000. Biogenic amine formation and degradation by
potential fish silage starter microorganisms. Int. J. Food
Microbiol. 57 (1), 107-114. Abstract
Fish waste can be advantageously upgraded into animal feed by
fermentation with lactic acid bacteria (LAB). This procedure is
safe, economically advantageous and environment friendly. The pH
value of the fish pastes decreases to below 4.5 during ensilage.
This pH decrease is partly responsible for preservation. Decreased
pH values and relatively low oxygen concentrations within the
silage facilitate decarboxylase activity. Biogenic amines may
constitute a potential risk in this kind of product since their
precursor amino acids are present in fish silage. It is of great
importance to ensure that the LAB strains chosen for starters do
not produce biogenic amines. Some bacteria, among which some LAB
species, are able to degrade these metabolites by means of amino
oxidases. This could be of interest for fish silage production, to
control biogenic amine build-up in this product. Seventy-seven LAB
cultures isolated from fish pastes submitted to natural
fermentation at two temperatures (15 and 22C) and selected
combinations of these isolates were examined for histamine,
tyramine, cadaverine and putrescine production. Of the isolates
tested, 17% were found to produce one or more of these biogenic
amines. The behaviour of diamine oxidase was tested under the
conditions present in fish silage. Addition of 12% sucrose or 2%
NaCl did not affect histamine degradation. Addition of 0.05%
cysteine decreased histamine degradation. Degradation occurred at
all temperatures tested (15, 22 and 30C), but not at pH 4.5.
Forty-eight potential fish silage starters were tested for
histamine degradation in MRS broth containing 0.005 g l1 histamine
and incubated at 30C. Indications were found that five of these
isolates could degrade as much as 2056% of the histamine added to
the medium within 30 h, when used as pure cultures. No histamine
degradation was observed with combinations of cultures. Histamine
degradation (5054%) by two of these isolates was also observed in
ensiled fish slurry.
http://www.researchgate.net/profile/Maria_Dapkevicius/publication/40137267_Biogenic_amine_formation_and_degradation_by_potential_fish_starter_microorganisms/links/0f317533fe186cb58a000000.pdfhttp://www.researchgate.net/profile/Maria_Dapkevicius/publication/40137267_Biogenic_amine_formation_and_degradation_by_potential_fish_starter_microorganisms/links/0f317533fe186cb58a000000.pdf
-
Michel Duteau and Amlie Janin, NSERC Industrial Research Chair
in Mine Life Cycle
Yukon College | 500 College Drive, PO Box 2799, Whitehorse,
Yukon Y1A 5K4
de Lurdes, M., Dapkeviius, E., Batista, I., Nout, M.R.,
Rombouts, F.M., Houben, J.H., 1998. Lipid and protein changes
during the ensilage of blue whiting (Micromesistius poutassou
Risso) by acid and biological methods. Food Chemistry. 63 (1),
97-102. Abstract
Fish waste is a potential source of protein for animal
nutrition. Ensilage could provide an advantageous means of
upgrading these residues. Careful control of the degree of
proteolysis and lipid oxidation is required to produce silages of
high nutritional value. This paper studies the changes in lipids
and protein during storage (15 days) of acid silages (with 0, 0.25
and 0.43%, w/w, of formaldehyde) and biological silages (with 10
and 20% molasses or dehydrated whey) prepared from blue whiting. A
remarkable reduction in protein solubilisation values was achieved
by adding formaldehyde. However, formaldehyde addition led to an
increase in the peroxide value of the oil extracted from the
silages. Ensiling by biological methods seems promising. It yielded
both a considerable reduction in protein solubilisation and in
basic volatile nitrogen when compared with acid ensilage. In
addition, the oil from biological silages had lower peroxide values
than the oil from acid silages with added formaldehyde.
DFO-MPO, 1987. Fish Silage Workshop. in: DFO-MPO, ed. Atlantic
Fisheries Development. Universit Sainte-Anne, Church Point, Nova
Scotia 103. Abstract
This publication contains the proceedings of the Fish Silage
Workshop held at Church Point, Nova Scotia, June 16-17, 1987. The
workshop was sponsored by the Canadian Department of Fisheries and
Oceans under the Fisheries Development Program and attracted about
130 participants. The proceedings contain fourteen papers presented
or distributed at the workshop. Included is a review of recent
developments in the production and use of fish silage concentrate
especially in Norway and two papers by manufacturers of silage
processing equipment. Several papers describe feeding trials with
trout and salmon, and several domestic animals. Other papers give
details of recent activities in Canada's Atlantic provinces,
including various pilot plant studies and trials with the use of
fish silage for fertilizer. The workshop was designed as an
information workshop and no recommendations for future development
were formulated.
Enes Dapkevicius, M.L., Nout, M.R., Rombouts, F.M., Houben,
J.H., 2007. Preservation of Blue-Jack Mackerel (Trachurus
Picturatus Bowdich) silage by chemical and fermentative
acidification. Journal of food processing and preservation. 31 (4),
454-468.
Abstract We compared acidified and lactic acid fermented silage
approaches for the preservation of blue-jack mackerel. Silages
acidified with formic and propionic acids had stable pH (3.8) and
low (19 mg/g N) levels of volatile nitrogen compounds (total
volatile basic nitrogen, TVBN), but relatively high (82 g/100 g)
final non-protein-nitrogen (NPN) values. The silage was fermented
with Lactobacillus plantarum LU853, a homofermentative lactic acid
bacterium with a high growth (0.51/h) and acidification rate at 37C
(optimum temperature), able to grow in the presence of 40 g/L NaCl
and to ferment sucrose and lactose. The silages at 37C reached safe
pH < 4.5 values within 4872 h, either (F2a) or not (F0), in
combination with 20 g/kg salt addition; F2a acidified more rapidly,
which may be an advantage for its microbiological stability.
Proteolysis resulting in 5359 g NPN/100 g N was lower in fermented
than in acidified silages; however, in fermented silages, the
levels of TVBN were much higher (5080 mg TVBN/g N) than generally
considered acceptable.
http://www.researchgate.net/profile/Maria_Dapkevicius/publication/235635415_Lipid_and_protein_changes_during_the_ensilage_of_blue_whiting_(Micromesistius_poutassou_Risso)_by_acid_and_biological_methods/links/54f5db100cf2ca5efefd3ada.pdfhttp://www.researchgate.net/profile/Maria_Dapkevicius/publication/235635415_Lipid_and_protein_changes_during_the_ensilage_of_blue_whiting_(Micromesistius_poutassou_Risso)_by_acid_and_biological_methods/links/54f5db100cf2ca5efefd3ada.pdfhttp://www.researchgate.net/profile/Maria_Dapkevicius/publication/235635415_Lipid_and_protein_changes_during_the_ensilage_of_blue_whiting_(Micromesistius_poutassou_Risso)_by_acid_and_biological_methods/links/54f5db100cf2ca5efefd3ada.pdfhttp://www.dfo-mpo.gc.ca/Library/103595.pdfhttp://www.researchgate.net/profile/Maria_Dapkevicius/publication/227714675_Preservation_of_blue-jack_mackerel_(Trachurus_picturatus_BOWDICH)_silage_by_chemical_and_fermentative_acidification/links/02e7e517f9c9061d80000000.pdfhttp://www.researchgate.net/profile/Maria_Dapkevicius/publication/227714675_Preservation_of_blue-jack_mackerel_(Trachurus_picturatus_BOWDICH)_silage_by_chemical_and_fermentative_acidification/links/02e7e517f9c9061d80000000.pdf
-
Michel Duteau and Amlie Janin, NSERC Industrial Research Chair
in Mine Life Cycle
Yukon College | 500 College Drive, PO Box 2799, Whitehorse,
Yukon Y1A 5K4
Groesbeck, C. N., 2003 Use heart girth to estimate the weight of
finishing pigs, Kansas State University
Cooperative Extension Service Swine Update Newsletter Spring,
2003.
Haskell, S. R., et al. Flavour studies on pork from hogs fed
fish silage. Canadian Journal of Animal Science 39.2 (1959):
235-239.
Jangaard, P., 1987. Fish silage: A review and some recent
developments. In Proceedings of Fish Silage Worksho p 8-33.
DFO-MPO, ed. Atlantic Fisheries Development. Universit Sainte-Anne,
Church Point, Nova Scotia. 103 p. Abstract
A brief summary of various enzymatic processes for preserving
fish is given with emphasis on Canadian contributions. Recent
developments in Norway are described in some detail as a result of
a visit to that country in March 1987. These include research and
development work on acid fish silage and silage concentrate and
their use as a feed especially for salmon and fur animals.
Summary Introduction
Capital costs for (fish silage production) equipment are
considerably lower than for a comparable fish meal plant and there
are no odor problems. One disadvantage is that transportation of
silage involves large quantities of water, and users should
therefore be located as close as possible to the plant. Historical
A better word to describe fish silage would perhaps be liquid fish,
liquefied fish protein or when more concentrated, protein
concentrate. In this report, fish silage is defined as silage
produced by adding inorganic and/or organic acids to lower the pH
sufficiently to prevent bacterial spoilage. The fish silage becomes
liquid because the tissue structures are degraded by a process
called autolysis by enzymes naturally present in the flesh. Lactic
acid fermentation One reason fish spoils more quickly than flesh or
warm blooded animals is that tissues become less acid post mortem
in contrast to mammalian tissues. By encouraging the growth of
lactic acid bacteria, the spoilagerprocesses leading to the
reduction of trimethylamine oxide to trimethylamine and the
degradation of amino acids to ammonia by spoilage bacteria are
suppressed. Lactic acid bacteria are well-known in dairy products
such as yogurt. Although these bacteria are natural inhabitants of
fish, they are present in low numbers. Fish also contains only
small amounts of free sugar which is the essential substrate for
growth of such bacteria (Raa et al., 1983; Mackie et al., 1971).
Therefore, to preserve fish or animal waste products by
fermentation, it is essential to add a sugar source, preferably
with a starter culture of proper lactic acid bacteria which, by
rapid conversion of the sugar to acid, preserves the whole mass. A
considerable amount of fermentable sugar must be added to obtain a
stable silage with a pH around 4; for example, 20 kg of a dry
mixture of malt and oatmeal was required for 100 kg of fresh
herring (Nelson and Rydin, 1963), or more than 10% molasses (Roa,
1965). [] Both spoilage bacteria and lactic acid bacteria will
contribute to the initial acid production because the conditions
are anaerobic and sugars are available, but growth of the lactic
acid bacteria will be favored as the silage becomes more acidic. If
the pH falls to below 4, lactobacilli will become the predominant
organism present and harmful bacteria (coliforms, enterococci,
typhoid
http://pubs.aic.ca/doi/pdf/10.4141/cjas59-031
-
Michel Duteau and Amlie Janin, NSERC Industrial Research Chair
in Mine Life Cycle
Yukon College | 500 College Drive, PO Box 2799, Whitehorse,
Yukon Y1A 5K4
bacteria and even spores of Clostridium botulinum) are destroyed
in such a silage (Raa et al., 1983). If oxygen is admitted to any
extent, then aerobic microorganisms such as yeasts may develop.
Yeasts are capable of growth at relatively low pH and utilize
carbohydrate and protein. Mold spoilage may also be a problem,
especially if any drying occurs, for instance at exposed surfaces
(Mackie et al., 1971). A company in Troms, Norway, called BIOTEC
Ltd. has developed a protein concentrate aimed at the fur animal
market []. The fish is heat treated first to deactivate thiaminase
and other enzymes and to stop microbial activity; fat can be
removed by a decanter and formic acid, molasses and antioxidants
added. When cooled, the lactic acid bacteria and finally a binder
meal are added to give the product its desired consistency. It is
claimed that the product can be stored for several months, that the
lactic acid bacteria also acts as an antioxidant and that the
flavor is superior to the bitter taste of acid silage. Acid
silage
In 1936, experiments were started in Sweden with the A.I.
Virtanen (AIV) process for preservation of fish and fish offal
intended for use as animal feeds. Results of the trials were
published by Edin (1940) and Olsson (1942). The Swedish experiments
included, besides the AIV process (Hydrochloric + sulphuric acids)
two other acid preservation methods: the Sulfuric Acid/Molasses
Method and the Formic Acid Method (H. Peterson, 1953). The chief
advantage of AIV acid over organic acids is its low cost, but this
is probably outweighed by the disadvantage in that it is a highly
corrosive liquid producing a corrosive product which requires
neutralization. Olsson found that formic acid limited the growth of
bacteria at a relatively high pH (4.0) as compared to mineral acids
like sulphuric acid (pH 2) and that no neutralization was necessary
before feeding the silage to animals. Backhoff (1976) found that
the enzymes mainly responsible for the liquefaction of fish were
those of the gut, skin and other parts of the fish, tather than
those of the flesh. Work in Canada on acid fish silage was carried
out at the Halifax Technological Station of the Fisheries Research
Board of Canada by Freeman and Hooglan (1956, a,b ). It was found
that the rate of autolysis increased with temperatures from 15oC to
37oC and reached a maximum after three days at 37oC. Researchers
from the Vancouver Technological Station of the Fisheries Research
Board of Canada found that liquefaction of the fish in an acid
medium was achieved in 72 hours at 37oC. A study by Strasdine and
Jones (1983) carried out at the British Columbia Research Council
Laboratory on silage from dogfish wastes found established that by
adding 1.5% formic acid and heating to 45oC, almost complete
liquefaction was achieved in 24 hours. In the 1980s, the Province
of Nova Scotia Department of Fisheries supported the construction
and operation of a small fish silage plant at Casey Fisheries in
Victoria Beach, Nova Scotia. Silage from this plant has been used
for feeding trials with pigs at the Agriculture Canada Research
Station in Nappan, Nova Scotia.
Acid silage production
Plant and Equipment
It is important for a plant of any size to have at least
automated acid addition with a pH meter downline controlling the
rate. It is claimed that it is better to stop autolysis soon after
liquefaction to cut down on bitter flavors (peptides), fat
autolysis (free fatty acids) and complete protein autolysis to
amino acids. It might therefore be desirable to have a heat
exchanger and holding cell to be able to heat the silage to 85oC or
so and hold it to inactivate enzymes. The next step would be to add
a decanter/separator to remove the oil from the silage. The
last
-
Michel Duteau and Amlie Janin, NSERC Industrial Research Chair
in Mine Life Cycle
Yukon College | 500 College Drive, PO Box 2799, Whitehorse,
Yukon Y1A 5K4
scenario, and of course the most expensive, would be to have an
evaporator to produce silage concentrate. A simplified sketch of a
basic silage plant is shown in Figure 4. The raw material is
brought to a feeding hopper with a screw feeder on the bottom.
Formic acid (and antioxidant) held in tan acid tank of suitable
resistant material (fiberglass or plastic coated, etc.) is fed to
the fish with a metering pump before the grinder, thereby ensuring
good mixing of acid with the fish. The fish should be ground so
that no pieces are larger than 3-4 mm in diameter (Tatterson,
1976). The mass is then pumped in a Progressive Cavity Pump (Mono
pump), where acid and fish are further mixed. A pH meter in the
line adjusts the addition of acid automatically, or stops the
plant, if the pH is not in the desired range (3.8 - 4). Example of
addition of an evaporation step is at the Royal Seafood Ltd. plant
in Bjugn, Norway, the silage is first heated to 95C, passed through
a decanter and centrifuge to separate oil and sludge (Sobstad,
1987). The water phase is passed through a flash evaporator at 55C
where it cools to 35C, is reheated and flash evaporated again until
the solid content reaches 50-55%. A second effect evaporator
operating at 35 and lower vacuum makes the system more energy
efficient.
The process
The enzymes of importance in silage are various proteinases that
break down proteins into peptides and individual amino acids and
lipases that break down fats into free fatty acids and
glycerol.
Protein changes
A silage gradually liquefies as connective protein tissues are
broken down (into peptides and individual amino acids) by enzymes
in the fish and become water soluble. This self-digestion is called
autolysis and the rate is dependent on the activity of digestive
enzymes in the raw material, the physiological condition of the
fish when caught, the pH, the temperature and the preservative
acids. The enzymes mainly responsible for liquefaction are from the
viscera, skin and other parts of the fish other than flesh. The
rate of autolysis is temperature dependant, and is quite low at
temperatures below 10oC (Figure 15). As autolysis progresses, oil
will be liberated and float to the top and bone fragments and
undissolved tissues go to the bottom. It is important that a means
of stirring the silage in the tank is provided for. There will
always remain a fraction of the protein which is resistant to
enzymatic digestion, for reasons not completely known. One drawback
of acid fish silage is that the product often has a bitter flavour
that could have an effect on animal acceptability of the product.
Several authors have linked the bitter flavours to certain types of
polypeptides formed as the protein molecules are broken down in the
autolysis.
Lipid (Fat) changes
Free Fatty Acids (FFA) increase with the storage period, and
with the temperature. An antioxidant should be added to the fish
silage, in order to limit oxidation of the fat. Common practice in
Norway is to add the antioxidant to the formic acid (200 ppm
ethoxyquin). An inert gas (C02, N2) could also be used over the
silage in the storage tanks. Other antioxidants possible are
gallates, hydroxyquinone, BHA, BHT and anisole. If the silage is to
be used to feed livestock, it is better to remove the oil as soon
as it is feasible and store it separately.
-
Michel Duteau and Amlie Janin, NSERC Industrial Research Chair
in Mine Life Cycle
Yukon College | 500 College Drive, PO Box 2799, Whitehorse,
Yukon Y1A 5K4
The product
Quality and Analytical methods
For formic acid silage, the pH is recommended to be between 4.0
and 4.3. If pH is above 4.5, there is the danger of bacterial
activity, decomposition and perhaps formation of toxic compounds.
The pH value is not constant and should be checked regularly,
especially when the silage is freshly produced, the temperature is
high or the ash or bone content is high. Silage from fish and fish
products has a certain buffering action. This means that relatively
large quantities of formic acid can be added without the pH
dropping correspondingly. It is therefore of interest for the user
to find out how many kilos have been used per tonne raw material.
When formic acid alone is used, the pH should not be below 3.8. The
lower the pH, the better the storage ability. The higher the pH,
the less acidic the finished feed will be. There has to be a
balance between the two (Pedersen, 1987).
A working group was formed in Norway to establish quality
standards for fish silage. The group has recommended that in
addition to protein and fat, both ash and dry matter (not fat-free
solids) be given. The reason for this is to be able to have a
certain control over how well fat and protein analyses were carried
out by the laboratories. Since % protein + % fat + % ash = % dry
matter, it is then possible to double check if the protein, and
especially the fat analyses, are correct. The value for ash will
indicate if the silage was made from whole fish, mostly viscera or
bony offal. The ash content of whole fish is usually in the 2-3%
range.
The concept of the term quality is difficult to define. In
commercial terms, it is often limited in the case of fish silage to
pH and the contents of protein, fat, dry matter and ash. Total
volatile nitrogen (Tot. Vol N) also often is cited, as well as the
Trimethylamine nitrogen (TMA-N) and Trimethylamine oxide nitrogen
(TMAO-N) content.
Just, A. 1982. The net energy value of balanced diets for
growing pigs. Livest. Prod. Sci. 8: 541555.
Kjos, N., Herstad, O., Skrede, A., verland, M., 2001. Effects of
dietary fish silage and fish fat on performance and egg quality of
laying hens. Canadian Journal of Animal Science. 81 (2),
245-251.
Abstract A total of 45 laying hens were fed a control diet, or
one of four diets containing 50 g kg1 fish silage and different
levels of fish fat (1.8, 8.8, 16.8 or 24.8 g kg1), to determine the
effect of fish silage and fish fat in the diet on performance and
egg quality. Fish silage did not affect feed intake, egg
production, fatty acid composition of yolk, yolk color or sensory
quality of eggs, compared with the control. The diets with 16.8 or
24.8 g kg1 fish fat decreased feed intake (P < 0.001), egg
production (P < 0.001), and hen-day egg production (P <
0.04), and increased yolk color index (P < 0.003). The
proportions of the fatty acid C22:1 (P < 0.001), and PUFA as the
sum of C18:2 n-6, C20:5 n-3, C22:5 n-3 and C22:6 n-3 (P < 0.02)
in egg yolk were highest for the fish silage diets with 24.8, 16.8
or 8.8 g kg1 fish fat, and lowest for the diet with 1.8 g kg1 fish
fat. Proportions of C18:1 (P < 0.001) and C20:1 (P < 0.001)
were lowest for the diets with 16.8 or 24.8 g kg1 fish fat. Egg
yolk cholesterol did not differ among treatments. The diet with
16.8 g kg1
http://pubs.aic.ca/doi/pdf/10.4141/A00-086http://pubs.aic.ca/doi/pdf/10.4141/A00-086
-
Michel Duteau and Amlie Janin, NSERC Industrial Research Chair
in Mine Life Cycle
Yukon College | 500 College Drive, PO Box 2799, Whitehorse,
Yukon Y1A 5K4
fish fat resulted in a more intense egg albumen whiteness as
measured by the sensory study, compared with the other diets (P
< 0.05). There was a linear relationship between dietary fish
fat level and increased off-taste intensity of egg yolk (P <
0.03). Introduction Krogdahl (1985) reported that hens performed
well on diets containing fish silage, without affecting the quality
of eggs. Experiments with fish oils in diets for laying hens have
shown that the levels of polyunsaturated fatty acids (PUFA) in egg
yolk is positively related to the level of fish oil in diets (Van
Elswyk et al. 1994; Herstad et al. 2000; Meluzzi et al. 2000). Fish
silage contains 35% fat with a high level of PUFA, including the
long-chain n-3 fatty acids C22:6 (DHA), C22:5 (DPA) and C20:5
(EPA). Fish silage may, therefore, increase the content of these
long-chain PUFA in eggs, and this may affect sensory quality of
eggs. However, n-3 enriched eggs may serve as a good source of
these fatty acids in human nutrition. It is reported that consuming
n-3 fatty acid enriched eggs affects human plasma lipids, thus such
eggs may improve human health by reducing the risk of
cardiovascular diseases (Hargis et al. 1991; Leskanich and Noble
1997). Objective Determine the effect of (defatted) fish silage and
fish fat on performance and egg quality when compared to fish meal.
Materials and Methods Experiment with formic acid fish silage,
defatted, and fish fat. Experiment performed on laying hens. RCBD
experimental design. 5 treatment groups. 45 hens used. 9
(replicate) hen per treatment group. Each hen was the experimental
unit. Individual wire cages of 47 X 22.5 cm2 were used. Initial age
of 22 weeks. Experiment conducted over two consecutive periods of
28 days (56 days total). The fish silage was prepared same as in
Kjos (1999) (from slaughter by-product of farmed Atlantic salmon),
except that Ethoxyquin was added as an antioxidant at 250 ppm wet
weight. Crude fat as HCl-ether extract was analysed in fish silage
and diets according to standard procedures described by the
Association of Official Analytical Chemists (1990). Metabolizable
energy of the diets was determined according to procedures
described by Krogdahl (1985). Thickness of albumen was determined
on cracked eggs using a micrometer, and Haugh unit was calculated
on the basis of thickness of albumen and egg weight. Yolk color
index was evaluated by Roche Yolk Colour Fan, (F. Hoffmann La Roche
Ltd., Basel, Switzerland). Cholesterol in egg yolk was determined
spectrophotometrically in Encore Chemistry System (Baker
Instruments, UK), using Cholesterol Enzumatique PAP 100, kit. Ref.
61 224 from bioMeriedux (France). Sensory analysis was conducted
according to international standards (ISO 3972 Sensory analysis
Methodology Method of investigating sensitivity of taste).]), using
a computerized system for recording of data (Compusense Five,
Compusense, Guelph, ON). Base ration was based on barley, oats,
maize gluten meal and soybean meal as main ingredients (and fish
meal). The diets were designed to meet or exceed the National
Research Council requirements for amino acids (NRC 1994). Rendered
fat consisting of approximately 70% lard and 30% tallow was used to
balance the level of metabolizable energy (ME) in all diets (11.8
MJ ME
-
Michel Duteau and Amlie Janin, NSERC Industrial Research Chair
in Mine Life Cycle
Yukon College | 500 College Drive, PO Box 2799, Whitehorse,
Yukon Y1A 5K4
kg DM1). Protein from fish silage accounted for 12% of total
protein in these treatment diets. Defatted fish silage used
contained 36 g kg1 crude fat. Control diet (CO): No fish silage; No
fish fat Diet 1: 50 g kg-1 defatted fish silage + 1.8 g kg-1 fish
fat (residual) Diet 2: 50 g kg-1 defatted fish silage + 8.8 g kg-1
fish fat Diet 3: 50 g kg-1 defatted fish silage + 16.8 g kg-1 fish
fat Diet 4: 50 g kg-1 defatted fish silage + 24.8 g kg-1 fish fat
Metrics (Performance): Weight gain (Average daily gain); Feed
intake (Average ME intake); Feed-to-gain ratio (feed efficiency
measured as kFUp kg1 of gain) (Egg Production): Egg production (g
day-1); hen-day egg production (%) (Egg Characteristics): Albumen
height; Yolk colour; Cholesterol; Fatty acid composition (Sensory
Quality of Eggs): Odour, off-odour, taste, off-taste after 35 days
and 7 days refrigerated storage. Results (Performance): Fish silage
did not affect feed intake, egg production, fatty acid composition
of yolk, yolk color or sensory quality of eggs, compared with the
control. Feed intake was highest for diets CO and A, and lowest for
diet C (16.8 g fish fat kg1) and diet D (24.8 g fish fat kg1). (Egg
Production): In the present study, an inclusion level of 50 g kg1
diet, supplementing 12% of the total protein, had no negative
effects on egg production. Egg production and egg weight were
highest for diets CO and A, and were significantly depressed when
the contents of fish fat were 8.8 g kg1 or higher (diets B, C and
D) - high levels of fish fat negatively influence egg production.
(Egg Characteristics): The diets with 16.8 or 24.8 g kg1 fish fat
increased yolk color index (P < 0.003). The proportions of the
fatty acid C22:1 (P < 0.001), and PUFA as the sum of C18:2 n-6,
C20:5 n-3, C22:5 n-3 and C22:6 n-3 (P < 0.02) in egg yolk were
highest for the fish silage diets with 24.8, 16.8 or 8.8 g kg1 fish
fat, and lowest for the diet with 1.8 g kg1 fish fat. Proportions
of C18:1 (P < 0.001) and C20:1 (P < 0.001) were lowest for
the diets with 16.8 or 24.8 g kg1 fish fat. Egg yolk cholesterol
did not differ among treatments. Adding up to 24.8 g kg1 fish fat
to the diet causes only minor changes in fatty acid composition of
egg yolk when compared with a fish meal based control. No
difference was found in egg yolk cholesterol among diets. (Sensory
Quality of Eggs): There was a linear relationship between dietary
fish fat level and increased off-taste intensity of egg yolk (P
< 0.03). To avoid reduced sensory quality of eggs, the fish fat
level should be kept below 24.8 g kg1. The diet with 16.8 g kg1
fish fat resulted in a more intense egg albumen whiteness, compared
with the other diets (P < 0.05). There were no significant
differences in any of the sensory traits between eggs from period 1
(stored at 4C for 35 d) and period 2 (stored at 4C for 7 d).
(Overall): High levels of fish fat in the diet caused reduced egg
production and egg weight, and tended to cause a modest increase in
the level of polyunsaturated omega-3 fatty acids in egg yolk. The
reduction in egg production and egg weight observed for the two
highest levels of dietary fish fat indicate that fish fat in diets
for laying hens should be kept below 17 g kg1. Discussion
-
Michel Duteau and Amlie Janin, NSERC Industrial Research Chair
in Mine Life Cycle
Yukon College | 500 College Drive, PO Box 2799, Whitehorse,
Yukon Y1A 5K4
(Performance): Krogdahl (1985) found no differences in feed
intake, weight gain and egg production of laying hens when herring
meal was replaced with fish silage (7.4 or 14.2% fish silage in the
diet, respectively). The highest level of dietary fish fat of 17.7
g kg1 tested by Krogdahl (1985) did not influence egg production.
Hargis et al. (1991) and Meluzzi et al. (2000) reported that 30 g
kg1 dietary menhaden oil did not affect egg production or egg
weight. Baucells et al. (2000) found no reduction on performance of
laying hens when feeding up to 40 g kg1 of fish oil. Whitehead et
al. (1993) observed that egg weight was depressed when fish oil was
fed in excess of 20 g kg1, and that feed intake and hen-day egg
production (%) was depressed at 60 g dietary fish oil kg1. Van
Elswyk at al. (1994) found significant differences in yolk and egg
weight when feeding menhaden oil at 30 g kg1. Scheideler and Fr