Chapter 3 Water hyacinth as alternative feed Pergaps the most realistic use of water hyacinth right at this moment is its use as alternative feed. Because – 1. Its high protein content 2. Its availability 3. Its low cost Water hyacinth can be used as feed in three forms – fresh, ensiled and wilted. To reduce its high fiber content, fermentation is used in some cases. What is ensiled form ? In ensiled form, grass or any other green fodder is stored in silo, in airtight condition. Drying is not used for silage. Ensiled cops are used for animal feed in winter. What is wilted form ? Wilted crops are partially air dried crops. Wilting is done before ensiling. There are many reports made throughout the world suggesting WH as a very good alternative animal feed. Some of its are mentioned here. For ruminants
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Chapter 3
Water hyacinth as alternative feed
Pergaps the most realistic use of water hyacinth right at this moment is its use as alternative feed.
Because –
1. Its high protein content
2. Its availability
3. Its low cost
Water hyacinth can be used as feed in three forms – fresh, ensiled and wilted. To reduce its high
fiber content, fermentation is used in some cases.
What is ensiled form ?
In ensiled form, grass or any other green fodder is stored in silo, in airtight condition. Drying is
not used for silage. Ensiled cops are used for animal feed in winter.
What is wilted form ?
Wilted crops are partially air dried crops. Wilting is done before ensiling.
There are many reports made throughout the world suggesting WH as a very good alternative
animal feed. Some of its are mentioned here.
For ruminants
There is no doubt that the cellulose content of water hyacinth can be used as a good source of
energy for ruminants (Mukherjee & Nandi, 2004). Para grass (Brachiaria mutica) has been
replaced with fresh WH in their cattle (Biswas & Mandal, 1988). Fresh WH performed better
than wilted WH for goat (Aregheore & Cawa, 2000). If WH is mixed with a rice straw based
diet, growth of beef cattle increased (Islam et al., 2009). Addition of 30% dried WH in basal diet
of wheat straw resulted in 500g daily live weight gain (Parashar et al., 1999). Wilting reduces
silage losses, it is important as WH contains low dry matter content (McDonald et al., 2011).
Ensiled WH was mixed with rice straw, urea and molasses. Upon feeding it to dairy cattle, it
resulted in better milk yield (Chakraborty et al., 1991). Sheep accepts both ensiled and wilted
WH (Abou-Raya et al., 1980; Baldwin et al., 1975). Although wilted WH cannot be used as feed
for sheep solely, it can be used upto 50% in their feed (Abdelhamid & Gabr, 1991). After
extracting mechanically its juice, WH can be used as feed for buffalo calves (Borhami et al.,
1992).
Pigs
In Vietnam, cooked or fresh WH reduced organic matter digestibility. But it did not affect feed
intake and concentrate usage was reduced upto 6% (Manh et al., 2002b; Son & Trung, 2002).
Ensiled WH costs low, so it suits small holder farms.
Rabbits
WH that was grown in waste water replaced alfalfa successfully in rabbit diet (Moreland et al.,
1991). Para grass was replaced upto 60% with WH and it resulted in better growth performance
(Thu & Dong, 2009).
Ducks
In the Mekong Delta of Vietnam, birds are fed with conventional diets but alternative feed like
WH and duckweed are provided to duck. (Sotolu, 2010; Men et al., 2002). Men and Yamasaki
(2005) found the
replacement upto 25% of a commercial diet by fresh WH to be economically profitable due to
the lower feed cost, but poor in performance. In China, WH has been successfully used as duck
feed. Replacement of traditional diet with WH results in higher daily feed intake, egg laying ratio
and egg quality (Jianbo et al., 2008).
Fish
WH can be a good feed source if its high fiber content can be reduced in any way. It is
recommended by Hertrampf & Piedad-Pascual for fresh water fish (Hertrampf & Piedad-
Pascual,2000). On the other hand, for tilapia feed it may not perform well as suggested by
Buddington due to high fiber content (Buddington, 1980). El-Sayed (2003) found that ensiled
WH showed better performance than fresh WH replacing wheat bran in diet upto 20% .The
supplementation of basal diet with WH can be as high as 50% for fish (Hertrampf & Piedad-
Pascual, 2000).
Water hyacinth as fish feed
Study for African catfish
Rapid growth rate of water hyacinth affects water chemistry in many ways.it reduces light
penetrationand dissolved oygen level in water, affects flora and fauna,increases rate of water loss
due to evaporanspiration. To make its practical use, it s being considered as alternative plant
protein source in livestock feed.
Water hyacinth contains high amount of cell wall material which is mainly cellulose and also a
high amount of amino acid. Fiber content is higher in whole water hyacinth plant than in leaves
only. Clarias gariepinus is a very common african catfish. To compare the digestibility of water
hyacinth plant as fish meal, following study was made.
Experimental work
Collection and processing of water hyacinth
Fresh water hyacinth plants were collected from Awba dam of university of Ibadan. They were
solar dried for 2 weeks. Leaves were ground to make WLM (water hyacinth leaves meal) and the
whole plant were ground to make WPM (water hyacinth plant meal). These two meals have
differences in composition. WLM has higher crude protein than WPM whereas WPM has higher
ash than WLM.
Table 3.1: proximate composition of WHMs
WHM CP (%) CL (%) C Fiber (%) ash (%) NFE (%)
WPM 24.17 2.37 19.62 11.35 42.49
WLM 28.2 4.7 14.79 7.03 45.28
How experimental diets were made
Three isoproteic (40% CP) diets were prepared, the main diet being WPM, WLM and SBM
(soya bean meal) respectively. SBM acted like control. There were other components that make
up the complete diet like fishmeal, groundnut cake, bone meal etc. Allowance was made to
accommodate 1% chromic oxide in each of three diets that served as marker.
Table 3.2: gross composition of experimental diets (g/100/DM)
Ingredients Diet 1 Diet 2 Diet 3
Fish meal 18.94 18.94 18.94
Groundnut cake 26.97 26.97 26.97
SBM 22.91
WPM 26.72
WLM 31.63
Yellow maize 25.18 21.37 16.46
Bone meal 1 1 1
Vit premix 2.5 2.5 2.5
Fish oil 1.5 1.5 1.5
Chromic oxide 1 1 1
Table 3.3: proximate composition of experimental diets (g/100/DM)
Parameter Diet 1 Diet 2 Diet 3
Crude protein 40.13 40.08 40.11
Fiber 4.38 6.47 5.51
Fat 7.14 4.21 4.86
Ash 4.62 6.11 6.3
NFE 43.73 43.13 43.22
Gross energy
(kcal/g/DM)
328.16 326.32 329.25
Digestibility study
90 catfish fingerlings of11.2 gram average weight were randomly distributed into 9 concrete
tanks of with 150 L capacity. Water supply source was deep well, flowrate of 2 L/min for 70
days. Dissolved oxygen, pH, ammonia – these parameters were taken using a combined digital
meter (YSI). Fish were fed twice (8:00, 18:00 hrs).
Faeces were collected from each tank before feeding and 8 hrs after feeding. Faeces were oven
dried at 48 degree celsius for 120 hrs. All meals, diets, fish samples and faecal wastes were
chemically analyzed for their proximate composition according to AOAC method. At the end of
the experiment, survival rates were determined.
Determination of growth, nutrient utilization and digestibility coefficient.
Following growth and nutrient utiization parameters were determined according to Aderlu et.al.
1. Mean weight gain (MWG)= (W2-W1)%
2. Specific growth rate (SGR) =(LogW2-LogW1)/(T2-T1)
W2=final weight of fish (gm)
W1=initial weight of fish(gm)
T2= end of experiment (days)
T1=beginning of experiment (days)
3. Protein efficiency ratio (PER)= weight gain (gm)/ protein intake (gm)
4. Feed conversion ratio (FCR)= Total feed intake/ weight gain(gm)
5. Protein intake= feed fed x crude protein of the feed
6. Nitrogen metabolism (Nm) = 0.549 x(a+b)xh/2
a= initial mean weight of fish (gm)
b= final mean weight of fish (gm)
h= experimental period (days)
7. Apparent digestibilty coefficient (ADC) = 102 – (102 x (1d/1f) x (Nf/Nd))
Nd=protein in diet
Nf=protein in faecs
1d=% Cr2O3 in diet
1f=% Cr2O3 in faecs
8. Survival rate (%)= ( (initial no.of fish stocked-mortality)/(initial no. of fish))x 100
Results and discussions
Table 3.4: growth performance and nutrient utilization of fishes fed SBM and WHM based
diets.
Parameter Diet 1 Diet 2 Diet 3
MWG (g) 23.08 14.79 19.13
WG(%) 67.38 56.84 63.05
Total feed intake (g) 76.43 79.64 80.11
SGR(%) 0.7 .52 0.62
Protein intake (g) 4.37 4.55 4.58
Nm 8.73 7.16 7.98
ADC (protein) 76.14 65.44 71.28
ADC (energy) 73.02 63.16 67.30
Survival rate (%) 100 100 100
From table 3.3, crude fiber was the highest in diet2 (WPM) and the lowest in diet 1 (SBM). Fish
that were fed diet 1 had the highest MWG, SGR. Fish under diet 2 had these in the lowest
amount. SBM (diet 1) is the conventional feed. But total feed intake and protein intake were
significantly higher in WHM based diets. Again, ADC was the highest in diet 1, diet 3 being the
intermediate and diet2 being the last. Survival rates were 100% for all, this is the most
important news.
Although temperature was constant throughout the experiment, pH and dissolved oxygen level
varied significantly for three different diet groups. Ammonia level was the highest in diet 2 and
the lowest in diet 1.
Lower weigh gain in WHM based diets may be due to their high fiber content. The results are in
line with Nwanna et al. (2008) who reported poor fish growth performance when fed diet with
crude fiber above 4.7% . Both WHM meals had fiber content much higher than this value.
Conclusion
This study reveals two important findings-
1. WLM is a better feed than WPM.
2. Only limitation for WPM as feed is high fiber content.
So, if water hyacinth leaves are processed in a suitable way, it can serve a dual purpose of
least cost fish diet and its effective mechanical control.
Study for Rohu fish
The previous study showed that unprocessed water hyacinth do not perform efficiently. In this
study, water hyacinth had been processed and showed tremendous good results.
Fishes do not like aquatic weeds like water hyacinth as their feed because of several factors-
1. Low protein content
2. Amino acid imbalance
3. Presence of antinutritional factor
4. Presence of crude fiber, cellulose, hemicellulose and lignin.
Most importantly Fish generally do not possess the enzyme cellulase significant
symbiotic gut flora capable of hydrolyzing the cellulose present in mcrophytes.
Why fermentation ?
It has been studied that inclusion rate can be done by adding enzymes to break down plant cell
walls so that nutritious cellular contents are liberated. Microbial fermentation is necessary in
organisms with diet which is high in fiber. Fermentation is the cheapest way to increase the
nutritional level through microbial synthesis.
While water hyacinth plant multiply at a rate of 15% of surface area per day, there must be some
processes to make this plant edible for fish and others- just to make a good use of it. So, this
study was performed.
Nine isoproteic (30% CP) and isocaloric (18.23 kJ/kg) experimental diets were made. One
reference diet was used as standard. Raw and fermented WH leaves were used in three different
proportion -20,30 and 40%.. water hyacinth leaves were fermented with fish intestinal bacteria.
Two specific strains of these bacteria were Bacillus subtilis CY5 (isolated from Cyprinus carpio) and B.
megaterium CI3 (isolated from Ctenopharyngodon idella) a commercial lactic acid bacteria (LAB) – Lactobacillus
acidophilus (lactobacil) was used along with B. subtilis CY5. The test specimen was Labeo
rohita, mostly herbivorous and very common in Asia.
Selected bacteria were allowed to grow in shake bottles containing 4% tryptone soya broth for
culture at 37oC for 24 hours to obtain viable cell no. 10^7/Ml broth. WH leaves were sundried
and ground, then moistened with a liquid basal medium whose composition is-
1. KH2PO4= 4g/L
2. NaHPO4= 4 g/L
3. MgSO4.7H2O= 0.2 g/L
4. CaCl2= 0.001 g/L
5. FeSO4.7H20= 0.004 g/L
Moistened leaves were autoclaved for sterilization. The sterilized leaf meal was inoculated with
B. subtilis and B. megaterium culture separately at the rate of 10^7 bacterial cells per gram of
dried leaf. It was kept for 15 days at 37 oC for fermentation.
Diet 1,2 and 3 were prepared with raw WH leaf meal. Diet 4,5 and 6 were prepared with B.
megaterium CI3 inoculated WH leaf meal. Diet 7,8 and 9 were formulated with WH leaf meal
fermented with B. subtilis CY5 with LAB. LAB was added at the rate of 10^6 cells per gram to
determine its synergistic effect. All diets contained 1% chromic oxide as digestibility marker.
Carboxymethylcellulose was used as binder.
Table 3.5 : composition (% dry weight) of experimental diets (on dry matter basis)