Nutritional evaluation of whole root and tuber crops as ... · Nutritional potentials of root and tuber crops •Cassava root is an energy-dense food. cassava has very efficient carbohydrate

Nutritional evaluation of whole root and tuber

crops as livestock feed

Dr. Bukola Babatunde, Department of Animal Husbandry, College of Agriculture, Fisheries & Forestry, Fiji

National University, Koronivia, Suva, Fiji

Introduction• High cost of imported livestock feed resources is a major factor

limiting the growth of livestock industry (especially non ruminants) in many developing countries • leads to expensive animal products.

• Feed ingredients represent 65 - 70% total cost of intensive non ruminant production system in many developing countries

• Energy resource like maize and other grains constitutes between 45 – 60% of finished feeds for these animals

• Fluctuating high cost of maize encourages the use of locally available alternative sources of energy, particularly the starchy roots and tubers that abound in many areas of humid tropics (Tewe & Egbunike, 1992).

Potentials of root and tuber crops• Root and tuber crops have the potential to provide more

dietary energy per hectare than cereals • Some root crops, such as taro and cassava- grown in tropical

climates all the year round increase food security. • important during the preharvest period of cereal crops,

when other foods are expensive or unavailable.• Many food-deficit countries are forced to import large

quantities of grain to meet local production shortfalls. • food imports put heavy drain on foreign exchange.

Root crops • Cassava - tapioca,

manioc, (Manihot esculenta)

• Sweet potato - kamote (Ipomoea batatas) s.

The root crops are plants with edible modified roots while both the tuber and corm crops have modified stem

Sweet potatoes

cassava

Tuber (stem crops)

• Potato - white potato, Irish potato, patatas (Solanum tuberosum)• Yam, ube, ubi, Chinese

taro, greater yam, water yam (Dioscorea alata)

Potatoes

Yam

Source: Levetin-Mcmahon. 2008. Starchy staples. In: Plants and Society. 5th ed. The McGraw-Hill Companies.

Corm crops• Taro/dalo, gabi, cocoyam,

dasheen, lesser yam, lesser asiatic yam (Colocasia esculentum)

• high yielding varieties of root and tuber crops - improvement programmes suggesting production in excess of human consumption will become available for feeding farm animals in such developing countries.

Source: Levetin-Mcmahon. 2008. Starchy staples. In: Plants and Society. 5th ed. The McGraw-Hill Companies. Retrieved from http://www.life.illinois.edu/ib/102/Levetin/14.%20Starchy%20Staples.pdf.

Dalo\cocoyam

Nutritional potentials of root and tuber crops• Ruminant animals can utilize raw roots and tubers crops

effectively without any detrimental effects• However, the extent of their practical use in non ruminant

feeding programmes is limited by:• toxic cyanogenic glycosides • low protein content • other undesirable substances, • dustiness of the dried products, • mouldiness during processing • high fibre of the peels (Tewe & Egbunike, 1992)

Use in non-ruminant feeding programmes (Tewe and Egbunike, 1992)

• For use in non ruminant feeding programmes – fresh root and tuber crop are subjected to processing techniques such as:• fermentation, • soaking, • boiling, • ensiling • Ovendrying• sun-drying

Need for processing• Root crops has two-thirds of their weight as water (25-32% DM) making

preservation, transport costs and general handling more difficult • To reduce microbial contamination - high moisture content levels

greater than 12% allow for microbial growth • Sun-drying in a humid environment results in the proliferation of microbial

organisms in the feed materials• To remove cyanogenic glycosides (linamarin and lotaustralin) and other

antinutrients toxic for nonruminants • bitter taste and reduce palatability of the roots. • Cocoyam contains irritating/acridity substance that causes burning

sensation. • To reduce the dustiness of the dried roots and tubers flour can cause

irritation of the respiratory tract unless feed is pelletized or oil is added.

Nutritive value of fresh root and tuber products compared with sorghum and maize (in percentages)

Sorghum (ground) *1

Maize*1 Sweet potato *2

Dalo *2 Yam *2 Cassava *2

Fresh

moisture 11.9 13.4 70.57 82.27 67.13 – 77.4 68.08

C. protein 7.5 9.4 3.13 5.47 2.51- 4.45 2.84

C. flbre 2.0 1.9 0.90 1.28 0.42-0.67 1.38

sol. carbohy. 74.6 70.1 24.54 11.03 27.49 28.05

Crude fat 2.32 3.64 0.79 0.20 0.14 – 0.15 0.18

starch 74.6 71.8 72.4 77.9 - 76.5

ash 1.65 1.62 0.97 1.03 0.78-1.05 0.85

Gross energy (kg/kg)

3940 4096 4061 3474 - 3909

*1: Source: H.K. Lim. 1967, * 2: Odebunmi et al (2007), Abdulrashid and Agwunobi (2009)

Anti nutritional factors in major root and tuber cropsFresh cassava root Anti-nutritional

factorLevels (mg/kgDM) Mode of elimination

Dried cassava roots

Hydrocyanic acid 233 - 1150 Fermentation, boiling, grating, sundrying, cooking ensiling

Fresh cassava peels Hydrocyanic acid 1300 - 2250 same

Dried cassava wastes

Hydrocyanic acid 57.2 same

Fresh cassava leaves

Hydrocyanic acid 2650 - 7200 same

Cocoyam tuber Irritating /acridity substance

- Cooking, sundrying, roasting fermentation

Oxalic acid 45.3 (g/100g DM)

saponin 0.53 – 7.9 (g/100gDM)

Sweet potato Trypsin inhibitor - Cooking, sundrying

Nutritional potentials of root and tuber crops• Cassava root is an energy-dense food. cassava has very efficient

carbohydrate production per hectare• produces about 250000 calories/hectare/d, which ranks it before maize, rice,

sorghum, and wheat (Okigbo 1980). • The root is a physiological energy reserve with high carbohydrate content,

which ranges from 32% to 35% on a fresh weight basis, Eighty percent of the carbohydrates produced is starch (Gil and Buitrago 2002); 83% is in the form of amylopectin and 17% is amylose (Rawel and Kroll 2003).

• Roots contain small quantities of sucrose, glucose, fructose, and maltose (Tewe and Lutaladio 2004)

• Raw cassava root has more carbohydrate than potatoes and less carbohydrate than wheat, rice, yellow corn, and sorghum on DM basis (Montagnac et al., 2009).

• The fiber content in cassava roots depends on the variety and the age of the root. Usually its content does not exceed 1.5% in fresh root and 4% in root flour (Gil and Buitrago 2002).

Purpose of the study• The aim of the study is to compare nutritional value of whole root and

tuber crops as livestock feed resources• A comparative analysis of proximate composition of whole root and tuber

crops commonly used as staple food in Fiji and other Pacific Island Country were studied

• The comparative effect of sundrying and ovendrying on nutritive quality of roots and tuber meal were studied.

Hypothesis/Research questions• Hypothesis: root and tuber crops have different nutrient composition • Null hypothesis: they have same nutrient composition

• Hypothesis: processing method affect nutrient composition of root and tuber crops differently• Null hypothesis: processing affect nutrient composition of root and tuber

crops in same way

Materials and Methodology

Potato/Sweet Potato/Cassava/Yam/Dalo

Fresh Oven-dried

Sundried

5 root and tuber crops

Root and Tuber crops

key

Potato Psweet potato SP

cassava CS

yam YM

dalo DLRaw (fresh) R

ovendried OV

sundried SU

Materials and Methodology

• Samples: Fresh potatoes, sweet potatoes, cassava, yam and taro/dalo purchased from the market were washed and cut into slices.

• Preparation: The cut pieces were sub-divided into three equal parts. One part was analysed as fresh samples, while remaining parts was sundried (SU) and ovendried.

• The ovendried and sundried samples were milled into meal using an electric grinder. • Standard methods of Association of Official Analytical Chemist (AOAC 2005)

were used to determine starch, crude protein, crude ash, total ash, crude fibre and moisture contents

• Total carbohydrate (NFE) was obtained by difference• The experiment was designed as 5 x 3 factorial experiment and data were

expressed on as-fed basis.• Interaction between type of tuber crop and processing on nutrient

concentration was tested using three-way ANOVA of General Linear model of SPSS version 22.

RESULT: Fresh whole root and tuber crops nutrient composition

moisture DM Fat Ash Crude P Crude F starch NFE0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

80.00

Nutrient composition

%composition

RUPEDP

RUPEDSP

RUPEDCA

RUPEDYA

RUPEDDL

fresh dalo and yam has comparative higher (P < 0.05) dry matter and NFE contents than other root and tuber crops. Potato and dalo has more starch in raw samples

Effect of processing on nutrient composition of whole potato

moisture DM Fat Ash Crude P Crude F starch NFE0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

80.00

90.00

100.00

RUPEDP

OVUPEDP

SNUPEDP

b

There were no differences (P > 0.05) in the DM content of sundried and ovendried whole potatoes. The processing methods enhances (P < 0.05) nutritive value of root and tuber crops compared to fresh samples. Oven drying is more effective (P < 0.05) in raising NFE fraction of whole potatoes than sundrying

a

Effect of processing on nutrient composition of whole sweet potato

moisture DM Fa

tAsh

Crude P

Crude Fsta

rch NFE0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

80.00

90.00

100.00

RUPEDSP

OVUPEDSP

SNUPEDSP

Oven drying improved (P< 0.05) DM and NFE of sweet potato than sundrying samples , Protein of sweet potato is not affected by processing methods

Effect of processing on nutrient composition of whole cassava

moisture DM Fa

tAsh

Crude P

Crude Fsta

rch NFE0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

80.00

90.00

100.00

RUPEDCAOVUPEDCASNUPEDCA

a

Sundrying improves DM and soluble carbohydrate fractions of cassava samples than oven drying method

b

Effect of processing on nutrient composition of Yam

moisture DM Fa

tAsh

Crude P

Crude Fsta

rch NFE0.00

10.0020.0030.0040.0050.0060.0070.0080.0090.00

100.00

RUPEDYA

OVUPEDYA

SNUPEDYA

a

Oven drying improved (P< 0.05) DM and NFE of Yam than sundrying samples , Protein of yam is not affected by two processing methods

b

Effect of processing on nutrient composition of Taro/Dalo

moisture DM Fat Ash Crude P Crude F starch NFE0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

80.00

90.00

100.00

RUPEDDL

OVUPEDDL

SNUPEDDL

ab

Oven drying improved (P< 0.05) DM, CP and fat fractions of Taro/dalo than sundrying samples, while sundrying increases CF and starch over ovendrying,

Results • Root and tuber crops have different

nutrient composition • Each whole root and tuber crops were

affected differently by processing methods,• However, there are significant interaction

effects (P < 0.05) between the type of tuber crop, and processing methods for dry matter, ash, crude protein, crude fibre and soluble carbohydrate fractions

• Fresh root and tuber crops have comparative low DM contents (DL > YM > CS > SP > P) compared to those processed by sundrying and oven drying.

• There were significant differences (P > 0.05) in DM between different root and tuber crops processed by two methods.

• Both processing methods have no effect on potato DM content.

• two processing methods enhances (P < 0.05) nutritive value of root and tuber crops compared to fresh samples.

• Sun drying is more effective (P < 0.05) in raising DM and NFE contents of root and tuber crops than oven drying.

• However, oven drying improved (P < 0.05) DM of SP, YM and DL, while sun drying improved (P < 0.05) DM content of cassava only.

• The protein contents of root and tuber crops were enhanced (P < 0.05) when processed but there were no significantly differences (P > 0.05) between sundried and oven dried root and tuber crops.

• sundrying has greater influence on DM content of unpeeled cassava (SU > OV)

• sundrying improved the starch component of whole root and tuber crop - Dalo > cassava > yam > P > SP

• Sun drying improves (P < 0.05) crude fibre of root and tuber crop samples compared to oven drying • Equally, soluble carbohydrate fractions of

sundried yam and dalo were significantly higher (P < 0.05) than potato, sweet potato and cassava• Reject• Null hypothesis: they have same nutrient

composition• Null hypothesis: processing affect nutrient

composition of root and tuber crops in the same way

Root and tuber crops as animal feedRoot and tuber crops

Substitution for maize

comment Author

cassava 40% (pigs)20 - 30% (poultry)

40% (cattle)

40% (goat and sheep

20% most economical for layers, high level acceptable for broiler than layers.higher milk and fat yields and live weight gains for dairy cattle

Gómez et al. (1984)

Pineda and Rubio, 1972Montilla et al. (1975) Devendra (1977

sweet potato 25% (poultry)50% (pig)

supplement 0.2-0.5% of lysine. horses, mules and hogs, for lactating dairy cows (satisfactory)

Yang (1982) Yeh et al. (1978)

Dalo 20 -25% replacement of maize in broiler

die ts

- At levels of 20 – 40% of dry matter, cocoyam silage supported adequate growth rate in young pigs[93].

Anigbogu(1997] and Abdulrashid and Agwunobi (2009) Esonu (2000)

Potato - - -

Yam - - -

Conclusion• Considering the nutritional characteristics, root and tuber crops

have the potential to be used as alternative energy supplements for non ruminant production.

• Performance of pigs and poultry fed varying levels of roots and tubers showed replacement value in non-ruminants diets at certain levels without detrimental effects.

• the use of these root crops and their by-products for maize replacement in intensive non-ruminant production systems requires adequate protein supplementation, sufficient sulphur-containing amino acids fortification and proper processing.

• various processing methods (e.g. sundrying, boiling, frying, fermentation and ensiling) can be employed to eliminate or reduce the anti-nutritional factors present.

• This will improve the quality and safety of these feed materials

References• Abdulrashid M and Agwunobi L N. 2009. “Taro cocoyam (Colocasia esculenta)

meal as feed ingredient in poultry”. Pakistan Journal of Nutrition 8: 666 – 673

• Anigbogu M M. “Effect of Replacing Corn with Taro (Colocasia asculenta Linn) Meal on the Live weight, Dressing Percentage and Cut-up yield and Litter Condition of Broiler Chicks” Proceeding of 2nd Annual Conference of Animal Science Association of Nigeria, Lagos. September, 1997

• AOAC. 2005. Official Methods of Analysis.17th Ed. Ass. Anal. Chem. Arlington, Virginia, USA

• Buitrago A (1990). La yuga en la alimentacion animal. Centro Internacional de Agricultura Tropical (CIAT). Cali, Colombia. pp. 10-18

• Esonu B O. “Animal Nutrition and Feeding: A Functional Approach” Memory Press, Oweri, Nigeria, pp. 198–204, 2000.

• Gil, J.L. & Buitrago, J. 2002. La yuca en la alimentación animal. In: La yuca en el Tercer Milenio. Ediciones CIAT. No. 327. 527 pp

• Levetin-Mcmahon. 2008. Starchy staples. In: Plants and Society. 5th ed. The McGraw-Hill Companies.

• Montagnac, J.A; Davis C.R and Tanumihardjo S.A (2009). Nutritional Value of Cassava for Use as a Staple Food and Recent Advances for Improvement

References• Okigbo BN (1980). Nutritional implication of projects giving

high priority of the production of staples of low nutritive quality. In the case of cassava (Manihont esculenta, Crantz) In the humid tropics West Africa. Food Nutr. Bull. 2:1-10.

• Rawel HM, Kroll J (2003). Importance of cassava (Manihot esculenta Crantz) as the main staple food in tropical countries. DLR. 99:102- 110.

• Tewe OO, Lutaladio N. 2004. Cassava for livestock feed in sub-Saharan Africa. Rome, Italy : FAO.

•END