Blue Mountain
Soya meal, an important component of ostrich diets
Originally published in Feed Mix Volume 8. No. 2
Ross G. Cooper*
and Fiona V. Benson**
*Department of Physiology,
University of Zimbabwe, P.O. Box MP 167, Mount Pleasant, Harare, Zimbabwe. Fax:
(263) (4) 333678. E-mail: rgcooper@hotmail.com
**Blue Mountain Feeds
International, Blue Mountain Farm, PO Box 267, Hopefield, 7355 Fax:
(27) 22 7230 2105 E-mail:
fiona@blue-mountain.net
Introduction
Nutrition is a key element
in ostrich production. It is only with an adequate knowledge of nutrient
requirements at each growth stage of the ostrich that the correct contents of
formulating diets will be realized. In the past, nutritional results obtained
for poultry have been erroneously adopted to fit ostrich diets, thus resulting
in various nutrition-related problems1. An accurate evaluation of
any diet, therefore, should determine the extent to which an ingredient will
provide essential nutrients for growth and development, the potential
utilization capacity of the nutrient and performance outcomes2.
Some studies describe the
anti-nutritional effects of soybean due to an interference with normal gut and
systemic metabolism3. However there are many personal observations
that soya meal is in fact beneficial as a good source of amino acids4-5
and minerals6 given correct processing procedures. These include
heat processing7 in order to denature inhibitory enzymes like urease
and haemagglutinin and an inclusion in the meal of not more than 25-30% Soya. Indeed
it is emphasized that soybean can be used in feed without detrimental effects
on growth rate and body conformation8. The aim of this article, therefore, is to discuss the importance
of soya meal in the diet of ostriches in terms of its beneficial effects on
growth and development.
Soya meal
Soybean meal is a concentrated source of protein and
energy and is lower in crude fiber than most other oilseed meals. The higher
protein, energy and lower fiber content of soybean meal enable formulation of diets
which are proven more efficient in the conversion of feed to meat in for most
livestock.
Soyabean meal is available in two grades. Both meals are produced following the same basic process - the only difference being that the 44% has some hulls blended back. Dehulled 47% protein soyameal is preferred by most nutritionists who wish to achieve a dense ration, as the difference is soyahulls that have no place in rations designed for production. Full fat Soya is the whole bean toasted and provides a high protein source and high fat source. The fat levels are too high for use in Ostrich rations.
Soybean meal provides the best balance for amino
acid deficient cereal grains 9.
Table 1 - demonstrates this very clearly. It is the most economical protein available to most livestock
producers and is much more uniform in composition than any of the by-products
available from the meat or fish industry.10 Arginine
has been reported to be thee most efficiently digested amino acid in dehulled
soybeans at 93% and lysine more digestible than sunflower. Other protein
sources are products such as: Cotton Cake - which carries a risk of ‘Gossypol’
Toxin. Peanut Meal that carries a risk
of Aflatoxins and is also low in lysine and methionine and has some extremes on
others such as arginine and threonine.
Soyabean meal has been proven the safest high protein cereal grain to
use in any livestock ration and has been used safely for many years in US
livestock and in recent years with Ostrich.
Table 1 11
Comparative Amino Acid
Composition of Oilseed Meals (1)(a)
|
&NBSP |
Soybean |
Dehulled |
Cottonseed |
Canola |
Peanut |
Rapseed |
Sunflower |
|
Arginine |
3.4 |
3.8 |
4.6 |
2.3 |
4.6 |
2.0 |
3.5 |
|
Lysine |
2.9 |
3.2 |
1.7 |
2.3 |
1.8 |
1.7 |
1.7 |
|
Methionine |
0.65 |
0.75 |
0.52 |
0.70 |
0.42 |
1.5 |
1.5 |
|
Cystine |
0.67 |
0.74 |
0.64 |
0.47 |
0.73 |
0.7 |
0.7 |
|
Tryptophan |
0.6 |
0.7 |
0.5 |
0.4 |
0.5 |
0.5 |
0.5 |
|
Histidine |
1.1 |
1.3 |
1.1 |
1.1 |
1.0 |
1.0 |
1.0 |
|
Leucine |
3.4 |
3.8 |
2.4 |
2.6 |
3.7 |
2.6 |
2.6 |
|
Isoleucine |
2.5 |
2.6 |
1.3 |
1.5 |
1.8 |
2.1 |
2.1 |
|
Phenylalanine |
2.2 |
2.7 |
2.2 |
1.5 |
2.0 |
2.2 |
2.2 |
|
Threonine |
1.7 |
2.0 |
1.3 |
1.7 |
1.2 |
1.5 |
1.5 |
|
Value |
2.4 |
2.7 |
1.9 |
1.9 |
1.9 |
2.3 |
2.3 |
Protein is essential in any ration for optimum growth and development, meat and egg production and reproduction. Ostriches perform best on rations that carry a high level of protein. The other grain sources of protein carry lower levels of protein compared to Soyameal, (with the exception of Peanut Meal that is too risky to use) making it more difficult, if not impossible, to formulate a productive ration for ostriches. See Table 2
Table 2.11
Comparative Composition of Various Oilseed
Meals (1)(a)
|
|
NRC Ref. No. |
Crude |
Ether |
Crude |
Energy(b) |
|
Soybean meal |
5-04-604 |
44.0 |
0.5 |
7.0 |
2240 |
|
Soybean meal(c) |
5-04-612 |
48.5 |
1.0 |
3.0 |
2475 |
|
Canola meal |
5-08-135 |
38.0 |
3.8 |
11.1 |
2110 |
|
Cottonseed meal |
5-07-872 |
41.0 |
0.8 |
12.7 |
1940 |
|
Linseed meal |
5-02-048 |
33.0 |
0.5 |
9.5 |
1400 |
|
Peanut meal |
5-03-656 |
48.0 |
1.5 |
6.8 |
2200 |
|
Rapeseed meal |
5-03-871 |
36.0 |
2.6 |
13.2 |
1770 |
|
Safflower meal |
5-07-959 |
42.0 |
1.3 |
15.1 |
2040 |
|
Sesame meal |
5-04-220 |
42.0 |
7.0 |
6.5 |
2255 |
|
Sunflower meal |
5-04-739 |
42.0 |
2.3 |
21.0 |
1760 |
(a) As-fed basis
(b) metabolizable energy for poultry
(c)
Dehulled
Improper oilseed processing damages amino acids,
rendering the proteins biologically unavailable.12 Care needs to be taken that the source of the meal
used is reliable and supplies a consistent product. After soyabeans have been cleaned, dehulled, flaked and deoiled,
the white flakes should be toasted (steam heated) to remove antinutritional
factors, especially trypsin inhibitors, thus removing factors that will upset
digestion.
Conclusion
Soyabean meal is a quality
protein source in ostrich feed, being typically 47.5% crude protein. As with
all ingredients, the quality must be correct and inclusion levels reasonable
and in balance to other ingredients in the rations. The importance of soyabean
meal in reducing the loss of mineral ions6, 14 should be
investigated further especially in the most vulnerable period of an ostrich
chick's life, 0-3 months. Indeed
ostrich rations including reasonable levels of high-grade soyabean meal have
been proven to far outperform any rations without soyabean meal. Hence the
necessity of including soyabean meal in ostrich diets.
References
1. Cilliers, S.C. 1998. Feedstuff evaluation,
metabolisable energy and amino acid requirements for maintenance and growth in
ostriches. Proceedings of the 2nd
International Ratite Conference, 21-25 September. Oudtshoorn, South Africa:
12-23.
2. Oldham, J.D. and Erasmus, G.S. 1990. Animal Performance as the Criterion for Feed
Evaluation. In: J. Wiseman and D.J.A. Cole (eds.) Feedstuff Evaluation. Butterworths,
London: 73-90.
3. Grant, G. 1989. Anti-nutritional effects of
soyabean: a review. Progress in Food and
Nutrition Science 13(3-4):
317-348.
4. Green, S., Bertrand, S.L., Duron, M.J. and
Maillard, R. 1987. Digestibility of amino acids in soyabean, sunflower and
groundnut meals, determined with intact and caecectomised cockerels. British Poultry Science 28(4): 643-652.
5. Angkanaporn, K., Ravindran, V. and Bryden,
W.L. 1996. Additivity of apparent and true ileal amino acid digestibilities in
soybean meal, sunflower meal, and meat and bone meal for broilers. Poultry Science 75(9): 1098-1103.
6. Shafey, T.M. and McDonald, M.W. 1991. The
effects of dietary concentrations of minerals, source of protein, amino acids
and antibiotics on the growth of and digestibility of amino acids by broiler
chickens. British Poultry Science 32(3): 535-544.
7. Perilla, N.S., Cruz, M.P., de Belalcazar, F.
and Diaz, G.J. 1997. Effect of temperature of wet extrusion on the nutritional value
of full-fat soyabeans for broiler chickens. British
Poultry Science 38(4): 412-416.
8. Aregheora, E.M. 1998. Nutritional evaluation
of Zambia indigenous soy bean (Glycine
max) and sunflower (Helianthus annus)
as protein sources in poultry and pigs diets. Nahrung - Food 42(5):
298-301.
9. Holle, D.G. 1995. Amino Acids. Ratite Feeds and Feeding 1-2: 58, 59.
10. Waterhouse, H.N. 1997. Soybean Meal Use in Ratite Feeds. Personal Communication.
11. Pierson, E.E., Porter, L.M. and Brown, R.D., Jr.
1980. Amino acid digestibility of dehulled soybean meal by adult turkeys. Poultry Science 59(4): 845-848.
12. Dale, N. 1996. Feedstuffs
July 17: 24.
13. Smith, K. and Associates. 1997. Advances in Feeding
Soybean Meal. Soybean Meal INFOsource.
[On-line] http://www.soymeal.org/ksmith1.htm
14. Hirabayashi, M., Matsui, T., Yano, H. and Nakajima,
T. 1998. Fermentation of soyabean meal with Aspergillus
usamii reduces phosphorus excretion in chicks. Poultry Science 77(4):
552-556.