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The effects upon rumen microbial protein synthesis of giving sheep diets of rolled barley and hay supplemented with increasing quantities of soya-bean meal

Published online by Cambridge University Press:  27 March 2009

J. A. Rooke
Affiliation:
Department of Agricultural Biochemistry and Nutrition, University of Newcastle upon Tyne, Newcastle upon Tyne, NE1 7RU
M. A. Overend
Affiliation:
Department of Agricultural Biochemistry and Nutrition, University of Newcastle upon Tyne, Newcastle upon Tyne, NE1 7RU
D. G. Armstrong
Affiliation:
Department of Agricultural Biochemistry and Nutrition, University of Newcastle upon Tyne, Newcastle upon Tyne, NE1 7RU

Extract

A ruminant animal is largely dependent upon microbial protein synthesized within the reticulorumen for amino acids to meet its requirements for maintenance and production. The major precursor for rumen microbial protein synthesis is ammonia arising both from degradation of feed proteins within the rumen and from nitrogen recycled to the rumen. The concentration of rumen ammonia-N required to sustain maximal rates of microbial protein synthesis in vivo has been variably reported to range from 22 to 235 mg ammonia-N/1 rumen fluid (Miller, 1982). Most experiments which have investigated the concentrations of rumen ammonia-N required for maximal rates of microbial protein synthesis have used the addition of urea to the diet as the means of increasing rumen ammonia-N concentrations. However, little attention has been paid to the effects upon rumen ammonia-N concentrations and upon the efficiency of rumen microbial protein synthesis of supplying increasing amounts of a readily degradable protein in the diet, although Beardsley et al.(1977) found that as increasing amounts of soya-bean meal were fed to sheep, net losses of N across the forestomachs of the sheep were increased. In this paper, two experiments are described in which increasing amounts of soya-bean meal were fed to sheep receiving a basal ration of rolled barley and hay; the digestion of organic matter (OM) and of amino acid N (AAN) within the rumen, the net quantities of microbial AAN entering the small intestine and the efficiency of rumen microbial AAN synthesis were measured.

Type
Short Notes
Copyright
Copyright © Cambridge University Press 1986

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References

Beardsley, G. L., Whitlow, L. W., Roffler, R. E. & Satter, L. D. (1977). Ruminal degradation of Boyabean meal protein in sheep fitted with duodenal re-entrant cannulae. Journal of Dairy Science 60, Supplement 1, 6667.Google Scholar
Beever, D. E., Thomson, D. J., Pfeffer, E. & Armstrong, D. G. (1971). The effect of drying and ensiling grass on its digestion by sheep. Sites of energy and carbohydrate digestion. British Journal of Nutrition 26, 123134.Google ScholarPubMed
Brown, G. R., Armstrong, D. G. & Macrae, J. C. (1968). The establishment in one operation of a cannula into the rumen and re-entrant cannulae into the duodenum and ileum of the sheep. British Veterinary Journal 124, 7882.CrossRefGoogle ScholarPubMed
Elliott, R. & Armstrong, D. G. (1982). The effect of urea and urea plus sodium sulphate on microbial protein production in the rumens of sheep given diets high in alkali-treated barley straw. Journal of Agricultural Science, Cambridge 99, 5160.CrossRefGoogle Scholar
Kang-Meznarich, J. D. & Broderick, G. A. (1981). Effect of incremental urea supplementation on ruminal ammonia concentration and bacterial protein formation. Journal of Animal Science 51, 422431.CrossRefGoogle Scholar
Miller, E. L. (1982). The nitrogen needs of ruminants. In Forage Protein in Ruminant Animal Production (ed. Thomson, D. J., Beever, D. E. and Gunn, R. G.). Occasional Publication, British Society of Animal Production, No. 6, pp. 7988. Thames Ditton: British Society of Animal Production.Google Scholar
Orskov, E. R., Fraser, C. & McDonald, I. (1972). Digestion of concentrates in sheep. 4. The effects of urea on digestion, nitrogen retention and growth in young lambs. British Journal of Nutrition 27, 491501.CrossRefGoogle ScholarPubMed
Ridgman, W. J. (1975). Experimentation in Biology. Glasgow and London: Blackie.Google Scholar
Rooke, J. A., Greife, H. A. & Armstrong, D. G. (1985). The digestion by heifers of silage-containing diets fed at two dry matter intakes. 1. Digestion of organic matter and nitrogen. British Journal of Nutrition 53, 691708.CrossRefGoogle Scholar
Snedecor, G. s. & Cochran, W. G. (1967). Statistical Methods, 6th edn.Ames, Iowa: Iowa State University Press.Google Scholar