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The effects of dietary nitrogen sources and levels on rumen fermentation, nutrient degradation and digestion and rumen microbial activity by wether sheep given a high level of molasses

Published online by Cambridge University Press:  02 September 2010

T. Yan ,
N. W. Offer  and
D. J. Roberts
T. Yan
Affiliation:
Grassland and Ruminant Science Department, Scottish Agricultural College, Crichton Royal Farm, Dumfries DG1 4SZ
N. W. Offer
Affiliation:
Scottish Agricultural College, Auchincruive, Ayr KA6 5HW
D. J. Roberts
Affiliation:
Grassland and Ruminant Science Department, Scottish Agricultural College, Crichton Royal Farm, Dumfries DG1 4SZ
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Abstract

A 4 × 4 Latin square design experiment with 3-week experimental periods was conducted with four wether sheep, each fitted with a permanent rumen cannula, to evaluate the effects of dietary protein sources and levels on fermentation and microbial activity in the rumen. Four complete diets were offered each containing (g/kg dry matter (DM)) molasses 248, grass silage 200 and barley straw 260. The control diet (C) also contained barley and soya-bean meal and the other three diets were supplemented with urea (CU), soya-bean meal (CS), and soya-bean meal and fish meal (CSF), respectively. This gave foods of similar concentrations of metabolizable energy (ME) and estimated fermentable ME (10·6 and 9·8 MJ/kg DM, respectively), but different levels (g/kg DM) of estimated effective rumen degraded dietary protein (ERDP) and digestible undegraded protein (DUP) (ERDP/DUP, 84/17, 109/17, 116/38 and 119/54 for diets C, CU, CS and CSF, respectively).

No clinical symptoms of ill health in the animals due to the feeding of molasses were observed during the experiment. The average pH values of rumen liquors obtained at various sampling times post feeding for diets C, CU, CS and CSF were 6·40, 6·49, 6·62 and 6·47 (s.e.d. 0·06 P < 0·05) respectively and average ammonia-nitrogen concentrations were 63, 81, 90 and 113 mg/l (s.e.d. 14·9, P < 0·02) respectively. The average concentrations of total volatile fatty acids in the rumen liquor were similar across the four treatments. The molar proportions of propionate and butyrate were higher for the diet C than for the other three diets (P < 0·05), while acetate was lower (P < 0·05). Supplementing with true protein (P < 0·05), but not with urea (P > 0·05), increased the molar proportions of isobutyrate and isovalerate. Whole tract apparent digestibilities of DM and organic matter did not differ significantly across the four treatments, but neutral-detergent fibre apparent digestibility (0·677, 0·672, 0·716 and 0·728 (s.e.d. 0·017) g/kg DM for diets C, CU, CS and CSF respectively) and the proportions of hay DM that disappeared in the rumen during 24 h incubation (0·223, 0·238, 0·284 and 0·271 (s.e.d. 0·019) g/kg DM) were significantly lower for diets C and CU than CS and CSF (P < 0·05). Urinary excretion of purine derivative nitrogen was similar across the four treatments. The results obtained from the present study indicate that there were no significant differences in the microbial crude protein synthesis in the rumen when a diet containing molasses was supplemented with urea or true protein. However, the supplementation of this control diet with true protein, but not with urea, did stimulate the degradation of hay DM in the rumen and the digestion of dietary fibre in the whole tract.

Keywords

dietary proteinmolassespurinesrumen fermentationsheep
Type
Research Article
Information
Animal Science , Volume 63 , Issue 1 , August 1996 , pp. 123 - 131
Copyright
Copyright © British Society of Animal Science 1996

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References

Agricultural and Food Research Council. 1992. Technical committee on responses to nutrients, Report no. 9. Nutritive requirements of ruminant animals: protein. Nutrition Abstracts and Reviews, Series B 62: 787–835.Google Scholar
Agricultural and Food Research Council. 1993. Energy and protein requirements of ruminants. An advisory manual prepared by the AFRC Technical Committee on Responses to Nutrients. CAB International, Wallingford.Google Scholar
Alexander, R. H. and McGowan, M. 1969. The assessment of nutritive value of silage by determination of in vitro digestibility on homogenates prepared from fresh undried silage. Journal of British Grassland Society 24: 195–198.CrossRefGoogle Scholar
Allison, M. J. 1970. Nitrogen metabolism of ruminal microorganisms. In Physiology of digestion and metabolism the ruminant (ed. Phillipson, A. T.). Oriel Press Ltd., England.Google Scholar
Allison, M. J., Bryant, M. P. and Doetsch, R. N. 1958. Volatile fatty acid growth factor for cellulolytic cocci of bovine rumen. Science 128: 474–475.CrossRefGoogle ScholarPubMed
Annison, E. F. 1975. Microbial protein synthesis in relation to amino acid requirements. In Tracer study on non-nitrogen protein for ruminants II. p. 141. Food and Agriculture Organization/International Atomic Energy Agency.Google Scholar
Borchers, R. 1977. Allantoin determination. Analytical Biochemistry 79: 612–613.CrossRefGoogle ScholarPubMed
Briggs, H. M. and Heller, V. G. 1943. The effect of adding blackstrap molasses, potassium salts, sucrose and com syrup to a lamb-fattening ration. Journal of Agricultural Research 67: 81–87.Google Scholar
Cameron, M. R., Klusmeyer, T. H., Lynch, G. L. and Clark, J. H. 1991. Effects of urea and starch on rumen fermentation, nutrient passage to the duodenum, and performance of cows. Journal of Dairy Science 74: 1321–1336.CrossRefGoogle Scholar
Chen, X. B., Ørskov, E. R. and Hovell, F. D. DeB. 1991. The use of intragastric infusion in studies on excretion of purine derivatives as a measure of microbial protein supply in ruminants. Proceedings of the sixth international symposium protein metabolism and nutrition, vol. 2. (ed. Eggum, B. O., Boisen, S., Borsting, C., Danfaer, A. and Hvelpund, T.), pp. 67–70. National Institute of Animal Science Research Centre, Foulum.Google Scholar
Demeyer, D. I. 1981. Rumen microbes and digestion of plant cell walls. Agricultural Environment 6: 295–337.CrossRefGoogle Scholar
Fawcett, J. K. and Scott, J. E. 1960. A rapid and precise method for the determination of urea. Journal of Clinical Pathology 13: 156–159.CrossRefGoogle ScholarPubMed
Harris, B. and Van Horn, H. H. 1982. Molasses in dairy nutrition. In Molasses in animal nutrition. National Feed Ingredients Association, Iowa.Google Scholar
Hume, I. D., Mior, R. J. and Somers, M. 1970. Synthesis of microbial protein in the rumen. 1. Influence of the level of nitrogen intake. Australian Journal of Agricultural Research 21: 283–296.CrossRefGoogle Scholar
Johnson, R. R. 1976. Influence of carbohydrate solubility on NPN utilization in the ruminant. Journal of Animal Science 43: 184–191.CrossRefGoogle Scholar
Keery, C. M., Amos, H. E. and Froetschel, M. A. 1993. Effects of supplementing protein source on intraruminal fermentation, protein degradability, and amino acid absorption. Journal of Dairy Science 76: 514–524.CrossRefGoogle ScholarPubMed
Kempton, T. J. and Leng, R. A. 1979. Protein utilisation of growing lambs. 1. Responses in growth and rumen function t o supplementation of a low-protein cellulosk diet with either urea, casein or formaldehyde-treated casein. British Journal of Nutrition 42: 289–302.CrossRefGoogle ScholarPubMed
Klusmeyer, T. H., McCarthy, R. D. and Clark, J. H. 1990. Effects of source and amount of protein on ruminal fermentation and passage of nutrients to the small intestine of lactating cows. Journal of Dairy Science 73: 3526–3537.CrossRefGoogle Scholar
Kropp, J. R., Johnson, R. R., Males, J. R. and Owens, F. N. 1977. Microbial protein synthesis with low quality roughage rations: level and source of nitrogen. Journal of Animal Science 46: 844–854.CrossRefGoogle Scholar
Lawes Agricultural Trust. 1988. Genstat 5 reference manual. Clarendon Press, Oxford.Google Scholar
McAllan, A. B. and Smith, R. H. 1983. Factors influencing the digestion of dietary carbohydrates between the mouth and abomasum of steers. British Journal of Nutrition 50: 445–454.CrossRefGoogle ScholarPubMed
Okorie, A. U., Buttery, P. J. and Lewis, D. 1977. Ammonia concentration and protein synthesis in the rumen. Proceedings of the Nutrition Society 36: 38A (abstr.).Google ScholarPubMed
Oldham, J. D., Buttery, P. J., Swan, H. and Lewis, D. 1977. Interactions between dietary carbohydrates and nitrogen and digestion in sheep. Journal of Agricultural Science, Cambridge 89: 467–479.CrossRefGoogle Scholar
Ørskov, E. R. and Ryle, M. 1990. Energy nutrition in ruminants. Elsevier Applied Science, London.Google Scholar
Pate, F. M. 1982. Molasses in beef nutrition. In Molasses in animal nutrition. National Feed Ingredients Association, Iowa.Google Scholar
Salter, D. N., Daneshvar, K. and Smith, R. H. 1979. The origin of nitrogen incorporated into compounds in the rumen bacteria of steers given protein- and urea-containing diets. British Journal of Nutrition 41: 197–209.CrossRefGoogle ScholarPubMed
Satter, L. D. and Slyter, L. L. 1974. Effect of ammonia concentration on rumen microbial protein production in vitro. British Journal of Nutrition 32: 199–208.CrossRefGoogle ScholarPubMed
Schaefer, D. M., Davis, C. L. and Bryant, M. P. 1980. Ammonia saturation constants for predominant species of rumen bacteria. Journal of Dairy Science 63: 1248–1263.CrossRefGoogle ScholarPubMed
Scott, M. L. 1953. Use of molasses in the feeding of farm animals. In Review and annotated bibliography. Technical series no. 9. Sugar Research Foundation Inc., New York.Google Scholar
Silva, A. T. and Ørskov, E. R. 1988. The effect of five different supplements on the degradability of straw in sheep given untreated barley straw. Animal Peed Science and Technology 19: 289–298.CrossRefGoogle Scholar
Standing Committee on Tables of Feed Composition. 1990. UK tables of nutritive value and chemical composition feedingstuffs (ed. Givens, D. I. and Moss, A. R.), pp. 102–103. Rowett Research Services Ltd, Aberdeen.Google Scholar
Stern, M. D. and Hoover, W. H. 1979. Methods for determining and factors affecting rumen microbial protein synthesis: a review. Journal of Animal Science 49: 1590–1603.CrossRefGoogle Scholar
Yan, T. 1994. The effects of feeding molasses on rumen fermentation, intake and milk production. Ph.D. thesis, University of Glasgow.CrossRefGoogle Scholar
Yan, T. and Roberts, D. J. 1992. The responses of lactating dairy cows to feeding of high molasses levels. Animal Production 54: 476A (abstr.).Google Scholar
Yan, T. and Roberts, D. J. 1993. The effects of dietary protein levels on the performance of lactating dairy cows given high levels of molasses. Animal Production 56: 424A (abstr.).Google Scholar
Yan, T. and Roberts, D. J. 1994. The response of dairy cows given high levels of molasses to dietary levels of fermentable metabolizable energy. Animal Production 58: 436A–437A (abstr.).Google Scholar