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Effects of the composition of grass silages on milk production and nitrogen utilization by dairy cows

Published online by Cambridge University Press:  02 September 2010

R. J. Dewhurst ,
A. M. Mitton ,
N. W. Offer  and
C. Thomas
R. J. Dewhurst
Affiliation:
Grassland and Ruminant Science Department, Scottish Agricultural College, Auchincruive, Ayr KA6 5HW
A. M. Mitton
Affiliation:
Grassland and Ruminant Science Department, Scottish Agricultural College, Auchincruive, Ayr KA6 5HW
N. W. Offer
Affiliation:
Grassland and Ruminant Science Department, Scottish Agricultural College, Auchincruive, Ayr KA6 5HW
C. Thomas
Affiliation:
Grassland and Ruminant Science Department, Scottish Agricultural College, Auchincruive, Ayr KA6 5HW
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Abstract

Sixteen varied grass silages metabolizable energy (ME): 9·76 to 11·99 MJ/kg ethanol-corrected toluene dry matter (TDM); crude protein (CP: 149 to 211 g/kg TDM; lactic acid: 3·5 to 134·7 g/kg TDM; butyric acid 0·4 to 46·7 g/kg TDM) were offered ad libitum to early-lactation dairy cows (12 per experiment) along with a fixed allocation of 7 kg/day of a standard concentrate. Four silages were offered in each of four incomplete change-over design experiments with three 21-day periods. This design meant that each cow was allocated to receive three of the four silages evaluated in that experiment. ME intake ranged from 108 to 262 MJ/day (mean 177 (s.d. 30·2)). Similar variation was obtained with milk yields (mean 26·5 (s.d. 4·36) kg/day), fat content (mean 37·7 (s.d. 5·60) g/kg) and protein content (mean 29·0 (s.d. 2·36) g/kg). Urinary purine derivative/creatinine ratio (PD/C), an index of microbial protein measured in spot samples (two per day) averaged 2·92 (s.d. 0·757) mol/mol. Allantoin made up an almost constant molar proportion of PD excretion (mean 0·876 (s.d. 0·0377)), with a small but significant (P < 0·001) decline of 0·0132 (s.d. 0·003) per unit increase in PD/C.

Maximal utilization of silage nitrogen occurred with silages having higher ME and lower CP concentrations. Urinary PD/C suggested that microbial protein yield varied in a way which would not be predicted in current schemes and that it was a major source of variation in milk protein yield under the conditions of the present experiment. Principal components regression confirmed independent effects of ME supply and MP supply (indexed by urinary PD/C) on milk protein yield. Further work should pursue the possibility of using the urinary PD/C technique to refine protein feeding at the farm level.

Keywords

dairy cowsgrass silagemilk compositionnitrogen balancepurines
Type
Research Article
Information
Animal Science , Volume 62 , Issue 1 , February 1996 , pp. 25 - 34
Copyright
Copyright © British Society of Animal Science 1996

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References

Agricultural Research Council. 1984. Nutrient requirements of ruminant livestock. Supplement 1. Commonwealth Agricultural Bureaux, Slough.Google Scholar
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: 788–835.Google Scholar
Alexander, R. H., Dixon, J. and McGowan, M. 1985. Introduction of I. C. P. A. E. S. to an agricultural laboratory. Specialist (December). Thermoelectron Ltd, Warrington.Google Scholar
Balcells, J., Guada, J. A., Castrillo, C. and Gasa, J. 1991. Urinary excretion of allantoin and allantoin precursors by sheep after different rates of purine infusion into the duodenum. Journal of Agricultural Science, Cambridge 116: 309–317.CrossRefGoogle Scholar
Balcells, J., Guada, J. A., Peiro, J. M. and Parker, D. S. 1992. Simultaneous determination of allantoin and oxypurines in biological fluids by high-performance liquid-chromatography. Journal of Chromaiography-Biomedical Applications 575:153–157.CrossRefGoogle ScholarPubMed
Barber, G. D., Givens, I., Kridis, M. S., Offer, N. W. and Murray, I. 1989. Prediction of the organic-matter digestibility of grass-silage. Animal Feed Science and Technology 28: 115–128.CrossRefGoogle Scholar
Chen, X. B., Hovell, F. D. DeB., Ørskov, E. R. and Brown, D. S. 1990. Excretion of purine derivatives by ruminants: effects of exogenous nucleic acid supply on purine derivative excretion by sheep. British journal of Nutrition 63: 131–142.CrossRefGoogle ScholarPubMed
Chen, X. B., Ørskov, E. R. and Hovell, F. D. DeB. 1990. Excretion of purine derivatives by ruminants: endogenous excretion, differences between cattle and sheep. British journal of Nutrition 63:121–129.CrossRefGoogle ScholarPubMed
Dewar, W. A. and McDonald, P. 1961. Determination of dry matter in silage by distillation with toluene. Journal of the Science of Food and Agriculture 12: 790–795.CrossRefGoogle Scholar
Dewhurst, R. J. 1989. Studies on energy and nitrogen metabolism in the rumen — investigation of less invasive techniques for these studies. Ph.D. thesis, University of Bristol.Google Scholar
Erb, R. E., Surve, A. H., Randel, R. D. and Garverick, H. A. 1977. Urinary creatinine as an index or urinary excretion of estrogen in cows prepartum and postpartum. Journal of Dairy Science 60: 1057–1063.CrossRefGoogle ScholarPubMed
European Economic Community. 1971. EEC Directive 71/ 250/EEC. Official journal No. L 155, 12.7.71. The feedingstuffs (sampling and analysis) regulations.Google Scholar
Hof, G., Tamminga, S. and Lenaers, P. J. 1994. Efficiency of protein utilization in dairy cows. Livestock Production Science 38: 169–178.CrossRefGoogle Scholar
Lawes Agricultural Trust. 1987. GENSTAT 5 reference manual. Clarendon Press, Oxford.Google Scholar
Lux, O., Naidoo, D. and Salonikas, C. 1992. Improved HPLC method for the simultaneous determination of allantoin and uric acid in plasma. Annals of Clinical Biochemistry 29: 674–675.CrossRefGoogle ScholarPubMed
McAllan, A. B. 1982. The fate of nucleic acids in ruminants. Proceedings of the Nutrition Society 41: 309–317.CrossRefGoogle ScholarPubMed
Ministry of Agriculture, Fisheries and Food. 1992. Prediction of the energy values of compound feedingstuffs for farm animals. Summary of recommendations of a working party sponsored by the Ministry of Agriculture, Fisheries and Food.Google Scholar
Minitab Inc. 1980. Minitab data analysis software. Pennsylvania State University, Pennsylvania.Google Scholar
Moorby, J. M., Dewhurst, R. J. and Marsden, S. 1996. Effect of increasing digestible undegraded protein supply to dairy cows in late gestation on the yield and composition of milk during the subsequent lactation. Animal Science In press.Google Scholar
Offer, N. W., Rooke, J. A., Dewhurst, R. J. and Thomas, C. 1993. Rapid assessment of silage fermentation characteristics by electrometric titration. Animal Production 56: 423 (abstr.).Google Scholar
Susmel, P., Stefanon, B., Plazzotta, M., Spanghero, M. and Mills, C. R. 1994. The effect of energy and protein intake on the excretion of purine derivatives. Journal of Agricultural Science, Cambridge 120: 251–263.Google Scholar
Thomas, P. C., Robertson, S., Chamberlain, D. G., Livingstone, R. M., Garthwaite, P. H., Dewey, P. J. S., Smart, R. and Whyte, C. 1988. Predicting the metabolisable energy (ME) content of compounded feeds for ruminants. In Recent advances in animal nutrition, (ed. Haresign, W. and Cole, D. J. A.), pp. 127–146. Butterworths, London.Google Scholar
Van Soest, P. J., Robertson, J. B. and Lewis, B. A. 1991. Methods for dietary fiber, neutral detergent fiber and nonstarch polysaccharides in relation to animal nutrition. Journal of Dairy Science 74: 3568–3597.CrossRefGoogle ScholarPubMed
Van Soest, P. J. and Wine, R. H. 1967. Use of detergents in the analysis of fibrous feeds. IV. Determination of plant cell wall constituents. Journal of the Association of Official Analytical Chemists 50: 50–55.Google Scholar
Verbic, J., Chen, X. B., MacLeod, N. A. and Ørskov, E. R. 1990. Excretion of purine derivatives by ruminants. Effects of microbial nucleic acid infusion on purine derivative excretion by steers. Journal of Agricultural Science, Cambridge 114: 243–248.CrossRefGoogle Scholar
Wainman, F. W., Dewey, P. J. S. and Boyne, A. W. 1981. Third report of the Feedingstuffs Evaluation Unit. Rowett Research Institute, Aberdeen.Google Scholar