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Effect of altering the non-structural: structural carbohydrate ratio in a pasture diet on milk production and ruminal metabolites in cows in early and late lactation

Published online by Cambridge University Press:  02 September 2010

V. R. Carruthers
Affiliation:
Dairying Research Corporation, Private Bag 3123, Hamilton, New Zealand
P. G. Neil
Affiliation:
Dairying Research Corporation, Private Bag 3123, Hamilton, New Zealand
D. E. Dalley
Affiliation:
Dairying Research Corporation, Private Bag 3123, Hamilton, New Zealand
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Abstract

The effect on digestibility, ruminal metabolites, microbial protein synthesis and milk production of manipulating the non-structural (NSC): structural (SO carbohydrate ratio in a predominantly pasture diet was investigated in cows in early (trial 1) and late (trial 2) lactation. Twenty-four cows in trial 1 and 15 cows in trial 2 were offered pasture only (P), 0·85 P plus 0·15 NSC/protein mixture (PR), and P plus an additional 0·1 (trial 1) or 0·15 (trial 2) NSC (PE) in a Latin-square arrangement. All diets were isonitrogenous and P and PR were isoenergetic. PE but not PR increased microbial protein synthesis and decreased ruminal ammonia and milk urea levels, compared with P. Efficiency of microbial synthesis (g N per kg digestible organic matter intake) was not altered by treatment. Treatments had minor effects on ruminal pH and no effect on volatile fatty acid concentrations. PE and PR did not affect milk yield or protein yield and decreased fat yield compared with P in trial 1. Milk yield was increased on PE and PR compared with P and was greater on PE than PR, in trial 2. Yields of fat and protein were higher on PE than on P and yield of protein was higher on PR than on P. The results suggest that increasing the ratio of NSC: protein by increasing total carbohydrate intake was more effective in improving nitrogen utilization in the rumen than was increasing the NSC: SC ratio without increasing carbohydrate intake.

Type
Research Article
Copyright
Copyright © British Society of Animal Science 1997

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References

Allen, M. S. 1995. Relationship between ruminally fermented carbohydrate and the requirement for physically effective NDF. Journal of Dairy Science 78: (suppl. 1) 265 (abstr.).Google Scholar
Armentano, L. E., Bertics, S. J. and Riesterer, J. 1993. Lack of response to addition of degradable protein to a low protein diet fed to midlactation dairy cows. Journal of Dairy Science 76: 37553762.CrossRefGoogle ScholarPubMed
Association of Official Analytical Chemists. 1984. Official methods of analysis, 14th edition. Association of Official Analytical Chemists, Washington, DC.Google Scholar
Bailey, R. W. 1958. The reaction of pentoses with anthrone. Biochemical Journal 68: 669672.CrossRefGoogle ScholarPubMed
Brookes, I. M. 1984. Effects of formaldehyde-treated and untreated casein supplements on performance of dairy cows offered ryegrass-clover pasture. New Zealand Journal Agricultural Research 27: 491493.CrossRefGoogle Scholar
Cameron, M. R., Klusmeyer, T. H., Lynch, G. C., Clark, J. H. and Nelson, D. R. 1991. Effects of urea and starch on rumen fermentation, nutrient passage to the duodenum, and performance of cows. Journal of Dairy Science 74: 13211336.CrossRefGoogle Scholar
Carruthers, V. R., Neil, P. G. and Dalley, D. E. 1996. Microbial protein synthesis and milk production in cows offered pasture diets differing in soluble: structural carbohydrate ratio. Proceedings of the New Zealand Society of Animal Production 56: 255259.Google Scholar
Carruthers, V. R. and Penno, J. W. 1995. Energy and protein supplementation in spring. Proceedings of the Ruakura Farmers' Conference 47: 5358.Google Scholar
Chase, L. E. 1993. Developing nutrition programs for high producing dairy herds. Journal of Dairy Science 76: 32873293.CrossRefGoogle ScholarPubMed
Chen, X. B. and Gomes, M. J. 1992. Estimation of microbial protein supply to sheep and cattle based on urinary excretion of purine derivatives — an overview of the technical details. Occasional publication, International Feed Resources Unit, Rowett Research Institute.Google Scholar
Dellow, D. W., Obara, Y., Kelly, K. E. and Sinclair, B. R. 1988. Improving the efficiency of utilisation of pasture protein by sheep. Proceedings of the Neiv Zealand Society of Animal Production 48: 253255.Google Scholar
Erdman, R. A. 1988. Dietary buffering requirements of the lactating dairy cow: a review. Journal of Dairy Research 71: 32463266.Google Scholar
Erwin, E. S., Marco, S. J. and Emery, E. M. 1961. Volatile fatty acid analysis of blood and rumen fluid by gas chromatography. Journal of Dairy Science 44: 17681771.CrossRefGoogle Scholar
Goering, H. K. and Van Soest, P. J. 1970. Forage fibre analyses (apparatus, reagents, procedures, and some applications). Agricultural handbook no. 379. ARS-USDA, Washington, DC.Google Scholar
Holmes, C. W. and Wilson, G. F. 1987. Milk production from pasture, pp. 107112. Butterworths Agricultural Books, London.Google Scholar
Kellaway, R. and Porta, S. 1993. Feeding concentrates: supplements for dairy cows. Dairy Research and Development Corporation, Australia.Google Scholar
Kolver, E. S., Muller, L. D. and Varga, G. A. 1995. Synchronising ruminal degradation of supplemental carbohydrate with pasture N in lactating dairy cows. Journal of Animal Science 73: (suppl. 1) 261 (abstr.).Google Scholar
Krishnamoorthy, U., Muscato, T. V., Sniffen, C. J. and Van Soest, P. J. 1982. Nitrogen fractions in selected feedstuffs. Journal of Dairy Science 65: 217225.CrossRefGoogle Scholar
MacGregor, C. A., Stokes, M. R., Hoover, W. H., Leonard, H. A., Junkins, L. L. Jr, Sniffen, C. J. and Mailman, R. W. 1983. Effect of dietary concentration of total nonstructural carbohydrate on energy and nitrogen metabolism and milk production of dairy cows. Journal of Dairy Science 66: 3950.CrossRefGoogle ScholarPubMed
Mansfield, H. R., Endres, M. I. and Stern, M. D. 1994. Influence of non-fibrous carbohydrate and degradable intake protein on fermentation by ruminal microorganisms in continuous culture. Journal of Animal Science 72: 24642474.CrossRefGoogle ScholarPubMed
National Research Council. 1989. Nutrient requirements of dairy cattle, 6th revised edition. National Academy of Science, Washington, DC.Google Scholar
Ørskov, E. R. 1994. Recent advances in understanding of microbial transformation in ruminants. Livestock Production Science 39: 5360.CrossRefGoogle Scholar
Ørskov, E. R., Reid, G. W. and McDonald, I. M. 1981. The effects of protein degradability and food intake on milk yield and composition in cows in early lactation. British Journal of Nutrition 45: 547555.CrossRefGoogle ScholarPubMed
Robertson, J. A. and Hawke, J. C. 1965. Studies on rumen metabolism. IV. Effect of carbohydrate on ammonia levels in the rumen of pasture-fed cows and in rumen liquors incubated with ryegrass extracts. Journal of the Science of Food and Agriculture 16: 268276.CrossRefGoogle Scholar
Russell, J. B. and Wilson, D. B. 1995. Why won't ruminal cellulolytic bacteria grow at low pH? Journal of Dairy Science 78: (suppl. 1) 264 (abstr.).Google Scholar
Sinclair, L. A., Garnsworthy, P. C., Newbold, J. R. and Buttery, P. J. 1993. Effect of synchronizing the rate of dietary energy and nitrogen release on rumen fermentation and microbial protein synthesis in sheep. Journal of Agricultural Science, Cambridge 120: 251263.CrossRefGoogle Scholar
Strobel, H. J. and Russell, J. B. 1986. Effect of pH and energy spilling on bacterial protein synthesis by carbohydrate limited cultures of mixed rumen bacteria. Journal of Dairy Science 69: 29412947.CrossRefGoogle ScholarPubMed
Therion, J. J., Kistner, A. and Komelius, J. H. 1982. Effect of pH on growth rate of rumen amylolytic and lactolytic bacteria. Applied and Environmental Microbiology 44: 428434.CrossRefGoogle Scholar
Ulyatt, M. J., Thomson, D. J., Beever, D. E., Evans, R. T. and Haines, M. J. 1988. The digestion of perennial ryegrass (Lolium perenne cv. melle) and white clover (Trifolium repens cv. Blanca) by grazing cattle. British Journal of Nutrition 60: 137149.CrossRefGoogle ScholarPubMed
Vuuren, A. M. van, Tamminga, S. and Ketelaar, R. S. 1990. Ruminal availability of nitrogen and carbohydrates from fresh and preserved herbage in dairy cows. Netherlands Journal of Agricultural Science 38: 499512.CrossRefGoogle Scholar
Vuuren, A. M. van, Tamminga, S. and Ketelaar, R. S. 1991. In sacco degradation of organic matter and crude protein of fresh grass (Lolium perenne) in the rumen of grazing dairy cows. Journal of Agricultural Science, Cambridge 116: 429436.CrossRefGoogle Scholar
Vuuren, A. M. van, Koelen, C. J. van der and Vroons-de Bruin, J. 1986. Influence of level and composition of concentrate supplements on rumen fermentation patterns of grazing dairy cows. Netherlands Journal of Agricultural Science 34: 457467.CrossRefGoogle Scholar