Hostname: page-component-7479d7b7d-pfhbr Total loading time: 0 Render date: 2024-07-10T18:28:28.805Z Has data issue: false hasContentIssue false

Milk production from grass silage diets: the relative importance of the amounts of energy and crude protein in the concentrates

Published online by Cambridge University Press:  02 September 2010

J. D. Sutton
Affiliation:
AFRC Institute of Grassland and Environmental Research, Hurley, Maidenhead SL6 5LR
K. Aston
Affiliation:
AFRC Institute of Grassland and Environmental Research, Hurley, Maidenhead SL6 5LR
D. E. Beever
Affiliation:
AFRC Institute of Grassland and Environmental Research, Hurley, Maidenhead SL6 5LR
W. J. Fisher
Affiliation:
AFRC Institute of Grassland and Environmental Research, Hurley, Maidenhead SL6 5LR
Get access

Abstract

To identify the separate and combined effects of energy and crude protein (CP) from concentrates on responses to concentrate feeding, 42 multiparous Friesian cows were given fixed amounts of concentrates with primary growth grass silage (194 g CP per kg dry matter (DM)) ad libitum for weeks 4 to 22 of lactation. A basal treatment of 3 kg DM per day of a standard concentrate (197 g CP per kg DM) was compared with 6 kg DM per day of the same concentrate (doubling energy and CP intake), 6 kg DM per day of a low-protein concentrate (106 g CP per kg DM) (doubling energy intake alone), or 3 kg/day of a high-protein concentrate (383 g CP per kg DM) (doubling CP intake alone). Results are presented in terms of main effects as interactions were not significant except for energy apparent digestibility. Silage intake was reduced by energy but increased by CP; in consequence extra energy from concentrates increased digestible energy (DE) intake but reduced CP intake and concentration whereas extra CP from concentrates increased not only DE intake but also CP intake and concentration. The ratio of the responses to CP compared with the responses to energy were 1·7 for milk yield, 0·9 for fat yield, 3·2 for protein yield and 1·4 for lactose yield. Energy reduced milk protein concentration and tended to increase milk fat concentration whereas CP had the opposite effect. The efficiency of converting food nitrogen to milk nitrogen was unaffected by extra CP but was increased, from 0·195 to 0·229, by extra energy. The poor response in milk protein yield and the reduction in its concentration with extra energy reflected the lower CP intake due to the reduced silage consumption. The experiment emphasizes the importance of concentrate CP supply in stimulating silage intake and yields of all milk constituents for diets containing fairly small amounts of concentrates.

Type
Research Article
Copyright
Copyright © British Society of Animal Science 1994

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Agricultural Research Council. 1980. The nutrient requirements of ruminant livestock. Commonwealth Agricultual 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: 787835.Google Scholar
Agricultural and Food Research Council. 1993. Technical Committee on Responses to Nutrients. Energy and protein requirements of ruminants. CAB International, Wallingford.Google Scholar
Aston, K., Thomas, C., Daley, S. R., Sutton, J. D. and Dhanoa, M. S. 1994a. Milk production from grass silage diets: effects of silage characteristics and the amount of supplementary concentrates. Animal Production 59: 3141.Google Scholar
Aston, K., Thomas, C., Daley, S. R. and Sutton, J. D. 1994b. Milk production from grass silage diets: effects of the composition of supplementary concentrates. Animal Production 59: 335344.Google Scholar
Cammell, S. B., Beever, D. E., Sutton, J. D., Spooner, M. C. and Haines, M. J. 1992. Body composition and performance of autumn-calving Holstein-Friesian dairy cows during lactation: energy partition. Animal Production 54: 475 (abstr.).Google Scholar
Castle, M. E. and Watson, J. N. 1976. Silage and milk production. A comparison between barley and groundnut cake as supplements to silage of high digestibility. journal of the British Grassland Society 31: 191195.Google Scholar
Cochran, W. G. and Cox, G. M. 1957. Experimental designs. Wiley and Sons, New York.Google Scholar
Emery, R. S. 1978. Feeding for increased milk protein. journal of Dairy Science 61: 825828.CrossRefGoogle Scholar
Gordon, F. J. 1979. The effect of protein content of the supplement for dairy cows with access ad libitum to high digestibility, wilted grass silage. Animal Production 28: 183189.Google Scholar
Gordon, F. J. 1984. The effect of level of concentrate supplementation given with grass silage during the winter on the total lactation performance of autumn-calving cows. journal of Agricultural Science, Cambridge 102: 163179.CrossRefGoogle Scholar
Ministry of Agriculture, Fisheries and Food, Department of Agriculture and Fisheries for Scotland and Department of Agriculture for Northern Ireland. 1975. Energy allowances and feeding systems for ruminants. Technical bulletin 33. Her Majesty's Stationery Office, London.Google Scholar
Oldham, J. D. and Smith, T. 1982. Protein-energy interrelationships for growing and lactating cattle. In Protein contribution of feedstuffs for ruminants (ed. Miller, E. L., Pike, I. H. and van Es, A. J. H.), pp. 103130. Butterworths, London.CrossRefGoogle Scholar
Rook, A. J., Fisher, W. J. and Sutton, J. D. 1992. Sources of variation in yields and concentrations of milk solids in dairy cows. Animal Production 54: 169173.Google Scholar
Spörndly, E. 1989. Effects of diets on milk composition and yield of dairy cows with special emphasis on milk protein content. Swedish journal of Agricultural Science 19: 99106.Google Scholar
Sutton, J. D., Morant, S. V., Bines, J. A., Napper, D. J. and Givens, D. I. 1993. Effect of altering starch: fibre ratio in the concentrates on hay intake and milk production by Friesian cows. journal of Agricultural Science, Cambridge 120: 379390.Google Scholar
Thomas, C. 1980. Conserved forages. In Feeding strategics for dairy cows (ed. Broster, W. H., Johnson, C. L. and Tayler, J. C.), pp. 8.18.14. Agricultural Research Council, London.Google Scholar
Thomas, C., Daley, S. R., Aston, K. and Hughes, P. M. 1981. Milk production from silage. 2. The influence of the digestibility of silage made from the primary growth of perennial ryegrass. Animal Production 33: 713.Google Scholar
Thomas, C. and Rae, R. C. 1988. Concentrate supplementation of silage for dairy cows. In Nutrition and lactation in the dairy cow (ed. Garnsworthy, P. C.), pp. 327354. Butterworths, London.CrossRefGoogle Scholar