Skip to main content Accessibility help
×
Home

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

  • J. D. Sutton (a1), K. Aston (a1), D. E. Beever (a1) and W. J. Fisher (a1)

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.

Copyright

References

Hide All
Agricultural Research Council. 1980. The nutrient requirements of ruminant livestock. Commonwealth Agricultual Bureaux, Slough.
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.
Agricultural and Food Research Council. 1993. Technical Committee on Responses to Nutrients. Energy and protein requirements of ruminants. CAB International, Wallingford.
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.
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.
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.).
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.
Cochran, W. G. and Cox, G. M. 1957. Experimental designs. Wiley and Sons, New York.
Emery, R. S. 1978. Feeding for increased milk protein. journal of Dairy Science 61: 825828.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.

Keywords

Related content

Powered by UNSILO

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

  • J. D. Sutton (a1), K. Aston (a1), D. E. Beever (a1) and W. J. Fisher (a1)

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed.