Hostname: page-component-586b7cd67f-t7fkt Total loading time: 0 Render date: 2024-11-26T22:05:36.760Z Has data issue: false hasContentIssue false

The influence of wilting and season of silage harvest and the fat and protein concentration of the supplement on milk production and food utilization by lactating cattle

Published online by Cambridge University Press:  02 September 2010

A. C. Peoples
Affiliation:
Agricultural Research Institute of Northern Ireland, Hillsborough, Co. Down BT26 6DR
F. J. Gordon
Affiliation:
Agricultural Research Institute of Northern Ireland, Hillsborough, Co. Down BT26 6DR
Get access

Abstract

This study was designed to examine the influence of pre-wilting and season of harvesting of silage on milk production and food utilization by dairy cattle and also the response to protein and fat concentration of the supplement given with silage. Twenty-four lactating British Friesian cows were used i n a four-period, partially balanced, change-over design experiment to evaluate 12 treatments consisting of three silage types (spring harvest unwilted (lUnW), autumn harvest unwilted (3UnW) and autumn harvest wilted (3W), each offered in addition to supplements containing both two crude protein levels (160 and 210 g/kg fresh weight) and two levels of inclusion of a fat supplement (0 and 100 g/kg fresh weight) in a 3 × 2 × 2 factorial arrangement. All supplements were offered at the same rate of 6·8 kg/day. Total diet digestibility and food utilization studies were carried out on all animals at the end of the third and fourth experimental periods.

The wilted silage (3W) had a higher digestibility than the unwilted (3UnW) material and animals offered 3W silage consumed proportionately 0·18 more silage DM and produced 1·6 MJ/day more milk energy output than those offered 3UnW. The total ration digesibility and food utilization data showed the animals given the 3W silage consumed 13·5 MJ more metabolizable energy (ME) per day than those offered the 3UnW silage and were less efficient at converting the ME available for production into milk energy output than those given the 3UnW silage (efficiencies were 0·58 and 0·53 for 3UnW and 3W silages respectively).

There were no differences between the digestibilities of the spring (lUnW) and autumn (3UnW) silages with the concentrations of digestible organic matter in the dry matter (DM) being 650 and 648 g/kg respectively. However, animals offered lUnW silage consumed proportionately 0·12 more DM and produced 1·05 kg/day more fat-corrected milk than those given 3UnW silage. The food utilization data indicated that this milk production difference could be accounted for by the higher ME intake on lUnW and that the efficiencies of conversion of ME available for production to milk energy output were similar with both seasons of harvests (efficiencies were 0·57 and 0·58 for lUnW and 3UnW respectively).

Increasing the crude protein concentration of the supplement from 160 to 210 g/kg increased silage DM intake, milk yield and milk energy output by 0·2 kg, 0·66 kg and 1·9 MJ/day respectively with the response being greatest with lUnW and least with 3UnW silage. Increasing the fat concentration of the supplement depressed silage DM intake but increased milk yield by 0·53 kg/day.

The effects of the treatments on total diet digestibility, energy and nitrogen utilization, and the volatile fatty acid concentrations of rumen fluid are also given.

Type
Papers
Copyright
Copyright © British Society of Animal Science 1989

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

REFERENCES

Agricultural Research Council. 1980. The Nutrient Requirements of Ruminant Livestock. Commonwealth Agricultural Bureaux, Slough.Google Scholar
Castle, M. E. and Watson, J. N. 1970. Silage and milk production: a comparison between grass silages made with and without formic acid. Journal of British Grassland Society 25: 6570.Google Scholar
Castle, M. E. and Watson, J. N. 1982. Silage and milk production: comparisons between unwilted and wilted grass silages made with different additives. Grass and Forage Science 37: 235241.CrossRefGoogle Scholar
Castle, M. E. and Watson, J. N. 1984. Silage and milk production: a comparison between unwilted and wilted grass silages. Grass and Forage Science 39: 187193.Google Scholar
Corbett, J. L., Langlands, J. P., McDonald, I. and Pullar, J. D. 1966. Comparison by direct animal calorimetry of the net energy values of an early and a late season growth of herbage. Animal Production 8: 1327.Google Scholar
Ganev, G., Ørskov, E. R. and Smart, R. 1979. The effect of roughage or concentrate feeding and rumen retention time on total degradation of protein in the rumen. Journal of Agricultural Science, Cambridge 93: 651656.Google Scholar
Gordon, F. J. 1980a. The effect of interval between harvests and wilting on silage for milk production. Animal Production 31: 3541.Google Scholar
Gordon, F. J. 1980b. The effect of silage type on the performance of lactating cows and the response to high levels of protein in the supplement. Animal Production 30: 2937.Google Scholar
Gordon, F. J. 1981. The effect of wilting of herbage on silage composition and its feeding value for milk production. Animal Production 32: 171178.Google Scholar
Gordon, F. J. and Peoples, A. C. 1986. The utilization of wilted and unwilted silages by lactating cows and the influence of changes in the protein and energy concentration of the supplement offered. Animal Production 43: 355366.Google Scholar
Gordon, F. J., Peoples, A. C. and Mayne, C. S. 1982. Some studies on protein supplementation with diets of grass silage for dairy cows. In Forage Protein Conservation and Utilisation (ed. Griffiths, T. W. and Maguire, M. F.), Proceedings of a Commission of European Communities Seminar, Dublin, pp. 203217.Google Scholar
Gordon, F. J., Unsworth, E. F. and Peoples, A. C. 1981. Protein supplementation of silage-based diets for milk production. 54th Annual Report, Agricultural Research Institute of Northern Ireland, pp. 1323.Google Scholar
Honing, Y. van der, Wieman, B. J., Steg, A. and DONSELAAR, B. VAN. 1981. The effect of fat supplementation of concentrates on digestion and utilization of energy by productive dairy cows. Netherlands Journal of Agricultural Science 29: 7992.CrossRefGoogle Scholar
Lonsdale, C. R. and Tayler, J. C. 1971. The effect of season of harvest and of milling on the nutritive value of dried grass. Animal Production 13: 384 (Abstr.).Google Scholar
McDonald, P. and Edwards, R. A. 1976. The influence of conservation methods on digestion and utilization of forages by ruminants. Proceedings of Nutrition Society 35: 201211.Google Scholar
Marsh, R. 1975. A comparison between spring and autumn pasture for beef cattle at equal grazing pressures. Journal of British Grassland Society 30: 165170.CrossRefGoogle Scholar
Marsh, R. 1979. The effects of wilting on fermentation n i the silo and on the nutritive value of silage. Grass and Forage Science 34: 19.Google Scholar
Mayne, C. S. and Gordon, F. J. 1984. The effect of type of concentrate and level of concentrate feeding on milk production. Animal Production 39: 6576.Google Scholar
Murphy, J. J. and Morgan, D. J. 1980. Effect of inclusion of protected and unprotected tallow in dairy rations on cow performance. An Foras Taluntais, Animal Production Research Report 1980, pp. 6061.Google Scholar
Ørskov, E. R. 1975. Manipulation of rumen fermentation for maximum food utilization. World Review of Nutrition and Dietetics 22: 152182.Google Scholar
Patterson, H. D. and Lucas, H. L. 1962. Change-over designs. Technical Bulletin, North Carolina Agriculture Experiment Station, No. 147.Google Scholar
Peoples, A. C. 1982. Some effects of type of silage and supplementation on the utilization of silage-based diets for milk production. Ph.D. Thesis, Faculty of Agriculture and Food Science, Queen's University, Belfast.Google Scholar
Reed, K. F. M. 1978. The effect of season of growth on the feeding value of pasture. Journal of British Grassland Society 33: 227234.Google Scholar
Unsworth, E. F. and Gordon, F. J. 1985. The energy utilisation of wilted and unwilted grass silages by lactating dairy cows. 58th Annual Report of the Agricultural Research Institute of Northern Ireland, pp. 1320.Google Scholar
Zimmer, E. and Wilkins, R. J. 1984. Eurowilt. Efficiency of silage systems. A comparison between unwilted and wilted silages. Landbauforschung, Völkenrode, Sonderheft 69: 88.Google Scholar