Hostname: page-component-586b7cd67f-tf8b9 Total loading time: 0 Render date: 2024-11-28T08:20:46.186Z Has data issue: false hasContentIssue false
  • English
  • Français

Prediction of the voluntary intake of grass silages by beef cattle. 1. Linear regression analyses

Published online by Cambridge University Press:  02 September 2010

A. J. Rook  and
M. Gill
A. J. Rook
Affiliation:
AFRC Institute for Grassland and Animal Production, Hurley, Maidenhead SL6 5LR
M. Gill
Affiliation:
AFRC Institute for Grassland and Animal Production, Hurley, Maidenhead SL6 5LR
Get access

Abstract

Data on individually recorded silage dry-matter intake (SDMI), concentrate dry-matter intake (CDMI) and live weight of steers and data on silage composition including toluene dry matter (TDM), pH, total nitrogen (N), ammonia nitrogen (NH3-N), volatile fatty acids (VFAs), digestible organic matter in the dry matter (DOMD) and neutral-detergent fibre (NDF) obtained from experiments conducted at three sites were used to obtain simple and multiple linear regressions of SDMI on other variables.

Live weight accounted for a high proportion of the variation in intake but this effect could generally be removed by scaling intake by live weight raised to the power of 0·75 (M0·75). CDMI was the most important factor affecting scaled intake in mixed diets. TDM, NH,-N and VFAs all had important effects on SDMI. The relationship of SDMI with TDM was curvilinear suggesting that there is little to be gained in intake terms from wilting to TDM above 250 g/kg. The effect of NH3-N appeared to be related more to its correlation with VFAs than with any other nitrogenous constituent while the VFAs appeared to have a direct effect on SDMI. The effects of N and pH on SDMI were generally small. DOMD and NDF had relatively little effect on SDMI. Significant differences in intercepts between sites were found for most relationships although common slopes were often found.

Keywords

beef cattleintakemathematical modelssilage
Type
Research Article
Information
Animal Production , Volume 50 , Issue 3 , June 1990 , pp. 425 - 438
Copyright
Copyright © British Society of Animal Science 1990

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
Baile, C. A. and Forbes, J. M. 1974. Control of feed intake and regulation of energy balance in ruminants. Physiological Reviews 54: 160–214.CrossRefGoogle ScholarPubMed
Barry, T. N., Cook, J. E. and Wilkins, R. J. 1978. The influence of formic acid and formaldehyde additives and type of harvesting machine on the utilization of nitrogen in lucerne silages. 1. The voluntary intake and nitrogen retention of young sheep consuming the silages with and without intraperitoneal supplements of D-L methionine. Journal of Agricultural Science, Cambridge 91: 701–715.CrossRefGoogle Scholar
Conrad, H. R., Pratt, A. D. and Hibbs, J. W. 1964. Regulation of feed intake in dairy cows. 1. Change in importance of physical and physiological factors with increasing digestibility. Journal of Dairy Science 47: 54–62.CrossRefGoogle Scholar
Cook, R. D. 1977. Detection of influential measures in linear regression. Technometrics 19: 15–18.Google Scholar
Demarquilly, C. 1973. [Chemical composition, fermentation characteristics, digestibility and voluntary intake of forage silages: changes compared to initial green forage.] Annales de Zootechnie 22: 1–35.CrossRefGoogle Scholar
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
Egan, A. R. 1965. Nutritional status and intake regulation in sheep. III. The relationship between improvement of nitrogen status and increase in voluntary intake of low-protein roughages by sheep. Australian Journal of Agricultural Research 16: 463–472.CrossRefGoogle Scholar
Elsden, S. R. and Gibson, Q. H. 1954. The estimation of lactic acid using eerie sulphate. Biochemical Journal 58: 154–158.CrossRefGoogle Scholar
Flynn, V. 1979. The effect of silage dry-matter digestibility in vitro on live-weight gain and carcass gain by beef cattle fed silage ad libitum. Animal Production 28: 423 (Abstr.).Google Scholar
Forbes, J. M. 1986. The Voluntary Food Intake of Farm Animals. Butterworths, London.Google Scholar
Gill, M., Rook, A. J. and Thiago, L. R. S. 1988. Factors affecting the voluntary intake of roughages by the dairy cow. In Nutrition and Lactation in the Dairy Cow (ed. Garnsworthy, P. C.), pp. 262–279. Butterworths, London.CrossRefGoogle Scholar
Haigh, P. M. and Hopkins, J. R. 1977. Relationship between oven and toluene dry matter in grass silage. Journal of the Science of Food and Agriculture 28: 477–480.CrossRefGoogle Scholar
Jones, G. M., Larsen, R. E. and Lanning, N. M. 1980. Prediction of silage digestibility and intake by chemical analyses or in vitro fermentation techniques. Journal of Dairy Science 63: 579–586.CrossRefGoogle ScholarPubMed
Kennedy, S. J. 1986. Sulphuric acid, an alternative silage additive to formic acid? Agriculture in Northern Ireland 60: 397–401.Google Scholar
Lawes Agricultural Trust. 1987. Genstat 5 Reference Manual. Clarendon Press, Oxford.Google Scholar
Lewis, M. 1981. Equations for predicting silage intake by beef and dairy cattle. Proceeding of the Sixth Silage Conference, Edinburgh, pp. 35–36.Google Scholar
Mertens, D. R. 1985. Effect of fiber on feed quality for dairy cows. Proceedings of the 46th Minnesota Nutrition Conference, pp. 209–224.Google Scholar
Mertens, D. R. 1987. Predicting intake and digestibility using mathematical models of ruminal function. Journal of Animal Science 64: 1548–1558.CrossRefGoogle ScholarPubMed
National Research Council. 1987. Predicting Feed Intake of Food-producing Animals. National Academy Press, Washington.Google Scholar
Osbourn, D. F., Terry, R. A., Outen, G. E. and Cammell, S. B. 1974. The significance of a determination of cell walls as the rational basis for the nutritive evaluation of forages. Proceedings of the 12th International Grassland Congress, Moscow, Vol. Ill, pp. 374–380.Google Scholar
Petchey, A. M. and Broadbent, P. J. 1980. The performance of fattening cattle offered barley and grass silage in various proportions either as discrete feeds or as a complete diet. Animal Production 31: 251–257.Google Scholar
Phillip, L. E., Buchanan-smith, J. G. and Grovum, W. L., 1981. Effects of infusing the rumen with acetic acid and nitrogenous constituents in maize silage extracts on food intake, ruminal osmolality and blood acid-base balance in sheep. Journal of Agricultural Science, Cambridge 96: 429–438.CrossRefGoogle Scholar
Rohr, K. and Thomas, C. 1984. Intake, digestibility and animal performance. In Eurowilt. Efficiency of Silage Systems: a Comparison between Wilted and Unwilted Silages (ed. Zimmer, E. and Wilkins, R. J.), Landbauforschung Volkenrode, Sonderheft 69, pp. 64–70.Google Scholar
Rook, A. J., Dhanoa, M. S. and Gill, M. 1990. Prediction of the voluntary intake of grass silages by beef cattle. 2. Principal component and ridge regression analyses. Animal Production 50: 439–454.Google Scholar
Taylor, St C. S., Moore, A. J. and Thiessen, R. B. 1986. Voluntary food intake in relation to body weight among British breeds of cattle. Animal Production 42: 11–18.Google Scholar
Thomas, C. and Gill, M. 1988. Principles of silage utilization and supplementation. In Efficient Beef Production from Grass (ed. Frame, J.), Occasional Symposium, British Grassland Society, No. 22, 115–128.Google Scholar
Van soest, P. J. and Wine, R. H. 1967. Use of detergents in the analysis of fibrous feeds. 4. Determination of plant cell-wall constituents. Journal of the Association of Official Analytical Chemists 50: 50–55.Google Scholar
Weddell, J. R. 1986. Report on the performance of Add-F, Scotsil and Ecosyl silage additives at the MacRobert Experimental Farm, Aberdeen, 1985-86. Scottish Agricultural, Colleges, Research and Development Note No. 32.Google Scholar
Weddell, J. R. and Hunter, E. A. 1984. Silage additive evaluation — the effect of a range of chemical additives on silage quality and on the dry matter intake and liveweight gain of beef steers. Proceedings of the Seventh Silage Conference, Belfast, pp. 79–80.Google Scholar
Wilkins, R. J. 1974. The nutritive value of silages. In University of Nottingham Conference for Feed Manufacturers 8 (ed. Swan, H. and Lewis, D.), pp. 167–189. Butterworths, London.CrossRefGoogle Scholar
Wilkins, R. J., Fenlon, J. S., Cook, J. E. and Wilson, R. F. 1978. A further analysis of relationships between silage composition and voluntary intake by sheep. Proceedings of the Fifth Silage Conference, Ayr,pp. 34–35.Google Scholar
Wilkins, R. J., Hutchinson, K. J., Wilson, R. F. and Harris, C. E. 1971. The voluntary intake of silage by sheep. 1. Interrelationships between silage composition and intake. Journal of Agricultural Science, Cambridge 77: 531–537.CrossRefGoogle Scholar