Hostname: page-component-cd9895bd7-8ctnn Total loading time: 0 Render date: 2024-12-28T03:24:11.157Z Has data issue: false hasContentIssue false
  • English
  • Français

An investigation into palatability as a factor responsible for reduced intake of silage by sheep

Published online by Cambridge University Press:  02 September 2010

J. G. Buchanan-Smith
J. G. Buchanan-Smith
Affiliation:
Department of Animal and Poultry Science, University of Guelph, Guelph, Ontario N1G 2W1, Canada
Get access

Abstract

To separate ingestive factors involving palatability from post-ingestive factors responsible for forage intake being depressed by ensiling, silages were evaluated using sham-fed animals. Protocol for all experiments was to formulate low dry matter (DM) silages from a high DM lucerne silage reconstituted with either water, solutions containing constituents commonly found in silage, or extracts of low DM silage. Solutions of silage constituents were adjusted before reconstitution to a pH typical of silage. Tests were performed by offering silages one at a time once daily to oesophageal fistulated sheep, maintained on lucerne hay, but starved for 5 h prior to the test. Intake was measured over 30 min. Sheep were adapted to intermediate levels of each test ingredient(s) before experiments were done to evaluate effects of four to five levels of each ingredient using Latin-square designs. Animals were sham fed during both periods of adaptation and of testing ingredient levels. Mean of 30-min intakes for control silages was 573 g DM. Lactic and acetic acids added together, to levels of 53·2 and 35·4 g/kg, respectively, enhanced intake with a linear response due to level (P < 0·05). Acetic acid added by itself to 88·0 g/kg depressed intake with a linear response due to level (P < 0·05) in which 10 g/kg added acetic acid depressed 30-min intake by 13·5 g. Acetic and butyric acids added together to levels of 36·2 and 54·4 g/kg respectively, were without effect as was ammonia added to 3·8 g/kg as ammonia nitrogen (N). A mixture of free amino acids added to a level of 9·2 g amino-N per kg was without effect, but at a level of 13·8 g/kg, intake was depressed to proportionately 0·75 of the control. A mixture of two amines and gamma amino butyric acid added to a level of 4·6 g N per kg caused a quadratic response (P < 005) in which intermediate levels enhanced intake but the highest level was without effect. An extract from good-quality silage had no effect on intake and that from a poor-quality silage enhanced intake in a linear manner (P < 0·05). These data indicate that elevation of acetic acid in silage without increases in amounts of other constituents decreased intake of silage through an effect on palatability. This conclusion modifies interpretation on the significance of palatability, determined from studies of ingestive behaviour of ruminants, as a factor to explain reduced intake of sheep given silage.

Keywords

acidspalatabilitysheepsilage
Type
Research Article
Information
Animal Production , Volume 50 , Issue 2 , April 1990 , pp. 253 - 260
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

Association of Official Analytical Chemists. 1980. Official Methods of Analysis. 13th ed. Association of Official Analytical Chemists, Washington, DC.Google Scholar
Buchanan-Smith, J. G. and Phillip, L. E. 1986. Food intake in sheep following intraruminal infusion of extracts from lucerne silage with particular reference to organic acids and products of protein degradation. Journal of Agricultural Science, Cambridge 106: 611–617.CrossRefGoogle Scholar
Buchanan-Smith, J. G. and Yao, Y. T. 1981. Effects of additives containing lactic acid bacteria and/or hydrolytic enzymes with an antioxidant upon the preservation of corn or alfalfa silage. Canadian Journal of Animal Science 61: 669–680.CrossRefGoogle Scholar
Campling, R. C. 1966. The intake of hay and silage by cows. Journal of the British Grassland Society 21: 41–48.CrossRefGoogle Scholar
Clancy, M., Wangsness, P. J. and Baumgardt, B. R. 1977. Effect of silage extract on voluntary intake, rumen fluid constituents, and rumen motility. Journal of Dairy Science 60: 580–590.CrossRefGoogle Scholar
Demarouilly, C. and Dulphy, J.-P. 1977. Effect of ensiling on feed intake and animal performance. Proceedings of the International Meeting on Animal Production from Temperate Grasslands, pp. 53–61.Google 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
Dulphy, J.-P., Remond, B. and Theriez, M. 1980. Ingestive behaviour and related activities in ruminants. In Digestive Physiology and Metabolism in Ruminants (ed. Ruckesbusch, Y. and Thivend, P.), pp. 103–122. MTP Press, Lancaster.CrossRefGoogle Scholar
Grovum, W. L. and Chapman, H. W. 1988. Factors affecting the voluntary intake of food by sheep. 4. The effect of additives representing the primary tastes on sham intakes by oesophageal-fistulated sheep. British Journal of Nutrition 59: 63–72.CrossRefGoogle ScholarPubMed
Jacobs, W. W., Beauchamp, G. K. and Kare, M. R. 1978. Progress in animal flavor research. In Flavor Chemistry of Animal Foods (ed. Bullard, R. W.), pp. 1–20. American Chemists Society, Washington, DC.Google Scholar
McDonald, P. and Edwards, R. A. 1976. The influence of conservation methods on digestion and utilization of forages by ruminants. Proceedings of the Nutrition Society 35: 201–211.CrossRefGoogle ScholarPubMed
Ohshima, M., McDonald, P. and Acamovic, T. 1979. Changes during ensilage in the nitrogenous components of fresh and additive treated ryegrass and lucerne. Journal of the Science of Food and Agriculture 30: 97–106.CrossRefGoogle Scholar
Steel, R. G. D. and Torrie, J. H. 1960. Principles and Procedures of Statistics. McGraw-Hill, New York.Google Scholar
Thomas, C. and Thomas, P. C. 1985. Factors affecting the nutritive value of grass silages. In Recent Advances in Animal Nutrition — 1985 (ed. Haresign, W. and Cole, D. J. A.), pp. 223–256. Buttcrworths, London.CrossRefGoogle Scholar
Wilkins, R. J., Hutchinson, K. J., Wilson, R. F. and Harris, C. E. 1971. The voluntary intake of silage by sheep. I. Interrelationships between silage composition and intake. Journal of Agricultural Science, Cambridge 77: 531–537.CrossRefGoogle Scholar