Hostname: page-component-78c5997874-8bhkd Total loading time: 0 Render date: 2024-11-06T12:22:23.776Z Has data issue: false hasContentIssue false

Complete diets given ad libitum to dairy cows—the effect of the level of inclusion of milled straw

Published online by Cambridge University Press:  27 March 2009

J. B. Owen
Affiliation:
School of Agriculture
E. L. Miller
Affiliation:
School of Agriculture
P. S. Bridge
Affiliation:
School of Veterinary Medicine, Cambridge University

Summary

Complete diets were given ad libitum to dairy cows over a whole lactation in order to study the voluntary intake of food, lactation performance and efficiency of feed conversion. The effect of including four levels 16, 24, 32 and 40 % of coarsely milled barley straw in the loose mix was studied for diets based mainly on barley or on sugar beet pulp, using a double 4 × 4 Latin square design.

The results confirmed that cows can perform normally when given complete diets for extended periods. Dry matter and digestible energy intake was depressed at the higher levels of straw inclusion and milk butterfat content at the lowest level. The net efficiency of conversion of metabolizable energy (M.E.) into milk was higher at the higher levels of straw. It is concluded that complete diets for the self-feeding of dairy cows should contain a minimum of about 24 % of coarsely milled straw and that estimated metabolizable energy intake and production were depressed by including straw at higher levels.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1969

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 (1965). The Nutrient Requirements of Farm Livestock. No. 2. Ruminants.Google Scholar
Burt, A. W. A. (1957). Influence of level of feeding during lactation upon the yield and composition of milk. Dairy Sci. Abstr. 19, 434.Google Scholar
Cochran, W. G. & Cox, G. M. (1957). Experimental Designs. New York: James Wiley and Sons.Google Scholar
Owen, J. B., Davies, D. A. R. & Ridgman, W. J. (1968). The control of voluntary food intake in ruminants. Proc. 2nd World. Gonf. Anim. Prod, Maryland, U.S.A. (in the Press).Google Scholar
Owen, J. B., Miller, E. L. & Bridge, P. S. (1968). A study of the voluntary intake of food and water and the lactation performance of cows given diets of varying roughage content ad libitum. J. agric. Sci., Camb. 70, 223235.CrossRefGoogle Scholar
Owen, J. B. & Nielsen, E. (1968). A study of factors affecting the efficiency of feed conversion in Red Danish heifers. J. agric. Sci., Camb. 70, 245252.CrossRefGoogle Scholar
Rook, J. A. F. (1961). Variations in the chemical composition of the milk of the cow. Dairy. Sci. Abstr. 23, 251.Google Scholar
Tyrrell, H. F. & Reid, J. T. (1965). Prediction of energy value of cow's milk. J. Dairy Sci. 48, 1215.CrossRefGoogle ScholarPubMed