Hostname: page-component-cd9895bd7-jn8rn Total loading time: 0 Render date: 2024-12-27T08:05:11.086Z Has data issue: false hasContentIssue false

Urea supplementation of roughage-based diets for cattle

Published online by Cambridge University Press:  27 March 2009

P. B. O'Donovan
Affiliation:
An Foras Taluntais (Agricultural Institute), Grange, Dunsany, Co. Meath, Republic of Ireland

Summary

Thirty-two growing bullocks were fed long barley straw ad libitum in each of three experiments; urea was added to the latter or to a diet of straw supplemented with either 1·36 or 2·72 kg meal. The amount of urea fed was 75 g per animal daily. In a fourth experiment, a basal allowance of 3·64 kg chopped hay was fed to thirty-two bullocks weighing 287 kg; in addition 4·55 kg of meal was fed in which none, one-half or all the supplemental nitrogen was supplied as urea. Rate of gain and straw intake of animals given straw only was similar to that of animals given straw and urea. Feeding 1·36 kg of either rolled barley or rolled barley supplemented with 10% soyabean meal, in addition to straw, did not elicit a response from urea. A response was obtained from urea when 2·72 kg of a barley–soyabean meal mixture was fed with straw. Blood urea concentrations generally reached a maximum at the third week of urea feeding and declined thereafter. Addition of urea to straw raised blood urea to about the same extent as incorporating urea with 1·36 kg of rolled barley. Blood concentrations were higher when the urea was fed with meal than when mixed with molasses. Nitrogen retention from urea was not significantly increased by feeding 1·36 kg of barley with straw ad libitum as compared to the retention on an all-straw ration. Slightly more nitrogen was retained when urea was added to rolled barley instead of a rolled barley–soyabean meal (10%) mixture. A ration of hay (3·64 kg) and 4·55 kg of barley promoted gains which were not significantly different from those of animals fed additional nitrogen as soyabean meal or urea. This indicates that the foregoing ration supplied enough nitrogen to meet the animals' requirement.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1968

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

Altona, R. E. (1966). Urea and biuret as protein supplements for range cattle and sheep in Africa. Outl. Agric. 5, 22–7.Google Scholar
Bloomfield, R. A., Welsch, C., Garner, G. B. and Muhrer, M. E. (1961). Effect of sixteen times a day feeding on urea utilization. J. Anim. Sci. 20, 926 (Abstr).Google Scholar
Campling, R. C., Freer, M. & Balch, C. C. (1962). Factors affecting the voluntary intake of food by cows. 3. The effect of urea on the voluntary intake of oat straw. Br. J. Nutr. 16, 115–24.Google Scholar
Coombe, J. B. & Tribe, D. E. (1960). The effect of urea on the utilisation of low-quality roughage by the ruminant. Proc. Aust. Soc. Anim. Prod. 3, 83–5.Google Scholar
Coombe, J. B. & Tribe, D. E. (1962). The feeding of urea supplements to sheep and cattle: the results of penned feeding and grazing experiments. J. agric. Sci. Camb. 59, 125–41.CrossRefGoogle Scholar
Coombe, J. B. & Tribe, D. E. (1963). The effects of urea supplements on the utilization of straw plus molasses diets by sheep. Aust. J. agric. Res. 14, 7092.CrossRefGoogle Scholar
Faichney, G. J. (1965). The effect of sucrose on the utilization of straw plus urea diets by sheep. Aust. J. agric. Res. 16, 159–67.CrossRefGoogle Scholar
Hemsley, J. A. & Moir, R. J. (1963). The influence of higher volatile fatty acids on the intake of urea—supplemented low quality cereal hay by sheep. Aust. J. agric Res. 14, 509–17.Google Scholar
Jeter, D. L. (1964). Utilization of non-protein nitrogen sources by ruminants. Proc. Am. Feed. Manuf. Assoc. Meeting. 05 1964, pp. 1215.Google Scholar
Nelson, A. B. & Waller, G. R. (1962). Urea in winter supplements for range beef cattle. J. Anim. Sci. 21, 387 (Abstr.)Google Scholar
O'Donovan, D. J. (1967). Supplementation of straw with urea for cattle. Irish J. agric. Res. 6, 284–87.Google Scholar
Raleigh, R. J. and Wallace, J. D. (1963). Effect of urea at different nitrogen levels on digestibility and on performance of growing steers fed low quality flood meadow roughage. J. Anim. Sci. 22, 330–34.CrossRefGoogle Scholar
Smith, F. H. (1967). Aspects of nitrogen metabolism in the ruminant: ‘A review’. Irish Vet. J. 21, 310.Google Scholar
Tagari, H., Dror, Y., Ascarelli, I. & Bondi, A. (1964). The influence of levels of protein and starch in rations of sheep on the utilization of protein. Br. J. Nutr. 18, 333–56.CrossRefGoogle ScholarPubMed
Unsworth, E. F., Lamb, C. S. & Armstrong, D. G. (1966). The effect of supplementation of roughages with Rumevite on their intake and digestibility by sheep. Proc. 9th Int. Congr. Anim. Prod. pp. 73 (Abstr.).Google Scholar