Author:
Stephenson RGA,Edwards JC,Hopkins PS
Abstract
Urea supplementation of lambing Merino ewes increased milk yield and lamb growth and survival rates in both pen and paddock studies. These productivity gains occurred in a semi-arid environment characterized by poor reproductive efficiency in Merinos. In pens, urea supplenlents fed to lactating ewes at the rate of c. 12 g/day stimulated intake of poor quality pasture hay (0.9 %nitrogen) by c. 30% and increased total nitrogen intake by c. 100%. Milk yield was improved by c. 50% and lamb growth rate by c. 140%. Sorghum grain supplements stimulated milk yield and lamb growth to a lesser extent than urea. The correlations found in pen studies between nitrogen intake and milk yield of ewes (r � 0.85; P < 0.05), and between ewe milk yield and lamb growth (r % 0.80; P < 0.01), prompted further investigations under paddock conditions. Ewes grazing dry pastures and supplemented with urea (8-10 glday) via drinking water yielded more milk (11-32%) than unsupplemented counterparts. Similarly, there were improvements in lamb growth (80-100%) and survival (c. 10%) in the supplemented groups.
Subject
General Agricultural and Biological Sciences
Cited by
20 articles.
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