The influence of energy and nitrogen supplementation of mature maize plants on wool growth of Dohne merino lambs.

The influence of supplementation of mature maize plants (6% crude protein; 11,4 MJ DE/kg) with both energy and nitrogen on wool production of Dohne merino lambs was investigated. A total of 130 lambs were fed mature maize plants supplemented with different levels of energy (12,5 and 13,7 MJ DE/kg) and nitrogen (11 and 14% crude protein where 0, 16,6 and 33,3% crude protein were respectively replaced by urea on an iso-nitrogenous basis). Supplementation with protein and energy resulted in improved wool growth rate and staple length and an increase in fibre diameter. Replacement of natural protein with urea tended to improve wool production at the 16,6% replacement level (P > 0,05), but a serious oppressive effect was evident at the 33,3% replacement level (P < 0,05).