Effect of supplementation on the performance of grazing Belgian Blue double-muscled heifers

Abstract

Six experiments were conducted to investigate the effect of a feed supplement on the performance of grazing Belgian Blue double-muscled (BBDM) heifers with an initial weight and age of 195 6 43 kg and 190 6 52 days. Treatments included were: Exp. 1: supplementation with beet pulp (BP): 2 kg/day per head v. ad libitum intake; Exp. .62 kg/day; P , 0.001), but partial feed conversion was similar. Supplying FSBM did not affect growth rate and partial feed conversion ( P . 0.10), but blood urea levels were reduced by FSBM ( P , 0.05). DDGS tended to increase growth rate (0.77 v. 0.59 kg/day; P , 0.10) compared with BP/SBM, without effect on partial feed conversion. Replacing BP by MS did not affect daily gain, but partial feed conversion tended to be higher (3.21 v. 3.60 kg/kg body weight (BW) gain; P 5 0.062). Increasing the supplement (80/20 BP/SBM) level from 3 to 4 kg daily, corresponding to 1.02% and 1.18% of the mean BW, respectively, resulted in a tendency ( P 5 0.121) for an increased growth rate. Grazing BBDM heifers of ,1 year of age necessitate extra protein besides an energy supplement to improve their performance. DDGS can replace SBM and BP can be replaced by MS.