Intensive cereal based rations for beef cattle are typically formulated to contain 175 g/kg DM crude protein. Many different sources of protein have been successfully used to supplement cereals. In this study, the performance of bulls fed three different protein supplements were compared, namely rapeseed meal (R), urea (U) and a combination of urea and soya (S). The study also examined the performance of beef cattle fed a yeast culture (Diamond V ‘XP’ Yeast - Rumenco).

A total of 48 Limousin x (Hereford x Friesian) suckled bull calves at approximately 8 months old were allocated to one of three treatments with four replicates per treatment. Two replicates from each treatment were fed 40 g/head/day of yeast culture. Each diet was fed ad libitum with free access to barley straw and water. The feed ingredient inclusions in the rations were: R, 0.775 barley, 0.15 rape, 0.05 molasses, 0.025 minerals; U, 0.85 barley, 0.10 mineralised urea concentrate (Promol™ Rumenco), 0.05 molasses; S, 0.80 barley, 0.10 mineralised urea concentrate, 0.05 soya and 0.05 molasses. The R diet was used as the control. The bulls were slaughtered at fat class 4L. Statistical analysis was by ANOVA unless otherwise indicated.