Abstract: To explore the effect of two kinds of nutrition additives on fattening and slaughter performance of Holstein bulls, 60 Holstein bulls were selected with similar body weight and month-old, and were randomly divided into 3 groups. The control group was fed the basal diet, the groups 1 and 2 added 100 g/d additives Ⅰ and Ⅱ in the basal diet. The adjustment period lasted for 14 days,and the experimental period lasted for 31 days.The results showed that the average daily gain in the groups 1 and 2 increased 0.32 and 0.37 kg (P<0.05) compared with the control group. Compared with the control group, carcass meat percentage, meat-bone ratio, thirteen cut meat weight of the group 2 showed significant differences (P<0.05),and dressing percentage, meat percentage and percentage of thirteen cut meat to meat weight in the groups 1 and 2 were not significant differences (P>0.05), but respectively increased by 2.96%,3.05%,1.47% and 1.89%, 2.82%, 2.39%. Compared with the control group, the profit of the groups 1 and 2 increased 1233.80 and 1370.20 yuan in the experimental period. The results suggested that fattening effect of the two kinds of nutrition additives on Holstein bulls were better and could produce better economic benefits.

Key words: Holstein bull; nutrition additives; fattening performance; slaughter performance; economic benefits