The effect of free or restricted acidified milk feeding of Finnish Ayrshire bull calves on the subsequent fattening and slaughter performance
H. KHALILI | M. RINNE | P. ASPILA
The aim of the research was to study whether the anticipated added weight gain from ad libitum acidified milk feeding compared to restricted milk feeding during the preweaning period can be maintained after weaning until slaughter. The study was conducted by comparing first the growth performance of eleven bull calves until an average age of 126 days (Phase 1) when the five calves were fed acidified milk either ad libitum (FM) for 17 weeks or when six calves were given acidified milk restrictively (5 l per day, RM) for nine weeks. Bulls had ad libitum access to grass silage and concentrate. Secondly, the performance of bulls having an average age of 175 days until slaughter (at an average age of 429 days) at a carcass weight of approximately 290 kg was assessed (Phase 2). All animals were fed grass silage ad libitum and concentrate at a level of 620 g kg-1 of dietary dry matter. Calves fed acidified milk ad libitum grew significantly (P < 0.01) faster than those fed restrictively during the first nine weeks of Phase 1 (1003 vs. 725 g per day). The bulls in the RM group grew a little but not significantly faster during Phase 2, the growth rates being 1197 vs. 1207 g per day. The feed conversion, weight (535 vs. 533 kg at slaughter) and slaughter results were equal. Similarly the life-time gains did not differ being 1174 (FM) and 1141 (RM) g per day, respectively. It can be concluded that the improved performance during early life did not improve growth during the fattening period.;
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