Abstract

In order to evaluate the productive and economic response of dairy bull production under two feeding systems, 16 Holstein-Friesian young bulls, born in Autumn of 2011 were evaluated. After a rearing period under pasture as a unique group, the animals with 14 months of age and on average 340 ± 20 kg LW were assigned to two feeding treatments, T1: pasture silage and 2% LW concentrate per animal per day, in confinement; T2: pasture silage and 1% LW concentrate and access to kale, on pasture. Eight bulls were assigned to each treatment. Treatments were isoproteic (14% CP) and iso- energetic (2.6 Mcal ME kg-1), dry matter basis. The study finished at 21 months of age, when the bulls reached an average of 550 kg LW. No statistical differences (P > 0.05) were found between treatment in daily liveweight gain, dressing percentage and carcass weight. However, significant differences (P < 0.05) were found in kidney fat with 4.44 kg an-1 (T1) and 2.61 kg an-1 (T2) and pH of 5.72 and 5.46, respectively. Intramuscular fat content of 1.94 and 0.90 (P < 0.05) were determined for T1 and T2, re- spectively. It was concluded that it is possible to finish dairy bulls at 21 months of age with adequate fat cover, and carcass quality; gross income was better from animals fished on pasture.