Effects of different initial weights on fattening performance, slaughter and carcass characteristics of Holstein Friesian and Brown Swiss young bulls

A total of 27 young bulls [13 Brown Swiss (BS) and 14 Holstein Friesian (HF)] were fed to investigate the effects of initial fattening weights [light weight group (LG= 176.0 +/- 13.5 kg) and heavy weight group (HG= 213.8 +/- 3.7 kg)] on the performance, slaughter and carcass traits. With increasing initial fattening weight, final weight (P<0.01), cold carcass weight (P<0.01), heart weight (P<0.05) and front and hind feet weight (P<0.05) increased. Final weight, total weight gain, amount of feed consumed per kg weight gain, spleen weight, yield grade and cutability values were in favour of BS compared to HF. All of the carcass measurements were significantly affected by the initial fattening weights in favour of bulls in HG. Average SEUROP conformation score of HG carcasses was one class better than that of LG carcasses. It was concluded that young bulls in HG had better slaughter characteristics, carcass measurements and percentage of kidney, pelvic and heart fat than these in LG, while performance and feed efficiency ratio of the animals in the different weight groups were not statistically different.