Masná užitkovost holštýnských telat poražených v živé hmotnosti 300 kg

Abstract

The aim of this work was to quantify basic feedlot performance and carcass value characteristics of Holstein bulls slaughtered as “young cattle” at 300 kg of live weight. The observation was carried out in a group of 12 Holstein bulls fattened in identical conditions and fed on a diet consisting of ad libitum amount of crushed grain (barley and wheat) and a limited amount of protein concentrate.The mean overall values were as follows: age and live weight at slaughter 275.9 days and 299.3 kg, daily weight gain and net weight gain since birth 0.962 kg and 0.527 kg, dressing percentage 48.3%, weight of cold right carcass half 71.0 kg, weight of bones 17.5 kg, weight of muscle 53.0 kg and separable fat 0.54 kg. The mean weight of hide was 21.6 kg. The great majority of calves were classified as O2, one calf graded R2. The forequarter to hindquarter ratio was 1.4 with mean weights 29.1 kg and 41.9 kg. The mean weight of neck was 3.9 kg, chuck 3.6 kg, shoulder 5.9 kg, fore shank 3.4 kg, loin 4.1 kg, filet 1.5 kg, round 18.2 kg and hind shank 1.3 kg. We found highly significant (P<0.01) coefficients of correlation between carcass weight and live weight at slaughter (r=0.963) or daily weight gain (r=0.723). Net weight gain since birth was highly significantly (P<0.01) correlated to live weight at slaughter (r=0.723) or to daily weight gain (r=0.982) and significantly correlated (P<0.05) to age at slaughter (r= –0.665).Despite the average or worse-than-average feedlot performance parameters our experimental Holstein bulls had an adequate proportion of muscle (comparable with other literature sources), a high ratio of bones and a very low proportion of fat. Thanks to small meat trim, weights of the main dissection parts of fore-and hindquarters were comparable to those usually found in young Holstein bulls.