Effect of weight at slaughter on the efficiency of fattening young cattle

Abstract

Thirty Simmental intact male calves divided into three slaughter weight groups (380, 420 and 460 kg) were used in order to study the effects of final weight on live weight gain (LWG), feed conversion and yield of carcass. The animals were fed on a high concentrate mixture based on ground maize 65% and on limited amounts of silage (up to 3 kg daily). The highest average LWG (1368 g) was achieved in animals slaughtered at the body weight of 436 kg, and it differed significantly (P < 0.01) from those slaughtered at higher (1207 g) or lower (1213 g) weights. Dressing percentage was affected by the various treatments, increasing with final body weight to give 57.1, 59.2 and 59.8% for the respective treatments. The difference between the first and the other two treatments was highly significant (P < 0.01) Daily intake of concentrates, SE and CP was higher in animals finished at 436 kg body weight than in those at 460 kg respectively by 3.4, 7.2 and 6.8% and in relation to animals slaughtered at 379 kg by 7.9, 2.9 and 11.6% respectively. This was probably related to the high gains of animals on treatment 2. The high consumption of nutrients by the bulls on treatment 2 resulted in higher gains and more efficient conversion of feeds and nutrients than by those on treatment 3. The increase in conversion of concentrate mixture amounted to 6.1%; of maize silage, 12.6%; of SE, 5.8% and of CP, 6.2%, while there were almost no differences between treatments 2 and 1.