INFLUENCE OF FEEDING INTENSITY AND SLAUGH TER WEIGHT ON THE FATTENINGAND SLAUGHTER PERFORMANCE OF SIMMENTAL HEIFERS

A feeding trial with 96 Simmental heifers was carried out to determine the influence of feeding intensity and slaughter weight on the fatten ing and slaughter performance. They were under uniform management usin g two different feeding intensities. The diet of group KF0 consisted o f forage only (grass silage ad libitum and 1 kg hay). In group KF2 2 k g concentrate (barley) were offered additionally to the forage. Repres entative groups were slaughtered at 400 (SGI), 450 (SGII) and 500 (SGI II) kg live weight in average. Additionally 27 heifers were fattened e xtensively on a low energy level fi om 245 to 462 kg live weight. In t he group KF0 daily gains continuously increased from SGI to SGIII (564 , 583 adv. 604 g). The average daily weight gain of group KF0 (584 g) was by 156 g lower than that of group KF2 (740 g). In group KF2 the av erage daily weight gain decreased with increasing body weight (SGI 757 , SGII 742, SGIII 694 g). Feed efficiency of group KF0 was hardly affe cted by slaughter weight. On the other hand, feed efficiency of group KF2 was significantly reduced at higher slaughter weights. Daily weigh t gains obtained in the extensive fattening trial were 482 g. Increasi ng slaughter weight and feeding intensity increased carcass fat conten t and reduced meat and bone content. Concerning the parameters of meat quality no essential influence on the quality of meat was to be notic ed apart from the fat content. With regard to output it can be conclud ed that the marginal income was negative, irrespective of feeding inte nsity and slaughter weight.