The effect of initial live weight on fattening performance in simmental crosbreed calves

This study was carried out to determine the effect of initial live weight on fattening performance in Simmental crosbreed calves. For this purpose, the present study was conducted at Avşar Gıda Tarım Hayvancılık Tarım San. ve Tic. A.Ş. farm located in Afyonkarahisar province. A total of 36 Simmental crossbred male calves aged between 8 and 11 months were used under intensive fattening conditions. The animals were divided into two groups of 18 each based on their initial live weights: Group I with animals weighing less than 250 kg, and Group II with animals weighing over 250 kg. Throughout the 260-day fattening period, live weight measurements were taken ten times. The animals were fed once daily with a complete ration consisting of three different concentrate feeds administered at the beginning, middle, and end of the fattening period, along with roughage including straw, dry alfalfa, and corn silage, provided ad libitum. The initial and final average live weights were 236.56 kg and 587.10 kg for Group I, and 291.70 kg and 674.40 kg for Group II, respectively. Total live weight gain, average daily gain (ADG), and Kleiber ratio were recorded as 350.50 kg, 1.348 kg/day, and 2.938 % for Group I, and 382.80 kg, 1.472 kg/day, and 2.892% for Group II, respectively. Between the 1st and 5th weighings, ADG was 1.497 kg/day for Group I and 1.617 kg/day for Group II; between the 5th and 10th weighings, it was 1.221 kg/day and 1.348 kg/day, respectively. The overall ADG during the fattening period averaged 1.348 kg/day for Group I and 1.472 kg/day for Group II statistically significant differences were observed between groups in terms of live weight gain, ADG, and Kleiber ratio (P < 0.05, P < 0.01). Carcass weight averages were 320.90 kg for Group I and 372.70 kg for Group II, with the difference being statistically significant (P < 0.01). Similarly, carcass yield percentages were 54.64 % and 55.24 % for Group I and II, respectively, and this difference was also statistically significant (P < 0.01). As a result, it was stated that evaluation of both groups throughout the 260-day fattening period revealed a statistical difference in performance, with Group II exhibiting significantly superior fattening efficiency and profitability compared to Group I. Keywords: Live weight at the beginning of fattening, Fattening performance, Live weight gain, Kleiber ratio, Simmental crossbreed