The effects of feeding methods during pre-weaning period on the fattening performance of male calves

The choice fed calves during pre-weaning period generally prefer soybeanmeal and make starter containing higher protein compared NRC 2001 suggestion for starter (18 vs 28–31% CP. There is, however, limited study evaluating long term effects of the starter protein content on fattening performance of male calves. Therefore the objective of the study was to test the effects of feeding methods during pre-weaning period on fattening performance of male calves. Total 28 male calves were used to test 2 feeding systems in pre-weaning period (total mixed ration (TMR) containing 10% alfalfa hay sized 1.5-2 cm and choice feeding with feed ingredients inTMR) on fattening performance of calves. The calves were housed individually. The choice fed calves received barley, wheat bran, soybean meal and alfalfa hay as free choice and ad libitum. All calves consumed 4 L whole milk in two meals daily. The choice fed calves preferred 5.6 % alfalfa hay, 29.6% wheat bran, 49.4 % soybean meal and 12.2 % barley and they formulated the diet containing 2.60 Mcal ME/kg, 30.8% CP, 27.2% NDF and 12.0% ADF, while control TMR contained 2.23 Mcal ME/kg, 17.9% CP, 25.0% NDF and 11.9% ADF. After weaning all calves were monitored under research farm rearing practice until fattening stage of the study. Both groups were fattened with standard TMR containing 85% concentrate having 12.5% CP and 2.65 Mcal ME/kg and 15% wheat straw during the fattening period. All calves were housed individual fattening paddocks sized 3mx6 m. Weight, feed intake and feed to gain were recorded biweekly for 12 wks. Initial body weights of choice fed calves and TMR fed calves were 221.2±12.5 and 219.0±12.0 kg, respectively. The study was carried out in a completely randomized design and analyzed by one way Anova procedure of SPSS. There were no differences in feed intake (9.8±0.28 kg/day for TMR vs. 9.4±0.24 kg/day for choice fed calves), daily gain (1.8±0.06 kg/day for TMR vs. 1.7±0.06 kg/day for choice fed calves), and feed to gain ratio (5.5±0.17 for TMR vs. 5.4±0.15 for choice fed calves). In conclusion, the high protein preference or choice feeding of the calves during pre-weaning period does not improve future fattening performance of male calves.