Abstract #W376

# W376
The effects of choice feeding during preweaning period on preweaning and postweaning growth performance of dairy calves.
Mohammad Wakil Hassani1, Murat Gorgulu*1, 1Cukurova University Agriculture Faculty Department of Animal Science, Adana, Turkey.

The aim of the study was to investigate the effects of choice feeding in preweaning period on growing performance of calf performance pre and postweaning period. Twenty-eight male and 28 female Holstein calves were used to test 2 feeding systems (TMR, total mixed ration, containing 10% alfalfa hay and choice feeding) and 2 sex (male and female) in a factorial arrangement. Before weaning TMR calves were fed with TMR containing 90% calf starter and 10% alfalfa hay and after weaning all calves were fed with the same TMR containing 50% calf grower and 50% alfalfa hay. Choice fed calves were fed with feed ingredients in TMR ad libitum and simultaneously. The choice fed calves before weaning preferred the diet containing lower alfalfa (10% vs. 5.78%, P < 0.05) and barley (52.29% vs. 15.87%, P < 0.05), and higher wheat bran (17.28% vs. 30.07%, P < 0.05) and SBM (17.73 vs. 45.39%, P < 0.05). Sex had no significant effects on diet preferences (P > 0.05). Choice feeding increased feed and nutrient intake (protein and fiber) and daily gain significantly (P < 0.05). After weaning, sex and feeding system during preweaning period had no effects on any parameters investigated (P > 0.05). But sex and feeding system interaction had significant effects on daily gain, feed and nutrient intakes (P < 0.05). The male calves fed TMR before weaning consumed more feed and nutrients and had higher daily gain than females but, choice fed calves in both sex had similar daily gain, feed and nutrient intake after weaning. When overall performance were evaluated, male calves had higher daily gain than females (P < 0.05). Sex × feeding system interaction had significant effects on feed and nutrient intake (P < 0.05). The male calves fed with TMR consumed more feed and nutrients than the females ones but this differences disappeared in choice feeding group. In conclusion, the results revealed that choice feeding may improve growth performance of calves by increasing protein intake before weaning and this effect may disappear after weaning. The female calve gave better response to choice feeding in respect to feed intake. This work was supported by Research Fund of the Cukurova University.

Key Words: choice feeding, calf, feeding system