Abstract
This experiment was carried out to compare the effect of early feed restriction of different regimens on subsequent growth performance, carcass composition, and lipid metabolism in male ducks. One hundred and twenty meat-type male ducks (White Pekin) were assigned to 4 treatments at 7 days of age, namely: ad libitum feeding (control), 50% of ad libitum intake, rice hull-diluted diet feeding, and skip day feeding. Ducks were restricted for feed between 8 to 14 days of age. During this period, dietary rice hull-treated group was given diet containing 11% CP and 1, 430 kcal ME/kg, whereas other treatment groups were offered diet containing 22% CP and 2, 900 kcal ME/kg. A commercial finisher diet for broilers (18% CP; 3, 180 kcal ME/kg) was resumed following feed restriction until 49 days of age. Compensatory growth was attained at 49 days of age irrespective of restriction regimens due largely to their fast growth rate with better nutrient utilization during recovery period. Carcass fat contents decreased in ducks fed 50% of ad libitum or diluted diet but not in those fed skip day feeding when compared with controls at 14 and 49 days of age. The activities of hepatic fatty acid synthetase (FAS) and acetyl-COA carboxylase (ACC) decreased in ducks fed 50% of ad libitum and fed diluted diet at the end of 7 days feed restriction and tended to further decrease at 49 days of age. Serum triacylglycerol concentrations also declined in ducks fed 50% of ad libitum or fed diluted diet at both 14 and 49 days of age. The results suggested that early feed restriction could be used to improve growth performance and carcass characteristic of meat-type ducks and diet dilution regimen may have an advantage for practical application in meat-type duck production.
