EVOLUTION OF CARCASS COMPONENTS DURING FO RCE-FEEDING OF MUSCOVY DUCKS

At 12 weeks of age, 70 Muscovy ducks were force-fed twice a day with m aize during 12 days. Body composition was measured at the beginning of cramming (MEG) and at 3, 6, 9, 12 days. Birds were slaughtered 6 hour s after the last meal. Liver's components were estimated: moisture, pr otein, ashes, lipids. Live weights were 4119 g, 4346 g, 4611 g, 4779 g and 5346 g at MEG, 3, 6, 9 and 12 days respectively. Liver weight inc reased from 100 g to 244 g, 288 g, 373 g and 516 g during the same per iods. No significant evolution was noticed at 3 days regarding the gre at increase of liver weight (+150 g). The amounts of adipose tissues a nd fillet muscles represented 49% and 6% of rotal weight gain, when th e share of the liver increase was nearly 37%, at the end of cramming. The early hepatic enhancement al 3 days of force-feeding, was merely i nduced by proteins, glucids and bound water. After this time, lipid st orage was proportional to ingested dry matter, and reached 260 g, near to 58,9% of total weight at the end of force-feeding. The other hepat ic components remained in the same magnitude. It was conclude that cra mming may be characterized by two periods: ur to 3 or 6 days, duck mod ify their metabolism under feeding constraints, after this time they r each a new nutritional status of overfed animals.