Revista Brasileira de Ciência Avícola
Print version ISSN 1516-635X
WU, L; GUO, X and FANG, Y. Effect of diet dilution ratio at early age on growth performance, carcass characteristics and hepatic lipogenesis of Pekin ducks. Rev. Bras. Cienc. Avic. [online]. 2012, vol.14, n.1, pp.43-49. ISSN 1516-635X. http://dx.doi.org/10.1590/S1516-635X2012000100008.
This study was conducted to test the hypothesis that proper diet dilution ratio at early age might improve feed conversion ratio (FCR) and reduce body fat deposition of meat-type ducks. One hundred and fifty 1-day-old male and female White Pekin ducks (44.5±1.0 g) were randomly assigned into three treatments with five replicates (pens) of 10 birds each, respectively representing the experimental diets with 0 (control), 40 or 60% rice hulls inclusion in the basal diet between 8 and 14 d of age. The basal diet was fed before and after this period. The results showed that diluting the diet with 40% rice hulls increased (p < 0.05) feed intake, decreased adjusted (excluding rice hulls) feed:gain and body weight gain of ducks during the diet-dilution period; ducks fed the diet with 40% rice hulls had better growth rate (p < 0.05) during the recovery period (15 to 42 d of age) and lower adjusted feed conversion ratio (p < 0.05) during the entire experimental period (1 to 42 d of age) than the control birds, but the same body weight (p > 0.05) as the controls at 42 d of age. The diet diluted with 60% rice hulls resulted in lower (p < 0.05) body weight at market age than the other treatments. The diet with 40% rice hulls reduced (p < 0.05) skin with fat and abdominal fat pad, crude fat content in the carcass and in breast meat, and increased (p < 0.05) carcass crude protein at 42 d of age. These changes may be explained by the lower (p < 0.05) activities of hepatic malic dehydrogenase (MDH), glucose-6-phosphate dehydrogenase (G-6-PDH) and fatty acid synthetase (FAS) enzymes both at 14 and 42 d of age in birds fed the diluted diets relative to the control birds. The results of this study indicate that feeding diets diluted with 40% rice hulls to Pekin ducks between 8 to 14 d of age may induce compensatory growth during the following recovery period, and may be used to improve FCR and to reduce body fat deposition at market age.
Keywords : Carcass composition; compensatory growth; diet dilution; hepatic lipogenic enzyme activity; Pekin ducks.