Abstract

Two hundred and forty day-old chicks with average body weight of 48.92±1.5 g were randomly distributed into 12 pens each with 20 chicks, representing four feeding regimen of T₁ (Unrestricted, Control), T₂ (Restricted at 7, 14, 21 and 28 days of age), T₃ (Restricted at 35, 42, 49 and 56 days of age) and T₄ (Restricted at 63, 70, 77 and 84 days of age). The experiment lasted for 22 weeks, during which feed intake and body weight changes were monitored. At the end of the experimental period, six pullets from each treatment were randomly selected and slaughtered to evaluate carcass yield, abdominal fat and weights and lengths of different parts of gastrointestinal tracts. The daily feed intake as well as body weight changes at different ages were non-significant (P>0.05). The feed efficiency also did not significantly varied (P>0.05). In contrast, the total feed intake (g) was significantly different (P<0.05) between treatments and birds under T₄ consume less. Dressed weight (g); abdominal fat free carcass (g); carcass with abdominal fat (g) and breast meat weights (g) were significantly (P<0.05) different. Abdominal fat weight was also highly significant (P<0.01) between the treatments. The weight and percentage of GIT and total giblet and parts of giblets were not (P>0.05) affected except liver weight which was higher (P<0.05) for T₃. Cost of feed consumed per kg live weight gain was lower for the feed restricted birds and it was the least for T₄. Besides, the labor cost was lower for the feed restricted groups. It is concluded that feed restriction at later days of age (T₄) is economically beneficial compared to the other early age restricted groups based on partial budget analysis. The results of this study suggested that the feed restriction at middle age (T₃) might be considered as beneficial in terms of carcass cut characteristics and T₄ on economic return.

Key words: Carcass yield characteristics, economic advantages, feed restriction, skip-a-day, Rhode Island Red pullet.