Effects of duration of feed restriction on compensatory growth of Leghorn cockerels

Effects of duration of feed restriction on growth of Leghorn cockerels was studied. Three-hundred sixty 7d-old Leghorn cockerels were allotted to 36 pens with 10 cockerels per pen. Treatments were ad libitum consumption of feed (AL) or feed intake was restricted to 80% of ad libitum intake for two (R-2), five (R-5), or eight (R-8) wk, followed by ad libitum feeding for the remainder of the experiment. Overall average daily gain (ADG) was greatest for birds in the AL (16.3 g/d) feeding regimen, intermediate for birds in the R-2 (15.8 g/d) regimen and lowest for birds in the R-5 (14.7 g/d) and R-8 (14.6 g/d) regimens (P<0.01). Daily dry matter intake (DMI) was greatest for birds in the R-2 feeding regimen, intermediate for birds in the R-5 regimen and lowest for birds in the AL and R-8 regimens (P<0.01). Feed efficiency was greatest (P<0.01) for birds in the AL feeding regimen and was similar among birds in the R-2, R-5 and R-8 regimens. Birds subjected to periods of feed restriction exhibited variable degree of compensatory growth when fed ad libitum, but it could not reach the level of those fed ad libitum throughout the feeding period.