Effect of Beginning Age of Feed Restriction on Growth Performance and Carcass Qualities of Broilers

An experiment was conducted to investigate the effects of beginning age of feed restriction for broilers on growth performance and carcass qualities.A simple factor design of experiment was adopted,240 one-day-old commercial generation AA broilers were randomly divided into four treatments,and each treatment contained 3 replicates;one was control group and other three groups were restricted ones.Control group birds were fed and watered at liberty during whole experiment period,so did birds out of restriction period.The beginning ages of restriction for birds were from 6 to 13d,9 to 15d and 12 to 18d respectively by providing 80% feed consumed of control ones on previous day,and the phase of restriction is 7 days.The result showed that BW at 21d of restricted groups broilers were significantly lower than control group broilers(P0.05),BW at 42d was not significantly different between control group and restricted groups broilers(P0.05).Feed intake,average body weight gain and feed conversion ratio of the broilers at all ages were not significantly affected by early restriction(P0.05),but they were decreased.Feed intake(P0.01) and average body weight gain(P0.05) of the broilers at 1d to 21d were significantly lower by early feed restriction;feed conversion was significantly lower by feed restricted from 6 to 13d(P0.05).The average daily feed intake,average body weight gain and feed conversion of birds from 22 to 42d were not significantly affected by early restriction(P0.05).The performance and the carcass characters of the broilers were not significantly affected by feed restriction during different time of early-age(P0.05),but live body weight at 42 d of the broilers which were feed restricted from 6 to 13d and 9 to16d were higher than the broilers of control group,this indicated that the compensatory growth was achieved more.Analysis by synthesis showed that the effect of feed restricted form 9 to 16d was better than other treatments.