EFFECT OF FEED RESTRICTION AND BREED ON COMPENSATORY GROWTH, ABDOMINAL FAT AND SOME PRODUCTION TRAITS OF BROILER CHICKS

The compensatory growth, abdominal fat and feed conversion ratio of br oiler chicks behind early feed restriction were studied. Chicks from t wo breeds, characterized as relatively fast and slow growth broilers, Lohmann and Hubbard were divided into four experimental groups of two replicate Fer breed in which one group was fed ad libitum, whereas the others were fed restricted to 20% or 30% or 40% of the full fed group in day 8, 9, 12 and 13 and recommenced ad libitum feeding thereafter. Final body weight did not differ among chicks restricted to 20 or 40% and those full fed. There was an early improvement in feed conversion ratio with imposing the restriction feeding over the control group, b ut final improvement was insignificant. Skin percentage and skin plus abdominal fat percentages were decreased with increasing the severity of feed restriction. Dressing percentage of the most severely fed rest riction group was higher than that of their control counterparts. Ther e were a decrease in mortality rate, abdominal fat and increase in car cass, boneless, and breast meat percentages with imposing FR treatment . Significant interaction between breeds and FR treatments in body wei ght and feed conversion ratio were observed. Body weight of Lohmann ch icks nas heavier than that of Hubbard chicks, with no difference in fe ed conversion ratio between breeds. Hubbard chicks showed lower mortal ity rate than Lohmann breed. Males had higher final body weight, morta lity rate and shank and keel lengths, while females had higher abdomin al fat, skin plus abdominal fat and boneless meat percentages.