Effects of Early Dietary Energy Restriction on Growth Performance,Slaughter Performance,Growth of Visceral Organs and Tibia Parameters of Broilers

This experiment was conducted to investigate effects of early dietary energy restriction on growth performance,slaughter performance and growth of visceral organs and tibia parameters of broilers. Three hundred 1-day-old Arbor Acres (AA) male broilers were selected and randomly divided into 4 groups with 5 replicates per group and 15 birds per replicate.Dietary energy of broilers from 1 to 21 d was restricted 0,5%,10% and 15% respectively from 8 to 14 d,and all other nutrients met the NRC (1994) requirement.On day 14 and 42 of the experiment,one bird of per replicate of each group was randomly selected to be slaughtered to determine slaughter performance,visceral organs and tibia parameters development. The results were as follows:①Feed intake of group 10% energy restriction was significantly higher than that of other treatment groups from 8 to 14 (P<0.05),and the body weight of group 10% energy restriction was significantly higher than that of control group (P<0.05). Feed conversion ratio of group 15% energy restriction was significantly higher than that of other treatment groups (P<0.05). Feed intake of group 10% energy restriction was significantly higher than that of other treatment groups from 15 to 42 d (P<0.05),and the 42-day-old body weight of group 10% energy restriction was significantly higher than that of other treatment groups (P<0.05).②Early dietary energy restriction did not significantly affect the slaughter performance of 42-day-old broilers (P>0.05).③Early dietary energy restriction could improve the heart weight of broilers from 8 to 14 d,and the heart weight of group 10% energy restriction was significantly higher than that of control group (P<0.05),the proventriculus weight of experimental groups were significantly higher than that of control group (P<0.05).The gizzard weight of group 10% energy restriction was significantly higher than that of other treatment groups (P<0.05).④The density of tibia of group 5% energy restriction was significantly higher than that of control group (P<0.05),and there were no significant differences between experimental groups and control group on the rest of tibia parameters (P>0.05). In conclusion,the optimum restriction level of dietary energy of broilers from 8 to 14 d was 10%.