摘要
The aim of this study was to determine the effects of supplementing organic forms of zinc(zinc acetate,ZnA)and inorganic zinc(zinc sulfate,Zn S)on performance,the gain to feed ratio(G:F)and skeletal characters in broilers from the first day to the 42th day.A total of 240-day-old broilers(Arbor Acres)were randomly distributed in four groups.A corn-soybean meal-based control diet containing recommended concentrations of inorganic trace minerals and other nutrients was prepared.On the basal diets,the control goup(CG)was supplemented with Zn S and the treatment group(TG)feeding diets were with different ZnA supplemental levels(80,100 and 150 mg·kg^-1)of ZnA.Each group was allotted randomly to five replicates and 12 broilers in each replicate and fed ad libitum from the first day to the 42th day.The results showed that supplementation of ZnA significantly increased(p<0.05)energy and phosphorus(P)compared to that fed Zn S on the 21th day.Calcium(Ca),tibia weight,ash weight,tibia Ca and tibia P in TG(80 mg·kg^-1 of ZnA)were the highest(p<0.05).The pancreas Zn content of TG was higher than that in CG and increased with the supplementation of ZnA.On the 42th day,the content of energy,crude protein(CP),Ca and tibia Ca in TG(80 mg·kg^-1 of ZnA)were the highest(p<0.05),the change of pancreas Zn was the same as the results on the 21th day,but enter extract(EE),tibia weight,tibia length,tibia width and ash weight were not affected(p>0.05)by ZnA.The results of this study showed that ZnA was better than Zn S in improving the early growth performance,nutrient utilization rate in broilers,the length and weight of broiler tibia,it promoted the calcium,phosphorus deposition and normal growth of tibia,and the optimum dietary ZnA level to feed was 80 mg·kg^-1.ZnA affected body Zn stores and the apparent metabolic rate of nutrients.
