Effect Of Zinc-Amino Acid Chelate On Growth And Metabolism Of Broilers

The objective of this study was to evaluate the effects of different zinc sources and zinc levels on performance, immune function, zinc deposition and nutrient metabolism of broiler chicks. It can provide scientific basis for zinc level in practical diet of broiler chicks on the basis of comparing those different zinc sources.Experiment 1. The Effects of Zinc-Amino Acid Chelate on Performance and Immune Function of Broiler chicksThe effects of different zinc sources and zinc levels on performance and immunity function of broiler chicks at 2 week-old were studied. A single factor and a 2*4 factorial arrangement of treatments in a completely random design was conducted. 270 male chicks were divided into 9 treatments (5 duplicates per treatment and each duplicate had 6 chicks) in random. The Control Group was fed semi-purified basic diet with 14.97mg/kg of zinc content. The Group 1 to 4 were added zinc-amino acid chelate(Zn-AA)at 20, 40, 60 and 80mg/kg. The Group 5 to 8 were added ZnSO₄·7H₂O at the same level as Zn-AA .The whole experiment was ended at 25 day.The result showed that: Feed gain ratio (F/G) was affected with dietary zinc levels significantly ( P<0.05). F/G of 60 and 80mg/kg zinc level groups were significantly higher than the groups which added zinc at lower level (P<0.05). There was no significant difference of performance among zinc sources groups, while ANAE activity and Serum ND antibody titer were affected with zinc sources, those two indexes of Zn-AA groups were higher than those of ZnSO4 groups (P<0.05). Zinc levels affected ANAE activity and Serum ND antibody titer significantly (P<0.05), and have a trend that those two indexes were increased with zinc levels were raised, those indexes of 60 and 80mg/kg zinc levels groups were higher than others significantly (P<0.05). It showed that adding organic and inorganic zinc in zinc deficiency diet can both improve performance and immune function of broiler chicks, and the effect of Zn-AA on improving immune function of broiler chicks was superior to inorganic zinc. Colligate the performance and immune indexes, the optimal zinc level in 14²5 day-old broiler chick was higher than 70mg/kg.Experiment 2. The Effects of Zinc-Amino Acid Chelate on tissue deposition rate and nutrient metabolism of Broiler chicksThe effects of different zinc sources and zinc levels on tissue deposition rate and nutrient metabolism of broilers at 2 week-old were studied. A single factor and a 2*4 factorial arrangement of treatments in a completely random design was conducted. 270 male chicks were divided into 9 treatments (5 duplicates per treatment and each duplicate had 6 chicks) in random. The Control Group was fed semi-purified basic diet with 14.97mg/kg of zinc content. The Group 1 to 4 were added zinc-amino acid chelate(Zn-AA)at 20, 40, 60 and 80mg/kg. The Group 5 to 8 were added ZnSO₄·7H₂O at the same level as Zn-AA .The whole experiment was ended at 25 day.The result showed that: The effect of zinc sources on zinc deposition in tibia and pancreas were significantly, and the deposition of Zn-AA group higher than that of ZnSO4 group (P<0.05). Zinc levels effected zinc content in tibia, pancreas and serum significantly (P<0.01), and have a trend that those contents were increased with zinc levels were raised, the zinc content in pancreas and serum in 80mg/kg zinc level group were highest, and the zinc content in pancreas and serum in 20 mg/kg zinc level group were the lowest, and those content in the two zinc levels groups were different form others groups significantly (P<0.05). Zinc content in tibia had similar variety law, the difference between groups except 20mg/kg zinc level group was no significant (P>0.05).Zinc sources significantly influenced content of blood glucose and serum total protein (P<0.01), and those indexes of Zn-AA group higher than ZnSO4 group. Zinc level also had significant effect on content of blood glucose and serum total protein, the content of blood glucose in 60mg/kg zinc level was higher than others groups significantly (P<0.05), and the content of serum total protein in 20mg/kg zinc level group was lower than others groups significantly (P<0.05). It showed that dietary zinc level influence tissue zinc deposition of broiler chicks directly, and Zn-AA had higher tissue zinc deposition efficiency. Besides, dietary zinc level influenced on glucose metabolism and protein metabolism, especially as Zn-AA.