Application Of Zinc-bearing Attapulgite And Zinc-bearing Clinoptilolite In Broiler Feed

Zinc-bearing attapulgite and zinc-bearing zeolite could improve performance and the antioxidant function of broilers,but the application in broiler feed was not enough.This study was conducted to evaluate the effect of zinc-bearing attapulgite(ZnAP)and zinc-bearing clinoptilolite(ZnCP)addition on growth performance,digestive enzyme activity,intestinal morphology,intestinal enterobacteria,meat quality,metal deposition in tissues,antioxidant function,immune organ index of broliers to provide a theoretical reference for the application of ZnAP and ZnCP.The first experiment was conducted to study the effects of ZnAP and ZnCP on growth performance,intestinal enterobacteria,intestinal morphology,digestive enzyme activity,nutrient apparent digestibility and immune organ index of broilers.A total of 240 one-day-old Arbor Acres chickens were randomly allocated into 5 groups with 6 replicates of 8 birds for a 42-d feeding trial.The dietary treatments were as follows:1.control(CON)fed a basal diet without Zinc sulfate or antibiotics;2.the basal diet plus 80 mg/kg Zn from Zinc sulfate;3.the basal diet plus 80 mg/kg Zn from Zinc sulfate and chlortetracycline(ANT);4.the basal diet plus 0.49%ZnAP containing 80 mg/kg Zn;5.the basal diet plus 0.53%ZnCP containing 80 mg/kg Zn.The results showed that compared with CON,ZnCP treatments caused positive effects on ADG and ADFI of broilers during 1-21 d(P<0.05),and ZnAP and ZnCP supplementation increased ADG and ADFI of broilers during 1-42 d(P<0.05)compared with Zinc sulfate and ANT treatments.The number of Lactobacillus in cecum was reduced by ZnAP at 21 d(P<0.05).Compared with other treatments,villus length in duodenum at 21 d and amylase activity in pancreas at 21 d and 42 d were also increased by ZnAP and ZnCP(P<0.05).Compared with ANT,ZnAP and ZnCP supplementation increased V/C value in duodenum at 21 d(P<0.05).Compared with other treatments,ZnCP treatment caused positive effects on the apparent metabolic rate of DM at 21 d and 42 d,the apparent metabolic rate of OM at 21 d,and ZnAP treatment significantly increased the apparent metabolic rate of OM at 42 d(P<0.05).Compared with CON and ANT,thymus index was increased by ZnCP treatment at 42 d(P<0.05).The second trial was conducted to study the effects of ZnAP and ZnCP on metal deposition in various tissues of broilers.The trial design and materials were the same as that in the first experiment.The results showed that compared with CON,Zinc sulfate and ANT,ZnAP and ZnCP supplementation significantly improved Zn content in pancreas at 21 d and 42 d and in liver at 42 d(P<0.05).Compared with CON,the content of Fe in breast muscle at 21 d and in whole blood and pancreas at 42 d were increased by ZnAP and ZnCP treatments,which was also greater than Zinc sulfate and ANT group in whole blood(P<0.05).Compared with CON,ZnAP and ZnCP supplementation significantly improved Mg content in pancreas in broilers at 42 d,and Mg content in leg muscle was improved by ZnAP supplementation at 42 d(P<0.05).Compared with CON,ZnCP supplementation caused positive effects on the contents of Cu in pancreas at 21 d and 42 d and in leg muscle at 21 d in broilers,ZnAP supplementation significantly increased Cu content in whole blood and pancreas at 42 d compared to Zinc sulfate,and Cu content had a higher value in pancreas by ZnCP treatment at 42 d than ANT(P<0.05).Compared with CON,the contents of Mn in breast muscle at 21 d and in pancreas at 42 d were significantly improved by ZnCP treatment,and compared with other treatments,ZnCP and ZnAP treatments caused positive effects on Mn content in whole blood at 42 d.Compared with Zinc sulfate,ZnCP and ZnAP treatments reduced Pb content in tibia at 21 d(P<0.05),and Cd content in pancreas was significantly reduced by ZnCP at 42 d(P<0.05).Compared with CON,ZnAP and ZnCP supplementation decreased Cr content in liver and breast muscle at 42 d(P<0.05).The third trial was conducted to study the effects of ZnAP and ZnCP on antioxidant function of breast muscle,leg muscle and liver and meat quality in broilers.Compared with CON,ZnCP supplementation increased CP content,decreased moisture content in breast muscle in broilers,and moisture content in breast muscle was significantly decreased by ZnAP and ANT treatments(P<0.05).Compared with CON,ZnAP and ZnCP treatments significantly decreased 48-h drip loss and 24 h b*value in breast muscle in broilers,and 45 min b*value in breast muscle,45 min L*value and 24 h b*value in leg muscle were also significantly reduced by ZnCP treatment(P<0.05).Compared with CON,all treatments decreased 21 d MDA content and increased 42 d T-AOC activity in breast muscle(P<0.05),and ZnCP supplementation caused more positive effects on T-AOC activity in leg muscle at 21 d and 42 d than ZnSO4 treatment(P<0.05).Under the conditions of this experiment,the diets added zinc-bearing attapulgite and zinc-bearing zeolite promoted the growth of broilers,improved digestive function,increased beneficial metals deposition in tissues,reduced deposition of heavy metals in tissue and improved meat quality.