Effects Of Different Forms Of Copper,Zinc And Manganese On Broiler Performance,Antioxidant Capacity And Intestinal Health Under Heat Stress

Microelements are essential nutrients in animals,which have a wide range of biological functions.As one of the common stimulants,heat stress often has a negative impact on poultry.The purpose of this study was to explore the effects of different copper sources and different forms of copper zinc manganese on broiler performance,antioxidant capacity and intestinal health under heat stress.The first experiment was to explore the effects of different copper sources on broiler performance,antioxidant capacity and intestinal health.768 healthy 1-day-old AA broilers with similar body weight were randomly divided into 6 groups,8 replicates in each group,16chickens in each replicate.Group A was the control group,and no additional copper source was added.The level of copper added in group B-F was 20 mg/kg.Mintrex^?Cu,Availa^?Cu100,Bioplex^?Cu,TBCC and CuSO₄·5H₂O was added respectively.The results showed that:1)in the experimental period of 1-42 days,the FCI of Availa^?Cu 100 group and CuSO₄·5H₂O group was significantly lower than that of Mintrex^?Cu group（P<0.05）.2)Serum antioxidant capacity index:on the 21st and 42nd day of the experiment,the activity of glutathione peroxidase（GPX）in Availa^?Cu 100 group and Bioplex^?Cu group was significantly higher than that in the control group,TBCC group and CuSO₄·5H₂O group（P<0.05）.3)On the 42nd day of the experimental period,the length of duodenal villi in Mintrex?Cu group and TBCC group was significantly higher than that in the control group,Availa?Cu group and Bioplex^?Cu group（P<0.05）.4)On the 21st day of the experiment,the number of lymphocytes in jejunum increased with the addition of Mintrex^?Cu,Availa^?Cu 100 and CuSO₄·5H₂O（P=0.09）.The number of lymphocytes in ileum increased with the addition of Mintrex^?Cu and CuSO₄·5H₂O（P=0.07）.On the 42nd day of the experiment,the number of lymphocytes in the lamina propria of duodenum increased with the addition of Availa?Cu100 and Bioplex^?Cu（P=0.09）.In conclusion,the addition of 20mg/kg of different copper sources to the feed has no significant effect on the growth performance of broilers.The addition of Availa^?Cu 100 and Bioplex^?Cu can significantly increase the activity of GPX in serum,so as to improve the antioxidant capacity of broilers.Mintrex^?Cu and TBCC can significantly increase the length of duodenal villi and the digestion of nutrients in 21-42 day old broilers.The addition of different copper sources with low doses does increase the number of intestinal lymphocytes,thus affecting the immunity of the intestinal tract to inflammation or infectious diseases and improving the intestinal health.The second experiment was designed to discuss the effects of different copper zinc manganese on growth performance,antioxidant and immune ability,intestinal health and bone development of broilers under heat stress.672 1-day-old AA broilers with similar body weight were randomly divided into three groups:A,B and C.each group contained 14 replicates,and each replicate contained 16 chickens.Group A was treated with 15 mg/kg copper sulfate,80mg/kg zinc sulfate and 80 mg/kg manganese sulfate.Group B was treated with the same amount of hydroxy organic microelements.Group C was treated with 50%microelements of group A and group B.On the 28th day of the experiment,AA broilers of each treatment were randomly divided into two treatments,one of which was treated with continuous heat stress.The temperature of the stress group was 36±1℃and that of the control group was 26±1℃.The results showed that:1)the average body weight and average daily gain of broilers in group C were significantly higher than those in group A（P<0.05）,and the average daily intake of broilers in group B was significantly higher than that in group A（P<0.05）;the average daily gain and average daily intake of broilers in group B were significantly higher than those in group A（P<0.05）,and the average daily intake of broilers in group B was significantly higher than that in group A（P<0.05）The feed to meat ratio was significantly lower in the heat stress group（P<0.05）.2)The activities of MDA in the liver of group A and group B were significantly higher than those of group C（P<0.05）,and the activities of SOD in the serum and liver of heat stress group were significantly higher than those of normal temperature control group（P<0.05）.3)The levels of IL 10 in group C at 21 days were significantly higher than those in group A（P<0.05）,and the levels of IL 4,IL 6 and IL 10 in heat stress group at 35 days were significantly higher than those in control group（P<0.05）.4)The length of jejunal villi in 35 day old normal temperature control group was significantly higher than that in heat stress group（P<0.05）,and the depth of crypt was significantly lower than that in heat stress group（P<0.05）.5)The content of trace element copper in tibia of 21day old group C was significantly higher than that of group A and B（P<0.05）;the length of tibia,the content of trace element zinc and the content of trace element manganese in 35 day old normal temperature control group were significantly higher than that of heat stress group（P<0.05）,while the content of trace element copper was significantly lower than that of heat stress group（P<0.05）.6)The relative expression of MLCK m RNA of jejunal barrier gene in group C was significantly higher than that in group A and B at 21 days old（P<0.05）;the relative expression of claudin-1 m RNA of jejunal barrier gene in group C was significantly higher than that in group A at 35 days old（P<0.05）;the relative expression of claudin-1m RNA of jejunal barrier gene in group C was significantly higher than that in group A（P<0.05）;the relative expression of Claudin-3 gene of jejunal barrier in group A was significantly higher than that in group A The relative expression of occludin m RNA in group C was significantly higher than that in group A and B（P<0.05）.In conclusion,the addition of Cu,Zn and Mn in the diet in the form of organic and inorganic can significantly increase the average weight and average daily gain of 1-21 day old broilers;can significantly increase the content of IL-10 in serum of 21 day old broilers,improve the immune response ability of the body;can reduce the activity of MDA and the degree of lipid peroxidation of liver cells in 21day old broilers;can significantly improve the expression of occludin at the age of 35 days,which is beneficial to maintain the integrity of intestinal barrier.In conclusion,the addition of 20mg/kg of Availa^?Cu 100 and Bioplex^?Cu to feed can significantly improve the activity of GPX in serum,thus improving the antioxidant capacity of broilers;Mintrex^?Cu can significantly improve the villus length of broilers in later period,improve the digestibility and absorption rate of nutrients,different addition of additional copper sources can effectively increase the number of intestinal lymphocytes,and affect the intestinal immune response Level.When Cu,Zn and Mn were added to the diet in the form of organic and inorganic,they had more advantages in the production performance,liver antioxidant capacity,immune capacity and intestinal integrity of broilers,while heat stress often brought about negative effects.