Effects Of Bile Acid And Vitamin E On Growth Performance,Serum Biochemical Indices,Antioxidant Function And Intestinal Microbes Of Broilers Under Chronic Heat Stress

The effects of adding bile acid and vitamin E to feed alone or in combination on growth performance,meat quality,serum biochemistry,liver oxidation resistance and intestinal function of broilers under chronic heat stress were studied,and their economic benefits and application prospects were analyzed.200 1d Kebao 500 broilers were selected and reared for 21 d.They were formally tested on 22d.They were randomly divided into 5 groups:normal temperature control group,heat stress control group and test group.500 mg/kgBA,200 mg/kgVE,500 mg/kg BA+200 mg/kgVE were added respectively.Each group had 4 replications,and each replicate had 10 chickens.The test period was 42 d.Samples were taken and relevant indexes were tested according to the test design.The test results are as follows:1.Effect of adding bile acid and vitamin E to feed on the performance of broilers under chronic heat stressThe addition of bile acid and vitamin E in the feed alone or in combination can obviously improve the average daily gain and daily feed intake of broilers and reduce the feed-to-meat ratio.When fed to 35 d,compared with CON group,ADG and ADFI in other test groups were significantly decreased(p<0.01),and F/G were significantly increased(p<0.01).After 42 d of feeding,compared with CON group,ADG and ADFI in other test groups were significantly decreased(p<0.01)and significantly decreased(p<0.01).F/G increased significantly(p<0.01),and bile acid and vitamin e added to the feed could increase the absorption of lipid.2.Effect of adding bile acid and vitamin E to feed on slaughter performance of broilers under chronic heat stressAdding bile acid and vitamin E alone or in combination in feed can improve various indexes of broiler slaughter performance.when fed to 28 d,compared with HS group,CON group total eviscerated weight,half eviscerated weight and pectoral muscle weight significantly increased(p<0.01),CON group leg muscle weight significantly increased(p<0.05),After 35 d of feeding,compared with HS group,the semi-clean chamber weight and pectoral muscle weight of CON group were significantly increased(p<0.01),the semi-clean chamber weight of VE group was significantly decreased(p<0.05),the abdominal fat rate of CON group was significantly decreased(p<0.05),and the abdominal fat rate of other additive groups had a decreasing trend(p<0.1).After 42 days of feeding,compared with HS group,the total and semi-net chamber weights of CON group were significantly increased(p<0.01),the subcutaneous fat weights of BA group and BA+VE group were significantly increased(p<0.01),and the chest muscle and leg muscle weights of CON group were significantly decreased(p<0.01).3.Effect of adding bile acid and vitamin E to feed on muscle quality of broilers under chronic heat stressThe addition of bile acid and vitamin E in feed alone or in combination can significantly improve the muscle pH value,drip loss rate and shear force in the early and middle stages of feeding,and improve the meat color,shear force,muscle color and drip loss rate in the later stages of feeding.After 28 days of feeding,compared with HS,the pH of leg muscles in BA group increased significantly for 24 hours(p<0.01),while the shear force of leg muscles in BA group decreased significantly(p<0.01).after 35 days of feeding,the pH of leg muscles in each experimental group increased significantly for 24 hours(p<0.01),the dripping loss of leg muscles in BA group increased significantly(p<0.01),and the shear force of leg muscles in BA+VE group decreased significantly(p<0.01).Redness a*of leg muscles in BA group decreased significantly(p<0.01),while redness a*of leg muscles in BA+VE group decreased significantly(p<0.01).when fed to 42 d,compared with HS group,ph of leg muscles in BA+VE group decreased significantly(p<0.05),and shear force of leg muscles in CON group and BA+VE group decreased significantly(p<0.01).4.Effect of adding bile acid and vitamin E to feed on biochemical indexes of broilers under chronic heat stress(1)liver functionThe addition of bile acid and vitamin E to the feed alone or in combination can improve the liver function of broilers under the condition of heat stress and relieve the damage to the liver caused by heat stress.At 28 d,compared with HS group,AST content in VE group and BA+VE group decreased significantly(p<0.05),TP content in VE group decreased significantly(p<0.01),TP content in BA group and BA+VE group decreased significantly(p<0.05),ALP content in other experimental groups decreased significantly(p<0.01).After 35 d of feeding,compared with HS group,ALP content in other experimental groups decreased significantly(p<0.01),D-Bil content in VE group decreased significantly(p<0.05),and D-Bil content in BA+VE group decreased(p<0.01).At 42d,compared with HS group,ALT content in BA group,VE group and BA+VE group decreased signifi cantly(p<0.05),ALP content in other experimental groups decreased significantly(p<0.05),D-Bil content in BA+VE group increased significantly(p<0.01),T-Bil content in con group increased significantly(p<0.05),and T-Bil content in BA+VE group increased significantly(p<0.01).(2)renal functionThe addition of bile acid and vitamin E to the feed alone or in combination can improve the kidney function of broilers under heat stress and reduce the metabolic burden on the kidney under heat stress.After 28 days of feeding,the UREA content in CON group,BA group and VE group decreased significantly(p<0.01)compared with HS group.compared with HS group,the UA content in con group,VE group and BA+VE group decreased significantly(p<0.05),and the UA content in BA group decreased significantly(p<0.01).After 35 days of feeding,the UREA content in CON group was significantly lower than that in HS group(p<0.05),while the UREA content in VE group and BA+VE group was significantly lower(p<0.05).The UA content in BA group and VE group decreased(p<0.1)and the UA content in BA+VE group increased significantly(p<0.05)compared with con group at 42d.Compared with HS group,UA content in BA+VE group increased significantly(p<0.05),UA content in BA group and VE group decreased(p<0.1).(3)blood sugar and blood lipidThe addition of bile acid and vitamin E to feed alone or in combination can effectively reduce blood sugar and blood lipid of broilers under heat stress.At 28 d,compared with HS group,GLU content in each additive group decreased significantly(p<0.01),TG content in other experimental groups decreased significantly(p<0.01).At 35 d,compared with HS group,GLU content in VE group and BA+VE group decreased significantly(p<0.05),TG content in other experimental groups decreased significantly(p<0.05),LDL-C content in BA group and BA+VE group decreased significantly(p<0.05).The HDL-C content in con group was significantly lower than that in HS group after 42 d of feeding(p<0.05).5.Effect of adding bile acid and vitamin E to feed on liver antioxidant function of broilers under chronic heat stressThe addition of bile acid and vitamin E to the feed alone or in combination can increase the content of antioxidant substances in the body of broilers under the condition of heat stress and improve the ability of the body to resist oxidation stress.After 28 d of feeding,compared with HS group,the content of T-SOD in BA group was significantly increased(p<0.05),and the content of T-AOC in con group was significantly increased(p<0.05).At 35 d,compared with HS group,MDA content in CON group increased significantly(p<0.05),MDA content in BA+VE group increased significantly(p<0.05).compared with HS group,T-SOD content in con group decreased significantly(p<0.01),T-SOD content in BA+VE group increased significantly(p<0.05).compared with HS group,GSH-px content in BA+VE group increased significantly(p<0.01),and T-AOC content in con group increased significantly(p<0.05).At 42 d,compared with HS group,MDA content in BA+VE group increased significantly(p<0.05),T-SOD content in BA+VE group increased significantly(p<0.01),and T-AOC content in VE group increased significantly(p<0.05).6.Effect of adding bile acid and vitamin E to feed on intestinal microbes of broilers under chronic heat stressThe addition of BA and VE in feed alone or in combination has no significant effect on stabilizing the microbial structure of small intestine.When fed to 28 d,the content of lactobacillus in duodenum and jejunum of VE group was significantly lower than that of HS group(p<0.05).when fed to 35 d,the content of Escherichia coli in jejunum of VE group was significantly higher than that of HS group(p<0.05).when fed to 42 d,the content of Escherichia coli in duodenum of BA+VE group was significantly higher than that of HS group(p<0.05),and the content of lactobacillus in jejunum was significantly higher than that of hs group(p<0.01).Conclusion:The above results can be concluded that the addition of 500 mg/kgBA or 200 mg/kgVE to the feed can improve the growth performance,slaughter performance,muscle quality,serum biochemical indexes and liver antioxidant function of broilers,and has no obvious improvement effect on the number and structure of intestinal flora.At the same time,the combined application of the two additives has no obvious synergistic effect.