Vitamin C And Vitamin E Supplementation Alleviates Oxidative Stress Induced By Dexamethasone And Improves Reproductive Performance In Breeder Roosters

Two experiments were conducted in the present study to determine the effect of dietary vitamin C or vitamin E supplementation on reproductive performance, antioxidant ability and the immune performance in dexamethasone(DEX)-induced oxidative stressed Lueyang black-boned roosters in order to provide a beneficial accumulation to establish the technology of nutrient regulation against stress in rooster production.Trail 1: Eighty 45-wk-old Lueyang black-boned breeder roosters were divided into 5groups. The negative and positive control groups were fed corn soybean meal basal diet, the trial groups were given basal diet supplemented with 300 mg/kg VC, 200 mg/kg VE, 300mg/kg VC+ 200 mg/kg VE, respectively. On 49 wk of age, positive group and trial groups were subcutaneous injected DEX 4 mg/kg body weight(BW) for 3 times every other day,negative group was sham injected saline. The experiment lasted for 5 weeks. Feed intake(FI)and BW were monitored weekly, semen samples were collected at the end of 2nd, 3rd and 5th week of trail period, blood samples were obtained at the end of 3rd and 5th week of trail period,four birds of each treatment were euthanized and the testicle were obtained at the end of 3rd week of trail.The results showed as follows: Injection of DEX significantly reduced body weight(P<0.05), supplementation of VE or VC+VE increased body weight under oxidative stress(P>0.05); High level of ADFI were associated with injection of DEX(P<0.05),Supplementation of VC could relief this adverse effect significantly(P>0.05); Injection of DEX significantly reduced plasma testosterone(P<0.05), supplementation of VC and VE increased significantly plasma testosterone of oxidative stressed roosters(P<0.05); Sperm activity significantly decreased in the DEX treatment(P<0.05), add alone or in combination of VC and VE enhanced sperm activity when supplemented to stress-induced birds(P<0.05);Low level of total antioxidant capacity(T-AOC) in testis were associated with the oxidative stress in testis(P<0.05), but supplementation of VC could enhance T-AOC in testis(P>0.05).Birds fed VE or VC+VE had very significantly lower malondialdehyde(MDA) than that of other groups(P<0.01).Trail 2: Eighty 45-wk-old Lueyang black-boned breeder roosters were divided into 5groups. The negative and positive control groups were fed corn soybean meal basal diet, the trial groups were given basal diet supplemented with 300 mg/kg VC, 200 mg/kg VE, 300mg/kg VC+ 200 mg/kg VE, respectively. On 49 w of age, positive group and trial groups were subcutaneous injected DEX 4 mg/kg body weight(BW) for 3 times every other day, negative group was sham injected saline. The experiment lasted for 5 weeks. Blood samples were obtained at the end of 2nd and 3rd week of trail period. Four birds of each treatment were euthanized and the livers were obtained at the end of 3rd week of trail. Serum antioxidant capacity, immune index and liver relative m RNA expression of antioxidant enzymes were measured. The results showed as follows: In the end of 5th week, supplementation of VC and VE significantly decreased serous MDA, and increased SOD(P<0.05). High level of serous GOP were associated with injection of DEX(P<0.05), supplementation of vitamins could relief this adverse effect significantly(P>0.05); In the end of 5th week, injection of DEX significantly reduced serous Ig M(P<0.05), but supplementation of VC and VE could enhance Ig M in serum(P>0.05). Birds fed VE or VC+VE had significantly higher Newcastle disease antibody titer than positive control group(P<0.05). Injection of DEX decreased the relative expression of SOD and GSH-Px in the livers of roosters(P>0.05), and supplementation of VE significantly improved, relative expression of GSH-Px compared with control group(P<0.05).In conclusion, the results of the present study demonstrate that supplementation of VC or VE could alleviate the negative impact the harmful effects of oxidative stress.Supplementation of VC or VE could improve semen quality and reproductive performance of oxidative roosters by improving the antioxygenic property of testicular tissue and seminal plasma, regulating antioxidase gene expression, promotingreproductive hormones and sperm formation;Supplenmentation of VC or VE could improve antioxidant and immune function of organism,enhancing the disease resistane consequently.Supplementation of VC, VE or their combination could alleviate the negative impact on reproductive performance of breeder roosters to some extent under oxidative stress. Moreover, the efficacy of combined addition of VC and VE in diet is better than individual supplementation.