低温环境下饲粮核黄素添加水平对蛋鸭激素分泌的影响

Effects of Riboflavin Supplementation on Hormonal Secretion of Laying Ducks at Low Ambient Temperatures

本试验旨在研究低温环境下饲粮核黄素添加水平对蛋鸭激素分泌的影响。试验采用两因素有重复完全交叉设计,温度设2个水平[适温(18±1)℃,T1;低温(2±1)℃,T2];核黄素设3个水平,在基础饲粮中分别添加4、16、32 m g/kg核黄素。选用12周龄健康的金定鸭(母)144只,随机分成6个处理,每个处理6个重复,每个重复4只,试验期为42 d。结果表明:低温对蛋鸭末体重和平均日增重(ADG)及其血清甲状腺素(T4)、胰岛素(Ins)、胰岛素样生长因子-Ⅰ(IGF-Ⅰ)、促黄体生成激素(LH)、孕酮(P4)和皮质醇(Cort)含量的影响没有达到显著水平(P>0.05);而对料重比(F/G,P<0.05)和平均日采食量(ADFI,P<0.01)及血清三碘甲腺原氨酸(T3,P<0.01)、生长激素(GH,P<0.01)、卵泡刺激素(FSH,P<0.01)和雌二醇(E2,P<0.01)含量有显著或极显著影响;环境温度和饲粮核黄素添加水平之间在蛋鸭末体重和ADG及其血清T4、E2和P4含量上未表现出互作效应(P>0.05),而在蛋鸭F/G(P<0.05)和ADFI(P<0.01)及其血清T3(P<0.05)、GH(P<0.01)、Ins(P<0.01)、IGF-Ⅰ(P<0.01)、FSH(P<0.01)、LH(P<0.01)和Cort含量(P<0.01)上有显著或极显著影响。由此可知,低温影响T3、GH、FSH和E2的分泌,而对血清T4、Ins、P4、Cort含量的影响没达到显著水平;环境温度和饲粮核黄素添加水平之间在F/G、ADFI、T3、GH、IGF-Ⅰ、FSH、LH上表现出互作效应。

The experiment was conducted to study the effects of riboflavin supplementation on hormonal secretion of laying ducks at low ambient temperatures.Two factors（temperature×riboflavin） interactive experimental design was used in the experiment.The ambient temperatures were（2±1） ℃ and（18±1） ℃,and supplemental levels of riboflavin in the diet were 4,16 and 32 mg/kg,respectively.A total of 144 laying ducks（Jinding duck,female,12 weeks old） were randomly allotted to 6 treatments with 6 replicates per treatment and each replicate comprised 4 ducks.The experiment lasted for 42 days.The results showed that low ambient temperatures had no significant effects on the final body weight and average daily gain（ADG）,and the contents of thyroxin（T4）,insulin（Ins）,insulin growth factor-Ⅰ（IGF-Ⅰ）,luteinizing hormone（LH）,progesterone（P4） and cortical hormone（Cort） in serum of laying ducks（P〈0.05）,but significantly affected the ratio of feed to gain（F/G,P〈0.05） and average daily feed intake（ADFI,P〈0.01）,and the contents of triiodothyronine（T3,P〈0.01）,growth hormone（GH,P〈0.01）,follicle-stimulating hormone（FSH,P〈0.01） and estradiol（E2,P〈0.01） in serum of laying ducks.There was no interaction on final body weight and ADG,and the contents of T4,E2 and P4 in serum of laying ducks between ambient temperature and riboflavin（P〈0.05）,whereas there was an interaction on F/G（P〈0.05） and ADFI（P〈0.01）,and the contents of T3（P〈0.05）,GH（P〈0.01）,Ins（P〈0.01）,IGF-Ⅰ（P〈0.01）,FSH（P〈0.01）,LH（P〈0.01） and Cort（P〈0.01） in serum of laying ducks.In conclusion,low ambient temperatures affect the secretion of T3,GH,FSH and E2,but do not affect the contents of Ins,T4,P4 and Cort in serum,and there is an interaction between temperature and riboflavin on F/G,ADFI,the contents of T3,GH,IGF-Ⅰ,FSH and LH.