腐植酸对蛋鸡产蛋后期产蛋性能、抗氧化及促产蛋激素分泌的影响

试验旨在探究天然腐植酸和合成腐植酸对蛋鸡产蛋后期生产性能、蛋品质、血清生化指标、抗氧化指标和激素水平的影响。选取52周龄体重、产蛋率相近的海兰白蛋鸡405羽,随机分成3个组,每组9个重复,每个重复15羽。对照组饲喂基础饲粮(CON组),试验组在基础饲粮中分别添加1 000 mg/kg的天然腐植酸A(HAA组)和合成腐植酸B(HAB组),预试期2周,正试期8周。结果表明:与CON组相比,添加腐植酸均可提高平均蛋重(P<0.05),降低不合格蛋率(P<0.05)和料蛋比(P<0.01),其中HAA组产蛋率极显著提高,HAA组的料蛋比低于HAB组(P<0.01);饲粮添加腐植酸对蛋品质无显著影响;与CON组相比,HAA组血清中白蛋白含量降低(P<0.05),HAB组乳酸脱氢酶活性提高(P<0.05),HAA组与HAB组血清中甘油三酯含量均降低(P<0.01);相比于CON组,添加HAB可提高谷胱甘肽过氧化物酶活性(P<0.05);与CON组相比,饲粮中添加腐植酸提高了血清中促黄体素水平(P<0.01),对促卵泡素水平有升高趋势(P=0.060),且HAA组中促卵泡素水平高于HAB组(P<0.01)。结果提示,腐植酸可促进机体促性腺激素分泌,改善机体抗氧化水平,显著提高产蛋后期蛋鸡的生产性能,且天然提取的腐植酸作用效果更佳。

Effects of Dietary Humic Acids Supplementation on Laying Performance,Antioxidant Capacity and Serum Gonadotropin Levels of Hens during Late Laying Period

This study was conducted to compare the effects of dietary natural or synthetic humic acids(HAs) supplementation on laying performance, egg quality, serum biochemical parameters, antioxidant capacity and hormone levels of laying hens during late period. A total of 405 52-week-old Hy-line white hens were selected and randomly divided into 3 groups with 9 replicates and 15 hens each. The control group(CON) was fed with basal diet and the experimental groups were fed with basal diet supplemented with 1 000 mg/kg of natural humic acid(HAA) or synthetic humic acid B(HAB). After 2 weeks adaptation to the basal diet, hens were fed the experimental diets for 8 weeks. The results showed that compared with CON,dietary supplementation with HAs increased average egg weight(P<0.05), reduced unqualified eggs rate and the ratio of feed to eggs(P<0.01). In addition, HAA supplementation improved laying rate(P<0.01) and the ratio of feed to eggs of HAA lowered than HAB(P<0.01). No significant differences on egg quality parameters were observed among groups. Compared with CON, dietary HAA supplementation decreased serum albumin(ALB) content(P<0.05) while HAB increased activity of lactate dehydrogenase(LDH)(P<0.05). Additionally, both HAA and HAB inclusion decreased serum triglyceride(TG)content(P<0.05). Inclusion of HAB to hens significantly increased glutathione peroxidase(GSH-Px) activity in comparison to CON(P<0.05). Dietary HAs inclusion increased luteinizing hormone(LH) levels(P<0.01) and tended to increase follicle stimulating hormone(FSH) level(P=0.060) in serum as compared to CON, and the level of FSH in HAA was higher than that in HAB(P<0.01). In conclusion, dietary humic acid supplementation might promote the secretion of gonadotropin and antioxidant capacity of laying hens, and therefore significantly improves the production performance. In this study, the natural humic acid is more effective in these improvements.