天然和合成腐植酸对热应激蛋鸡生产性能、血清促性腺激素浓度、肝脏抗氧化能力和肠道形态结构的影响

Effects of Natural and Synthetic Humic Acids on Performance,Serum Gonadotropin Concentrations,Liver Antioxidant Capacity and Intestinal Morphological Structure of Laying Hens under Heat Stress

本试验旨在探讨饲粮中添加天然和合成腐植酸对热应激蛋鸡生产性能、血清促性腺激素浓度、肝脏抗氧化能力和肠道形态结构的影响。选用60周龄、体重[(1.32±0.24)kg]相近、产蛋率[(80.16±0.21)%]一致的健康海兰白蛋鸡540只,随机分成4个组,每组9个重复,每个重复15只鸡。对照组1在常温[(25±1)℃]条件下饲养,饲喂基础饲粮;其他组在高温[(35±1)℃]条件下饲养,分别饲喂基础饲粮(对照组2)及在基础饲粮中添加1000 mg/kg天然腐植酸(腐植酸A组)和1000 mg/kg合成腐植酸(腐植酸B组)的试验饲粮。试验期4周。结果表明:1)与对照组1相比,对照组2蛋鸡的产蛋率(LR)、平均日采食量(ADFI)、血清促黄体激素(LH)浓度、空肠绒毛高度(V)、绒毛高度/隐窝深度(V/C)和回肠V极显著降低(P<0.01),不合格蛋率(UER)、死亡率、肝脏丙二醛(MDA)含量和过氧化氢酶(CAT)活性极显著增加(P<0.01);与对照组2相比,饲粮中添加天然腐植酸极显著提高蛋鸡的LR、血清LH浓度、空肠V、V/C和回肠V(P<0.01),极显著降低不合格蛋率、肝脏MDA含量和CAT活性(P<0.01)。综上所述,饲粮中添加腐植酸可提高蛋鸡的抗氧化能力,调节血清促性腺激素浓度,改善生产性能,减轻热应激对肠道的损伤,且在本试验条件下天然腐植酸效果更佳。

This study was conducted to explore the effects of dietary natural and synthetic humic acids(HAs)on performance,serum gonadotropin concentrations,liver antioxidant capacity and intestinal morphological structure of laying hens under heat stress.Five hundred and forty healthy Hy-Line White laying hens of 60-week-old with similar body weight of[(1.32±0.24)kg]and consistent laying rate of[(80.16±0.21)%]were randomly divided into 4 groups with 9 replicates per group and 15 hens per replicate.Laying hens in control group 1 were fed a basal diet at normal temperature[(25±1)℃],and the others were fed a basal diet(control group 2)and the basal diets supplemented with 1000 mg/kg natural humic acids(group humic acids A)and 1000 mg/kg synthetic humic acids(group humic acids B)at high temperature[(35±1)℃].The experiment lasted for 4 weeks.The results show as follows:1)compared with control group 1,laying rate(LR),average daily feed intake(ADFI),serum luteinizing hormone(LH)concentration,jejunum villus height(V)and the ratio of villus height to crypt depth(V/C)and ileum V of laying hens in control group 2 were significantly decreased(P<0.01),and unqualified eggs rate(UER),mortality,liver malondialdehyde(MDA)content and catalase(CAT)activity were significantly increased(P<0.01).Compared with control group 2,dietary natural humic acids significantly increased LR,serum LH concentration,jejunum V and V/C and ileum V of haying hens(P<0.01),and significantly decreased UER,liver MDA content and CAT activity(P<0.01).In conclusion,dietary humic acids can increase antioxidant capacity,regulate serum gonadotropin concentrations,improve performance and alleviate intestine injury caused by heat stress of laying hens,and the effects of natural humic acids is better in this experiment.