饲养密度和硫辛酸对肉鸡血清指标、行为及骨骼发育的影响

本试验旨在研究高饲养密度条件下饲粮中添加硫辛酸(LA)对肉鸡血清指标、行为及骨骼发育的影响。试验选取健康状况良好、体重相近的1530只21日龄爱拔益加(AA)肉鸡,随机分成3组,即常规饲养密度组(ND组,15只/m^2,饲喂基础饲粮)、高饲养密度组(HD组,18只/m^2,饲喂基础饲粮)和高饲养密度+LA组(HD+LA组,18只/m^2,在基础饲粮在添加300 mg/kg LA),每组6个重复。试验期为3周。结果表明:1)与ND组相比,HD组肉鸡血清钙含量和碱性磷酸酶(ALP)活性显著下降(P<0.05),血清皮质酮(CORT)含量以及还原型辅酶Ⅱ氧化酶(NOX)和髓过氧化物酶(MPO)活性显著上升(P<0.05)。2)与ND组相比,HD组肉鸡行走、梳翅、采食频次与时间占比显著降低(P<0.05),而饮水频次以及饮水和趴卧时间占比显著升高(P<0.05)。3)与ND组相比,高饲养密度显著降低肉鸡胫骨与股骨直径、重量、密度、强度以及钙、磷、灰分和矿物盐含量(P<0.05)。4)与HD组相比,HD+LA组肉鸡血清钙含量和ALP活性显著升高(P<0.05),血清CORT含量以及NOX和MPO活性显著下降(P<0.05);采食频次和时间占比显著增加(P<0.05),饮水频次和趴卧时间占比显著降低(P<0.05);胫骨质量以及钙、磷含量与股骨密度、强度和钙含量显著上升(P<0.05)。综上所述,高饲养密度致使肉鸡发生氧化应激,改变了肉鸡行为,并使肉鸡骨骼质量下降,而饲粮中添加LA能在一定程度上缓解高饲养密度对肉鸡造成的损伤。

Effects of Stocking Density and Alpha-Lipoic Acid on Serum Indexes,Behavior and Bone Development of Broilers

This experiment was conducted to investigate the effects of dietary supplemented with alpha-lipoic acid(LA)on the serum indexes,behavior and bone development of broilers under high stocking density condition.In the experiment,a total of 1530 Arbor Acres AA()broilers at the age of 21 days with good health and similar body weight were selected and randomly divided into three groups,they were normal stocking density group(ND group,15 birds/m^2,basal diet),high stocking density group(18 bird/m^2,basal diet)and high stocking density+LA group(HD+LA group,18 birds/m^2,basal diet+300 mg/kg LA),and each group had 6 replicates.The experimental period was 3 weeks.The results showed as follows:1)the serum calcium content and alkaline phosphatase(ALP)activity of broilers were significantly decreased(P<0.05),and the corticosterone(CORT)content,NADPH-oxidase(NOX)and myeloperoxidase(MPO)activities were significantly increased(P<0.05)in HD group compared with the ND group.2)Compared with the ND group,the walking,combing and feeding frequencies and time proportions of broiler’s walking,feeding and combing were significantly decreased(P<0.05),and the frequency and time proportion of drinking were significantly increased in HD group(P<0.05).3)High stocking density significantly lowered the diameter,weight,density,strength and the contents of calcium,phosphorus,ash and mineral of tibia and thighbone compared with the ND group(P<0.05).4)Compared with the HD group,the serum calcium content and ALP activity of broilers were significantly increased(P<0.05),and the content of CORT and the activities of NOX and MPO were significantly decreased in the HD+LA group(P<0.05);the feeding frequency and time proportion of broilers were significantly increased(P<0.05),and the drinking frequency and lying time proportion were significantly decreased in the HD+LA group(P<0.05);the tibia weight and Ca and P content and the thighbone density,strength and calcium content of broilers were significantly increased in the HD+LA group(P<0.05).In conclusion,high stocking density leads to oxidative stress,modifies the behavior and lowers the bone quality of broilers.Dietary addition of alpha-lipoic acid can alleviate the damage to broilers caused by high stocking density to a certain extent.