Goo Doyun, Kim Jong Hyuk, Park Geun Hyeon, Delos Reyes Jomari Badillo, Kil Dong Yong
Department of Animal Science and Technology, Chung-Ang University, Anseong-si,Gyeonggi-do 17546, Korea.
Animals (Basel). 2019 Mar 21;9(3):107. doi: 10.3390/ani9030107.
The present experiment was conducted to investigate the effect of heat stress (HS) andstocking density (SD) on growth performance, breast meat quality, and intestinal barrier functionin broiler chickens. Experimental treatments included two different ambient temperatures (20 °C:thermoneutral conditions, or 27.8 °C: HS conditions) and two different SD (low: 9 birds/m2 andhigh: 18 birds/m2) in a 2 × 2 factorial arrangement. A total of 1140 21-day-old broiler chickens wereallotted 1 of 4 treatments with five replicates. At the end of the experiment (35 days of age), twobirds per replicate were euthanized for sample collections. The results indicated no interactionsbetween HS and SD for all measurements. For main effects, HS decreased (p < 0.05) the growthperformance of broiler chickens. Similarly, high SD also decreased (p < 0.05) body weight gain andfeed intake. HS decreased (p < 0.01) jejunal trans-epithelial electric resistance (TER), whereas highSD did not affect TER. Neither HS nor high SD affected jejunal tight junction-related geneexpressions; however, high SD reduced (p < 0.05) occludin expression. In conclusion, HS and highSD are key environmental factors decreasing broiler performance; however, the interactive effectsof HS and high SD are not significant under the current conditions.
本试验旨在研究热应激（HS）和饲养密度（SD）对肉鸡生长性能、胸肉品质和肠道屏障功能的影响。试验处理包括两种不同的环境温度（20℃：热中性条件，或27.8℃：热应激条件）和两种不同的饲养密度（低：9只/m²和高：18只/m²），采用2×2析因设计。总共1140只21日龄肉鸡被分配到4种处理中的1种，每种处理有5个重复。在试验结束时（35日龄），每个重复选取2只鸡进行安乐死以采集样本。结果表明，所有测量指标中热应激和饲养密度之间均无交互作用。对于主效应，热应激降低了（p<0.05）肉鸡的生长性能。同样，高饲养密度也降低了（p<0.05）体重增加和采食量。热应激降低了（p<0.01）空肠跨上皮电阻（TER），而高饲养密度对TER没有影响。热应激和高饲养密度均未影响空肠紧密连接相关基因的表达；然而，高饲养密度降低了（p<0.05）闭合蛋白的表达。总之，热应激和高饲养密度是降低肉鸡生产性能的关键环境因素；然而，在当前条件下，热应激和高饲养密度的交互作用不显著。
