Poultry Institute, Chinese Academy of Agriculture Sciences, Yangzhou, Jiangsu, 225125, PR China; Department of Animal Science and Technology, Shandong Agricultural University, Taian, Shandong, 271018, PR China.
Poultry Institute, Chinese Academy of Agriculture Sciences, Yangzhou, Jiangsu, 225125, PR China.
J Therm Biol. 2022 Apr;105:103219. doi: 10.1016/j.jtherbio.2022.103219. Epub 2022 Feb 25.
This study investigated the effects of a low-protein diet supplemented with high lysine, methionine, and threonine levels on production performance, antioxidant capacity, intestinal morphology, duodenum gene expression and intestinal microorganisms in yellow feather broilers under cyclic heat stress. A total of 162 yellow feather broilers that were 42 d of age were selected and randomly divided into three groups: the control group (CONT, CP 16%), heat stress group (HS, CP 16%), and heat stress with low protein and high amino acid group (HS_LP, CP 14.5%). Following 14 d heating stress period, the HS_LP group showed no significant effect on production performance compared with the HS group. After a 28 d feeding trial, compared with the HS group, the HS_LP group significantly reduced feed: gain at 15-28 d (P < 0.05), had a tendency to reduce feed: gain at 1-28 d (P = 0.056). Compared with the HS group, the serum catalase enzyme activity tended to be higher (P = 0.067), and liver glutathione peroxidase enzyme activity was significantly decreased (P < 0.05) in the HS_LP group. Other antioxidant capacity indexes were not significantly different between the two groups (P > 0.05). Duodenum (P < 0.05) and ileum (P < 0.05) villus height were significantly increased, duodenum villus height: crypt depth ratio (P < 0.05) and jejunum crypt depth (P < 0.05) were significantly decreased, and jejunum villus height was significantly reduced (P < 0.05) in broilers fed the HS_LP diet. Compared with the HS group, the mRNA level of Claudin-1 was significantly increased (P < 0.05), and had a tendency to increase Occludin (P = 0.060) in the HS_LP group. In addition, the HS_LP group significantly increased Nitrosomonas abundance (P < 0.05) and had a tendency to reduce unidentified_Mollicutes abundance (P = 0.083) at the genus level compared with the HS group. This information is useful to formulate diets that correct the decrease in amino acid consumption associated with the reduced voluntary feed intake of broilers under heat stress.
本研究旨在探讨在周期性热应激条件下，饲粮低蛋白并添加高赖氨酸、蛋氨酸和苏氨酸水平对黄羽肉鸡生产性能、抗氧化能力、肠道形态、十二指肠基因表达和肠道微生物的影响。试验选择 42 日龄的 162 只黄羽肉鸡，随机分为 3 组：对照组（CONT，CP 16%）、热应激组（HS，CP 16%）和热应激低蛋白高氨基酸组（HS_LP，CP 14.5%）。经过 14 d 的加热应激期后，与 HS 组相比，HS_LP 组的生产性能无显著差异。经过 28 d 的饲养试验，与 HS 组相比，HS_LP 组 15-28 d 的料重比显著降低（P<0.05），1-28 d 的料重比有降低趋势（P=0.056）。与 HS 组相比，HS_LP 组血清过氧化氢酶活性有升高趋势（P=0.067），肝脏谷胱甘肽过氧化物酶活性显著降低（P<0.05）。两组其他抗氧化能力指标无显著差异（P>0.05）。HS_LP 组十二指肠（P<0.05）和回肠（P<0.05）绒毛高度显著增加，十二指肠绒毛高度：隐窝深度比值（P<0.05）和空肠隐窝深度（P<0.05）显著降低，空肠绒毛高度显著降低（P<0.05）。与 HS 组相比，HS_LP 组 Claudin-1 的 mRNA 水平显著升高（P<0.05），Occludin 有升高趋势（P=0.060）。此外，与 HS 组相比，HS_LP 组 Nitrosomonas 的丰度显著增加（P<0.05），未鉴定的_Mollicutes 的丰度有降低趋势（P=0.083）。这些信息有助于制定饲粮方案，纠正因热应激下肉鸡自愿采食量降低而导致的氨基酸消耗减少的问题。
