Nutrition and Animal-Microbiota Ecosystems Laboratory, Department of Biosystems, KU Leuven, 3000-Heverlee, Belgium; Precision Livestock and Nutrition Unit, Gembloux Agro-Bio Tech, University of Liège, Gembloux, Belgium.
Nutrition and Animal-Microbiota Ecosystems Laboratory, Department of Biosystems, KU Leuven, 3000-Heverlee, Belgium.
Poult Sci. 2024 Oct;103(10):104158. doi: 10.1016/j.psj.2024.104158. Epub 2024 Aug 2.
Variation in body weight (BW) within broiler flocks is a significant challenge in poultry production. Investigating differences in gut-related parameters between low (LBW) and high BW (HBW) chicks may provide insights into the underlying causes of BW heterogeneity. 908 day-old male broiler chicks were reared until d 7 and then ranked into LBW and HBW groups. Thereafter, performance parameters were compared between BW groups periodically. On d 7, 14, and 38, visceral organ characteristics, intestinal permeability, and duodenal and ileal histomorphology were examined. Expression profiles were analyzed for 79 ileal genes related to gut barrier function, immune function, nutrient transport, gut hormones, nutrient receptors, metabolism, and oxidation using high-throughput qPCR. Student's t-tests were performed to compare measurements. Multivariate statistics, including partial least square regression (PLSR) analysis, were applied to identify combinations of key genes discriminating BW groups, offering predictive capability for phenotypic variations. The HBW group remained heavier at each timepoint, which could be explained by higher feed intake. The HBW group had shorter relative small intestine length but higher villus height and villi height/crypt depth ratios. The LBW group demonstrated increased intestinal permeability on d 38. The LBW group showed upregulation of immune response genes including TNF-α on d 7 and CYP450 on d 38, while the HBW group showed higher AHSA1 and HSPA4 expressions on d 7. The LBW group had upregulation of the metabolism genes mTOR and EIF4EBP1 on d 7 and the satiety-induced hormone cholecystokinin on d 14, while the HBW group tended to increase expression of the hunger hormone ghrelin on d 38. Genes related to gut barrier function, nutrient transport, and oxidation categories were consistently upregulated in the HBW group. PLSR models revealed 4, 12, and 11 sets of key genes highly predictive of BW phenotypes on d 7, 14, and 38, respectively. These findings suggest that growth rates are linked to the intestinal size, structure, and function of broiler chickens, offering insights into the underlying mechanisms regulating BW.
肉鸡群体内体重（BW）的变化是家禽生产中的一个重大挑战。研究低体重（LBW）和高体重（HBW）雏鸡之间与肠道相关的参数差异，可能有助于深入了解 BW 异质性的潜在原因。908 只 1 日龄雄性肉鸡雏鸡饲养至 7 日龄，然后按 BW 分为 LBW 和 HBW 组。此后，定期比较 BW 组之间的性能参数。在 7、14 和 38 日龄时，检查内脏器官特征、肠道通透性以及十二指肠和回肠组织形态学。使用高通量 qPCR 分析 79 个与肠道屏障功能、免疫功能、营养转运、肠道激素、营养受体、代谢和氧化相关的回肠基因的表达谱。使用学生 t 检验比较测量值。应用多元统计分析，包括偏最小二乘回归（PLSR）分析，以确定区分 BW 组的关键基因组合，为表型变异提供预测能力。HBW 组在每个时间点都保持更重，这可以用更高的采食量来解释。HBW 组的相对小肠长度较短，但绒毛高度和绒毛高度/隐窝深度比值较高。LBW 组在 38 日龄时表现出更高的肠道通透性。LBW 组在 7 日龄时表现出 TNF-α和 CYP450 等免疫反应基因的上调，而 HBW 组在 7 日龄时表现出 AHSA1 和 HSPA4 的表达较高。LBW 组在 7 日龄时表现出 mTOR 和 EIF4EBP1 等代谢基因的上调，以及 14 日龄时饱腹诱导激素胆囊收缩素的上调，而 HBW 组在 38 日龄时表现出饥饿激素 ghrelin 表达增加的趋势。与肠道屏障功能、营养转运和氧化类别的基因在 HBW 组中持续上调。PLSR 模型分别在 7、14 和 38 日龄时揭示了 4、12 和 11 组高度预测 BW 表型的关键基因。这些发现表明，生长速度与肉鸡的肠道大小、结构和功能有关，为调节 BW 的潜在机制提供了深入了解。
