NCG layer

Supplementation of exogenous additives is a strategy to improve laying performance of layers by regulating uterine function. N-Carbamylglutamate (NCG) as an activator for endogenous arginine synthesis has the potential to regulate the laying performance of layers, but its effects have not been fully understood. This study investigated the effects of dietary supplementation of NCG on production performance, egg quality, and uterine gene expression in layers. A total of 360 45-week-old layers with a genetic line of Jinghong No. 1 were used in this study. The experimental period was 14 weeks. All birds were divided into 4 treatments with 6 replicates per treatment and 15 birds per replicate. Dietary treatments were based on a basal diet and supplemented with 0, 0.08, 0.12, or 0.16% NCG to form C, N1, N2, and N3 groups. We found that layers in group N1 had higher egg production rate than those in group C. Egg weight was significantly reduced, while eggshell thickness was significantly improved, by treatment. However, the albumen height and Haugh unit were the lowest in group N3. Based on the above results, groups C and N1 were selected for further transcriptomics analysis of uterine tissue by RNA-seq. More than 7.4 Gb clean reads and 19,882 tentative genes were obtained using the Gallus gallus genome as a reference. T ranscriptomics analysis in uterus tissue revealed that 95 differentially expressed genes (DEGs) were upregulated and 127 DEGs were downregulated. Functional annotation and pathway enrichment analysis showed that DEGs in uterine tissue were mainly enriched in glutathione metabolism, cholesterol metabolism, and glycerolipid metabolism, etc. Vitamin A metabolism-related gene, RBP1, nutrient transport-related gene, ALB, protein synthesis-related gene, METTL21C, and calcium transport-related gene, RYR2, CACNB2, RAMP3, and STAC, were significantly regulated by 0.08% NCG supplementation. Therefore, we concluded that NCG supplementation at a dose of 0.08% improved production performance and egg quality of layers by regulating Q6 uterus function.

外源添加剂饲喂是通过调控子宫功能，改善蛋鸡产蛋性能的有效策略。N-氨甲酰谷氨酸（N-Carbamylglutamate, NCG）作为内源性精氨酸合成激活剂，具备调控蛋鸡产蛋性能的潜力，但其具体作用效果尚未完全明确。本研究探究了日粮中添加NCG对蛋鸡生产性能、蛋品质以及子宫组织基因表达的影响。本试验共选用360只45周龄的京红1号（Jinghong No.1）蛋鸡，试验周期为14周。将所有试验鸡随机分为4组，每组设6个重复，每个重复15只鸡。各组日粮以基础日粮为基础，分别添加0、0.08%、0.12%及0.16%的NCG，对应设为C组、N1组、N2组与N3组。结果显示，N1组蛋鸡的产蛋率显著高于C组；试验组蛋鸡的蛋重显著降低，但蛋壳厚度得到明显改善。然而N3组的蛋白高度与哈氏单位（Haugh unit）为所有组别中最低。基于上述试验结果，本研究选取C组与N1组的子宫组织进行RNA测序（RNA-seq）转录组学分析。以鸡（Gallus gallus）基因组为参考序列，共获得超过7.4 Gb的clean reads以及19882个候选基因。子宫组织转录组学分析显示，共鉴定得到95个上调差异表达基因（differentially expressed genes, DEGs）与127个下调DEGs。功能注释与通路富集分析结果表明，子宫组织中的DEGs主要富集于谷胱甘肽代谢、胆固醇代谢以及甘油脂代谢等通路。0.08%的NCG添加可显著调控维生素A代谢相关基因RBP1、营养转运相关基因ALB、蛋白质合成相关基因METTL21C以及钙转运相关基因RYR2、CACNB2、RAMP3与STAC的表达水平。因此，本研究得出结论：日粮中添加0.08%的NCG可通过调控Q6子宫功能，改善蛋鸡的生产性能与蛋品质。