Liu Hui, Xu Kangqi, Wang Huimin, Lin Hai, Yang Xiaoyan, Wang Xiaojuan, Zhao Jingpeng, Ma Baishun, Shu Quanxian, Lu Yanbo, Jiao Hongchao
Department of Animal Science, Shandong Agricultural University, Key Laboratory of Efficient Utilization of Non-grain Feed Resources (Co-construction by Ministry and Province), Shandong Provincial Key Laboratory of Animal Nutrition and Efficient Feeding, Taian 271018, Shandong Province, China; Animal Husbandry and Veterinary Service Center of Xintai City, Xintai 271200, Shandong Province, China.
Department of Animal Science, Shandong Agricultural University, Key Laboratory of Efficient Utilization of Non-grain Feed Resources (Co-construction by Ministry and Province), Shandong Provincial Key Laboratory of Animal Nutrition and Efficient Feeding, Taian 271018, Shandong Province, China.
Poult Sci. 2024 Dec;103(12):104375. doi: 10.1016/j.psj.2024.104375. Epub 2024 Oct 3.
The aim of this study was to investigate the effects of low-protein diets and the sustained release of synthetic amino acids (AA) on the performance, intestinal barrier function and nitrogen excretion of laying hens. Two hundred eighty-eight 39-week-old Hyline brown laying hens of were randomly divided into 3 groups with 8 replicates per group. The crude protein level in the control group (CON) was 16%, the crude protein levels in the crystal AA supplement group (LCP-CAA) and microencapsulated AA group (LCP-MAA) were both 13%, and the AA levels in the LCP-CAA and LCP-MAA groups were consistent with that in the CON group. The experiment lasted 12 wk, and production performance was assessed weekly. The FCR and ADFI values were significantly greater for the LCP-CAA group than for the CON and LCP-MAA groups (P < 0.05). Two hours after feeding, His levels were significantly greater in the LCP-CAA group than in the LCP-MAA group (P < 0.05); 4 h after feeding, the contents of Met, Thr, Leu and Val were significantly greater in blood from the LCP-MAA group (P < 0.05); 6 h after feeding, Trp, Ile and Arg levels were significantly greater in the LCP-MAA group (P < 0.05). The chylase content significantly decreased in the duodenum of the LCP-CAA group (P < 0.05), and the chylase and trypsin were contents increased in the ileum of the LCP-MAA group (P < 0.05). In the LCP-MAA group, significantly increased mRNA expression levels of Occludin, ZO-1 in duodenum; Occludin, ZO-1, yLAT1 in jejunum; and ZO-1 in ileum were detected at 8 and 12 weeks (P < 0.05). The fecal nitrogen content significantly decreased in the low protein diet group (P < 0.01). In conclusion, reducing dietary crude protein levels and supplementing with microencapsulated AAs can improve intestinal barrier function, promote digestive enzyme secretion, increase the expression of AA transporters, improve dietary protein utilization efficiency, and reduce nitrogen emission in laying hens.
本研究旨在探讨低蛋白日粮及合成氨基酸（AA）缓释对蛋鸡生产性能、肠道屏障功能及氮排泄的影响。288只39周龄海兰褐蛋鸡随机分为3组，每组8个重复。对照组（CON）粗蛋白水平为16%，晶体氨基酸补充组（LCP-CAA）和微囊化氨基酸组（LCP-MAA）粗蛋白水平均为13%，LCP-CAA组和LCP-MAA组的氨基酸水平与CON组一致。试验持续12周，每周评估生产性能。LCP-CAA组的料重比（FCR）和平均日采食量（ADFI）值显著高于CON组和LCP-MAA组（P<0.05）。采食后2小时，LCP-CAA组的组氨酸水平显著高于LCP-MAA组（P<0.05）；采食后4小时，LCP-MAA组血液中甲硫氨酸、苏氨酸、亮氨酸和缬氨酸含量显著更高（P<0.05）；采食后6小时，LCP-MAA组的色氨酸、异亮氨酸和精氨酸水平显著更高（P<0.05）。LCP-CAA组十二指肠中淀粉酶含量显著降低（P<0.05），LCP-MAA组回肠中淀粉酶和胰蛋白酶含量升高（P<0.05）。在LCP-MAA组中，8周和12周时十二指肠中闭合蛋白（Occludin）、紧密连接蛋白1（ZO-1）；空肠中Occludin、ZO-1、y+氨基酸转运体1（yLAT1）；回肠中ZO-1的mRNA表达水平显著升高（P<0.05）。低蛋白日粮组粪便氮含量显著降低（P<0.01）。综上所述，降低日粮粗蛋白水平并补充微囊化氨基酸可改善蛋鸡肠道屏障功能，促进消化酶分泌，增加氨基酸转运体表达，提高日粮蛋白质利用效率，并减少氮排放。
