Department of Animal Sciences, University of Illinois, Urbana 61801.
Ajinomoto Co. Inc., Tokyo, Japan 104-8315.
J Dairy Sci. 2022 Sep;105(9):7805-7819. doi: 10.3168/jds.2022-21934. Epub 2022 Aug 6.
Feeding rumen-protected methionine as an indispensable amino acid source has been shown to improve reproductive performance in dairy cows, but the effect of feeding rumen-protected lysine (RPL) during the peripartum period on reproductive performance is not well explored. Therefore, we aimed to determine the effects of feeding RPL (AjiPro-L Generation 3, Ajinomoto Heartland Inc.) prepartum, postpartum, or both on follicular dynamics, uterine health, and mRNA gene expression of the endometrium. Seventy-five multiparous Holstein cows were assigned to 1 of 2 dietary treatments with or without RPL in a randomized, complete block design. A 2 × 2 factorial arrangement of treatments was used. Prepartum (-28 d to calving), animals were fed a diet (68% of dietary DM from forage) with RPL [PRE-L; 0.54% RPL of dietary dry matter intake] or without RPL (PRE-C). After calving, half of the cows from each prepartum treatment group were assigned to a diet (56% forage) with RPL (PRE-L POST-L; PRE-C POST-L; 0.40% RPL of dietary dry matter intake) or without RPL (PRE-C POST-C; PRE-L POST-C) until 28 d in milk (DIM). Vaginal discharge was detected with a Metricheck device (Simcro) to detect metritis, and at 28 DIM polymorphonuclear leukocytes were evaluated as a percentage of the epithelial cells using a cytology brush (Andwin Scientific) and an endometrial tissue biopsy was collected for mRNA expression and histology. The first postpartum follicular growth cycle was monitored at 7, 10, 11, 13, 15, 17, 19, 21, 23, 25, 27, and 28 DIM via transrectal ultrasonography. Time to first ovulation did not differ between treatments and averaged 18 ± 1.6 DIM. Follicular diameter at first ovulation was not affected by the treatments, but the growth rate of dominant follicle before first ovulation tended to be lower for cows in POST-L in comparison with cows in POST-C. Prevalence of fetid vaginal discharge and metritis did not differ between treatments. Cows in PRE-L POST-L had lower polymorphonuclear leukocytes percentage at 15 and 28 DIM than cows in PRE-L POST-C, PRE-C POST-L, and PRE-C POST-C. Feeding RPL prepartum downregulates the expression of TLR4, SLC7A6, EHMT2, and tends to downregulate the expression of PTGES3 in uterine tissues at 28 DIM. Additionally, it upregulates the expression of APOL3 and NFKB1, and tends to upregulate the expression of AHCY and MAT2A. In conclusion, feeding RPL pre- and postpartum improved indicators of uterine immune status, but did not change days to first ovulation postpartum.
给反刍动物保护性蛋氨酸作为必需氨基酸来源已被证明可以提高奶牛的繁殖性能，但在围产期给反刍动物保护性赖氨酸（RPL）的效果尚未得到很好的探索。因此，我们旨在确定产前、产后或两者同时给反刍动物保护性赖氨酸（AjiPro-L Generation 3，Ajinomoto Heartland Inc.）对卵泡动态、子宫健康和子宫内膜 mRNA 基因表达的影响。75 头经产荷斯坦奶牛按随机完全区组设计分为 2 种日粮处理组，分别为添加或不添加 RPL。采用 2×2 因子处理安排。产前（-28 天至分娩），动物饲喂含有 RPL[PRE-L；日粮干物质摄入量的 0.54%RPL]或不含 RPL（PRE-C）的日粮（68%来自饲料的日粮 DM）。分娩后，每组前一半的奶牛被分配到含有 RPL（PRE-L POST-L；PRE-C POST-L；日粮干物质摄入量的 0.40%RPL）或不含 RPL（PRE-C POST-C；PRE-L POST-C）的日粮中，直到产奶后 28 天（DIM）。使用 Metricheck 设备（Simcro）检测阴道分泌物以检测子宫内膜炎，并在 28 DIM 时使用细胞学刷（Andwin Scientific）评估多形核白细胞作为上皮细胞的百分比，并采集子宫内膜组织活检进行 mRNA 表达和组织学检查。通过直肠超声检查在产后第 7、10、11、13、15、17、19、21、23、25、27 和 28 DIM 监测产后首次卵泡生长周期。首次排卵时间在处理之间没有差异，平均为 18±1.6DIM。首次排卵时的卵泡直径不受处理的影响，但与 POST-C 组相比，POST-L 组的主导卵泡在首次排卵前的生长速度较低。阴道恶臭分泌物和子宫内膜炎的发生率在处理之间没有差异。与 PRE-L POST-C、PRE-C POST-L 和 PRE-C POST-C 相比，PRE-L POST-L 的奶牛在 15 和 28 DIM 时的多形核白细胞百分比较低。产前和产后给反刍动物保护性赖氨酸可下调 28DIM 时子宫组织中 TLR4、SLC7A6、EHMT2 的表达，并下调 PTGES3 的表达。此外，它还上调了 APOL3 和 NFKB1 的表达，并上调了 AHCY 和 MAT2A 的表达。总之，产前和产后给反刍动物保护性赖氨酸可改善子宫免疫状态的指标，但不改变产后首次排卵时间。
