Stella S L, Velasco-Acosta D A, Skenandore C, Zhou Z, Steelman A, Luchini D, Cardoso F C
Department of Animal Sciences, University of Illinois, Urbana, IL, USA.
The Colombian Corporation for Agricultural Research (CORPOICA), Bogotá, Colombia.
Theriogenology. 2018 Jul 1;114:116-125. doi: 10.1016/j.theriogenology.2018.03.033. Epub 2018 Mar 26.
During the transition from prepartum to early lactation, dairy cows often experience negative energy balance (NEB) that may result in reproductive stress and decreased fertility. The objective of this study was to observe the effects of rumen-protected methionine (RPM) on plasma amino acid concentrations, uterine cytology, immunohistochemistry (IHC) of glutathione peroxidase 1 (GPX) and superoxide dismutase 1 (SOD), and to confirm neutrophil extracellular trap (NET) formation. Multiparous Holstein cows (n = 20) were randomly assigned to two treatments starting at 21 d before calving until 73 days in milk (DIM). Treatments were: CON (n = 9, no supplementation, TMR with a Lys:Met = 3.5:1) and MET (n = 11, TMR + Smartamine M with a Lys:Met = 2.8:1). Uterine endometrial biopsies, uterine cytology, and blood samples from the coccygeal artery or vein were collected at 15, 30, and 73 DIM. Blood plasma samples were analyzed for amino acids and metabolites. Uterine biopsies were analyzed for NET formation, neutrophil numbers, as well as GPX and SOD by IHC. Additionally, uterine cytology was analyzed for polymorphonuclear neutrophil (PMN) to epithelial cell percentage. Cows in CON had lower methionine plasma concentrations (18.05 ± 2.0 μM) than cows in MET (30.39 ± 1.6 μM). Cows in CON had greater cystine plasma concentrations (3.62 ± 0.3 μM) than cows in MET (2.8 ± 0.3 μM). No treatment differences were observed for SOD or GPX in the endometrium. Cows in CON tended to have a high score for positively immunolabeled GPX cells at 15 DIM than cows in MET. No treatment differences were observed for the percentage of PMN in uterine cytology, number of neutrophils, or extent of NET formation in the endometrium. A treatment by time interaction was observed for PMN percentage and the number of neutrophils: cows in MET tended to have greater PMN percentages than cows in CON at 15 DIM which decreased for subsequent days and cows in MET had greater neutrophil numbers in the endometrium at 30 DIM than cows in CON. In conclusion, dietary supplementation of RPM altered plasma amino acid concentrations and increased neutrophil infiltration in the postpartum period, suggesting improved uterine immunity.
在从产前到泌乳早期的过渡阶段，奶牛常经历负能量平衡（NEB），这可能导致生殖应激和繁殖力下降。本研究的目的是观察瘤胃保护性蛋氨酸（RPM）对血浆氨基酸浓度、子宫细胞学、谷胱甘肽过氧化物酶1（GPX）和超氧化物歧化酶1（SOD）的免疫组织化学（IHC）的影响，并确认中性粒细胞胞外陷阱（NET）的形成。经产荷斯坦奶牛（n = 20）在产犊前21天开始至产奶73天（DIM）被随机分配到两种处理。处理方式为：对照组（n = 9，不补充，赖氨酸：蛋氨酸= 3.5:1的全混合日粮）和蛋氨酸组（n = 11，全混合日粮+ Smartamine M，赖氨酸：蛋氨酸= 2.8:1）。在15、30和73 DIM采集子宫子宫内膜活检组织、子宫细胞学样本以及尾动脉或尾静脉血样。分析血浆样本中的氨基酸和代谢物。通过免疫组织化学分析子宫活检组织中的NET形成、中性粒细胞数量以及GPX和SOD。此外，分析子宫细胞学样本中多形核中性粒细胞（PMN）与上皮细胞的百分比。对照组奶牛的血浆蛋氨酸浓度（18.05±2.0 μM）低于蛋氨酸组奶牛（30.39±1.6 μM）。对照组奶牛的血浆胱氨酸浓度（3.62±0.3 μM）高于蛋氨酸组奶牛（2.8±0.3 μM）。子宫内膜中SOD或GPX未观察到处理差异。对照组奶牛在15 DIM时免疫标记阳性的GPX细胞得分倾向于高于蛋氨酸组奶牛。子宫细胞学中PMN百分比、中性粒细胞数量或子宫内膜中NET形成程度未观察到处理差异。观察到PMN百分比和中性粒细胞数量存在处理与时间的交互作用：蛋氨酸组奶牛在15 DIM时的PMN百分比倾向于高于对照组奶牛，随后几天下降，且蛋氨酸组奶牛在30 DIM时子宫内膜中的中性粒细胞数量高于对照组奶牛。总之，日粮补充RPM改变了血浆氨基酸浓度，并增加了产后中性粒细胞浸润，表明子宫免疫力得到改善。
