Abstract: To reduce feed costs，improve the breeding efficiency of sows，and promote sustainable development in the pig industry，this study investigated the effects of varying valine to lysine（Val/Lys） ratios in low⁃protein diets on the immune function of sows and the microbiota in their milk. Sixty sows with similar body conditions and mating times（fourth parity Landrace × Large White）were selected as the experimental subjects. The minimum nutritional requirements for lactating sows per NRC standards were used as the standard for low⁃protein diets. The sows were randomly divided into six groups：a normal protein group（17% CP，Val/Lys = 0.87）and five low⁃protein diet groups （14.3% CP，Val/Lys ratios of 0.64，0.74，0.84，0.94，and 1.04）. Each sow was accompanied by 12 piglets，and the experiment lasted from the first day of lactation to the 21st day of weaning，a total of 21 days. The results showed that low⁃protein diets without additional valine decreased（P<0.05）the abundance of the B⁃cell marker CD11b in the mammary glands of sows，while increasing the Val/Lys ratio in low⁃protein diets increased（P<0.05）the abundance of CD11b in the mammary glands. Low⁃protein diets without additional valine decreased（P<0.05）the concentration of SIgA in colostrum，while increasing the Val/Lys ratio in low⁃protein diets increased（P<0.05）the concentration of SIgA in colostrum. Low ⁃ protein diets without additional valine significantly decreased （P<0.05） the relative abundance of Bacteroidetes， Fusobacteria， and Acidobacteria at the phylum level and Fusobacterium and Staphylococcus at the genus level in the milk microbiota of lactating sows，while increasing the Val/Lys ratio in low⁃ protein diets increased the relative abundance of these microbiotas. In conclusion，low⁃protein diets without additional valine impair the cytokine and microbial diversity of sows，and increasing the Val/Lys ratio in low⁃protein diets can mitigate these negative effects and help maintain the production performance of sows.

Key words: Low Protein Diets, Valine, Sow, Milk microbiota

摘要： 为降低饲料成本，提升母猪养殖效益，促进养猪业的可持续发展，该文旨在探究低 蛋白日粮中缬氨酸与赖氨酸比例（Val/Lys）对母猪乳汁细胞因子及其微生物的影响。试验选取 60头体况及配种时间相近的二元杂母猪（四胎长白×大白）作为试验对象，基于NRC 标准计算 泌乳期母猪最低营养需要量为低蛋白日粮标准，将母猪随机分为6组：正常蛋白组（17% CP， Val/Lys=0.87）和5个低蛋白日粮组（14.3% CP，Val/Lys分别为0.64、0.74、0.84、0.94和1.04）。每 头母猪带仔12头，试验从哺乳期第1天开始至第21天断奶时结束，持续21 d。结果表明：低蛋 白日粮不额外添加缬氨酸降低了（P<0.05）母猪乳腺B细胞标志物CD11b的丰度，增加低蛋白 日粮中的Val/Lys提高（P<0.05）乳腺CD11b的丰度。低蛋白日粮不额外添加缬氨酸显著降低 （P<0.05）泌乳母猪乳汁微生物Chao1指数，增加低蛋白日粮中的Val/Lys提高（P<0.05）Chao1指 数。低蛋白日粮不额外添加缬氨酸显著降低（P<0.05）乳汁微生物门水平上Bacteroidetes、Fuso? bacteria和Acidobacteria以及属水平上Fusobacterium 和Staphylococcus 的相对丰度，增加低蛋白 日粮中的Val/Lys提高这些微生物的相对丰度。综上所述，低蛋白日粮不额外添加缬氨酸会损 害母猪的乳汁细胞因子和微生物的多样性，增加低蛋白日粮中的Val/Lys可缓解这个影响，保 障母猪的泌乳性能。

关键词: 低蛋白日粮, 缬氨酸, 母猪, 乳汁微生物