Purdue University, West Lafayette, IN 47907, USA.
J Anim Sci. 2011 Jun;89(6):1908-21. doi: 10.2527/jas.2009-2539.
The objectives of this study were to determine the influence of a Saccharomyces cerevisiae fermentation product on innate immunity and intestinal microbial ecology after weaning and transport stress. In a randomized complete block design, before weaning and in a split-plot analysis of a 2 × 2 factorial arrangement of yeast culture (YY) and transport (TT) after weaning, 3-d-old pigs (n = 108) were randomly assigned within litter (block) to either a control (NY, milk only) or yeast culture diet (YY; delivered in milk to provide 0.1 g of yeast culture product/kg of BW) from d 4 to 21. At weaning (d 21), randomly, one-half of the NY and YY pigs were assigned to a 6-h transport (NY-TT and YY-TT) before being moved to nursery housing, and the other one-half were moved directly to nursery housing (NY-NT and YY-NT, where NT is no transport). The yeast treatment was a 0.2% S. cerevisiae fermentation product and the control treatment was a 0.2% grain blank in feed for 2 wk. On d 1 before transport and on d 1, 4, 7, and 14 after transport, blood was collected for leukocyte assays, and mesenteric lymph node, jejunal, and ileal tissue, and jejunal, ileal, and cecal contents were collected for Toll-like receptor expression (TLR); enumeration of Escherichia coli, total coliforms, and lactobacilli; detection of Salmonella; and microbial analysis. After weaning, a yeast × transport interaction for ADG was seen (P = 0.05). Transport affected (P = 0.09) ADFI after weaning. Yeast treatment decreased hematocrit (P = 0.04). A yeast × transport interaction was found for counts of white blood cells (P = 0.01) and neutrophils (P = 0.02) and for the neutrophil-to-lymphocyte ratio (P = 0.02). Monocyte counts revealed a transport (P = 0.01) effect. Interactions of yeast × transport (P = 0.001) and yeast × transport × day (P = 0.09) for TLR2 and yeast × transport (P = 0.08) for TLR4 expression in the mesenteric lymph node were detected. Day affected lactobacilli, total coliform, and E. coli counts. More pigs were positive for Salmonella on d 7 and 14 than on d 4, and more YY-TT pigs were positive (P = 0.07) on d 4. The number of bands for microbial amplicons in the ileum was greater for pigs in the control treatment than in the yeast treatment on d 0, and this number tended to decrease (P = 0.066) between d 1 and 14 for all pigs. Similarity coefficients for jejunal contents were greater (P = 0.03) for pigs fed NY than for those fed YY, but pigs fed YY had greater similarity coefficients for ileal (P = 0.001) and cecal (P = 0.058) contents. The number of yeast × transport × day interactions demonstrates the complexity of the stress and dietary relationship.
本研究的目的是确定酿酒酵母发酵产物对断奶和运输应激后先天免疫和肠道微生物生态的影响。在随机完全区组设计中，在断奶前和断奶后 2×2 酵母培养（YY）和运输（TT）析因安排的裂区分析中，3 日龄仔猪（n=108）在窝内（区组）随机分配至对照组（NY，仅喂牛奶）或酵母培养物日粮（YY；以牛奶形式提供 0.1 g 酵母培养物产品/kgBW），从第 4 天到第 21 天。在断奶（第 21 天）时，随机将一半的 NY 和 YY 仔猪分配到 6 小时的运输（NY-TT 和 YY-TT）中，然后转移到保育舍，另一半直接转移到保育舍（NY-NT 和 YY-NT，其中 NT 是没有运输）。酵母处理是 0.2%酿酒酵母发酵产物，对照处理是饲料中 0.2%谷物空白 2 周。在运输前第 1 天（d1）和运输后第 1、4、7 和 14 天，采集血液进行白细胞测定，收集肠系膜淋巴结、空肠和回肠组织以及空肠、回肠和盲肠内容物进行 Toll 样受体表达（TLR）；计数大肠杆菌、总大肠菌群和乳杆菌；检测沙门氏菌；以及微生物分析。断奶后，ADG 出现了酵母×运输的互作（P=0.05）。运输影响了断奶后的 ADFI（P=0.09）。酵母处理降低了红细胞压积（P=0.04）。发现白细胞（P=0.01）和中性粒细胞（P=0.02）计数以及中性粒细胞与淋巴细胞比值（P=0.02）存在酵母×运输的互作。单核细胞计数显示出运输（P=0.01）的影响。在肠系膜淋巴结中，检测到 TLR2 的酵母×运输（P=0.001）和酵母×运输×天（P=0.09）以及 TLR4 表达的酵母×运输（P=0.08）的互作。天影响了乳杆菌、总大肠菌群和大肠杆菌的计数。与断奶第 4 天相比，断奶第 7 和 14 天更多的猪呈沙门氏菌阳性，且更多的 YY-TT 猪呈阳性（P=0.07）。与断奶第 0 天相比，在控制处理组的猪肠道组织中微生物扩增子的条带数量更多，而在酵母处理组中，这一数量在第 1 天至第 14 天之间趋于减少（P=0.066）。与 NY 组相比，YY 组仔猪空肠内容物的相似系数更大（P=0.03），但 YY 组仔猪回肠（P=0.001）和盲肠（P=0.058）内容物的相似系数更大。酵母×运输×天的互作数量表明了应激和饮食关系的复杂性。
