Tang M, Laarveld B, Van Kessel A G, Hamilton D L, Estrada A, Patience J F
Animal Biotechnology Center, Department of Animal & Poultry Science, University of Saskatchewan, Saskatoon, SK, Canada.
J Anim Sci. 1999 Dec;77(12):3191-200. doi: 10.2527/1999.77123191x.
The effect of segregated early weaning (SEW) on postweaning small intestinal development was investigated in SEW and control (CON) pigs. Small intestines were collected from a total of 15 pigs killed at 11 (preweaning), 15 (3 d postweaning), and 34 d of age. At 3 d postweaning, the SEW and CON pigs had shorter villi (P<.01), deeper crypts (P<.01), and reduced (P<.01) ratios of villus height:crypt depth (V:C) compared with preweaning. Weaning also reduced specific activities of lactase (P<.01) in duodenum and ileum and alkaline phosphatase (ALP) (P<.05) in duodenum and jejunum. Sucrase activity in the three regions of the small intestine marginally decreased in both groups at 3 d postweaning. The mucosal protein:DNA ratio in duodenum and jejunum increased (P<.05) in SEW and CON pigs at 3 d postweaning compared with preweaning pigs. The SEW and CON treatments resulted in differences in postweaning gut development. At 15 d of age in SEW pigs, the mucosal protein:DNA ratio in duodenum and jejunum were 20 and 25.5% (P<.05) less, respectively, than those in CON pigs. However, at 34 d, these ratios in duodenum, jejunum, and ileum were 43.5 (P<.05), 24.3, and 32.9% (P<.05) greater, respectively, in SEW pigs than in CON pigs. Longer villi, shorter crypts (P<.01), and higher V:C ratios (P<.01) in jejunum and ileum were observed in SEW pigs vs CON pigs at 34 d of age. The specific activities of lactase in duodenum (P<.01) and jejunum (P<.05) and of ALP in duodenum (P<.01) were higher in SEW pigs. Sucrase activity in duodenum, jejunum, and ileum was 21.7, 46.3 (P<.05), and 11.2% greater in SEW pigs at 34 d of age. These results demonstrate differences in postweaning gut development between SEW and CON pigs. Furthermore, the number of intraepithelial lymphocytes in jejunum was greater (P<.001) in 34-d-old SEW pigs compared with CON pigs. Microscopy revealed a thick mucus coating over epithelial cells in the ileum of 34-d-old CON pigs that was not apparent in the SEW pigs. These observations are consistent with reduced pathogen exposure associated with SEW. We suggest that segregated early weaning advances postweaning gut maturation, which is consistent with improved growth and feed efficiency observed in SEW pigs.
研究了隔离早期断奶（SEW）对SEW仔猪和对照（CON）仔猪断奶后小肠发育的影响。从总共15头在11日龄（断奶前）、15日龄（断奶后3天）和34日龄处死的仔猪中采集小肠。断奶后3天，与断奶前相比，SEW仔猪和CON仔猪的绒毛较短（P<0.01）、隐窝更深（P<0.01），绒毛高度与隐窝深度之比（V:C）降低（P<0.01）。断奶还降低了十二指肠和回肠中乳糖酶的比活性（P<0.01）以及十二指肠和空肠中碱性磷酸酶（ALP）的比活性（P<0.05）。断奶后3天，两组仔猪小肠三个区域的蔗糖酶活性均略有下降。与断奶前仔猪相比，SEW仔猪和CON仔猪在断奶后3天十二指肠和空肠中的黏膜蛋白与DNA比值增加（P<0.05）。SEW和CON处理导致断奶后肠道发育存在差异。在15日龄的SEW仔猪中，十二指肠和空肠中的黏膜蛋白与DNA比值分别比CON仔猪低20%和25.5%（P<0.05）。然而，在34日龄时，SEW仔猪十二指肠、空肠和回肠中的这些比值分别比CON仔猪高43.5%（P<0.05）、24.3%和32.9%（P<0.05）。在34日龄时，与CON仔猪相比，SEW仔猪空肠和回肠的绒毛更长、隐窝更短（P<0.01），V:C比值更高（P<0.01）。SEW仔猪十二指肠（P<0.01）和空肠（P<0.05）中乳糖酶以及十二指肠中ALP的比活性更高。34日龄时，SEW仔猪十二指肠、空肠和回肠中的蔗糖酶活性分别高21.7%、46.3%（P<0.05）和11.2%。这些结果表明SEW仔猪和CON仔猪断奶后肠道发育存在差异。此外，34日龄的SEW仔猪空肠中上皮内淋巴细胞的数量比CON仔猪更多（P<0.001）。显微镜检查显示，34日龄CON仔猪回肠上皮细胞上有一层厚厚的黏液涂层，而在SEW仔猪中不明显。这些观察结果与SEW仔猪病原体暴露减少一致。我们认为，隔离早期断奶促进了断奶后肠道成熟，这与SEW仔猪生长和饲料效率提高的现象一致。
