Effect of early-weaned stress on serum cortisol, intestinal morpho- logy and permeability in piglets | 早期断奶应激对仔猪血清皮质醇含量和肠形态及肠屏障通透性的影响

Chinese. 探讨早期断奶对仔猪应激、肠形态和肠通透性的影响。选取32头杜长大三元杂交仔猪，于21日龄断奶，并于21，22，25，28和35日龄取样观察肠形态，检测血清皮质醇含量、血浆D-乳酸含量和二胺氧化酶（Diamine oxidase，DAO）活性及尿乳果糖与甘露醇比率。仔猪于21日龄断奶后，其血清皮质醇含量于22日龄迅速上升，并达极显著水平（P＜0.01），断奶后1周内均维持在较高水平（P＜0.05），至35日龄仍处于显著水平（P＜0.05）；21日龄断奶后，仔猪的肠形态发生明显变化，肠绒毛高度下降、隐窝加深，断奶后1周内的损伤最为明显，于28日龄时开始修复，至35日龄时基本恢复；21日龄断奶仔猪的血浆D-乳酸含量、二胺氧化酶（DAO）活性及尿中乳果糖与甘露醇比率在22日龄迅速升高，至35日龄时仍维持在较高水平，且与断奶前相比差异显著（P＜0.05）。断奶应激状态下，仔猪的血清皮质醇含量升高，肠屏障严重受损，通透性增加明显先于形态变化，但通透性的恢复却滞后于形态学重建。因此，肠屏障功能能够更好地反映断奶仔猪的肠道状态。

English. The experiment studied the effect of early-weaned stress on serum cortisol, intestinal morphology and permeability in piglets. A total of 32 piglets were weaned at 21 d. Intestinal morphology, serum cortisol, DAO activity, plasma D-lactate level, and urine lactulose mannitol ratio were measured at 21, 22, 25, 28, 35 d of age. The results showed that the serum cortisol levels increased immediately at 22 d (P＜0.01), and remained high level in the 1 week postweaning (P＜0.05), even at 35 d (P＜0.05); Intestinal morphogenesis obviously changed during the early stage of weaning. Villous height declined, and crypt depth increased, especially in the 1 week postweaning; the intestinal tissue repaired at 28 d and recovered at 35 d. Plasma D-lactate level, DAO activity and urine lactulose mannitol ratio increased immediately at 22 d and significantly remained high level to day 35 compared with that before weaning (P＜0.05). It is concluded that intestinal mucosal barrier is subject to serious damage for early-weaned stress, and permeability increase is obviously prior to morphological changes, but the permeability lags behind the restoration of the morphological. So, intestinal barrier function better reflects the state of intestine.