粘杆菌素对断奶仔猪血液电解质稳态的影响

本试验选用21日龄断奶的三元杂交仔猪40头，按单因子设计分为2组，处理1饲喂添加0．02％粘杆菌素日粮，处理2饲喂基础日粮，试验期28d。观察并记录每天的腹泻情况，计算各周的腹泻指数；并分别于试验的第7、14和28d考察仔猪前腔静脉血中电解质水平的变化以及各肠段大肠埃希氏菌和乳酸杆菌的数量。结果表明粘杆菌素能显著抑制各肠段大肠埃希氏菌的繁殖，防治仔猪腹泻（P〈0．05），显著提高血清磷、镁和亚铁离子含量（P〈0．05）。结果提示粘杆菌素可增强仔猪抗应激能力，降低腹泻导致的水和电解质损失，维持血液内环境的平衡。

Effects of Colistin on Electrolytes Homeostasis of Blood in Early Weanling Piglets

This experiment was conducted to investigate the effects of colistin on electrolytes homeostasis of blood and its underlying mechanism in early weanling piglets, Forty piglets, weaned at 21 d postnatal were assigned to 2 groups, repre-senting supplementation with 0 or 0.2 g/kg colisti to maize-and soybean meal-based diets(n = 20 for each group). Diar-rhea index were determined from d 0 to 7,8 to 14,15 to 21 and 22 to 28 respectively. The blood samples were collected from precaval vein on d 7,14 and 28 to determine the concentration of serum electrolytes. The piglets were slaughtered to sample the digestas from jejunum, ileum and cecum in asepsis status followed the blood sampling. Results showed that colistin significantly reduced(P <0.05)the diarrhea index from d 0 to 7,8 to 14 and 15 to 21 ,respectively. The E. coli contents in jejunum ,ileum and cecum on d 7 ,in jejunum and ileum on d 14 and in ileum and cecum on d 28 of colistin group were significantly higher(P < 0.05) compared with those of control group, respectively. The concentrations of ser-um phosphorus,magnesium and ferrous ions on d 7, of phosphorus, magnesium, ferrous and sodium ions on d 14 and phosphorus and ferrous ions on d 28 of colistin group were significantly higher (P < 0.05) than those of the control group. Collectively, colistin could prevent the diarrhea in early-weaned piglets through restraining E. coli propagating and keep blood internal environment homeostasis.