Department of Animal Sciences and Industry, Weber Hall, Kansas State University, Manhattan 66506-0201, USA.
J Anim Sci. 2010 May;88(5):1642-8. doi: 10.2527/jas.2009-2259. Epub 2010 Jan 15.
Enteric disease and immune challenge are processes that have detrimental effects on the growth performance of young swine. The current study tested the hypothesis that salmonella-induced enteric disease would perturb the endocrine growth axis in a serovar-dependent fashion. Specifically, we evaluated the effects of Salmonella enterica serovar Typhimurium (Typhimurium) and serovar Choleraesuis (Choleraesuis) on critical regulatory components of growth in young swine. Weaned pigs were housed 2 per pen with ad libitum access to feed and water in a 14-d experiment. Pigs were then repeatedly fed 10(8) cfu of either Choleraesuis or Typhimurium in dough balls, with control pigs receiving dough without bacteria. Bacteria were refed twice weekly. Rectal temperatures were monitored daily from d 0 to 7 and ADFI was measured through d 14. Pigs were weighed and samples of serum were obtained for circulating IGF-I on d 0, 7, and 14. At the conclusion of the study, samples of semitendinosus muscle and liver were obtained and subsequently assayed for IGF-I, IGFBP-3, and IGFBP-5 mRNA. Rectal temperatures were elevated in pigs given Choleraesuis from d 2 through 7 (P < 0.05) when compared with control pigs and pigs fed Typhimurium. Pigs receiving Choleraesuis had a substantially decreased feed intake on d 2, 3, 4, 7, 8, 9, and 10 (P < 0.01), with a trend for a reduction on d 5 (P = 0.08), and they experienced an approximately 25% reduction in BW compared with control pigs and pigs given Typhimurium by the conclusion of the study. Pigs given Choleraesuis also experienced marked reductions in circulating IGF-I on d 7 (P < 0.01 vs. control and Typhimurium), with reductions of lesser magnitude on d 14 (P = 0.07 vs. control and P < 0.05 vs. Typhimurium). Inoculation tended to affect liver IGFBP-3 mRNA (P = 0.08), for which expression tended to be elevated in pigs given Typhimurium and Choleraesuis. In contrast, IGFBP-3 mRNA relative abundance was increased (P < 0.03) in pigs given Typhimurium compared with control pigs. Muscle IGF-I mRNA was reduced in pigs given Choleraesuis compared with control pigs and pigs given Typhimurium (P < 0.05). Treatment tended to affect muscle IGFBP-3 mRNA (P = 0.10). Oral inoculation of growing pigs with Choleraesuis disrupted feed intake and BW gain, and this was accompanied by decreases in circulating IGF-I and reduced muscle expression of mRNA for IGF-I and IGFBP-3.
肠病和免疫挑战是对仔猪生长性能有不利影响的过程。本研究检验了这样一个假设，即沙门氏菌引起的肠病会以血清型依赖的方式扰乱内分泌生长轴。具体来说，我们评估了肠炎沙门氏菌血清型（肠炎沙门氏菌）和霍乱弧菌血清型（霍乱弧菌）对仔猪生长的关键调节成分的影响。在为期 14 天的实验中，断奶仔猪每栏 2 头，自由采食饲料和水。然后，用面团球给猪喂食 10（8）cfu 的霍乱弧菌或肠炎沙门氏菌，对照组猪喂食不含细菌的面团。每周两次重新喂食细菌。从第 0 天到第 7 天，每天监测直肠温度，从第 14 天开始测量 ADFI。猪在第 0、7 和 14 天称重，并采集血清样本以检测循环 IGF-I。在研究结束时，采集半腱肌和肝脏样本，随后测定 IGF-I、IGFBP-3 和 IGFBP-5mRNA。从第 2 天到第 7 天，给予霍乱弧菌的猪直肠温度升高（P <0.05），与对照组猪和给予肠炎沙门氏菌的猪相比。给予霍乱弧菌的猪在第 2、3、4、7、8、9 和 10 天（P <0.01）的采食量显著降低，第 5 天（P = 0.08）呈减少趋势，与对照组猪和给予肠炎沙门氏菌的猪相比，体重在研究结束时减少了约 25%。给予霍乱弧菌的猪循环 IGF-I 也显著降低（P <0.01 与对照组和肠炎沙门氏菌相比），第 14 天（P = 0.07 与对照组相比，P <0.05 与肠炎沙门氏菌相比）降低幅度较小。接种倾向于影响肝脏 IGFBP-3mRNA（P = 0.08），其表达在给予肠炎沙门氏菌和霍乱弧菌的猪中趋于升高。相比之下，与对照组猪相比，给予肠炎沙门氏菌的猪的 IGFBP-3mRNA 相对丰度增加（P <0.03）。与对照组猪和给予肠炎沙门氏菌的猪相比，给予霍乱弧菌的猪的肌肉 IGF-ImRNA 减少（P <0.05）。治疗有影响肌肉 IGFBP-3mRNA 的趋势（P = 0.10）。给生长猪口服接种霍乱弧菌会破坏采食量和体重增加，这伴随着循环 IGF-I 的减少和肌肉 IGF-I 和 IGFBP-3mRNA 表达的减少。
