Gabler Nicholas K, Koltes Dawn, Schaumberger Simone, Murugesan G Raj, Reisinger Nicole
Department of Animal Science, Iowa State University, Ames, IA.
BIOMIN Holding GmbH, Getzersdorf, Austria.
Transl Anim Sci. 2018 Jan 25;2(1):1-10. doi: 10.1093/tas/txx003. eCollection 2018 Feb.
Heat stress negatively affects performance and intestinal integrity of pigs. The objective of this study was to characterize the effects of diurnal heat stress () on nursery-grower pig performance, intestinal integrity, and lipopolysaccharide () translocation. Forty-eight nursery-grower gilts, individually penned, were randomly assigned to two treatments. Twenty-four pigs were then exposed to dHS for 3 d, 6 h at 38°C and 18 h at 32°C, at 40-60% humidity. The remaining pigs were maintained under thermal neutral () conditions. Changes in pig rectal temperatures (), respiration rates (), performance, and blood parameters were evaluated. Additionally, ex vivo ileum integrity was assessed with the Ussing chamber by measuring transepithelial resistance (), and 4 kDa fluorescein isothiocyanate ()-dextran () and FITC-LPS mucosal to serosal flux. As expected, dHS increased pig Tr and RR ( < 0.05) and reduced pig performance ( < 0.05) on the 3-d period. Compared with TN, ileum TER ( = 0.04), FITC-LPS ( < 0.001), and FD4 ( = 0.011) permeability were significantly increased due to dHS. Compared with TN pigs, dHS increased serum endotoxin by 150% ( = 0.031). Altogether, 3-d dHS significantly reduced pig performance and intestinal integrity and increased blood endotoxin concentrations.
热应激对猪的生产性能和肠道完整性产生负面影响。本研究的目的是描述昼夜热应激（dHS）对保育-生长育肥猪生产性能、肠道完整性和脂多糖（LPS）转运的影响。48头单独饲养的保育-生长育肥小母猪被随机分配到两种处理中。然后，24头猪在38°C下暴露于dHS 3天，每天6小时，在32°C下暴露18小时，湿度为40-60%。其余的猪在热中性（TN）条件下饲养。评估猪直肠温度（Tr）、呼吸频率（RR）、生产性能和血液参数的变化。此外，通过测量跨上皮电阻（TER）以及4 kDa异硫氰酸荧光素（FITC）-葡聚糖（FD4）和FITC-LPS从黏膜到浆膜的通量，用尤斯灌流小室评估离体回肠的完整性。正如预期的那样，dHS在3天期间提高了猪的Tr和RR（P<0.05）并降低了猪的生产性能（P<0.05）。与TN相比，由于dHS，回肠TER（P = 0.04）、FITC-LPS（P<0.001）和FD4（P = 0.011）的通透性显著增加。与TN猪相比，dHS使血清内毒素增加了150%（P = 0.031）。总之，3天的dHS显著降低了猪的生产性能和肠道完整性，并增加了血液内毒素浓度。
