USDA-ARS Livestock Issues Research Unit, Lubbock, TX 79403, USA.
J Anim Sci. 2011 Jan;89(1):52-8. doi: 10.2527/jas.2010-2944. Epub 2010 Sep 17.
The effects of active dry yeast, Saccharomyces cerevisiae boulardii (Scb), on the immune/cortisol response and subsequent mortality to Escherichia coli lipopolysaccharide (LPS) administration were evaluated in newly weaned piglets (26.1 ± 3.4 d of age). Barrows were assigned to 1 of 2 treatment groups: with (Scb; n = 15) and without (control; n = 15) the in-feed inclusion of Scb (200 g/t) for 16 d. On d 16, all piglets were dosed via indwelling jugular catheters with LPS (25 μg/kg of BW) at 0 h. Serial blood samples were collected at 30-min intervals from -1 to 6 h and then at 24 h. Differential blood cell populations were enumerated hourly from 0 to 6 h and at 24 h. Serum cortisol, IL-1β, IL-6, tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ) concentrations were determined via porcine-specific ELISA at all time points. In Scb-treated piglets, cumulative ADG increased (P < 0.05) by 39.9% and LPS-induced piglet mortality was reduced 20% compared with control piglets. White blood cells, lymphocytes, and neutrophils were increased (P < 0.05) in Scb-treated animals before LPS dosing compared with control piglets before being equally suppressed (P < 0.05) from baseline in both treatments after LPS dosing with a return to baseline by 24 h. Suppression of circulating cortisol concentrations (P < 0.05) was observed in Scb-treated piglets from -1 h to 1 h relative to LPS dosing compared with control animals before both peaked equally and subsequently returned to baseline. Peak production (P < 0.05) of IL-1β and IL-6 was less in Scb-treated piglets after LPS administration compared with controls before both equally returned to baseline. Peak TNF-α production in Scb-treated animals was accelerated 0.5 h and was greater (P < 0.05) than peak production in control piglets, after which both equally returned to baseline. The peak production of IFN-γ was greater and had increased (P < 0.05) amplitude persistence for 3 h in Scb-treated animals compared with control piglets before both equally returned to baseline. These results highlight the previously unidentified effects of Scb administration on immune and cortisol responses and the subsequent impact on growth and endotoxin-induced mortality in weaned piglets.
评估了活性干酵母（酿酒酵母 boulardii，Scb）对新断奶仔猪（26.1±3.4 日龄）免疫/皮质醇反应及随后对大肠杆菌脂多糖（LPS）给药的死亡率的影响。公猪被分配到 2 个处理组中的 1 个：饲料中添加 Scb（200 g/t）（Scb；n=15）和不添加 Scb（对照；n=15），共 16 天。在第 16 天，所有仔猪均通过颈内留置导管以 25μg/kg BW 的剂量在 0 小时接受 LPS 给药。从-1 小时到 6 小时，每隔 30 分钟采集一次连续的血液样本，然后在 24 小时采集一次。从 0 小时到 6 小时，每小时计数一次不同的血球群体，并在 24 小时时再次计数。通过猪特异性 ELISA 在所有时间点测定血清皮质醇、IL-1β、IL-6、肿瘤坏死因子-α（TNF-α）和干扰素-γ（IFN-γ）浓度。与对照组仔猪相比，在 Scb 处理的仔猪中，累积 ADG 增加了 39.9%（P<0.05），LPS 诱导的仔猪死亡率降低了 20%。与对照组仔猪相比，在 LPS 给药前，Scb 处理的动物中的白细胞、淋巴细胞和中性粒细胞增加（P<0.05），然后在两种处理中均从基线同等抑制（P<0.05），在 24 小时时恢复到基线。与对照组动物相比，在 LPS 给药前 1 小时到 1 小时之间，Scb 处理的仔猪中循环皮质醇浓度的抑制（P<0.05）。与对照组仔猪相比，在 LPS 给药后，IL-1β和 IL-6 的峰值产生（P<0.05）较少，然后均同等恢复到基线。在 Scb 处理的动物中，TNF-α的峰值产生提前 0.5 小时，且高于对照组仔猪的峰值产生（P<0.05），然后两者均同等恢复到基线。IFN-γ的峰值产生更高，并且在 Scb 处理的动物中持续时间更长（P<0.05），持续 3 小时，然后两者均同等恢复到基线。这些结果突出了 Scb 给药对免疫和皮质醇反应的先前未被识别的影响，以及对断奶仔猪生长和内毒素诱导死亡率的后续影响。
