M'Sadeq Shawkat A, Wu Shu-Biao, Choct Mingan, Forder Rebecca, Swick Robert A
School of Environmental and Rural Science, University of New England, Armidale, NSW, Australia.
School of Animal and Veterinary Science, The University of Adelaide, Roseworthy, SA, Australia.
Poult Sci. 2015 May;94(5):898-905. doi: 10.3382/ps/pev035. Epub 2015 Mar 11.
The use of a yeast cell wall extract derived from Saccharomyces cerevisiae (Actigen(®)) has been proposed as an alternative to in-feed antibiotics. This experiment was conducted to investigate the efficacy of yeast cell extract as an alternative to zinc bacitracin or salinomycin using a necrotic enteritis challenge model. A feeding study was conducted using 480-day-old male Ross 308 chicks assigned to 48 floor pens. A 2 × 4 factorial arrangement of treatments was employed. The factors were: challenge (- or +) and feed additive (control, zinc bacitracin at 100/50 mg/kg, yeast cell wall extract at 400/800/200 mg/kg, or salinomycin at 60 mg/kg in starter, grower, and finisher, respectively). Diets based on wheat, sorghum, soybean meal, meat and bone meal, and canola meal were formulated according to the Ross 308 nutrient specifications. Birds were challenged using a previously established protocol (attenuated Eimeria spp oocysts) on d 9 and 10(8) to 10(9) Clostridium perfringens (type A strain EHE-NE18) on d 14 and 15). Challenged and unchallenged birds were partitioned to avoid cross contamination. Challenged birds had lower weight gain, feed intake and livability compared to unchallenged birds on d 24 and d 35 (P < 0.05). Birds given zinc bacitracin, yeast cell wall extract, or salinomycin had improved weight gain and livability when compared to control birds given no additives. Challenge × additive interactions were observed for feed intake and weight gain on d 24 and d 35 (P < 0.01). The additives all had a greater positive impact on feed intake, weight gain, and livability in challenged than unchallenged birds. All challenged birds showed higher necrotic enteritis lesion scores in the small intestine sections when compared to unchallenged birds (P < 0.01). Birds fed yeast cell wall extract exhibited increased villus height, decreased crypt depth, and increased villus:crypt ratio when challenged. Yeast cell wall extract, zinc bacitracin, and salinomycin were effective in preventing performance decline from necrotic enteritis in the current study. This study indicates that yeast cell wall extract has promise as a tool for controlling necrotic enteritis.
源自酿酒酵母的酵母细胞壁提取物（Actigen(®)）已被提议作为饲料中抗生素的替代品。本试验旨在使用坏死性肠炎攻毒模型研究酵母细胞提取物替代杆菌肽锌或盐霉素的效果。采用480日龄雄性罗斯308肉鸡进行饲养试验，将其分配至48个地面围栏中。试验采用2×4析因设计。因素包括：攻毒（-或+）和饲料添加剂（对照组、100/50 mg/kg杆菌肽锌、400/800/200 mg/kg酵母细胞壁提取物或分别在雏鸡、中鸡和大鸡阶段添加60 mg/kg盐霉素）。根据罗斯308营养标准配制以小麦、高粱、豆粕、肉骨粉和油菜籽粕为基础的日粮。在第9天和第10天使用先前建立的方案（减毒艾美耳球虫卵囊）对鸡进行攻毒，并在第14天和第15天使用10(8)至(9)A型产气荚膜梭菌（EHE-NE18菌株）进行攻毒。对攻毒和未攻毒的鸡进行分区以避免交叉污染。在第24天和第35天，与未攻毒的鸡相比，攻毒的鸡体重增加、采食量和成活率较低（P<0.05）。与未添加添加剂的对照鸡相比，给予杆菌肽锌、酵母细胞壁提取物或盐霉素的鸡体重增加和成活率提高。在第24天和第35天观察到攻毒×添加剂对采食量和体重增加的交互作用（P<0.01）。与未攻毒的鸡相比，添加剂对攻毒鸡的采食量、体重增加和成活率的积极影响更大。与未攻毒的鸡相比，所有攻毒鸡小肠段的坏死性肠炎病变评分更高（P<0.01）。攻毒时，饲喂酵母细胞壁提取物的鸡绒毛高度增加、隐窝深度降低且绒毛：隐窝比值增加。在本研究中，酵母细胞壁提取物、杆菌肽锌和盐霉素可有效防止坏死性肠炎导致的生产性能下降。本研究表明，酵母细胞壁提取物有望成为控制坏死性肠炎的工具。
