Gérard-Champod M, Blanquet-Diot S, Mazuranok L, Alric M
Equipe de Recherche Technologique, Conception, Ingénierie et Développement de l'Aliment et du Médicament, Université Clermont-Ferrand I, Centre de Recherche en Nutrition Humaine Auvergne, Institut Fédératif de Recherche Santé 79, Clermont-Ferrand, France.
J Anim Sci. 2009 May;87(5):1664-75. doi: 10.2527/jas.2008-1564. Epub 2008 Dec 19.
A study was conducted to characterize the bacterial and biochemical composition of the jejunoileal content of veal calves and the effect of pre-slaughter fasting time. At 22 wk of age, 22 preruminant Prim'Holstein calves fed milk replacer and pellets (mainly composed of corn) were slaughtered at 6, 12, or 24 h after their last meal. Chyme samples were collected from the jejunoileal compartment just after slaughter, and pH and redox potential were immediately measured. Culture-based methods were used to determine the concentrations of total anaerobic microflora, lactate-utilizing bacteria, Bacteroides fragilis group, Lactobacilli, Bifidobacteria, Enterococci, and 2 potential pathogenic species, Escherichia coli and Clostridium perfringens. Concentrations of l-lactate, ammonia, and short-chain fatty acids (SCFA) were determined on frozen samples. The biochemical composition (DM, total protein, lactose, galactose, glucose, minerals, AA profile, and fatty acid profile) of the jejunoileal content was determined only on samples from the 6-h fasted group. Microflora concentrations were greater (P < 0.01) in the 6-h fasted group compared with the 12- and 24-h fasted groups, involving a decreased pH (P < 0.05) and greater lactate and SCFA concentrations, both linked directly to the fermentative state of the microorganisms. The 6-h fasted group showed the least interanimal variability in bacterial group levels, except for Cl. perfringens, which presented increased interanimal variability regardless of fasting time. At 6 h postprandial, the jejunoileal content of veal calves seemed to be in a stable state, allowing the creation of a database on its biochemical composition. This study is a key first step in the development of an in vitro system for modeling the jejunoileal ecosystem of veal calves. This model will provide a useful tool for assessing the effects of feed additives on intestinal microflora.
开展了一项研究，以描述小牛肉牛空肠回肠内容物的细菌和生化组成以及宰前禁食时间的影响。22头22周龄的反刍前普里姆荷斯坦犊牛，以代乳粉和颗粒饲料（主要由玉米组成）喂养，在最后一餐6、12或24小时后屠宰。屠宰后立即从空肠回肠腔采集食糜样本，并立即测量pH值和氧化还原电位。采用基于培养的方法测定总厌氧微生物群、利用乳酸的细菌、脆弱拟杆菌群、乳酸杆菌、双歧杆菌、肠球菌以及两种潜在致病菌大肠杆菌和产气荚膜梭菌的浓度。对冷冻样本测定L-乳酸、氨和短链脂肪酸（SCFA）的浓度。仅对禁食6小时组的样本测定空肠回肠内容物的生化组成（干物质、总蛋白、乳糖、半乳糖、葡萄糖、矿物质、氨基酸谱和脂肪酸谱）。与禁食12小时和24小时的组相比，禁食6小时组的微生物群浓度更高（P<0.01），pH值降低（P<0.05），乳酸和SCFA浓度更高，这两者都与微生物的发酵状态直接相关。除产气荚膜梭菌外，禁食6小时组在细菌菌群水平上的动物间变异性最小，产气荚膜梭菌的动物间变异性无论禁食时间如何都有所增加。餐后6小时，小牛肉牛的空肠回肠内容物似乎处于稳定状态，这有助于建立其生化组成的数据库。本研究是开发用于模拟小牛肉牛空肠回肠生态系统的体外系统的关键第一步。该模型将为评估饲料添加剂对肠道微生物群的影响提供有用的工具。
