Agris Mundus-Sustainable Development in Agriculture, Montpellier SupAgro, Ministere de l'Agriculture, Montpellier, France.
Foodborne Pathog Dis. 2012 Oct;9(10):945-51. doi: 10.1089/fpd.2012.1251. Epub 2012 Sep 6.
Reducing Salmonella in poultry has been a paramount goal of the poultry industry in order to improve food safety. Inclusion of high-fiber fermentable feedstuffs in chicken diets has been shown to reduce the incidence of Salmonella colonization in laying hens, but no work has been performed in growing birds. Therefore, the present study was designed to quantify differences in artificially inoculated cecal Salmonella Typhimurium populations in growing layer chicks (n = 60 in each of two replications) fed 0%, 25%, and 50% of their diet (w/w) replaced with alfalfa meal from day (d) 7 to d14 after hatch. Alfalfa supplementation reduced cecal populations of Salmonella by 0.95 and 1.25 log10 colony-forming unit per gram in the 25% and 50% alfalfa groups compared to controls. Alfalfa feeding reduced (p < 0.05) the number of cecal- and crop-positive birds compared to controls. Increasing levels of alfalfa increased (p < 0.05) total volatile fatty acids (VFA) and the proportion of acetate in the cecum. Surprisingly, alfalfa inclusion did not negatively impact average daily gain (ADG) in birds over the 7-d feeding period. Alfalfa inclusion at 50% of the diet increased (p < 0.05) the number of bacterial genera detected in the cecum compared to controls, and also altered proportions of the microbial population by reducing Ruminococcus and increasing Clostridia populations. Results support the idea that providing a fermentable substrate can increase gastrointestinal VFA production and bacterial diversity which in turn can reduce colonization by Salmonella via natural competitive barriers. However, further studies are obviously needed to more fully understand the impact of changes made in diet or management procedures on poultry production.
减少家禽中的沙门氏菌一直是家禽行业的首要目标，目的是提高食品安全。在鸡饲料中添加高纤维可发酵饲料已被证明可以降低产蛋母鸡中沙门氏菌定植的发生率，但在生长鸡中尚未进行研究。因此，本研究旨在定量比较在孵化后第 7 天至第 14 天，用苜蓿粉替代 0%、25%和 50%日粮（w/w）饲养的生长层雏鸡（每个重复 60 只）盲肠中人工接种的肠炎沙门氏菌 Typhimurium 种群的差异。与对照组相比，苜蓿添加物使 25%和 50%苜蓿组的盲肠沙门氏菌种群分别减少了 0.95 和 1.25 log10 菌落形成单位/克。与对照组相比，苜蓿喂养降低了盲肠和鸡舍阳性鸟类的数量（p < 0.05）。苜蓿水平的增加（p < 0.05）增加了盲肠中的总挥发性脂肪酸（VFA）和乙酸的比例。令人惊讶的是，苜蓿添加物在 7 天的喂养期间并未对鸟类的平均日增重（ADG）产生负面影响。与对照组相比，日粮中添加 50%的苜蓿增加了盲肠中检测到的细菌属的数量（p < 0.05），并通过降低瘤胃球菌和增加梭状芽孢杆菌种群来改变微生物种群的比例。结果支持这样的观点，即提供可发酵的底物可以增加胃肠道 VFA 的产生和细菌多样性，从而通过天然竞争障碍减少沙门氏菌的定植。然而，显然需要进一步的研究来更全面地了解饮食或管理程序的变化对家禽生产的影响。
