Microbial ecology and nutrient fermentation in the upper gastrointestinal tract of poultry

动物的胃肠道被丰富多样的正常非致病细菌群落定居，这些细菌对宿主既有有益的影响，也有有害的影响。对宿主有益的例子包括排除病原体和合成必要的维生素。对寄主的不利影响包括微生物发酵或竞争某些选定的营养物质，增加对某些营养物质的需求，降低消化和吸收能力。在家禽中，最大的细菌种群出现在农作物中，即上消化道的食道外袋和靠近盲囊末端的成对盲囊，称为盲囊。该项目将专注于利用基于基因组DNA核苷酸序列的分子技术来确定家禽作物中的细菌数量和种类。我们将确定饲喂策略和饮食结构的差异如何影响作物中细菌的组成、数量和发酵活性。大多数商业动物饲料都添加了一些相对昂贵的成分，如氨基酸，以满足它们的营养需求。由于作物中的细菌有机会通过发酵利用营养物质，然后宿主才能吸收它们自己使用，我们将确定这种情况发生的程度以及改变饲养策略的影响。

The gastrointestinal tract of animals is colonized by an abundant and diverse community of normal non-pathogenic bacteria which have both beneficial and detrimental effects on their host. Examples of benefits to the host include exclusion of pathogens and synthesis of essential vitamins. Detrimental effects on the host include microbial fermentation or competition for certain selected nutrients, increasing the requirement for certain nutrients and reducing digestive and absorptive capacity. In poultry, the largest bacterial populations are found in the crop, an out pouching of the oesophagus in the upper tract and in paired blind sacs near the end of the tract termed ceca. This project will focus on determining the number and species of bacteria in the crop of poultry using molecular techniques based on nucleotide sequence of genomic DNA. We will determine how differences in feeding strategies and diet composition affect the composition, number and fermentation activity of bacteria in the crop. Most commercial animal diets are supplemented with a number of relatively expensive ingredients such as amino acids in order to meet their nutrient requirements. Since bacteria of the crop have opportunity to utilize the nutrients by fermentation before the host can absorb them for their own use, we will determine the extent to which this occurs and impact of changing feeding strategies.