Xylanase supplementation affects the caecal microflora of broilers

The gut harbours a highly evolved and complex microbial ecosystem containing a vast number of diverse populations. For example, microbes make up approximately 600 glkg of the wet weight of poultry excreta. The proper feeding of poultry should therefore consider the provision of "correct" substrates for the microflora to keep it stable. Search for natural alternatives to antibiotics is a major research topic in the feed industry due to the ban of feed antibiotics in some countries. An experiment was conducted to examine the effect of xylanase supplementation of a wheat-based diet on 'Clostridium perjringens', the bacterium responsible for necrotic enteritis, and on the total anaerobes in broilers. Broilers were raised on a commercial starter to d 17 and then were switched to two experimental diets (ME type diet used by Mollah et ai., 1983), one of which contained a xylanase (2.5g1kg; supplied by Novo Nordisk). One bird from each treatment was killed every other day to d 39. The total caecal anaerobes and 'C. perfringens' were counted (Figures 1 and 2, respectively).