The term dysbacteriosis is used to describe a phenomenon where the healthy equilibrium of the gut flora is disrupted. Poultry farmers often notice a decrease in litter quality. Aside from being a risk factor for development of food pad dermatitis, poor gut health due to dysbacteriosis often leads to antibiotic use in broiler. Dysbacteriosis affects animal welfare and feed conversion efficiency, making prevention all the more important.
Normally the small intestine contain barely any bacteria, whereas the large intestine and caeca contain billions. Non-pathogenic intestinal bacteria, known as commensal bacteria, play an important role in gut health by preventing adhesion to the gut wall by pathogenic bacteria. This equilibrium of healthy gut microbes can be disrupted by various causes, resulting in overgrowth of pathogenic bacteria (for example pathogenic Escherichia coli and Clostridium spp. strains). One of nature’s protective measures to get rid of the unwanted gut inhabitants, is to increase the rate of excretion: commonly known as diarrhea. In severe cases, the protective mucosal barrier of the gut wall is penetrated by the pathogenic bacteria creating an infection (enteritis). When caused by Clostridium perfrigens type A, this infection of the gut is generally known as necrotic enteritis.
Dysbacteriosis is characterized by wet litter, often with the presence of shed mucosa (“slime”) and/or gas in the caecal fraction. In all cases of dysbacteriosis, water consumption increases. Coccidiosis is a common risk factor for dysbacteriosis: pathogenic Clostridium spp. strains will often overgrow the commensal intestinal flora due to damage to the gut wall. Enteritis requires the immune system to function at maximum capacity to prevent bacteria from entering the blood stream. The significant amount of energy needed for this battle, comes from rerouting energy from growth to the immune system. Growth and feed conversion are affected negatively by this rerouting as well as the loss of appetite that often occurs in sick animals.
To determine the optimal approach for prevention of dysbacteriosis, the specific risk factors have to be determined on site. Post mortem examination, blood work, feed analysis and other diagnostic tools can be used to map the most likely cause of dysbacteriosis at a farm specific level. Although some cases of dysbacteriosis (and enteritis) can be treated using antibiotics, success is not guaranteed. As mentioned earlier, coccidiosis can be an underlying cause for dysbacteriosis, but several gut-associated viruses are known to cause problems as well.
For more information on dysbacteriosis and other questions about intestinal health in poultry, don’t hesitate to contact us.