PhD Research, Newcastle University

PhD Research, Newcastle University

To find ways of preventing or curing chicken coccidiosis without using in-feed drugs which render products unhealthy for human consumption

Unfortunately, this project was not successful

Coccidiosis, caused by Eimeria species, is the most important disease plaguing the poultry industry in the world today. Symptoms of include anorexia and malabsorption of nutrients leading to reduced weight gain. Current coccidiosis control measures involve the use of in-feed anti-coccidia drugs and vaccines which are not sustainable. Development of drug resistance, lack of cross-species protection for Eimeria vaccines, and the fact that using multiple species vaccine can cause lesions that may predispose birds to other infections.

Even of greater concern are public health issues relating to the fact that in-feed drugs do leave deposits in broiler tissue that may become toxic to humans consuming broiler meat. Therefore, my research focuses on having a deeper understanding of coccidia infections in broilers to help the development of control measures that do not rely on or minimizes, at the least possible, the use of in-feed anti-coccidia drugs.

Experiments I have conducted so far investigated how selection for improved performance traits in modern broilers affect their resistance and tolerance to coccidia infection, the effects of coccidiosis on broiler bone development and whether manipulating dietary vitamin D, Calcium and Phosphorus can help to improve skeletal integrity for coccidia-infected broilers.

Results suggest that resistance and tolerance to coccidia infection is not impaired by selection for improved performance traits in broilers, neither is skeletal development penalised to a higher degree for fast than slow growing broilers. Although slow growing broilers compared to fast generally show higher bone quality but the impact of coccidia infection in relation to body weight was similar for both genotypes. Results also revealed that the source and level of vitamin D is important for broiler performance and bone mineralization during coccidia infection.

The next experimental trial i want to conduct for which I require funding will examine whether or not reducing early growth rate for modern fast growing broilers can improve bone mineralization and limit penalties on skeletal development in the face of coccidia infection will be investigated. Knowledge of these should help the development of better control measures for this important disease.