Genetic Perspective of Ascites Syndrome in Meat-Type Chickens

Pulmonary hypertension syndrome (ascites) is a metabolic disorder in fast-growing broilers. Inconsistency of oxygen requirement and the cardiovascular ability make the birds susceptible to ascites. Incidence of ascites was accompanied by right ventricular hypertrophy, fluid accumulation in the abdominal cavity and finally mortality. The objective of the current study was to review the genetic basis of ascites syndrome and investigation of indicator traits of ascites syndrome to use in selection indices for reducing ascites susceptibility in broilers. Developing a breeding objective to increase body weight and to reduce ascites susceptibility in broilers is of ongoing interest, because the ascites syndrome is still a major challenge for poultry breeders. The blood gas parameters, which measured early in life, make it possible to design alternative selection schemes to reach birds resistance to ascites. In this way, ascites susceptibility can be effectively reduced but it might be comes at a cost, including a reduction in selection response for growth rate, due to genetic correlations. Based on the best combination of traits considered, reduction in gain for growth rate might be decreased, although with limited efficiency. Also, marker-assisted selection can be used effectively to reduce ascites susceptibility with respect to benefit-costs analysis.