Investigation And Control Of Broiler Ascites Syndrome In Donghai County

Broiler ascites syndrome , also known as broiler pulmonary hypertension, is a devastating metabolic disease that affects young, fast-growing commercial broilers, and has been reported from many parts of the world. Worldwide, approximately 4% of all broilers die from ascites, amounting to a loss estimated at 1 billion dollars annually. Only in China, an average incidence of 4.5% was reported, which counts for a loss of about 468 million dollars annually. The primary triggers for AS under most conditions of commercial broilers growth include fast growth and cool temperature. Both triggers increase the metabolic requirement for oxygen and thereby force the heart to increase its cardiac output. Pulmonary hypertension is initiated whenever the relatively inelastic pulmonary vasculatrue of susceptible broilers cannot accommodate the rapidly increasing cardiac output at a low pulmonary arterial pressure, or when inappropriate constriction of the pulmonary vasculature directly evaluate the pulmonary vascular resistance to pulmonary blood flow. After the onset of pulmonary hypertension, susceptible broilers proceed through a cascade of events to terminal AS, including systemic hypoxmia, pulmonary vascular remodeling, right-sided congestive heart failure, increased intravascular pressure in the liver portal system and, ascites.The paper investigated the occurrence and death rate, and the triggers of AS in DongHai county from march 2006-september 2007. The investigation indicated that AS occurred interpersed in DongHai county, the occurrence rate and death rate were 1.7%-29.8%, and 1.35%-29.25%, respectively, the death rate of broilers with AS hit 77.7-97.8%. broilers of 28-49 days age was much more susceptible to AS than any other ages. although AS could occur all the year round, the incidence was mainly in cold seasons(spring and winter), especially during March o May, and December to February. male broilers were more vulnerable to females.Sixty broilers were equally divided to a control group (C group), a heart swelling group (H group), a AS group (A group). All broilers' hematological and blood biochemical parameters were measured, thus pave the ground for clinical diagnosis and prevention of AS. The results are shown as follows: hematological parameters PCV, RBC, and Hb in group A were significantly higher than group H (P<0.05), and more significantly higher than group C (P<0.01), While those parameters of group H were also significantly higher than group C (P<0.05); The values of MCV and MCH between group H and A had no evident difference (P>0.05), however, both pronounced lower compared with group C (P<0.05). the values of MCHC in all three groups had no obvious difference (P>0.05). blood biochemical values of ALB and Fn in group A apparently lower than group C (P<0.05), the values of Fn in group A significantly lower than group H (P<0.05). the values of TP in group A lower than in group H and C, but the difference was inappreciable (P>0.05).To better prevent and control of AS in DongHai County, on the basis of questionnaire survey of epidemiology of 1553 samples in 366villages, and preventive experiment promotion. Broilers' dietary supplemented with compound prescription can effectively prevent and control AS, and elevated the cure rate of AS.