INCIDENCE OF ASCITES SYNDROME AND RELATED PATHOLOGIES IN FEED RESTRICTED BROILERS RAISED AT SIMULATED HIGH ALTITUDE

Authors: Balog, Janice; ANTHONY, NICHOLAS - UNIVERSITY OF ARKANSAS; COOPER, MARK - UNIVERSITY OF ARKANSAS; KIDD, BRENDA - UNIVERSITY OF ARKANSAS; Huff, Geraldine; Huff, William; Rath, Narayan

Submitted to: Western Poultry Disease Conference
Publication Type: Proceedings
Publication Acceptance Date: 12/12/1998
Publication Date: N/A
Citation: N/A

Interpretive Summary: Ascites syndrome is a metabolic disease of poultry that results in enlargement of the heart and fluid build-up in the body cavity. The disease is very similar to congestive heart failure in humans. In chickens, this disease is thought to be caused by the bird's heart and lung capacity not being able to keep up with the bird's rapid growth rate. It has been shown that the incidence of ascites syndrome can be significantly reduced through feed restriction. This experiment was conducted to determine if feed restriction could be used to reduce the incidence of ascites in broilers raised in a hypobaric (high Altitude) chamber, without adversely affecting weight gain. Commercial male broiler chicks were divided to place 360 birds in the hypobaric chamber, at a simulated 9,500 ft above sea level, and 240 birds were placed at local elevation (1,300 ft above sea level). At each altitude, there were 4 treatments: 1.) Full fed controls; 2.) Feed available for 8 hours each day for 6 weeks, the duration of the study; 3.) Feed available for 8 hours a day during the first 3 weeks, then full feed for the remaining 3 weeks; and 4.) Full feed for the first week, then 3 weeks of 8 hour feed availability, then 2 weeks of full feed. At the end of the study, blood samples were taken and birds were examined, scored for ascites and organ weights were recorded. Birds grown in the hypobaric chamber with full feed had a significantly higher incidence of ascites syndrome and had blood profiles typical of ascites syndrome. Birds raised in the hypobaric chamber and subjected to restricted feeding (Groups 3 & 4) had weight gains comparable to full fed controls and had profiles typical of ascites, yet did not have a high incidence of ascites mortality.

Technical Abstract: It has been demonstrated that the incidence of ascites syndrome can be significantly reduced through feed restriction. Unfortunately, the restriction programs practiced also have a detrimental effect on growth characteristics. This experiment was conducted to determine if feed restriction could be used to reduce the incidence of ascites in broilers raised in a hypobaric chamber, without adversely affecting weight gain. A total of 600 commercial broiler males were utilized for this study. Birds were divided to place 360 birds in the hypobaric chamber, at a simulated 9,500 ft above sea level, and 240 birds were placed at local elevation (1,300 ft above sea level). At each altitude, there were 4 treatments: 1.) Full fed controls; 2.) Feed available for 8 hours each day for 6 weeks, the duration of the study; 3.) Feed available for 8 hours a day during the first 3 weeks, then full feed for the remaining 3 weeks; and 4.) Full feed for the first week, then 3 weeks of 8 hour feed availability, then 2 weeks of full feed. Birds and feed were weighed weekly and mortalities were necropsied to determine the cause of death. At the end of the study, blood samples were taken and birds were necropsied, scored for ascites and organ weights were recorded. Birds grown in the hypobaric chamber with full feed had a significantly higher incidence of ascites syndrome and had hematological profiles typical of ascites syndrome. Birds raised in the hypobaric chamber and subjected to restricted feeding (Groups 3 & 4) had weight gains comparable to full fed controls and had profiles typical of ascites syndrome, yet did not have a high incidence of ascites mortality. Clinical chemistries reflected the feeding status of the birds.