Physiologic and Electrocardiographic Changes Occurring in Broilers Reared at Simulated High Altitude

Abstract

An experiment was conducted to determine whether differences in the electrocardiograms (EKGs) of broilers reared at simulated high altitude from the day of hatch can be used to predict which birds are developing ascites. In three replicate experiments, conducted with 100 broilers per replicate, birds were reared at a simulated altitude of 3000 meters or at ambient atmospheric pressure. Lead I, II, and III EKGs were obtained from all birds on days 0, 14, 28, and 42. No consistent significant differences were seen on day 0 in the amplitude of the R or S wave or total amplitude of the QRS complex when broilers that developed ascites while being reared at simulated high altitude were compared with unaffected birds reared at simulated high altitude and with birds reared at ambient atmospheric pressure. On days 14 and 28, the average amplitude of the S wave and the total amplitude of the QRS complex were significantly higher in the ascites group than in the two other groups. Packed cell volumes were significantly higher in birds reared at simulated high altitude at all sampling days (days 14, 28, and 42) than in those reared at ambient atmospheric pressure, and they were significantly higher in the ascites group on day 28 than in the two other groups. Birds in the ascites group weighed significantly less than the two other groups by day 14, and this trend persisted.

Effect of citric acid on electrocardiographic parameters of broiler chickens with pulmonary hypertension

“…Our previous study on electrocardiographic parameters of cold-induced pulmonary hypertensive broilers demonstrated significant elevations of the T and S waves, in agreement with the reports of Owen et al (1995) and Martinez et al (1997). Those results could also be used as evidences that dilation and hypertrophy of the ventricles were the primary cause of the increased S wave amplitude (prolonged ventricular depolarisation) (Hassanpour et al, 2005).…”

Ascites Syndrome in Broiler Chickens - A Physiological Syndrome Affected by Red Blood Cell

“…Thus, enhanced erythropoiesis, and not plasma volume reduction, was found to be involved in the hemodynamics of the ascitic broilers [89]. This finding could also account for the blood congestion and the increased blood viscosity [90] that contribute to the enhanced cardiac workload [103,134], blood pressure [103], and blood-flow resistance [111] in AS chickens.…”

“…The hypobaric chamber has been shown to be an effective tool for simulating high altitude and consistently inducing AS [102][103][104][105][106]; it simulates high altitude conditions by generating a partial vacuum, thereby reducing the partial pressure of O2. Anthony and Balog [106], by simulating an altitude of 2,900 m above sea level, successfully induced 66% AS in a commercial sire line.…”

“…It was found that a hypobaric chamber with a reduced O2 partial pressure, equivalent to that at 2,900 m above sea level, successfully induced 66% AS in a commercial sire line, suggesting full exposure of genetic variation in AS susceptibility [103]. Surgical inactivation of one lung induced AS in all or most of the susceptible individuals [32,68,183,184].…”

Putative cardiotoxic compounds extracted from meat meal as a potential risk factor for the development of heart failure in fast-growing commercial broilers

“…Clinical observations and necropsy findings from several studies indicate that many commercial broilers show subclinical signs of heart condition, and are at higher risk of heart failure (Odom et al, 1992;Owen et al, 1995;Olkowski et al, 1997Olkowski et al, , 1998Olkowski et al, , 1999Olkowski et al, , 2001Olkowski et al, , 2003Olkowski, 2007). However, factors that may increase the risk of heart failure in broilers are poorly understood.…”