Abstract
Studies were conducted to investigate the effects of dietary supplementation with marine algae (MA) as a source of omega-3 fatty acids on thrombocyte aggregation and the incidence of pulmonary hypertension syndrome (PHS) in the broiler chicken. Broilers were either reared under hypobaric conditions (simulated altitude 2900 m) to induce PHS or under normobaric conditions (altitude 96.7 m). Broilers were fed a 0.8% MA diet in the first experiment and a 5.8% MA diet in the second experiment for a period of five reeks. Compared to normobaric broilers, hypobaric broilers had lower body weights, increased hematocrit levels, and greater right ventricular weight to total ventricular weight (RV/TV) ratios. Body weights, lung weights, and hematocrit levels were not different between either dose of MA and control-fed birds in either environment. RV/TV ratios were not different between 0.8% MA-fed and control-fed broilers in the first experiment. There were no differences in the rate of PHS mortality under hypobaric conditions between control-fed and 0.8% MA-fed birds. In the second experiment, 5.8% MA-fed broilers reared under hypobaric conditions had a greater RV/TV ratio than control-fed birds in the same environment, and an increased rate of PHS mortality. Compared to normobaric broilers, hypobaric broilers produced less nitric oxide in the right pulmonary artery, significant after four weeks of hypobaric exposure. Thrombocyte counts were reduced in hypobaric broilers at four and five weeks of age. There were no consistent differences in whole blood or thrombocyte-rich plasma aggregation between any diet or environment group. These data suggest that dietary supplementation of 5.8% MA appears to enhance right ventricular hypertrophy and increase PHS-mortality in hypobaric-reared broilers. Additionally, changes in the rate of thrombocyte aggregation do not seem to be correlated with these results nor with the development of PHS in the broiler chicken.
Carpenter, Amy Renee (1999). Dietary supplementation of marine algae and the modification of thrombocyte aggregation parameters in avian pulmonary hypertension syndrome. Master's thesis, Texas A&M University. Available electronically from
https : / /hdl .handle .net /1969 .1 /ETD -TAMU -1999 -THESIS -C362.