EFFECT OF DIETARY FLAX OIL AND HYPOBARIC HYPOXIA ON RIGHT-VENTRICULARHYPERTROPHY AND ASCITES IN BROILER-CHICKENS

1. The effect of dietary flax oil on growth rate, blood haemoglobin co ntent, mortality and incidence of pulmonary hypertension and ascites i n broilers at ambient pressure and at reduced atmospheric pressure was examined. 2. Birds were housed either in hypobaric chambers simulatin g 1000, 1500 or 2200 m altitude or in pens at ambient atmospheric pres sure and fed on diets containing 100 g/kg added fat as either an anima l/vegetable (A/V) blend or flax 3. Birds raised under hypobaric condit ions had a decreased growth rate and increased mortality, blood haemog lobin content, and incidence of pulmonary hypertension and ascites com pared to the groups at normal atmospheric pressure. 4. Broilers fed on the diet containing flax oil showed no difference in growth rate or b lood haemoglobin content compared to birds fed on the A/V fat diet rai sed at the same altitude. 5. Inclusion of flax oil in the diet decreas ed mortality and the incidence of ascites at 2200 m and pulmonary hype rtension at 1500 m. 6. Flax oil may be an effective method of reducing ascites and pulmonary hypertension in broilers without affecting perf ormance.