The effect of dietary flax oil and antioxidants on pulmonary hypertension and ascites in broiler chickens

Walton, John-Peter
Journal Title
Journal ISSN
Volume Title
University of Guelph

This thesis is an investigation of the effect of dietary supplementation of flax oil and antioxidants on pulmonary hypertension (PH), ascites, growth and haematological parameters in broiler chickens. Under hypobaric hypoxia, the inclusion of 5% flax oil in broiler diets has been previously shown to increase erythrocyte deformability, and reduce whole blood viscosity and PH. In this thesis, when a diet containing 2.5% flax oil was fed, it did not significantly reduce PH in broilers subjected to hypobaric hypoxia. Using a cold temperature model, 5% flax oil diets tended to reduce PH and ascites compared to control birds fed a diet containing an A/V blend oil, but the differences were not significant (P > 0.05). PH was not the cold temperature model with diets containing 2.5% flax oil, or with the supplementation of added antioxidants (vitamins C and E). Combining antioxidants with 5.0% flax oil increased ascites, mortality and PH compared to feeding the 5% flax oil diet alone. When a 5% flax oil diet was fed to birds under hypobaric conditions, treatment with cyclo-oxygenase or lipoxygenase inhibitors did not affect PH compared to control birds. The results suggest that the decreases in PH due to the feeding of flax oil are likely due to increases in erythrocyte deformability, and not the production of vasoactive arachidonic acid metabolites.

dietary supplementation, flax oi, antioxidants, pulmonary hypertension, ascites, growth, haematological parameters, broiler chickens