Sudden death syndrome in broilers: dietary fat supplementation and its effect on tissue composition

The effects of dietary fat sources on the general performance of broiler chickens and the incidence of sudden death syndrome (SDS) were investigated in two experiments. In Experiment 1, a wheat-soy diet supplemented with sunflower oil was found to improve significantly (P less than .05) performance characteristics and reduce the mortality attributed to SDS as compared with the same diet supplemented with tallow. The blood lipid parameters--total lipids, triglycerides, and cholesterol at 4 and 7 weeks of age--were not affected (P greater than .05) by the type of fat used in the diet. In Experiment 2, wheat-soy diets were supplemented with either tallow or sunflower oil at the same dietary levels and two stocking densities (.09 m2/bird or .08 m2/bird). The sunflower oil diet significantly (P less than .05) improved the general performance of the birds and reduced mortality from SDS. Bird density had no significant effect. Fatty acid composition of the heart and liver tissues from SDS birds showed differences when compared with culled birds (leg problems) from the same experimental period. In the heart tissue, increased palmitic (16:0) and oleic (18:1) acids were observed, while linoleic (18:2) and arachidonic (20:4) acids were lower. Liver tissue showed increased 18:1 and lower 18:2 and 20:4. Analysis for copper and zinc in heart tissue did not indicate significant (P greater than .05) treatment effects, but calcium concentration was significantly (P greater than .05) higher in SDS than culled birds. Analysis performed on the liver tissue showed significant (P lesser than .05) differences in copper and zinc between these two groups of birds.