A study was conducted to examine the effects of different oils on the plasma corticosterone concentrations of broiler chickens fed ad libitum or deprived of feed for 24 hours. A total of 36 Ross broilers were randomly assigned to one of three dietary treatments at 10 days of age and fed a grower diet supplemented with 60 g/kg soybean oil (rich in linoleic acid, C18:2n-6), linseed oil (rich in a-linolenic acid, C18:3n-3) or fish oil (rich in C14:0, C16:0, C16:1n-7, C20:1n-9; eicosapentaenoic acid and docosahexaenoic acid, EPA, C20:5n-3 and DHA, C22:6n-3), respectively, for 18 days. Dietary supplementation of fish oil resulted in lower (P < 0.05) baseline plasma corticosterone levels of chickens fed ad libitum for 18 days compared to soybean and linseed oil supplementations. Feed deprivation for 24 h induced a significant (P < 0.05) increase in corticosterone concentration in every treatment group compared to the ad libitum-fed birds. The hormone levels of feed-deprived birds did not differ significantly among groups fed diets supplemented with different oils.
Keywords: Polyunsaturated fatty acids; broiler chickens; fish; oil; plasma corticosterone.