The effect of n-6/n-3 fatty acid ratios on broiler breeder performance, hatchability, fatty acid profile and reproduction.

This experiment was conducted to study the effect of dietary omega6 (n-6) to omega3 (n-3) fatty acid (FA) ratios on performance and reproduction of broiler breeders. In experiment 1, 400 females and 40 males (30 week age) of Ross 308 broiler breeder (20 females and two males in each pen) were randomly assigned to one of the four diets with n-6/n-3 FA ratios of 4, 6, 8 and 16 (control). As a measure of hatchability, fertility of eggs and general incubation traits, 1,200 eggs (60 eggs from each pen) were collected and incubated for 21 days and embryo liver and brain fatty acid profile in 14 and 21 days were determined. In experiment 2, 48 males (three males in each pen) randomly assigned to one of the four diets with n-6/n-3 FA ratios of 4, 6, 8 and 16 (control). Semen was collected twice weekly, and semen volume, spermatozoa concentration and motility and alive and dead spermatozoa were estimated. Egg production and egg mass were decreased by n-6/n-3 FA ratios of 4:1 and 6:1 (p < .05). There were no significant differences between treatments on breeder's body weight, eggs fertility and hatchability, embryonic mortality and semen features. Linolenic acid, eicosapentaenoic acid, docosahexaenoic acid and total n-3 of egg yolk, semen, testis and liver and brain of embryo and day-old chicken were increased while concentration of linoleic acid, arachidonic acid and docosatetraenoic acid of mentioned tissues were decreased by increasing n-6/n-3 FA ratios (p > .05). In conclusion, absolute amount of n-3 and n-6 FAs in broiler breeder diet may be more important than n-6/n-3 FA ratios and to consider reproductive and performance traits of breeders, it is necessary to supply higher levels of n-3 and n-6 FA with respect to n-6/n-3 FA ratios.