Optimum size of feeder grids in relation to the welfare of broiler breeder females fed on a separate sex basis

1. The rate of eating food was studied in two experiments to assess the relationship between head width and size of feeder grids in broiler breeder females. 2. The optimum grid size for food intake was 4 mm wider than head width. 3. Physical injury should be avoided if the grid aperture is 2 mm wider than the maximum head width in the flock measured at the posterior edge of the mandibles. 4. The rate of eating was decreased in all grid sizes examined compared to feeders without grids but the importance of this observation for the welfare of broiler breeders is not clear.