Feed Space Allowance and Perch Design Criteria for Broiler Breeders Determined by Biometric Data.

The equipment used in broiler breeder houses is an important factor in allowing the expression of the various behaviours of the animals, and thus realizing high welfare standards. Presently, detailed requirements for the equipment in broiler breeder houses are not specified in Germany, especially feed space and perch design allowance. One reason is that basic biometric data on broiler breeders are lacking. To close this gap, a pilot study was conducted, and birds' width, weight, and feet were measured. Broiler breeders at 22 weeks of age (50 female and 17 male) were weighed and photographed digitally, and their body widths were calculated from the photographs. Female broiler breeders weighed 2791.80 ± 334.99 g on average and showed a body width of 20.63 ± 1.88 cm. For males, a mean of 3615.88 ± 432.46 g was measured with a body width of 21.94 ± 2.32 cm. Our examinations revealed that a trough side length of 21.00 cm per hen and 22.00 cm per cock must be provided to ensure that all broiler breeders have equal access to feed. The same dimensions should be planned as the perch length for each animal. Measurements of broiler breeders' feet (506 female and 150 male Cobb 500) were performed at 60 weeks of age. The length of each toe and the width and length of the foot pad of both sexes were photographed and measured digitally. Female broiler breeders' feet showed an average length of 10.14 cm, and male birds showed a length of 12.05 cm. Based on recommendations for the perch design for laying hens, round and oval perches for broiler breeders should have a circumference of at least 11.30 cm (female) or 13.40 cm (male). For angular perches, the upper contact area should have a width of 2.80 cm (female) or 3.40 cm (male). The obtained biometric data could be a useful basis for the development of legal requirements for broiler breeders.