Fig. 1

Broiler and layer females differ in growth rate and reproduction efficiency, but not in the accumulation of the visceral fat. a BW measurements were obtained in a follow-up experiment of broiler breeders and layer hens, grown together from hatch with free access to food (n = 50 for each bird’s type; P < 0.001 at all ages including the day of hatch). b The number of large yellow follicle of ≥8 mm were counted in the ovary of the broiler and layer females at the first week of lay (4 month of age; n = 10 for each group). c Percentages of visceral fat (fat weight/live BW) were analyzed in the same birds shown in (b). d Percentages of visceral weight of broiler and layer chickens were measures when reaching 1 Kg BW. n = 10 for each bird’s type. *** P < 0.001