Eggshell temperature during early and late incubation affects embryo and hatchling development in broiler chicks.

This study aimed to investigate effects of eggshell temperature (EST) during early and late incubation on embryo and hatchling development of broiler chicks. A total of 720 eggs were randomly allocated to 3 treatment groups: control EST (37.8°C during the first 14 d and 36.8°C between d 15 and 21 of incubation), early high EST (as control, but 38.9∘C between d 4 and 7), and late high EST treatment (37.8°C during the first 14 d and 38.2°C between d 15 and 21). At d 18 of incubation, the length of the femur, tibia, and metatarsus were found to be lower in the early high EST treatment than in both other treatment. Hatchability was higher in the early high and control EST treatment than in the late high EST treatment (Δ = 4.2% on average; P = 0.02), whereas the opposite was found for late term embryonic mortality (Δ = 4.0% on average; P = 0.02). Navel score was higher for the late high EST treatment than for the early high EST and control treatment (1.36 vs. 1.19 and 1.17, respectively; P < 0.001). At hatch, chick weight, and organ weights were lower in the late high EST treatment than in the control treatment, with the early high EST treatment in between. At hatch, most femur, tibia, and metatarsus characteristics were lower for the early high EST treatment compared to both other treatments. The same was found for tibia ash, Ca, and P concentrations. Blood ALP and P levels were higher in the control group than in both other treatment groups. It can be concluded that early high EST particularly affected bone development during incubation, whereas late high EST particularly resulted in a decline in hatchability and chick quality in broiler chicks.

Comparison of Performance, Egg Quality, and Yolk Fatty Acid Profile in Two Turkish Genotypes (Atak-S and Atabey) in a Free-Range System.

Consumer interest in buying eggs from animal welfare-friendly systems with outdoor access is increasing, leading to an increase in the need for knowledge on genotypes suitable for free-range systems. Two Turkish laying hen genotypes, Atak-S (brown, n = 210) and Atabey (white, n = 210), were reared in a free-range system from 19-72 weeks of age, and their suitability for the system was assessed based on laying performance, egg quality, and yolk fatty acid profile. Mean hen-day and hen-housed egg production were found to be higher in Atabey than Atak-S (p < 0.01). The brown eggs from Atak-S hens tended to be heavier than the white eggs from Atabey hens (p < 0.01). Brown eggs obtained from Atak-S hens had a stronger shell structure (p < 0.01), while white eggs from Atabey hens had higher mean yolk index, albumen index, and Haugh unit than brown eggs (p < 0.05). At 56 weeks of age, total saturated fatty acid content in yolk was higher in white eggs than in brown eggs (p < 0.01). These findings related to genotype could help free-range egg producers in their choices for more profitable production and for meeting consumer demands on egg quality and egg yolk fatty acid levels.

Comparison of Behavioral Time Budget and Welfare Indicators in Two Local Laying Hen Genotypes (Atak-S and Atabey) in a Free-Range System.

Free-range systems are considered to improve bird health and welfare, thereby satisfying consumer demands. Behavioral time budget, fear level and clinical welfare indicators were compared for two Turkish laying hen genotypes, Atak-S (brown) and Atabey (white), reared in a free-range system. A total of 420 laying hens (210 Atak-S, 210 Atabey) were studied between 19 and 72 weeks of age. Higher percentages of eating and drinking behavior, feather pecking, and explorative pecking were observed for Atak-S hens, whereas Atabey hens were preening, walking-standing, and resting more. The duration of tonic immobility was longer, and the number of inductions was lower in Atabey compared with Atak-S hens. Atabey hens had less keel bone damages and better plumage conditions on the breast, wing, and tail at 56 and 72 weeks of age than Atak-S hens. Footpad dermatitis was more common in Atabey hens at 40 weeks, whereas Atak-S hens had a higher prevalence of footpad dermatitis with moderate lesions at 72 weeks of age. These findings indicate that free-range Atak-S hens may be more prone to keel bone damage and development of feather pecking, but they showed less foot lesions and were less fearful.