The short-term effects of delayed feeding (DF) for 2 d posthatching were measured in neonate chicks and compared to early feeding (EF). Chicks from 10 independent families were used in this study to determine whether genetic background control of growth may be influenced by EF and DF. Early feeding maintained significant interfamily body weight variations from hatch to 4 d of age, whereas there...

Two experiments examined the effects of regular video stimulation on open-field behaviour in Ž . Ž . domestic chicks tested in the presence Experiment 1 or absence Experiment 2 of the familiar video image. In Experiment 1, socially housed chicks were either exposed daily from 2 to 8 days Ž . Ž . of age to the video image of a computer screensaver SS in their home cage, or not N . At 9, 10 or 11...

The metabolite 25-hydroxy vitamin D3 (25-OHD) can complement or replace vitamin D3 in poultry rations, and may influence broiler production and immune function traits. The effect of broiler breeder dietary 25-OHD on egg production, hatchability, and chick early innate immune function was studied. We hypothesized that maternal dietary 25-OHD would support normal broiler breeder production and a ...

The effects of maternal n-6 and n-3 fatty acid (FA) supplementation on hatched chick tissue FA profile, antioxidant status, and ex vivo eicosanoid production by the cardiac tissue were investigated. Eggs with low, medium, and high levels of n-3 FA were obtained by feeding Cobb breeder hens were fed a corn-soybean meal-based diet containing 3.5% sunflower oil (low n-3), 1.75% sunflower oil plus ...

Oxidative stress may cause various neuronal dysfunctions and modulate responses to many centrally acting drugs. This study examines the effects of oxidative stress produced by hydrogen peroxide (H2O2) on sedation induced by diazepam or xylazine as assessed in 7-14 day-old chicks. Day-old chicks were provided with either plane tap water (control group) or H2O2 in tap water as 0.5% v/v drinking s...

Haemoglobins of chicks, yearlings and known-age sub-adults of the royal penguin were investigated by starch-gel electrophoresis at pH 8-6. Two haemoglobin components were observed in yearlings and sub-adults. These were assumed to be the haemoglobins of adults. Another three haemoglobin components were observed in 3-week-old chicks. In seven out of eight fledging chicks, these chick haemoglobin...

The cytoplasmic serine/threonine ribosomal protein S6 kinase (S6K1) plays a critical role in controlling protein translation. There is evidence that amino acids regulate S6K1 and protein synthesis in avian species, but the effect of dietary protein level on the activation of S6K1 in neonatal chicks is unknown. Therefore, the aim of the present experiment was to investigate the effect of differe...

Exposure of chicks to a high ambient temperature (HT) has previously been shown to increase neuropeptide Y (NPY) mRNA expression in the brain. Furthermore, it was found that NPY has anti-stress functions in heat-exposed fasted chicks. The aim of the study was to reveal the role of central administration of NPY on thermotolerance ability and the induction of heat-shock protein (HSP) and NPY sub-...

Biological predispositions influence approach and avoid responses from the time of birth or hatching. Neonates of species that require parental care (e.g. human babies and chicks of the domestic fowl) are attracted by stimuli associated with animate social partners, such as face-like configurations, biological motion and self-propulsion. The property of being filled is used as a cue of animacy ...

In the current study, commercial broiler breeder hens were mated with either commercial broiler breeder males (B/B) or artificially inseminated with semen from Leghorn cockerels (B/L). Embryos and chicks from each mating were used to study the effects of paternal genotype on breast muscle myosin expression without the confounding effects of differences in egg size and embryo development due to ...