this experiment was conducted to investigate the effects of different levels of l-carnitine on productive performance, egg quality and blood parameters in laying hens. forty-eight hy-line w-36 egg layers were weighed at 90 weeks of age and randomly allocated into 16 cages (three hens per cage). four dietary treatments were prepared by supplementing l-carnitine (0, 50, 100 and 150 mg/kg of diet)...

Hatching asynchrony in avian species generally leads to a size hierarchy among siblings, favouring the first-hatched chicks. Maternally deposited hormones affect the embryo and chick's physiology and behaviour. It has been observed that progesterone, a hormone present at higher levels than other steroid hormones in egg yolks, is negatively related to body mass in embryos, chicks and adults. A d...

Bull spermatozoa were pellet frozen on dry ice in a TES buffer containing combinations of egg yolk and glycerol to determine which component of an extender afforded cryoprotection to the spermatozoa. Neither buffer nor buffer plus glycerol protected sperm cell motility in the absence of egg yolk, while sperm cells frozen in egg yolk buffer in the absence of glycerol had 24% postthaw motility (P...

Understanding reproductive performance in ecologically impoverished vs. more sustained anthropogenic habitats is critical to assess population health status and to develop land use and conservation management strategies. We compared resourcebased maternal effects, reproductive performance, and offspring quality in a model migratory passerine bird, the European starling (Sturnus vulgaris). We as...

Blue-green and brown-spotted eggshells in birds have been proposed as sexual signals of female physiological condition and egg quality, reflecting maternal investment in the egg. Testing this hypothesis requires linking eggshell coloration to egg content, which is lacking for brown protoporphyrin-based pigmentation. As protoporphyrins can induce oxidative stress, and a large amount in eggshells...

A method is described for the chromatographic separation of mixtures of egg-yolk proteins of low solubility, by using a hydrophobic column (phenyl-Sepharose) and eluting with increasing concentrations of aqueous urea at low pH. The resolving power of the method was established by tests on proteins and protein fragments of known sequence. The theoretical basis for the method remains, however, un...

This experiment was conducted, during a seven-week period to investigate, the effects of using various levels of garlic cloves and turmeric rhizome powders, on laying hens’ performance, egg quality characteristics and cholesterol content in yolk. Two hundred and sixteen, 27-weeks old Novogen white laying hens were assigned randomly into nine treatments with eight replicates of three birds each....

Egg yolk low-density lipoproteins (LDL) and soybean lecithin were evaluated as replacements for egg yolk in extenders used for the cryopreservation of brown-bear spermatozoa. The motility, viability and acrosomal status of post-thawed spermatozoa were analysed, and an egg-yolk extender was used as a control. The total antioxidant capacity of these extenders was tested. Soybean lecithin showed a...

Although the particulate fraction of egg yolk (yolk granules) has attracted the attention of investigators since Miescher (1) and Hoppe-Seyler (2)) reliable information concerning the distribution of the yolk constituents between its soluble phase and the granules is lacking. Separation of both phases is difficult, owing to the high viscosity of egg yolk. For this reason, all information concer...