The relationship between egg size and composition (relative amounts of lipid, protein, and water) can play an important role in determining neonate size, quality, or the amount of post-hatching care observed in many reptiles. We evaluated the relationship among egg wet mass, non-polar lipid mass, water content, shell dry mass, and lean dry mass within and among seven clutches of the Diamondback...

The effects of light intensity (LI) from photostimulation to 45 wk of age on egg production parameters and egg size characteristics were examined in four layer strains. Floor housed pullets were raised in a light-tight facility from 1 d of age until housing in individually illuminated cages at 17 wk of age. At 17 wk of age, two white egg strains, ISA-White (ISA-W) and Shaver 2000 (S2000), and t...

one hundred forty-four 26-wk-old white hy-line layers (w-36) were fed commercial diets containing 0, 1.5, 3 and 5% surplus date for three period of 28 days each to study the effects of dietary surplus date on hen performance (egg production, egg weight, egg mass, feed intake, feed conversion ratio ‘fcr’ and body weight gain) and egg quality parameters (haugh unit score, yolk colour index, yolk ...

THe effect of three levels of non-phytate phosphorus (NPP) (3.0, 2.1, and 1.7 g/kg) and two levels of 3-phytase (F) (0 and 150 phytase units (FTU)/kg) together with a high dietary calcium concentration (approximately 41.0 g/kg) on the performance characteristics, egg quality, pH of the digestive tract, and tibia bone quality of ISA Brown hens housed in enriched cages was evaluated. THe diets wi...

Broad geographic patterns in egg and clutch mass are poorly described, and potential causes of variation remain largely unexamined. We describe interspecific variation in avian egg and clutch mass within and among diverse geographic regions and explore hypotheses related to allometry, clutch size, nest predation, adult mortality, and parental care as correlates and possible explanations of vari...

Female birds of several species have control over the production of daughters and sons. However, most studies failed to find a relationship between egg size and sex. This is intriguing as adjustment of egg size would constitute a powerful tool for the female to meet different resource demands of the sexes, particularly in size dimorphic species. Our results show that, within clutches of black-h...

This research was carried out to compare the productivity performance of three lines local quail. The results showed a significant superiority in daily gain weight (3.76 g/day/quail) and marketing (167.2 g/quail) for brown quail over other colors. Also, differences were found dressing ratio between males (67.8%) females (65.76%). As egg production quail, it desert colors number eggs produced, a...

To evaluate the possibilities of applying plasma retinol as a biomarker of response in seabirds exposed to chronic low levels of organochlorines, the relationship between yolk content of polychlorinated biphenyls (PCBs) and plasma retinol levels were studied in newly hatched shag chicks (Phalacrocorax aristotelis) from the coast of central Norway. The mean concentration of 29 PCB-congeners (Sig...

Hatching studies with Heterodera glycines typically have been conducted with a mixture of egg-mass and encysted eggs. Laboratory research was conducted to compare hatching of H. glycines eggs from external egg masses with that of eggs extracted from within females and cysts (encysted eggs). Egg-mass eggs were collected by soaking infected soybean roots in 0.5% sodium hypochlorite, and encysted ...