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...

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 ...

The aim of the study was to evaluate the effect of sodium nitrate consumption on egg quality and quantity, and some blood parameters of native breeder hens of West Azerbaijan province. One hundred native hens were used from wk 25 to 32 of age. These birds were divided into two groups. One group was fed the control diet (CD) but the other fed the same diet supplemented with 4.2 g/kg sodium nitra...

the aim of this study was to investigate the effects seaweeds gracilariopsis persica in diets on performance and tsh, t3 and t4 hormones in serum of laying quail. a total of 112 laying quails were randomly allocated into four dietary treatments (diets containing 0, 1, 3 and 5% seaweed) with 4 replicates of 7 birds each. the birds were fed on experimental diets for 12 weeks. eggs were collected ...

s of papers 19 series were fed to the same strain of layers starting at 31 wk of age. Broken line regression analysis provided the following isoleucine estimates (g/day): Series 1 egg production, 0.46; Series 1 egg mass, 0.58; Series 2 egg production, 0.52; Series 2 egg mass, 0.50.

The experiment was carried out in poultry experimental station belonging to NRC, Cairo, Egypt. A total of 120 Fayoumi layers, 45 weeks old, were randomly divided into four equal groups. Each group included three replicates (10 hens in each). The first group was fed the control diet containing 3.3% gram Ca, whereas, the other three received diets containing 2.8, 2.6 and 2.4% gram Ca, respectivel...

We investigated whether among-sibling differences in the phenotypes of juvenile fish were systematically related to the position in the egg mass where each individual developed during oogenesis. We sampled eggs from the front, middle and rear thirds of the egg mass in female brown trout of known dominance rank. In the resulting juveniles, we then measured traits that are related to individual f...