Dispersal distances overestimate the gene-flow scale l (the square-root of the mean squared distance travelled from birth to reproduction) when egg laying is concentrated early in dispersal and when there is mortality during dispersal. If egg laying follows a square-root normal distribution in time, as it does in several Drosophila species, then l is reduced to about 0.6 of that estimated from ...

The aim of the current study was to determine the effects of different eggshell temperatures (EST) during 10 to 18 d of incubation on embryonic development, hatchability, chick quality, first-week broiler performance. The EST were maintained within the temperature ranges of 33.3 to 36.7, 37.8 to 38.2, and 38.9 to 40.0°C for the low, control, and high EST treatments, respectively. From d 15 to 1...

There has been much confusion over the significance of spirochaetes found in the caeca of laying hens and the impact they may have on egg production. In recent years, the situation has been made clearer and the presence of such species as Brachyspira pilosicoli have been shown to cause a mild, chronic disease in both layers and breeders and to reduce egg production by reportedly 5%. In the Unit...

A total 2400 hatching eggs were obtained from Japanese quails breeders ranged from 100 to 150 days of age used to analyze the effect of shell color on fertility, hatchability, embryonic mortality and malposition as well as internal and external egg quality. Results revealed that shell color had significant effect on fertility and scientific hatchability while it doesn't affect commercial hatcha...

Four thousands and two hundred hatching eggs were obtained from Bandarah chicken to evaluate the effect of chemical and natural eggs disinfectants and fumigation on egg weight loss, embryonic mortality, hatchability, hatch time, chick weight, and chick weight loss. Three incubation trials were done, each one contained 1400 hatched eggs and divided into fourteen treatments (100 eggs per each). F...

1. A total of 257 farmers with free ranging laying hens (organic and conventional) in Switzerland, France and The Netherlands with 273 flocks were interviewed to determine the relationships between the genotype of the hens, management conditions and performance. 2. Almost 20 different genotypes (brands) were present on the farms. In France, all birds were brown feathered hens laying brown egg...

Rearing of the black soldier fly, Hermetia illucens, in mass production systems is increasing. Its use as both a bio-converter organic waste and feed for other livestock has transformed it into one most produced insects world. As result, new research needed to evaluate risk insect diseases affecting thus productivity. While some studies have focused on larval stage flies, date, few assessed ris...

Terrestrial eggs have evolved repeatedly in tropical anurans exposing embryos to the new threat of dehydration. Red-eyed treefrogs, Agalychnis callidryas, lay eggs on plants over water. Maternally provided water allows shaded eggs in humid sites to develop to hatching without rainfall, but unshaded eggs and those in less humid sites can die from dehydration. Hatching responses of amphibian eggs...

in this study, the effects of culban seed (vicia peregrine l.) on live body weight, feed intake, feed efficiency, egg production, egg quality characteristics, egg yolk fatty acid profiles and yolk cholesterol content in laying hens were investigated. the experiment consists of seven treatment groups with ten replications containing one laying hen in each and for 32 weeks old seventy laying hen ...