A genome scan was performed to detect chromosomal regions that affect egg production traits in reciprocal crosses between two genetically and phenotypically extreme chicken lines: the partially inbred line New Hampshire (NHI) and the inbred line White Leghorn (WL77). The NHI line had been selected for high growth and WL77 for low egg weight before inbreeding. The result showed a highly signific...

The negative relationship between offspring number and offspring size provides a classic example of the role of trade-offs in life history theory. However, the evolutionary transitions in egg size and clutch size that have produced this negative relationship are still largely unknown. Since body size may affect both of these traits, it would be helpful to understand how evolutionary changes in ...

Data of four layers flocks (#31-34) from North Carolina Layer Performance and Management Test of the Department of Agriculture and Consumer Services were used in the meta-analysis to find if an increase in space allowance can affect egg production traits in white and brown layers. Effects of space allowance of 310 and 413 cm2/bird on layers performance were compared in this study. The increase ...

Keeping Japanese quail is an economic way for producing egg, because of their early sexual maturity (laying egg after 35 days), high egg production (250–270 eggs per year), resistance to most of poultry disease and great egg production persistency on a high level (approximately 14–18 months) (MURAKAMI and ARIKI, 1998). Japanese quail maturation happens in about 6 weeks of age and mature females...

Do reproducing female reptiles adaptively manipulate phenotypic traits of their offspring by selecting appropriate nest sites? Evidence to support this hypothesis is indirect, mostly involving the distinctive characteristics of used (vs. available) nest sites, and the fact that physical conditions during egg incubation can modify hatchling phenotypic traits that plausibly might influence fitnes...

Three White Leghorn strains, their two-way crosses, and two commercial lines were used to evaluate the effects of aging on heterosis (H), reciprocal effects, and additive (A), Z-chromosome (Z), and heterotic effects and their variances on egg quality traits during the first laying cycle. Egg weight (EW), specific gravity (SG), Haugh unit (HU), and albumen height (AH) were measured at 240, 350, ...

The present study was conducted to determine egg production traits and egg quality characteristics in black and brown lines of Japanese quail. A total of 500 quails comprising 400 females and 100 males obtained from two breeding centers were raised according to the standard procedure for Japanese quail. They were grouped in according to their plumage colours. Age at first egg-laying has been re...

this study was conducted to evaluate the effects of different levels of butyric acid triglyceride and prebiotics on performance, egg quality traits and blood lipids of laying hens.  a 2 × 4 factorial experiment with 4 levels of butyric acid triglyceride (0%, 0.15%, 0.30%, 0.45%) and 2 levels of prebiotic (0 and 0.15%) based a completely randomized design were conducted. one hundred and ninety-t...

hadi ghaemi1, ali nobakht2*, sarayen razzaghzadeh1 1-west azarbijan jahad and agriculture faculty, iran 2- maragheh branch, islamic azad university, west azarbaijan, iran      *corresponding author email: [email protected]     received: 1 august 2013  accepted: 21 november 2013       abstract   this experiment was conducted to evaluate the effects of different levels of apple pulp and multi-...