this experiment was conducted to evaluate the effects of different levels of calcium (ca) and phosphorus (p) on performance native hens of khorasan province. a total of 400 native hens from khorasan station were used in a completely randomized design (factorial experiment) with 8 treatments, 5 replicates and 10 hens in each replicate of  age 26 to 50 weeks. eight experimental diets based on cor...

The present research was designed to examine the genetic analysis of egg weight, egg yolk weight and egg albumen weight of Bovan Neva Black laying hens at 25, 51 and 72 weeks. For this purpose, thirty birds were selected from the layer flock in the Babcock University Teaching and Research Farm. They were individually housed in separate labeled battery cage. A total of thirty eggs were collected...

The objectives of our study were to propose a new definition for persistency of egg production and to develop a mathematical model to describe the egg production curve, one that includes a new measure for persistency, based on the proposed definition, for use as a selection criterion to improve total egg production. Persistency of egg production is an important determining factor for total egg ...

Egg production curves describe the laying patterns of hen populations over time. The objectives of this study were to fit the weekly egg production rate of selected and nonselected lines of a White Leghorn hen population, using nonlinear and segmented polynomial models, and to study how the selection process changed the egg-laying patterns between these 2 lines. Weekly egg production rates over...

A majority of laying hens fracture their keel bones during the laying cycle. It is not easy for a farmer to identify hens with fractures and hen survival rate seems high. Thus, the effect of both recent and healed fractures on bird welfare is unclear. We aimed to investigate the impact of these keel-bone fractures on hens’ production and behaviour. The egg production, mobility and behaviour of ...

effects of mating sex ratios on production performance in indian peafowl were investigated at punjabwildlife research institute, gatwala faisalabad. research was conducted from may through august 2007 toexplore the most productive mating sex ratio. the sex ratios have a significant effect on egg production.maximum mean eggs (1.63) were produced by the sex ratio 1:2 while maximum egg fertility (...

The present study was designed to determine the effect on laying performance and egg quality resulting from total substitution of soybean meal (SBM) with low-fiber sunflower meal (SFM; Helianthus annus L.) meal in diet of hens. ISA Brown layers, 28 wk of age, were randomly allocated to 2 dietary treatments and fed for 10 wk. The hens were kept in a free-range environment and fed 2 wheat middlin...