The egg-laying rates of hens approximately 470 days of age exhibited a positive correlation to blood melatonin levels. The hens with an egg-laying rate <30%, 30~90% and ≥90% had blood melatonin levels of 5.8 ± 2.6, 74.0 ± 32.9 and 445.9 ± 115.3 ng/ml, respectively. When 10 mg of melatonin was implanted into the hens at 300, 360, 470 and 550 days of age, the egg-laying rates increased 4.63 ± 0.4...

BACKGROUND: Old laying hens are more prone to dietary calcium (Ca) and phosphorus (P) deficiencies as they absorb Ca and P less efficiently than younger hens. OBJECTIVES: In a 2×2 factorial design, the influence of diets with two levels of available phosphorus (AP) and phytase enzyme on the laying performance, egg quality and tibia bone characteristics of laying hens at their late 2nd productio...

The aim of the study was to evaluate egg shell quality characteristics, mineral content in the egg shell, and serum mineral concentration during the egg formation process as influenced by oviposition time and ambient temperature at the beginning and end of the laying cycle in laying hens and broiler breeders. Egg shell quality deteriorated significantly at the higher temperature and was lower i...

Onion and its flavonoid component, quercetin, increase bone density in rabbits, rodents, and humans. The purpose of this study was to determine whether there is a similar effect of onion on laying hens. Thirty-two Hy-line W36 White Leghorn hens at 30 weeks of age were randomly divided into 2 groups, i.e., control and treatment (n = 16). The hens were kept at 2-hen cages, each cage providing 658...

Artificial neural networks (ANN) have shown to be a powerful tool for system modeling in a wide range of applications. The focus of this study is on neural network applications to data analysis in egg production. An ANN model with two hidden layers, trained with a back propagation algorithm, successfully learned the relationship between the input (age of hen) and output (egg production) variabl...

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...

This experiment was conducted to evaluate the effects of single or multi-particle size limestone on the egg shell quality, egg production, egg quality and feed intake in laying hens. A total of 280 laying hens (ISA brown) were used in this 10-wk trial. Laying hens were randomly assigned to 4 treatments with 14 replications per treatment and 5 adjacent cages as a replication (hens were caged ind...

A 3 × 2 factorial arrangements with completely randomized design, with a total of 72 Leghorn Hy-line (W-36) laying hens in the second cycle (98 wk old) of production were randomly assigned to 24 wire cages (45.7×30×30 cm3) and fed with diets containing three levels of guar meal (GM; 0, 4 and 8%) and two levels of β-mannanase (Hemicell®) enzyme (0.00 and 0.05%) for 12 wk period. There...