The study was conducted to determine the effects of layers‟ diets containing 0, 100, 150 and 200 mg/kg vitamin C on vitamin A and C concentrations in serum of layers. A total of 80 Isa brown layers (28 weeks of age) were used in this study. There were a control and three treatment groups each containing 20 hens. The experimental period lasted 8 weeks. Serum vitamin A and vitamin C concentration...

1. The impact of feeding sources n-3 fatty acids (FA) to ISA Brown and Shaver white breeders their offspring on antibody titres plasma FA profile was examined. 2. Breeders were fed eithe...

ISA Brown hens were fed diets supplemented with the synthetic carotenoids Carophyll Red and Carophyll Yellow at 20 and 15 mg/kg, respectively, lutein at 250 mg/kg, and the algae Chlorella at 12.5 g/kg. The synthetic carotenoids, lutein, and Chlorella significantly increased egg weight (P < 0.001), shell weight (P < 0.001), and thickness (P = 0.017) and decreased the yolk/albumen ratio (P = 0.03...

The well-being of laying hens in cages of 5, 10, 20 and 40-birds/cage, and enrichment with perches, nest boxes and scratch pads, was assessed using behavioral and physiological parameters. Laying hens were Lohmann Brown (n = 360) and White Leghorns (n = 360), housed from 17 to 65 weeks of age. Behavioral parameters were; the percentage of birds per cage roosting on perches, claw length (n = 288...

The serotonergic system has been shown to be implicated in the regulation of mood and feeding behavior. Previous studies have identified a polymorphism in the 5'-flanking region of the serotonin transporter ( 5 - HTT ) gene of Lohmann Brown (LB) laying hens. The deleted variant D was found to be associated with increased body weight. The objective of this study was to address whether the increa...

This study evaluated the effects of dietary Ca and P levels on laying hens housed in floor pens (F) or cages (C). Two hundred fifty-six 1-dold pullets, Lohmann Brown (B) and Bovan White (W) intermingled in equal numbers, were placed into 8 F. One hundred twenty-eight 1-d-old caged pullets were allocated into 32 layer C at 14 wk of age. Hens were given isocaloric and isoprotein diets containing ...

The effect of moult on eggshell mechanical properties, on composition and concentrations of organic matrix components and on eggshell microstructure was investigated. The observed changes were studied to understand the role of organic matrix and eggshell microstructure in eggshell strength. Moult was induced by zinc oxide (20 g zinc/kg diet) in 53 ISA Brown laying hens at 78 weeks of age. No di...

Public concern about the welfare of hens kept in conventional cages has become an important issue worldwide. This study examined the effects of conventional cages (CC) and floor pens (FP) on hens’ health and egg production. A total of 84 19-wk-old Bovan Brown hens were randomly assigned into 2-bird cage (n = 12), providing 968 cm2 floor space per hen or 10-bird floor pens (n = 6), providing 371...

An experiment was conducted to determine the distribution of nitrogen-15 in tissues of laying hens receiving different levels of N-CCC in diets. Twenty brown laying hens were divided into four groups and randomly assigned into one of four dietary treatment groups consisting of 0, 5, 50 and 100 ppm N-CCC inclusion. The hens were individually fed with the N-CCC diets in battery cages for 11 days ...