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...

Free range feeding pattern puts the chicken in a mixture of growth materials and enteric bacteria excreted by nature, while it is typically unique condition materials and enteric bacteria in commercial caged hens production. Thus, the gastrointestinal microflora in two feeding patterns could be various. However, it remains poorly understood how feeding patterns affect development and compositio...

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 producti...

this experiment was conducted to evaluate the effects of different levels of dried aerial parts powderand extract of pennyroyal­ (mentha pulegium) medicinal plant on performance, egg traits, blood biochemical and immunity parameters of laying hens. two-hundred-fifty-two hi-line (w36 strain) laying hens from 46 until 58 weeks of age were used in a completely randomized design in 7 treatments and...

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 objective of the present study is to research the effect of dietary vitamin E (Vit E) on laying performance, lipid peroxidation and antioxidative status in laying hens under experimentally induced oxidative stress conditions via Dexamethasone (DEX) administration. A total of 60 Egyptian local strain (Gimmizah) laying hens at 36 weeks of age were housed in individual cages in an open-sided b...

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 ...

this experiment was conducted to evaluate the effects of using rice bran, combo multi-enzyme and probiotic (protexin) in diet on performance, egg traits, biochemical parameters and blood cells of commercial laying hens. this experiment carried out using 384 hi-line (w36) laying hens in a completely randomized design as factorial (2×2×2) arrangement with two levels of rice bran (0 and 10%), two ...

Two breeds of chickens were used to develop reference family and detect QTLs affecting egg quality traits: cocks of a native Polish breed Green-Legged Partidgenous (GlP) and hens of Rhode Island Red (RIR). During the first 100 days of the laying period, the GlP hens lay about 40 eggs weighting on average 50 g, whilst the RIR flock laid 83 eggs with a mean weight of 60 g. QTL analysis of egg qua...

More recent research has primarily focused on the importance of different "normal" behaviors in relation to animal welfare in a commercial operation. Research indicates, for example, that laying performance of chickens is influenced by human interaction. Producers should walk through the laying house a couple of times per day, selecting times that fit into the flock's egg laying cycle, such as ...