Colibacillosis is one of an economically significant disease in the poultry industry, especially for meat breed chickens. Recently it has become a serious problem for layer especially when the birds start laying and also at the later stage of laying. In Japan, the productivity of field laying hens improved when the Δcrp avian colibacillosis live vaccine ("Gall N tect CBL") was used. The surviva...

Studies performed in vitro suggest that a novel 12 amino acid RF amide peptide, isolated from the quail hypothalamus, is a gonadotrophin inhibitory hormone (GnIH). The aim of the present study was to investigate this hypothesis in the domestic chicken. Injections of GnIH into nest-deprived incubating hens failed to depress the concentration of plasma luteinizing hormone (LH). Addition of GnIH t...

Two experiments were conducted to determine whether taurine supplementation to laying hens would influence laying performance. In Experiment 1, a total of 120 White Leghorn hens were fed diets supplemented with 0, 0.25, or 0.5% taurine for 5 wk. Egg weight was reduced significantly by supplementing 0.25 and 0.5% taurine; however, taurine did not affect other laying performance variables. In Exp...

this study aimed to decrease the cholesterol content of egg yolk of laying hens through inclusion of barley malt rootlets in the diets. forty-two, 54-week-old, lohman laying hens were fed for a 12 weeks laying period on 3 iso-caloric and iso-nitrogenous diets contained 0 (control), 25.5 or 51.1g barley malt rootlets/kg. inclusion of barley malt rootlets at 25.5 or 51.1g/kg diet significantly de...

This experiment was conducted to evaluate the effects of different levels of Portulaca oleracea (PO),medicinal plant, on performance, egg traits, blood biochemical and immunity parameters of laying hens. One hundred eighty Hi-Line (W-36 strain) mature laying hens 65 up to 76 weeks of age were allotted in a completely randomized design consisting of 5 treatments and 3 replicates (12 birds per re...

An experiment was conducted to study the effect of Epinephrine (EP) and bromocriptine (BR) on productive traits of laying hens. Thirty White Leghorn hens, 50 weeks old, were divided into three equal treatments (with 10 hens for each treatment): control, physiological serum (0.5 mL/hen/week), EP (0.5 mL/hen/week) and BR (100 g/kg of body weight (BW); w/v in absolute alcohol). Hens were injected ...

Recent studies have reported the use of IgY antibody in the prevention or treatment of diseases in animals. IgY can be obtained in large amounts from the yolk of chicken eggs through a low-cost process. This study evaluated the effect of different routes of inoculation on antibody production and spleen morphological characteristics of laying hens (White Leghorn) inoculated with sheep red blood ...

Poultry treated with pharmaceutical products can produce eggs contaminated with drug residues. Such residues could pose a risk to consumer health. The following is a review of the information available in the literature regarding drug pharmacokinetics in laying hens, and the deposition of drugs into eggs of poultry species, primarily chickens. The available data suggest that, when administered ...

this experiment was conducted to investigate the effects of different levels of l-carnitine on productive performance, egg quality and blood parameters in laying hens. forty-eight hy-line w-36 egg layers were weighed at 90 weeks of age and randomly allocated into 16 cages (three hens per cage). four dietary treatments were prepared by supplementing l-carnitine (0, 50, 100 and 150 mg/kg of diet)...

Egg production rate is a positive economical factor in commercial laying hens. In egg industry, the only source of income is the number and weight of eggs laid in a laying cycle, therefore, researchers have been trying to find approaches to increase the egg number in each laying cycle. In general, a hen lays eggs in clutches with a pause of one or a few days in between the clutches (pause days)...