Eggs from 31-wk-old ISA-White and ISA-Brown hens were sampled immediately after lay and after periods of storage of 1, 3, 5, and 10 d at room temperature. Longer periods of storage resulted in lower albumen weight and albumen height and higher albumen pH. Eggs from ISA-Brown hens had more albumen and shell than those from ISA-White hens, likely due to differences in selection history rather tha...

Isoflavones are phytoestrogens which have estrogen-like activity in animals and humans with structure similar to 17-β-estradiol and capable of binding to estrogen receptors (ERs).This experiment was conducted to demonstrate the effect of isoflavones on estradiol concentration in blood and its influence on the productive performances in ISA Brown laying hens fed with supplemented feed with large...

Ammonia (NH3) emissions from laying hens are affected by nutrient content of the diet, manure quantity, and manure properties such as moisture content, nitrogen content, and pH. These production traits may vary with strain of the hen. However, limited information is available concerning the effects of laying-hen genetics on manure properties and NH3 emission. This study was conducted to compara...

The aim of this study was to investigate the possibility to modificate the total lipid and cholesterol level, as well as fatty acid composition of egg yolks, by supplementing diets of laying hens with different fats. The trial was conducted in two six week experiments. Experiment I was conducted on 180 Isa Brown hens assigned to two age categories: 36 months old (O), and 27 weeks of age young (...

to determine the effect of graded levels of low glucosinolate CM, up to complete replacement of soybean meal, on the performance of laying hens. Wheat-based diets were formulated on a digestible amino acid basis with 4 levels of CM (0 to 16.7%) and fed to 3 commercial laying hen strains, Lohmann Brown (LOH), ISA Brown (ISA), and Lohmann LSL (LSL). Rations were fed from 19 to 59 wks of age, with...

................................................................................................................................ 37 CHAPTER 1: General Introduction ......................................................................................... 44 TYPES OF BIRD-TO-BIRD PECKING .................................................................................. 47 HOUSING SYSTEMS ...........

A total of 2123 eggs obtained from Brown Leghorn hens (unselected since 1965, ISA Brown, commercial brown egg layer) and Babcock hens (commercial white egg layer) at 32, 50, and 68 wk of age were used to investigate relationships among measures of albumen quality and a functional property of albumen. The eggs were sampled fresh and after storage for 5 and 10 d. At sampling, eggs were weighed an...

To prevent penetration of Salmonella into eggs, a clear understanding of various factors influencing bacterial penetration could be a valuable tool in planning intervention strategies. Penetration was assessed by replacing the egg contents with a selective medium that allowed visualising Salmonella growth on the inside of the shell by candling. Only eggshells without visual abnormalities were u...

Providing light during incubation is being investigated as a method to improve welfare in later life poultry. This would more closely approximate chicken natural environment compared the current darkness. Previous studies showed promising results of on broiler welfare, but little known about effects laying hens. Especially, information its hatching characteristics (hatch time, hatchability, chi...

Egg and eggshell quality were assessed under three different circumstances: challenge with infectious bronchitis virus (IBV) of complete-fed and choice-fed Isa Brown laying hens; the provision of calcium supplement in the form of either oyster shell or limestone chips and either choice-fed or included in a complete ration; a comparison of three different strains before, during and after an indu...