During recent decades productivity of laying hens increased substantially (Elliot, 2008). Not only egg number, egg mass, and feed conversion has increased but also persistency of lay has improved. As such, this must have implications on the optimal amino acid nutrition of current laying hen strains. Simply stated, increasing egg mass output per hen means an increased amino acid output which has...

OBJECTIVE The objective of this experiment was to investigate the effect of dietary β-mannanase on productive performance, egg quality, and utilization of dietary energy and nutrients in aged laying hens raised under hot climatic conditions. METHODS A total of 320 84-wk-old Hy-line Brown aged laying hens were allotted to one of four treatments with eight replicates in a completely randomized ...

CRBP1 (cellular retinol binding protein 1) and CRBP3 (cellular retinol binding protein 3), are important components of the retinoid signaling pathway and take part in vitamin A absorption, transport and metabolism. Based on the role of vitamin A in chicken laying performance, we investigated the polymorphism of CRBP1 and CRBP3 genes in 349 chickens using single strand conformation polymorphism ...

An experiment was conducted to study the effects of substitution soybean meal (SBM) with canola meal (CM) and formulated diets based on total and digestible amino acid on performance, egg quality, organs weight and blood parameters of laying hens from 73 to 83 weeks of age. A total of 128 laying hens were distributed by completely randomized design in a 2×2 factorial arrangement with 2 protein ...

In present study, two trials had been conducted to evaluate the effects of Spirulina platensis (SP) on growth performance, carcass characteristics, egg quantity and quality traits, and immunity response of Japanese quails. In trial 1, a total number of 180 one-day-old Japanese quails were randomly assigned into 6 groups, 3 replicates with 10 quail chicks per replicate. Experimental die...

With the Weihenstephan funnel nest box, 12 laying hen flocks were tested for their individual laying performance, egg quality, and nesting behavior in a noncage environment. During the whole observation period of 8 yr, a transponder-based data recording system was continuously improved and resulted in a recording accuracy of 97%. At peak production, heritabilities for the number of eggs laid ar...