Variation in the ovocalyxin-32 gene in commercial egg-laying chickens and its relationship with egg production and egg quality traits.
Avian eggshell quality is an important trait for commercial egg production, as the eggshell is the primary packaging material and antimicrobial barrier for the internal food resource. Strong eggshells are essential to ensure that eggs can reach their final destination without damage. Ovocalyxin-32 (OCX32) is a matrix protein found within the outer layers of the eggshell and in the cuticle. Numerous reports in the literature have identified association between variants in the gene encoding this protein, OCX32, and various eggshell quality traits. Thus, OCX32 is a candidate gene for selection for eggshell traits in commercial poultry populations. Sequencing of exons 2-6 of the OCX32 gene in eight elite brown and white eggshell commercial egg-laying lines revealed 28 SNPs and one SNP/indel. Eighteen of these SNPs were predicted to alter the amino acid sequence of the protein. Clusters of SNPs in complete linkage disequilibrium were found in both exons 2 and 6. A total of 19 different versions or protein-sequence haplotypes of the OCX32 protein were inferred, revealing considerable variation within commercial lines. Genotypes for 13 of the SNPs were determined for 330-1819 individuals per line. Trait association studies revealed a significant effect of OCX32 on shell color in white egg lines and line-specific significant effects on albumen height, early egg weight, puncture score, and yolk weight. Three of the lines showed a significant change in OCX32 frequency over time, indicating selection pressure for certain variants of this gene during the breeding program.
Evaluation of Beta-Adrenergic Agonist Theophylline Function in Reducing Inflammation on Blood Metabolites and Egg Quality Traits in Laying Hens at the end of Production Period
Extended Abstract Introduction and Objective: Since the phenomenon of inflammation is considered as one of the significant challenges in different sectors of the livestock industry, so this study aims to evaluate the inflammatory strategy of Theophylline (a Phosphodiesterase, PDE inhibitor) on some production characteristics in laying hens at the late period of egg production (The severity of ...متن کامل
Evaluation of Laying Performance and Egg Qualitative Characteristics of Indigenous Hens Reared in Rural Areas of Isfahan Province
This study was carried out to investigate the egg production performance and egg quality characteristics of the indigenous chickens reared in rural areas of two different climates of Isfahan province. Totally, 2160 indigenous chickens were studied in this research. Two dominant climatic regions (cold and hot) were determined for Isfahan province. In each climate, two towns and three villages...متن کامل
Genetic Analysis of Egg Quality Traits in Bovan Nera Black Laying Hen under Sparse Egg Production Periods
The present research was designed to examine the genetic analysis of egg weight, egg yolk weight and egg albumen weight of Bovan Neva Black laying hens at 25, 51 and 72 weeks. For this purpose, thirty birds were selected from the layer flock in the Babcock University Teaching and Research Farm. They were individually housed in separate labeled battery cage. A total of thirty eggs were collected...متن کامل
A ten-week trial was carried out to determine the effect of different levels of nano-calcium carbonate (NCC) on egg production performance and egg quality. A completely randomized experiment was designed comprising 6 treatments, each with 4 replicates of 5 hens. Groups 1 and 2 were fed diets containing 8.06% and 6.045% calcium carbonate (CC) as positive and negative control respectively. Groups...متن کامل
Effect of Dietary Supplementation of Liquid Prebiotic and Antibiotic on Egg Production, Egg Quality, Blood Parameters, Immune System Response of Layer Hens at Post Molt Period
Extended Abstract Introduction and Objective: The inclusion of prebiotics in layer hen diets can act as a growth-promoting antibiotic replacer and have beneficial effects on egg production and egg quality. This study aimed to investigate the effects of liquid prebiotic on the post-molt laying performance, egg quality at different storage temperatures and times, immune system function, and bloo...متن کامل