Production Performance and Egg Quality of Laying Hens as Influenced by Genotype and Rearing System

Abstract

The aim of this study was to evaluate the effect of rearing systems and genotypes on production performance and egg quality. Isa Brown and New Hampshire genotypes were used in this study. These two genotypes were housed in floor and organic rearing systems. During the experimental period, which lasted one year (52 weeks), the following production performance parameters were recorded: egg production, daily egg mass, feed consumption, feed conversion efficiency, and mortality. Fifteen eggs per group were collected for analysis at 64 weeks of hen age. These samples were evaluated for external parameters (egg weight and egg shape index), internal parameters (albumen height, Haugh unit, and the proportions of albumen, yolk and shell), eggshell quality parameters (shell thickness, shell deformation and shell breaking strength), and eggs' chemical composition (dry matter, minerals, protein and lipids). Generally, Isa Brown hens had better production performance than New Hampshire hens. At the same time, organic New Hampshire layers performed better than floor-reared ones. Genotype had a significant effect on all ten egg quality parameters (external, internal and eggshell quality), rearing system independently affected only egg weight, and the interaction of the observed factors significantly influenced seven parameters. Genotype had a significant effect on three of the four chemical composition parameters, while no significant effect of the rearing system was established on the chemical composition of eggs. The rearing system x genotype interaction significantly affected the eggs' protein content.

Genotype and ginger (Zingibar officinale) rhizome powder dietary supplementation affect egg quality indices of aged layer chickens

“…In the present study, signi cantly higher HU was observed in round eggs compared to sharp eggs in HEN and this was consistent with Duman et al (2016). This may be related to the larger size (hence higher albumen proportion) of round eggs compared to sharp eggs in this genotype and this agreed with the ndings of previous studies (Leiboldt et al, 2018;Nolte et al, 2021;Rakonjac et al, 2021).…”

“…The signi cantly improved EW in ginger group could be responsible for the improvement in EL, ESA, and EV observed in this group and this could be attributed to the health promoting effects of ginger probably due to its content of bene cial bioactive compounds (Nemati et 2023) however, reported nonsigni cant effect of ginger on ESI at 8 weeks of lay but signi cant effect at 10 weeks of lay which suggests an age dependent effect. Genotypic differences in YW and YR as were observed in the present study agreed with previous studies (Nolte et al, 2021;Rakonjac et al, 2021;. The higher YW in SB eggs is attributable to the larger egg size however; these eggs had lower YR compared to HEN eggs indicating that selection for higher egg size (egg weight) in hens may not proportionately improve egg yolk content.…”

“…Egg quality is in uenced by phylogenetic, genetic and environmental factors (Lieboldt et al, 2015;Rakonjac et al, 2021). Variations in egg quality characteristics have been reported between species, breeds and strains of chickens; rearing systems, stocking densities, diets, and age of birds (Ozenturk and Yildiz, 2020).…”

Phenotypic correlation between egg quality indices in 85-weeks-old layer chicken genotypes

“…Skrbic et al, 2011;Rakonjac et al, 2021). The perfect positive correlation of ED with ESA and EV in HEN were in agreement withAlkan et al (2015) andTyasi et al (2022).…”

Population Pharmacokinetics and Absolute Oral Bioavailability of Lasalocid after Single Intravenous and Intracrop Administration in Laying Hens

“…3,10,14 The ISA Brown (IB) hens are a popular commercial hybrid chicken known globally for their outstanding egg-laying performance. 15,16 The Green-legged Partridge (GLP) hens are a popular Polish native breed of chicken that are reared for both egg and meat production. 17,18 Although their laying performance is much lower compared to IB hens, eggs from GLP hens are gaining popularity due to their high nutritive and sensory value as well as being perceived as "organic".…”