Effect of layer genotype on physical characteristics and nutritive value of organic eggs

Abstract

The aim of the study was to evaluate the quality of organic eggs from hens of different genotypes and ages. The study investigated the physical characteristics, nutritive value and foaming properties of egg whites from Hy-Line Brown commercial layers, native Greenleg Partridge hens included in the conservation program, and Araucana hens laying blue-shelled eggs. Genotype had an effect on egg weight, albumen height and Haugh units. The vitamin A content of egg yolks was greater for Greenleg Partridge compared to Hy-Line Brown hens (P < 0.05). The n-6/n-3 PUFA ratio in egg yolks from Greenleg Partridge hens was lower, while the EPA, DHA and PUFA n-3 content were higher than in egg yolks from Hy-Line Brown hens (P < 0.05). Egg yolk cholesterol concentration was similar for the studied hen breeds (P > 0.05). Layer age had a significant effect on egg weight, yolk weight and color, and the presence of meat and blood spots (P < 0.05). Efecto del genotipo de gallinas ponedoras en las características físicas y el valor nutritivo de huevos ecológicos RESUMEN El presente estudio se propuso evaluar la calidad de huevos ecológicos producidos por gallinas de diferentes genotipos y de distintas edades. En este sentido, el estudio investigó las características físicas, el valor nutritivo y las propiedades espumantes de las claras de huevos provenientes de ponedoras comerciales Hy-Line Brown, de gallinas arborófilas pativerdes nativas incluidas en un programa de conservación y de gallinas araucanas (o mapuche), cuyos huevos tienen cáscara azulverdosa. Al respecto se estableció que el genotipo determina el peso del huevo, la altura de la albúmina y las unidades Haugh. En comparación con las gallinas Hy-Line Brown, se constató que el contenido de yemas de los huevos procedentes de la variedad arborófila pativerde fue mayor (P < 0.05), mientras que la ratio PUFA n-6/n-3 de las yemas de huevos de esta última variedad de gallina fue menor y el contenido de EPA, DHA y PUFA n-3 más elevado (P < 0.05). La concentración de colesterol de las yemas fue similar en todas las razas estudiadas (P < 0.05). Por último, se comprobó que la edad de las ponedoras tuvo un efecto significativo en el peso del huevo, el peso de la yema y el color, así como en la presencia de manchas de carne y de sangre (P < 0.05).

The Influence of Sex on the Slaughter Parameters and Selected Blood Indices of Greenleg Partridge, Polish Native Breed of Hens

“…Recently, these birds have gained popularity, due to the consumers’ conviction about the reduced cholesterol content in the obtained eggs. The results of research in this area are not entirely clear, due to the fact that some authors indicate the existence of such a relationship [ 12 ], while others do not confirm similar observations [ 13 ].…”

Comparison of Performance, Egg Quality, and Yolk Fatty Acid Profile in Two Turkish Genotypes (Atak-S and Atabey) in a Free-Range System

“…Egg exterior characteristics, namely egg shape index, eggshell breaking strength, and shell thickness, are important quality parameters in commercial handling and transport [36,40]. In the present study, egg quality parameters were affected by both genotype and age.…”

Phenotypic correlations between egg quality traits, albumen pH and ovalbumin levels in four varieties of Japanese quail (Coturnix coturnix japonica)

“…The percentage of yolk and albumen pH had a moderately significant positive correlation (0.350). Yolk color is influenced by genotype, age and diet [26,27,28]. In addition, dos Santos et al [29] reported that the yolk color decreased during storage under both at room temperature and refrigerator.…”