Quality traits of eggs from autosexing Easter eggers

H. Lukanov1*, A. Genchev1, A. Pavlov2, I. Penchev1

1Department Animal Science – monogastric and other animals, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria
2Department of Pharmacology, Physiology of animals and Physiological chemistry, Faculty of Veterinary Medicine, Trakia University, 6000 Stara Zagora, Bulgaria

(Manuscript received 5 July 2016; accepted for publication 31 August 2016)

Abstract. The main egg quality traits were investigated in two autosexing F1 Easter egger crosses. Partridge Araucana roosters were used as carriers of the eggshell biliverdin pigmentation gene. Maternal forms used for obtaining the two experimental crosses were high-producing layer hens carrying the sex-linked S and B genes. Experimental groups comprised F1 crosses of partridge Araucana roosters with white mutational Rhode Island hens or hens with barred colour mutation. The aim of the study was to investigated the quality traits of blue-green eggs produced by autosexing hens. The egg quality was evaluated at 38 weeks of age. Studied traits comprised egg weight (g), shape index, albumen index (AI), Haugh units (HU), yolk index (YI), yolk colour (Roche scale), percentages of albumen, yolk and eggshell (%), eggshell surface (cm2), eggshell density (mg/cm2), average eggshell thickness (μm) and eggshell colour. The group W was outlined with the highest egg weight – 61.03±0.47 g, and group A – with the lowest (50.91±0.32 g). The albumen and yolk quality was the best in group A, where albumen index was 0.075±0.002, Haugh units – 76.53±0.8 and yolk index – 0.491±0.009. The analysis of eggshell colour showed that eggs of group A were with the highest lightness (L*) value (73.60±0.77), whereas eggs of groups W and AW had egg lightness of 60.45±0.53 and 61.11±0.55 (p<0.001) respectively. The shell colour index (SCI) demonstrated a certain overlap of values in eggs with protoporphyrin and biliverdin taints. After introduction of a correction coefficient and recalculation of SCI*, the values of green eggs assumed a negative sign and could be distinguished from brown eggs.