The impact of eggshell colour and spot area in Japanese quails: II. Slaughter and carcass characteristic

Sema Alasahan,Gulsen Copur Akpinar,Sibel Canogullari,Mikail Baylan

doi:10.1590/s1806-92902016000900002

Sema Alasahan, Gulsen Copur Akpinar + Show 2 more

Open Access

https://doi.org/10.1590/s1806-92902016000900002

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Abstract

This study was carried out to investigate the effects of eggshell colour and spot properties (colour and size of the spot area) on growth performance and carcass traits of Japanese quail (Coturnix coturnix japonica) eggs. Study material were allocated to five groups according to their eggshell and spot colours: black spots on greyish white coloured eggshell (I), blue spots on greyish white coloured eggshell (II), diffuse brown spots on greyish brown coloured eggshell (III), brown spots on light green colored eggshell (IV), and small brown spots on greyish brown coloured eggshell (V). The size of the spotted area was determined in each egg group using digital image analysis. The groups did not differ for body weight and length of the shank at the end of the growth period. However, the groups differed significantly for carcass yield after slaughter (not eviscerated) and carcass yield. These parameters were highest in Group I (82.08 and 76.09%) and lowest in Group III (80.20 and 73.86%). Digital image analysis demonstrated that heart length, cardiac fat area, gizzard width, and intestine length varied between the groups. Cardiac fat area was largest in Group III (0.86 cm2) and smallest in Group V (0.65 cm2). Gizzard width was greatest in Group I (2.63 cm) and smallest in Group V (2.47 cm). Intestine length was greatest in Group V (78.45 cm) and smallest in Group IV (72.39 cm). Body weight, shank length, and slaughter and carcass weight do not vary in relation to eggshell colour or the size of the spotted area. The lengths of intestine and heart, gizzard width, and cardiac fat area do vary in relation to eggshell colour or the size of the spotted area.

Highlights

The eggshell provides mechanic protection for the egg content and the developing embryo
This study was carried out to investigate the effects of eggshell colour and spot properties on growth performance and carcass traits of Japanese quail (Coturnix coturnix japonica) eggs
Shank length, and slaughter and carcass weight do not vary in relation to eggshell colour or the size of the spotted area

Summary

Introduction

The eggshell provides mechanic protection for the egg content and the developing embryo. It serves as a barrier against microorganisms and as a source of calcium for the embryo. It has been reported that the intensity of the blue-green colour of the eggs of the pied flycatcher (Ficedula hypoleuca), apart from being positively correlated with the biliverdin content of the eggshell, is an indicator of the nutritional status of the laying females (Moreno et al, 2006). Duval et al (2013) reported that the eggshell of the eggs laid by female quails fed a diet with a restricted antioxidant capacity contained more protoporphyrin and less biliverdin. The pigments held responsible for the formation of reddish spots in spotted eggs, according to the structuralfunction hypothesis, namely, the protoporphyrins, are deposited in the parts of the eggshell characterized by less calcium deposition. García-Navas et al (2011) reported that in eggs of blue tit (Cyanistes caeruleus), the level of the protoporphyrin pigment in the eggshell is partly correlated with eggshell thickness

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