The impact of eggshell colour and spot area in Japanese quails: I. eggshell temperature during incubation and hatching results

ABSTRACT This study was carried out to investigate the effects of eggshell colour and spot properties (colour and size of the spot area) on eggshell incubation temperature and hatching outcomes of Japanese quail eggs (Coturnix coturnix japonica). Study material was 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 coloured 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. Mean relative weight losses of hatched and unhatched eggs between days 0-10 and 0-14 of embryonic development were 4.76% and 10.48% and 9.17% and 15.46%, respectively. The mean eggshell temperatures of hatched and unhatched eggs measured at the equatorial region on days 10 and 14 during embryonic development were 36.92 and 37.79 ºC and 36.84 and 37.18 ºC, respectively. Eggshell temperatures at the equatorial region on days 10 (36.89 ºC) and 14 (37.57 ºC) of embryonic development were lower than the fixed temperature of the incubator (37.6 ºC). Fertility, hatchability of fertile eggs, and hatchability and embryonic mortality rates do not vary in relation to eggshell colour or the size of the spotted area.

摘要 本研究旨在探究蛋壳颜色与斑点特征（斑点颜色、斑点区域面积大小）对日本鹌鹑（Coturnix coturnix japonica）蛋壳孵化温度及孵化结局的影响。研究材料根据蛋壳及斑点颜色分为五组：灰壳白底色具黑色斑点组（I）、灰壳白底色具蓝色斑点组（II）、灰壳棕底色具弥散状棕色斑点组（III）、浅绿壳具棕色斑点组（IV），以及灰壳棕底色具小型棕色斑点组（V）。采用数字图像分析法测定各组鹌鹑蛋的斑点区域面积。在胚胎发育第0~10天及第0~14天，已孵化蛋与未孵化蛋的平均相对重量损失分别为4.76%、10.48%与9.17%、15.46%。于胚胎发育第10天、第14天在赤道区域测得的已孵化蛋与未孵化蛋的平均蛋壳温度分别为36.92℃、37.79℃与36.84℃、37.18℃。胚胎发育第10天（36.89℃）与第14天（37.57℃）的赤道区域蛋壳温度均低于孵化器设定温度（37.6℃）。受精率、可育蛋孵化率、孵化率及胚胎死亡率均与蛋壳颜色或斑点区域面积无显著关联。