Effect of physical characteristics of hatching eggs laid by Lueyang chicken on hatchability | 略阳乌鸡种蛋物理特征与孵化率的关系

Chinese. 为了解种蛋的物理特征与其孵化率的关系，建立一套适合略阳乌鸡种蛋挑选的标准，以提高其孵化率，本研究在20000羽略阳乌鸡1周所产的种蛋中随机选取550枚进行孵化，并分析蛋壳颜色、蛋重、蛋壳厚度、蛋形指数和18d失水率与孵化率的关系。结果显示：蛋色和蛋壳厚度对孵化率的影响均不显著（P〉0．05）；蛋重偏小的蛋孵化率最高（77．13％），但与中等大小（74．77％）和偏大（73．39％）的蛋相比差异不显著（P〉0．05）；18d失水率越高孵化率越低，但组间差异不显著（P〉0．05）。蛋形指数对孵化率有显著影响（P〈0．05），偏圆形蛋的孵化率（短轴／长轴为0．79～0．85，83．19％）显著高于卵圆形（短轴／长轴为0．74～0．78，76．07％）和偏长形种蛋（短轴／长轴为0．68～0．73，69．31％）；相关分析结果显示，各指标间均存在显著的弱相关关系（r=0．092―0．165，P〈0．05）。研究结果表明几项指标对孵化率均有一定影响，但以蛋形指数的影响最为明显，因此在略阳鸟鸡种蛋挑选时应优先考虑偏圆形蛋。

English. Hatchability has a close relationship with the physical characters of hatching eggs. To establish a set of selective criteria of hatching eggs fitting for Lueyang chicken and to further improve its hatchability, this experiment was carried out to determine the relationship of eggshell color, egg weight, eggshell thick, egg shape index, ratio of egg water loss in 18 d and hatchability. 550 hatching eggs were randomly selected to hatch from eggs laid by 20 000 Lueyang chickens within one week. The results showed that eggshell color and eggshell thick have no a significant effect on hatchability（P〈0.05）. Hatchability（77. 13%） of small size eggs was the highest compared to ones of medium （74.77%） and large size（73.39% ） eggs,however the difference did not reach statistical significance（ P〉0.05）. The ratio of egg water loss in 18 d had a negative effect on hatchability despite it was not significant（ P〈0.05）. Egg shape index had a significant effect on hatchability（ P〈0. 05） ,where hatchability of round eggs（ratio of the maximum breadth and length ：079 - 0.85,83.19% ） is superior to ones of normal shape（0.74 - 0.78,76.07 % ） and narrow shape eggs （0.68 - 0.73,69.31% ）. Correlation analysis showed that there are significant weak correlations between several egg traits（r = 0. 092- 0. 165, P〈0.05）. The data indicated that several indexes are relevant to hatchability to some extents,of which the effect of egg shape index on hatchability is the most significant one. Thus, it recommends that round eggs should be preferably selected for hatching eggs of Lueyang chicken.