高橋, 紀代志

TAKAHASHI, Kiyoshi

Shape of Hen's Egg. I. Eggs of Crossbred (WL♂×NH♀) Hens. I. ISHIBASHI and K. TAKAHASHI. Faculty of Horticulture, Chiba University, Matsudo, Japan. Tech. Bull. Fac. Hort. Chiba Univ., No.15: 105〜113, 1967. The shape was compared between eggs laid by crossbred hens derived from New Hampshire hens mated with White Leghorn cocks (WL♂×NH♀) and eggs laid by purebred White Leghorn (WL) and New Hampshire (NH) hens. The materials used consisted of 1, 660WL, 3, 496NH, and 6, 874 WL♂×NH♀ eggs produced for 365 days after the first eggs were laid. In the crossbred WL♂×NH♀ hens, the tendency of heterosis was observed in sexual maturity at the first egg laying, in the number of eggs produced, and egg weight. The eggs produced by WL, NH, and WL♂×NH♀ hens showed an average coefficient of shape of 71.67, 76.21, and 74.56, respectively. They decreased in coefficient of shape with the advance in days after the first-egg laying or with an increase in egg weight. A close correlation was observed between egg weight and the length (r=0.753〜0.818) or width (r=0.792〜0.911) of the egg.