コリデール種緬羊と同雑種F1との産毛能力の比較

This study has been carried out to compare the wool producing ability of the Corriedale hoggets with that of the Corriedale F1 cross hoggets that were produced by crossing the Corriedale on the other breeds of sheep to create a new type of sheep for mutton and lamb production in Japan. The F1 cross hoggets used for the comparison of the wool producing ability, wool yield and characters of 5 Corriedale hoggets were 6 Corriedale × Southdown, 6 Corriedale × Romney Marsh and 3 corriedale × Border Leicester F1 cross hoggets. Wool yields(grease fleece and clean fleece yield) and wool characters(wool fineness, stretched length of wool, number of crimps and wool density) at about 9 months after birth between the Corriedale and F1 cross hoggets born in spring were compared in 1959 and 1960. The results obtained are summarized as follows; (1)No significant differences in grease fleece and clean fleece yield between the Corriedale breed and F1 crosses were observed. However, the fleece yields of the Romney Marsh and Border Leicester F1 crosses were higher than the Corriedale breed, while the fleece yield of the Southdown F1 cross lower than the Corriedale breed. (2)There was no significant difference in the wool fineness between the Corriedale breed and F1 crosses, except in the wool fineness(significant at 0.1% level) between the Corriedale breed and Border Leicester Fl cross. The wool fineness of the Romney Marsh and Border Leicester F1 crosses was greater than the Morrisdale breed, while the wool fineness of the Southdown F1 cross a little smaller than the Corriedale breed. (3)Difference in the stretched length of wool between the Corriedale breed and F1 crosses, except in the stretched length of wool(significant at 1% level) between the Corriedale breed and Southdown Fl cross, was not significant. The stretched length of the Romney marsh and Border Leicester F1 crosses was greater than the Corriedale breed, while the stretched length of the Southdown F1 cross smaller than the Corriedale breed. (4)The numbers of crimps of the Coriedale breed, and Romney Marsh and Border Leicester F1 crosses were significantly different at 0.1% and 1% levels. The number of crimps in the Corriedale breed was the largest, while the difference in the crimp number between the Corriedale breed and F1 crosses was considerably small. (5)The wool density showed no significant difference between the Corriedale breed and Southdown F1 cross, while a significant difference was seen at 5% and 0.1% levels between the Corriedale breed and Romney Marsh and Border Leicester F1 crosses. The wool density of the Corriedale breed was smaller than the South down and Romney Marsh F1 crosses, but greater than the Border Leicester F1 cross.