Studies on deep-freezing preservation of chicken semen : II. On the progeny test by making use of freezing fowl semen

　-79℃で3ヵ月間凍結保存した精液を用いて人工受精し， 得られた白レグ雄鶏の精液の一般性状を調べ，更にこの雄鶏を白レグ雌4羽に交配してその受精率，ふ化率，ふ化雛の性比および生時体重等を調べ，引きつづき雛の発育状態を観察した結果は次の如くである.
1. 凍結精液よりふ化した雄鶴のー射精時当りの平均射精量は0.13±0.06 ml. であった.
2. 精子濃度は1mm3 当り平均4.12±1.22百万でー射精当りの総精子数は0.543±0.310 十億であった.
3. 採取精液のpHは平均7. 18±0.19 であった.
4. 採取精液中の畸形精子の割合は平均11. 0±6.3% であった，
5. -79℃で3ヵ月間凍結保存した精液からふ化した雄鶏を白レグ雌4羽に交配した場合， 交配後2週間の平均受精率およびふ化率はそれぞれ78.8% ，53.9% であった.
6. 上述の交配試験の結果得られた雛14 羽の性比は8♂♂ : 6♀♀で雄鶏がやや多いように思われる.
7. ふ化雛の初生体重は平均43.03±1.82g で従来の白レグ雛の平均初生体重37.5 g 1亡くらべて約16%増重の雛が得られた.
8. 得られた雛はいずれも極めて活潑で，普通の卵からふ化した雛とくらべて何等異なるところがなく順調な発育をつづけている.

The present experiments have examined the general properties of semen produced by the cock hatched from the deep-freezing semen stored for three months at -79°C. The cock was mated with four White Leghorn hens to examine the fertility, hatchability of the eggs produced by the hens. Further the abnormalities, sex ratio and growing conditions of chicks hatched from their fertilized eggs were studied in order to inquire into the progeny test. The results can be summarized as follows;

1. The amount of semen at one operation was 0.13 ± 0.06 ml average.
2. Semen concentration per 1 mm3 was 4.12 ± 1.22 millions average and the total number of spermatozoa per ejaculation was 0.543 ± 0.310 billions average.
3. pH-value of the semen was 7.18±0.19 on the average.
4. The percentages of abnormal spermatozoa in the semen was 11.0 ± 6.3 on the average.
5. The fertility and hatchability of the eggs produced by crossing between the cock hatched from the deep-freezing semen stored for three months at -79°C and the four White Leghorn hens were respectively 78.8 percent and 53.9 percent on the average during two weeks after mating.
6. Sex ratio in the present experiments showed 8 ♂♂ : 6 ♀♀, or emerged with 57.1 percent males among 14 chicks. Male seems to be slightly in evidence in the ratio of sexes.
7. Live weight of a-day-old chicks was 43.03 ± 1.82 g on the average and about 16 percent heavier than that of a normal one day old White Leghorn chick before.
8. The progenies gained by the present experiments showed a very active behavior and no abnormality compared to chicks hatched from normal nest eggs.