Fertility of Frozen Fowl Semen Stored for Long Term (9 Years)

グリセリンの最終濃度7%の5%ブドウ糖・卵黄液で4倍に希釈した鶏精液を急速凍結法によって液体窒素中に9年間保存し,融解後の精子の活力,奇形率を調べ受精試験を行なった結果は次の如くである。
1. 9年間凍結保存した鶏精子の融解後の平均活力は75%(++以上)で,これまでの3か月,2年および5年間凍結保存した精子の活力にくらべやや低下を示した。
2. 9年間凍結保存した鶏精子の平均奇形率は8.3%で,3か月,2年,5年間凍結保存した精子のそれにくらべむしろ低く,凍結保存期間が長くなるにつれ奇形率が増加する傾向は認められなかった。
3. 1週目受精率は46.8%,2週目受精率は14.3%で,1週目受精率は3か月,2年,5年間凍結保存精子のそれにくらべ幾分低下したが,2週目受精率は3か月凍結保存精子による受精率より高かったが,2年,5年間凍結保存精子による受精率にくらべるとさらに低下した。

Fowl semen diluted with 5% glucose egg-yolk solution which contained 7% glycerol in its final concentration and quickly frozen by liquid nitrogen was stored at -196°C for 9 years. The motility, abnormality and fertility of the spermatozoa in thawed semen were studied and showed the following results.
1. The percentage of motile spermatozoa in thawed semen stored for 9 years was 75% on the average. The spermatozoa motility was slightly low as compared with that of the previous ones which had been stored for 1/4, 2 and 5 years.
2. The percentage of abnormal spermatozoa in thawed semen stored for 9 years was 8.3% on the average. This spermatozoa abnormality is rather low as compared with that of our previous works and did not seem to be adversely affected by the long storage time.
3. The fertility of the thawed semen was 46.8% in the first week and 14.3% in the second week. The first week fertility decreased in some degree as compared with the previous three results and the second week fertility decreased more than that of 2 and 5 years storage with the exception of 1/4 year.