Studies on Deep Freezing Preservation of Fowl Semen

Abstract

The condition of the semen stored by the present freezing method which requires only 17 minutes from the collection of semen until the completion of freezing was compared with that stored by the previous freezing method which required about 87 minutes to finish the same processes. Comparison was made in respect of the motility of spermatozoa after thawing, the percentage of the abnormal spermatozoa, especially neck-bending spermatozoa, and the fertility. The results are as follows.1. The motility of spermatozoa upon thawing was higher in the semen stored for 7, 41, 46, 55 and 62 days by the present freezing method than in the semen stored by the previous method for the same period. On the average the motility was 88.3% in the former and 80.8% in the latter.2. Examination of the thawed semens mentioned in the preceding paragraph showed that the percentage of neck-bending spermatozoa averaged 14.9% in the semens frozen by the present method and 29.0% in those frozen by the previous freezing method. Thus, there was observed striking difference between the two treatments.3. Insemination experiment using the semen frozen by the present method gave 60.0% of the fertility in the first week following insemination; this result may be regarded as a remarkable progress over the previous method which usually gives the corresponding fertility of less than 30%.4. The duration of fertility was 6 days on the average and the longest of it was 10 days in the present experiment.