Significance of Semen Quality Test in the Diagnosis of Breeding Difficulty in Bulls

Abstract

Semen quality tests were performed on 195 semen samples collected from 116 bulls consisting of 41 Holsteins and 75 Japanese natives, all of which had been in active service in main artificial insemination centers. As a result, it was found out that 56 bulls had secreted semen the quality of which was within a normal range of fluctuation and that the remaining sixty had produced semen of abnormal quality.
1. Of 124 samples derived from normal bulls, 18 per cent was less than 4ml. One half of the 18 per cent had been collected from bulls less than 3 years old. The average number of spermatozoa was more than one billion per ml.
2. The activity of spermatozoa, as determined by the capillary method, was variable depending upon the functions of the auxiliary sexual glands. The deformity rate of spermatozoa per specimen was within 12 per cent in 80 per cent of bulls examined.
3. The average amount of fructose per sample was 456.9±277.2mg/dl in 124 samples of normal semen.
4. Some bulls used for artificial insemination secreted semen the properties of which beyond a normal range of variation. Such abnormal conditions include a reduced amount of ejaculation, aspermia, lowered activity of spermatozoa, and increase in number of deformed spermatozoa.
5. Biopsy of the testis was helpful to determine whether a breeding difficulty was derived from some disorder in the hypophysis or in the testis itself. It is also useful to decide a method of treatment and make a prognosis.