Single layer colloid centrifugation technique improves motility, viability and chromatin integrity of ram spermatozoa after thawing.

The cell membrane of ram spermatozoa is more sensitive to the freezing process than in other species due to its composition. As a result, the quality and viability of frozen thawed ram spermatozoa are often poor, which together with the specific structure of the ewe's cervix are the main reasons for lower fertility in ewes after intracervical insemination. In the present study we investigated the effects of semen centrifugation through a single layer of a species-specific colloid (Androcoll-O) on post-thaw quality of ram spermatozoa. Motility, viability and morphology were analysed 0, 6, 12 and 24 h after thawing. DNA fragmentation index (%DFI) of the samples was assessed 0 h after thawing, by SCSA™. Membrane and acrosome integrity of spermatozoa were analysed by Sybr-14/PI/PNA test 0 h after thawing. The proportion of motile spermatozoa was significantly higher in SLC - selected samples in comparison to control (not SLC - selected) samples at 0, 6, 12 (P < 0.001) and 24 h (P < 0.05). The proportion of viable spermatozoa was also significantly higher in SLC - selected samples in comparison to control samples at all times (P < 0.001). The proportion of abnormal acrosomes and morphologically abnormal spermatozoa (MAS) were significantly lower in SLC - selected samples compared to control samples at all times (P < 0.001). Analysis of chromatin stability revealed significantly lower %DFI values in SLC - selected samples compared to control samples (P < 0.001). The SYBR-14/PI/PNA test also revealed significantly better values in SLC - selected compared to control samples (P < 0.05). In conclusion, single layer colloid centrifugation significantly improved post-thaw quality and longevity of ram spermatozoa, making it suitable for artificial insemination initiatives.

Establishment of a pregnancy following intravaginal insemination with epididymal semen from a dog castrated due to benign prostatic hyperplasia.

Benign prostatic hyperplasia was diagnosed in an American Staffordshire Terrier of high breeding value presenting concurrent haematuria. Castration as a treatment was synchronized with the oestrus cycle of a bitch selected for insemination. After castration the cauda epididymis was flushed with Gent semen extender and collected spermatozoa were filtered and analysed by Hamilton Thorn computer assisted sperm analysis. A total of 7 ml semen containing 742 x 10(6) spermatozoa with 76.5% mean motility was used for insemination. Intravaginal insemination of the bitch was performed with an insemination catheter for dogs (Kruuse, Marslev, Denmark) on the day when plasma progesterone levels reached 9.9 ng/ml. Normal pregnancy without complications resulted in eight live-born puppies 63 days after insemination. This is the first report of a normal pregnancy and birth of puppies from a bitch inseminated with epididymal semen obtained from a dog affected by benign prostate hyperplasia.