Elaboration of massage technique for semen collection and examination of semen characteristics in chinchilla (Chinchilla lanigera)

Abstract

The practice of artificial insemination for the long-tailed chinchilla has not been fully elaborated to date, and existing data available regarding their reproduction properties is contradictory. Until now, the collection of semen for chinchillas has been most-commonly obtained using electro-ejaculation methods exclusively. The primary objective of this study was the development of a manual technique for semen collection which meets all animal welfare requirements. An additional aim was to determine the basic spermatological parameters, such as motility, concentration, type and ratio of morphological abnormalities and live/dead cell ratio, under typical northern-hemisphere conditions, in Hungary. Over a 3 month period, a special massage technique was developed for the study, and using this method, the sperm parameters of 46 males were subsequently analyzed weekly for a period of one year. Approximately 66% of chinchillas responded positively to this technique, with the success rate of semen-collection attempts showing no variation between seasons. Average sperm concentration for the whole year was 935.17 million/ml using this method. Total cell motility was the highest in winter (90.3%), and the lowest in spring (84.3%). The proportion of live, intact cells were above 80% on average for the year, while the ratios of live, morphologically abnormal and dead cells were 6% and 14%, respectively. We found that midpiece abnormalities occurred in the highest proportion (0.95%-3.38%), while the head abnormalities showed the lowest ratio (0.01%-0.15%). Standard deviation among the parameters was relatively high, with the spring season proving to be the weakest in terms of sperm quality. This study has demonstrated that, semen can be successfully collected without the use of electro-ejaculation or anesthesia. Furthermore, although spermatological parameters do exhibit some fluctuation for the different times of the year, semen collected is nonetheless suitable for the purpose of artificial insemination of chinchillas at any time.