Possibilities of using the European bison (Bison bonasus) epididymal spermatozoa collected post-mortem for cryopreservation and artificial insemination: a pilot study

Abstract

BackgroundEuropean bison is the largest mammal in Europe with the population of approximately 4000 individuals. However, there is no report of post-mortem spermatozoa collection and cryopreservation from this species and the aim of this study was to test if the epididymal spermatozoa collected post-mortem from European bison are suitable for cryopreservation and artificial insemination (AI).MethodsEpididymides were collected post-mortem from two European bison bulls at age of 8 (bull 1) and 11 year (bull 2). Epididymal sperm was harvested by making multiple incisions in caudae epididymidis, which were then rinsed with extender. The left epididymis of bull 1 was rinsed with BioXcell (IMV, France), whereas the right epididymis of bull 1 and the right and left epididymides of bull 2 were rinsed with the extender based on Tris, citric acid, glucose, egg yolk, glycerol, antibiotics and distilled water (extender II). The diluted semen was cooled to 5 degrees C, and frozen in liquid nitrogen vapour. Then, properties of the frozen/thawed semen were examined with the use of computer-assisted semen analysis system, and thirty cows and nine heifers of domestic cattle were artificially inseminated.ResultsMotility of fresh spermatozoa collected from the right epididymis of bull 1 was 70% (spermatozoa diluted with extender II), and from the left one was 60% (spermatozoa diluted with BioXcell), whereas motility of fresh spermatozoa collected from bull 2 was 90% (spermatozoa diluted with extender II). Spermatozoa motility just after thawing were 11 and 13% in bull 1, respectively for spermatozoa collected from the left and right epididymis and 48% in bull 2. As a result of AI of domestic cows and heifers with the frozen/thawed European bison spermatozoa, two pregnancies were obtained in heifers. One pregnancy finished with a premature labour after 253 days of pregnancy, and the second one after 264 days of pregnancy.ConclusionsThis is the first report showing pregnancy in the domestic cattle following AI with frozen-thawed European bison spermatozoa collected post-mortem. The protocol of spermatozoa collection, dilution, and cryopreservation presented in this paper may be useful for the creating genetic resource bank in the European bison.

Morphological defects of epididymal spermatozoa in male roe deer (Capreolus capreolus) during the reproductive season

“…This is in agreement with the results of this study, as the percentage of abnormal spermatozoa found was relatively low. This would facilitate the creation of germplasm banks of not only endangered species (Ptak et al 2002, Kozdrowski et al 2011) but also those that could be at risk in the future (Holt and Pickard 1999). In addition, epididymal spermatozoa collected postmortem could be used for artificial insemination (Garde et al 2006, Morrow et al 2009), in vitro fertilization (Garcia-Alvarez et al 2009) and in vitro embryo production (Comizzoli et al 2001, Martins et al 2007).…”

Obtaining Wisent early blastocyst in vitro is a basic for protection and creation of biodiversity for this threatened species

“…Spermatozoa had previously been isolated from the epididymis of a male Wisent culled from another herd in Białowieża, out of the reproductive season, and frozen (Kozdrowski, Niżański, Dubiel, & Olech, ). Thawed spermatozoa were capacitated by the swim‐up method in 1 ml of TL stock solution for sperm capacitation (MINITUBE, Delevan, USA) with 6 mg/ml bovine serum albumin fraction V (BSA V) and 50 μg/ml gentamicin, pH 7.4.…”

“…Spermatozoa had previously been isolated from the epididymis of a male Wisent culled from another herd in Białowieża, out of the reproductive season, and frozen (Kozdrowski, Niżański, Dubiel, & Olech, 2011).…”

Cryopreservation in mammalian conservation biology: current applications and potential utility

“…75 This is the procedure of choice for small animals such as deer and squirrels, given the small size of the epididymis, [76][77][78] but it has also been used for large animals (camels, antelopes, European bisons, and Cantabrian brown bears). 75,[79][80][81] Retrograde flushing is another method of sperm collection that involves the injection of a buffered medium inside the vas deferens using a syringe. The pressure pushes the sperm toward an incision in the cauda epididymis, generally near the junction with the corpus, where the gametes are recovered.…”