Effect of testicle postmortem storage on goat frozen-thawed epididymal sperm quality as a tool to improve genebanking in local breeds

Abstract

The interest to develop assisted reproductive technologies and cryobanking for farm animal genetic resource conservation has recently increased. However, cryopreservation for ex-situ management of genetic diversity sometimes is not routinely feasible, owing to the lack of facilities (AI centres, laboratories) and expertise near the local breed farming area. In these cases, epididymal sperm obtained from slaughtered or castrated animals, associated with the possibility of managing rather long periods between animal death, sperm recovery and freezing, would increase the opportunities to create semen storages. This investigation addresses the pre-freeze/post-thaw quality of goat epididymal sperm as a function of testicle storage temperature (environment or +5°C) and time elapsed between animal's death and sperm recovery (0, 24, 48, 72 h) to establish the optimal protocols for the recovery and cryopreservation of epididymal sperm in this species. Testicles of 50 mature bucks collected at the abattoir were divided in two groups: half of the testicles (n = 50) were transported to the laboratory at environment temperature (E), whereas the remaining half (n = 50) at a refrigeration temperature (R) of +5°C. In the two groups (E) and (R), one testicle from each pair was processed after slaughter forming the time 0 groups (0E and 0R). The contralateral testicle was processed after 24, 48 or 72 h of storage, at the corresponding temperature. Sperm motility and kinetic parameters, viability and morphology were assessed in pre-freeze and post-thaw samples. Until 48 h postmortem, both E and R temperatures are able to maintain good pre-freeze epididymal sperm quality. After 48 h postmortem, R temperature is fundamental to reduce epididymal sperm quality decay in pre-freeze samples. Moreover, testicle refrigeration also has a positive impact on post-thaw samples, allowing a lower decline through time considering total motility, kinetics parameters, sperm viability and sperm abnormalities. Therefore, when sperm cryopreservation is not immediately practicable, goat testicles should be transported and stored at 5°C up to a maximum of 48 h postmortem to ensure an acceptable sperm quality.

Cryopreservation and its effects on motility and gene expression patterns and fertilizing potential of bovine epididymal sperm

“…Reports in some ruminants such as bovine, goat and red deer indicate spermatozoa from epididymides are less tolerant to cryopreservation than spermatozoa from an ejaculate (Chaveiro, Cerqueira, Silva, Franco, & Moreira da Silva, 2015; Martins et al., 2009; Turri, Madeddu, Gliozzi, Gandini, & Pizzi, 2014; Zomborszky, Zubor, Toth, & Horn, 1999), especially when maintained in testes without blood flow and refrigerated during storage (Martins et al., 2009). After cryopreservation, the motility and its pattern were evaluated using CASA in the current study.…”

Effects of post-mortem storage conditions of bovine epididymides on sperm characteristics: investigating a tool for preservation of sperm from endangered species

“…The method for retrograde flushing resulted in a satisfying recovery of spermatozoa, as found previously in different species (Sankai et al ., 2001; Kaabi et al ., 2003; Martinez-Pastor et al ., 2005; Lone et al ., 2011; Turri et al ., 2013). Motility and viability at 0 h tended to be lower compared with results after 24 and 48 h storage.…”

“…This could indicate variation between the testicles from one individual, but could also be caused by the fact that T0 testicles were not refrigerated at 5°C but kept for up to 3 h at room temperature before being processed. Refrigeration of the epididymis has resulted in sustained motility and viability (Lone et al ., 2011; Turri et al ., 2013; Takeo et al ., 2014), probably as a result of the reduced metabolic rate of spermatozoa at 5°C (Salamon and Maxwell, 2000). When stored for 48 h, the motility and viability declined, illustrating a storage effect also found by Martins et al .…”

“…Spermatozoa that did not take up stain (white) were counted as live membrane-intact cells, whereas spermatozoa with detectable eosin (pink) were counted as dead membrane-damaged cells. The following morphological categories were recorded as described by Blom (1983): tail coilings, deformations, abnormal heads (small, giant) and tail segment missing (Turri et al ., 2012, 2013). The percentage of each abnormality was calculated.…”

Implementation and cost analysis of a regional farm animal cryobank: an Italian case study

“…The sheep species is known requiring long training periods for semen collection (Woelders et al 2012); moreover, AI is not routinely used for Brianzola sheep breed. Thus, for Brianzola sheep, epididymal sperm was extracted from the testicles of slaughtered animals (Turri et al 2014). Goat semen was collected on farms through repeated semen collections, by using an artificial vagina and females in oestrous as teasers.…”