Storage of boar semen

Evaluation of swine fertilisation medium (SFM) efficiency in preserving spermatozoa quality during long-term storage in comparison to four commercial swine extenders

“…These findings emphasise the importance of the buffering capacity of extenders and can contribute to explain the better results obtained with SFM and AeG. Johnson et al (2000) reported that spermatozoa metabolism tended to decrease with an increased tendency of acidification (pH under 7.2). These authors stated that intracellular acidosis enables spermatozoa to survive longer due to an impaired glycolitic metabolism and a consequent reduction in their motility.…”

“…Before in vitro motility analyses, the semen samples are heated and re-oxygenated and this manipulation is sufficient to resume motility. This hypothesis has also been confirmed by the observation that, in the boar, the pH in the cauda epididymis is approximately 6.5 (Rodriguez-Martinez et al, 1990) while, after ejaculation and mixing with accessory sex gland secretions, the pH increases from 7.2 to 7.5 (Johnson et al, 2000). This increase is able to render spermatozoa fully motile for fertilisation processes.…”

“…Again SFM is especially rich in BSA and EDTA, chelating compounds very effective in sequestering divalent metal ions, especially Ca 21 , preventing the initiation of capacitation (Johnson et al, 2000). These are the main differential characteristics between SFM and others diluents tested.…”

“…Such a phenomenon can be composed of non-regulated capacitation-like modifications (Bailey et al, 2000), structural and functional changes (Johnson et al, 2000), loss of DNA integrity (Fraser and Strzezek, 2004) and membrane fatty acid peroxidation (Cerolini et al, 2000); these modifications can be postponed by using various extenders (Huo et al, 2002). Long-term extenders have some advantages; they allow better organisation at semen collection centres, longdistance transport and the possibility of conducting tests on the semen before use (Gadea, 2003); however the storage of semen for long time before insemination reduces the subsequent viability of spermatozoa in the female genital tract, requiring an accurate timing of AI (Johnson et al, 2000).The purpose of the present study was therefore to analyse the ability of SFM, in comparison to four commercial extenders, which have been extensively tested also in field studies, in preserving the quality and the longevity of diluted boar semen stored at 16.58C for 15 days, by evaluating -E-mail: marialaura.bacci@unibo.it 269 parameters representing some of the main predictive tests for boar semen, which are relevant for their fertilising ability. …”

Successful cryopreservation of whole sheep ovary by using DMSO-free cryoprotectant

“…Furthermore, these extenders could substitute some phospholipids on the membrane, thereby decreasing the phase transition temperature [34]. And the amount of cholesterol in a membrane influences its thermotropic behavior [35]. Cholesterol intercalates into the lipophilic core of the membrane, associating with the fatty acyl chains of the phospholipids, and inhibits fatty acids from interacting with other fatty acids when the membrane is cooled [36].…”