Abstract
Irreversible damage caused by cold shock has been assumed to occur when boar semen is exposed to temperatures below 15°C. Identification of the lower critical temperature at which extended boar semen undergoes cold shock, however, has yet to be defined. The aims of this study were to 1) identify the cold-shock critical temperature and time on extended boar semen as assessed by sperm motility and morphology, and 2) determine the effects on fertility of using extended porcine semen exposed to this critical temperature and time. For Objective 1, ejaculates from 18 boars were collected, analyzed and extended in Androhep® to 50 × 10 6 sperm/mL. Doses (4 × 10 sperm) from each ejaculate were exposed to 5 storage temperatures (8, 10, 12, 14 and 17°C). Sperm motility and morphology (including acrosomes) were assessed following collection and at 12-h intervals for 48-h. Decreases in sperm motility occurred within the first 12-h at all temperatures. Sample motility dropped below 70% within 12-h in the 8°C group and by 48-h in the 10°C group. Sample motility was >75% in the 12, 14 and 17°C (control) groups throughout the trial. The percentage of morphologically abnormal sperm cells, including acrosomes, did not change within or between treatment groups over the 48-h storage period. In Objective 2, boar ejaculates (n=9) were handled as in the first objective and were equally divided into treated (12°C for ≤ 60-h) and control (17°C for ≤ 60-h) groups. Using a timed, double insemination technique, 135 sows were bred by AI using either 12°C (n=74) or 17°C (n=61) extended, stored semen. No differences were observed in the farrowing rate (93 vs 95%), total offspring born (11.58 vs 11.61) or number live born (10.68 vs 10.63) between 12 and 17°C groups, respectively. The results demonstrate that acceptable fertility can be obtained with Androhep® extended boar semen exposed to temperatures as low as 12°C for up to 60-h, and that cold shock appears to occur in vitro when extended boar semen is exposed to storage temperatures below 12°C.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
