Cold storage could revolutionize pig semen transport, study suggests
Researchers found that storing boar semen at 4°C instead of the standard 16-18°C may preserve fertility for a week, potentially solving a major logistics problem for the global swine industry. If validated further, the finding could cut costs and complexity in transporting breeding semen, especially during hot months when maintaining precise temperatures is expensive and difficult.
Originaltitel: Sperm quality and <em>in vitro</em> fertilizing ability of boar spermatozoa stored at 4 °C versus conventional storage for 1 week
<p><strong>Introduction:</strong> Since boar spermatozoa show a marked deterioration in sperm quality when cooled, insemination doses are usually stored at 16-18 degrees C. However, maintaining this temperature during transport of semen doses is challenging, particularly during the summer months. An alternative could be to store the doses at 4 degrees C if cold-shock to the sperm could be prevented. The objective of this study was to evaluate boar sperm quality and fertility in in vitro fertilization after storage in AndroStar Premium at 4 degrees C for 1 week.</p><p><strong>Methods:</strong> Insemination doses (n = 9) in AndroStar Premium from a commercial boar semen collection station were transported to the laboratory at approximately 20 degrees C. At the laboratory, sperm quality evaluation and was preformed and each dose was split; half of each ejaculate was stored in a climate-controlled box at 16-18 degrees C, the other was slowly cooled to 4 degrees C. Both samples were stored for 1 week before further sperm quality evaluation and in vitro fertilization (IVF) were performed. Mean values were tested using generalized linear regression, with treatment and boar as fixed factors; p <= 0.05 was considered significant.</p><p><strong>Results:</strong> Sperm membrane integrity (mean +/- sem: 91 +/- 0.05 and 83 +/- 0.09% for 16 and 4 degrees C, respectively) and superoxide production (6.79 +/- 2.37 and 13.54 +/- 6.23% for 16 and 4 degrees C, respectively), were different between treatments. The DNA fragmentation index was lower in cold-stored samples than in conventionally stored samples (3.74 +/- 2.25 and 7.40 +/- 3.36% for 4 and 16 degrees C, respectively). The numbers of oocytes developing to blastocyst on Day 6 (mean +/- sd: 9.0 +/- 8.0 and 6.0 +/- 5.0%, for storage at 16 and 4 degrees C, respectively) were not different between treatments.</p><p><strong>Discussion:</strong> Therefore, storage of boar semen doses in AndroStar Premium at 4 degrees C for up to 7 days would be a viable alternative to current praxis.</p>