In the swine industry, the choice of semen extender plays a crucial role in reproductive efficiency. Traditionally extender has been classified into long, medium and short acting. However, we should prioritise the overall performance of the extender over the days of storage. The extender is the medium in which the sperm is preserved until insemination, so we must ensure that the sperm is protected from all external factors to which it is exposed during processing, transport and storage.

The performance of the extender is of particular importance when faced with certain climatic conditions such as high temperatures. In these cases, the use of high performance porcine semen extender becomes more relevant, as it offers a better protection of the spermatozoa compared to BTS extenders.

Limitations of BTS in Hot Climates

Among swine producers who inseminate with 24-hour fresh semen, the use of short acting extender such as BTS has become widespread. These extenders allow the properties of the sperm to be maintained for a limited period of time, usually 24-72 hours. However, their efficacy may be compromised in high temperature conditions, which are common in many regions during the summer or in hot climates.

Adverse factors due to high temperatures include:

  • Thermal Stability: Porcine semen is very sensitive to temperature and susceptible to thermal shock. Membrane stabilisers in high performance extender products can cushion the damage caused by high temperatures.
  • Limited antioxidant protection: In hot environments, spermatozoa can suffer thermal shock, leading to changes in cell metabolism and ultimately oxidative damage. High-yield extenders have antioxidants that protect sperm from this damage.
  • Reduced antibacterial protection: High temperatures lead to increased bacterial growth. BTS diluents are less able to block bacterial growth and prevent the effects of contamination.

BTS extenders are optimal for semen preservation under normal conditions. However, if we are faced with certain conditions such as high temperatures, high performance extenders ensure better preservation and therefore better prolificacy and fertility results.