Poster Presentation ESA-SRB-APEG-NZSE 2022

Fertility of Bos indicus bull sperm in SpermSafe-B following seven days of ambient temperature storage. (#414)

Erin K Klein 1 2 , Mohammad Bahrami 1 2 , Allan J Gunn 3 4 , Cyril P Stephen 3 4 , Aleona Swegen 1 2 , Robert John Aitken 1 2 , Zamira Gibb 1 2
  1. Priority Research Centre for Reproductive Science, University of Newcastle, Callaghan, NSW, Australia
  2. Infertility and Reproduction Research Program, Hunter Medical Research Institute, New Lambton Heights, NSW, Australia
  3. School of Animal and Veterinary Sciences, Charles Sturt University, Wagga Wagga, NSW, Australia
  4. Graham Centre for Agricultural Innovation, Wagga Wagga, NSW, Australia

The precise timing required for successful fixed-time artificial insemination (AI) can be a logistical challenge for producers with large, diverse herds of cattle. A novel method of bull sperm storage at ambient temperature has been developed to avoid the damaging freeze/thaw process, with the aim of extending the post-insemination lifespan of sperm in the female reproductive tract. Previously, this novel method of ambient temperature sperm storage in SpermSafe-B has shown promising results when fixed-time AI using 7-day stored sperm was performed on 2-year-old virgin Bos taurus heifers (n=18; 14 of 18 pregnant). To assess the fertility of Bos indicus sperm in this medium, a herd of 12 heifers (9 Bos indicus, 1 taurine-indicine cross, and 2 full Bos taurus) underwent a 12-day oestrus synchronisation protocol and were each inseminated with approximately 25 million 7-day stored Bos indicus sperm. At least 67% (8/12) of the heifers are known to have been cycling and all had body condition scores between 2 and 3. At a 35-day ultrasonographic pregnancy diagnosis, six of the 12 heifers (50%) were confirmed pregnant. These findings demonstrate that the fertility of Bos indicus sperm can be maintained in SpermSafe-B for 7 days of storage at room temperature and that these stored sperm have the capacity to achieve pregnancy in Bos indicus females. Ambient temperature sperm storage using SpermSafe-B could be a viable alternative for Bos indicus breeds, as well as Bos taurus breeds, when AIs will be performed within 7 days of semen collection. Although viability and motility have been maintained beyond 7 days of storage, there is a significant increase in viable sperm with destabilised membranes between days 10 and 14 (%M540 positive live cells: 19.4±5.70% vs. 47.4±7.64%; P≤0.005), suggesting 10 days may be the maximum duration of fertility for sperm stored in SpermSafe-B.