Practical Method for Freezing Buck Semen

Abstract

Although several protocols for cryopreserving buck semen are described in the literature, they differ widely in factors such as season and method of semen collection, extender and sperm concentration. Therefore, choosing a protocol that is suitable for a particular on-farm situation can be problematic. In the present study, semen was collected by artificial vagina from seven bucks on a farm located approximately 90 minutes’ drive away from the laboratory, about 6 weeks before the start of the goat breeding season. The semen was immediately extended in warm semen extender containing soy lecithin and was placed in an insulated box with a cold pack for up to 4 h, during semen collection from the remaining bucks and subsequent transport to the laboratory. Following centrifugation at 4 °C and resuspension in the soy lecithin extender to a sperm concentration of 800 × 106 spermatozoa/mL, 0.25 mL plastic straws were filled and frozen in racks 4 cm above the surface of liquid nitrogen. This simple protocol resulted in an acceptable post-thaw quality for all seven bucks, with a mean post-thaw motility of 55 ± 21% and mean fragmented chromatin of 3.27 ± 1.39%. Normal sperm morphology was >90% in all ejaculates. The semen was sent to a gamete bank for long-term storage.

Validation of double freezing protocol for Beetal buck (Capra hircus) spermatozoa

“…These are frequently used at AI centres in goats (Bearden et al, 2004; Kaewkesa et al, 2016; Leboeuf et al, 2000; Purdy, 2006; Soares et al, 2015), rams (Byrne et al, 2000) and bull (Arav, Zeron, et al, 2002; Motemani et al, 2017). In a recent study, different freezing protocols were adapted on freezing buck semen into a workable protocol to suit the local farm conditions (Morrell et al, 2022).…”

Seminal quality comparison of first and second cryopreserved ejaculates of Alpine kid goats by flow cytometry

“…Although discarding the first ejaculate is a common practice, studies point to a decrease in sperm quality after the first (Martins et al, 2006) or fourth and fifth ejaculates (Shamsuddin et al, 2000), demonstrating the inconclusiveness of this recommendation. Furthermore, some studies using adult goats observed inconsistent results regarding seminal characteristics such as mass activity and sperm concentration, volume and motility (Shamsuddin et al, 2000;Barkawi et al, 2006;Gopinathan et al, 2021;Morrell et al, 2022).…”