Interactions between Straw Size and Thawing Rates on the Cryopreservation of Agouti (Dasyprocta aguti) Epididymal Sperm

Abstract

This study verifies the interactions between straw size and thawing rates and their impact on the epididymal sperm from this species. Caudae epididymidum from 10 agoutis were subjected to retrograde washing using a coconut water extender (ACP-109c(®) ). Epididymal sperm were evaluated and extended in ACP-109c(®) plus egg yolk (20%) and glycerol (6%). The samples were packaged in 0.25- or 0.50-ml straws, frozen in liquid nitrogen and thawed at 37°C/1 min or 70°C/8 s, followed by a re-evaluation. The use of 0.25-ml straws thawed at 37°C/1 min provided a value of 26.6% for sperm motility. No interactions between straw size and thawing rates were verified on agouti sperm (p > 0.05), but when 0.5-ml straws were thawed at 70°C/8 s, sperm vigour decreased significantly (p < 0.05). It is recommended that the agouti epididymal sperm cryopreserved in ACP-109c(®) extender should be packaged in 0.25- or 0.50-ml straws and thawed at 37°C/60 s.

Interactions Among Different Devices and Electrical Stimulus on the Electroejaculation of Captive Agoutis (Dasyprocta leporina)

“…The functional integrity of the sperm membrane was evaluated by a hypo‐osmotic swelling (HOST) test, using distilled water (0 mOsm/l) as the hypo‐osmotic solution (Silva et al. ).…”

“…; Silva et al. , ). However, this method requires the euthanasia of the individuals, therefore justifying the tentative to improve the electroejaculation protocols for the species.…”

Reproduction in agouti (Dasyprocta spp.): A review of reproductive physiology for developing assisted reproductive techniques

“…Application of ART as an initial step for developing methods for sperm recovery is required. Of late, methods for obtaining spermatozoa by retrograde epididymal washing (Ferraz et al, 2011;Silva et al, 2011Silva et al, , 2012Castelo et al, 2015) or electroejaculation (Mollineau et al, 2008;Martinez et al, 2013;Castelo et al, 2016) have been described for agouti.…”

“…In agouti, Ferraz et al (2011) were the first to demonstrate the possibility of obtaining spermatozoa by means of retrograde washing in animals previously submitted to orchiectomy, and they obtained a concentration of 748 ± 418.66 spermatozoa/mL. Subsequently, the technique was applied in the same species of agouti by Silva et al (2011Silva et al ( , 2012, in which a volume of 300 ± 2 μL was recovered with a concentration of 1.4 ± 0.3 × 10 9 spermatozoa/mL. Using the same method in D. leporina, Castelo et al (2015) were able to recover a total volume of 1.65 ± 0.22 mL with a concentration of 1.04 ± 0.2 × 10 6 spermatozoa/mL.…”

“…They verified that ACP-109c would be the most suitable diluent for processing and cryopreservation of these cells. Subsequently, the same group, studying the interactions between straw size (0.25 or 0.50 mL) and thawing rates (37°C for 60 s or 70°C for 8 s) for epididymal sperm, demonstrated that epididymal sperm of agouti could be efficiently cryopreserved in both 0.25 mL or 0.50 mL straws and thawing should be conducted at 37°C for 60 s. The use of 0.25 mL and 0.5 mL straws thawed at 37°C for 60 s provided a value of 26.6% and 18.4% for sperm motility, respectively (Silva et al, 2012).…”