Assessment of the interaction between straw size and thawing rate and its impact on in vitro quality of post-thaw goat semen

Francisco Silvestre Brilhante Bezerra,Tiago Da Costa Dantas,Bruno Rodrigo Simão,Alexandre Rodrigues Silva,Thibério De Souza Castelo,Érika Aparecida Araújo Dos Santos

doi:10.1590/s1516-35982012000300016

Francisco Silvestre Brilhante Bezerra, Tiago Da Costa Dantas + Show 4 more

Open Access

https://doi.org/10.1590/s1516-35982012000300016

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Abstract

The objective of this study was to analyze interactions between different straw sizes and thawing rates on the post-thaw goat semen parameters. Twenty-one ejaculates (seven per animal) were collected from three stud bucks by using an artificial vagina. After evaluation, the semen was extended in Tris-egg yolk-glycerol and packed in 0.25 and 0.50 mL straws, followed by storage in liquid nitrogen. Thawing was performed using two different rates: 37 oC/1 min and 55 oC/7 s. The interaction between the 0.5-mL straw and the thawing rate of 55 oC/7 s promoted higher progressive motility. When the effect of straws alone was analyzed, it was verified that the use of the 0.50 mL straw promoted better conservation than the 0.25 mL one for progressive motility and acrosomal integrity, after the frozen-thawing procedures. Optimal results for progressive motility were achieved when goat semen was frozen in 0.5 mL straws and thawed in water at 55 oC/7 s.

Highlights

Cryopreservation as a technique for goat semen storage supports a genome resource bank for an indeterminate period of time
Straws containing goat semen are thawed at 37 oC in a water bath for 12-30 s (Watson, 2000; Cabrera et al, 2005), but another slow protocol (5 oC/2 min in water bath) was demonstrated with lesser efficiency (Deka & Rao, 1987)
A total of 30.8±2.0% sperms with functional membrane integrity were found in the hypoosmotic swelling test (HOST) for fresh semen, which demonstrates that membrane damage still exists in the beginning of the experiment

Summary

Introduction

Cryopreservation as a technique for goat semen storage supports a genome resource bank for an indeterminate period of time. Freezing and thawing induce detrimental effects on the ultra-structure, biochemistry, and functional integrity of the sperm (Watson, 2000), resulting in a reduction of motility, membrane integrity and fertilizing ability (Purdy, 2006) Many factors, such as freezing rate (Chemineau et al, 1991), extender (Hashemi et al, 2007), cryoprotectant (Lopes et al, 2009), dilution rate (Evans & Maxwell, 1987; Ritar et al, 1990a) and packaging method (Maxwell et al, 1995; Paulenz et al, 2004) affect the quality of frozen-thawed semen from different species. Straws containing goat semen are thawed at 37 oC in a water bath for 12-30 s (Watson, 2000; Cabrera et al, 2005), but another slow protocol (5 oC/2 min in water bath) was demonstrated with lesser efficiency (Deka & Rao, 1987). Tuli et al (1991) observed significantly higher progressive motility on goat semen thawed at 70 oC/7 s, compared with the thawing rates of 37 oC/2 min or 40 oC/20 s

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