Influence of the thawing rate on the cryopreservation of semen from collared peccaries (Tayassu tajacu) using Tris-based extenders

Abstract

The objective was to evaluate the influence of the thawing rate on the quality of frozen-thawed (cryopreserved in Tris-based extenders) semen obtained from collared peccaries (Tayassu tajacu). Semen from 13 sexually mature collared peccaries males were collected by electroejaculation, and evaluated for motility, vigor, sperm viability, membrane integrity, and sperm morphology. Semen was divided in two equal portions: the first was diluted in Tris-fructose and the other in Tris-glucose, with egg yolk (20%) and glycerol (3%) added to each portion. Extended semen was frozen in liquid nitrogen and thawed using two thawing protocols (37 degrees C for 1 min or 55 degrees C for 7 s, followed by an additional 30 s at 37 degrees C). There were no significant differences between the two extenders after extension, chilling, or glycerol addition. After thawing at 37 degrees C, there were 37.9 +/- 4.2% and 28.5 +/- 5.1% motile spermatozoa for samples extended in Tris-fructose and Tris-glucose, respectively, with 33.8 +/- 3.7% and 28.2 +/- 3.5% motile spermatozoa after thawing at 55 degrees C (no significant differences). Furthermore, there were no significant interactions between extenders and thawing protocols for any semen end point. In conclusion, semen from collared peccaries was successfully cryopreserved in Tris-based extenders and thawed with two protocols (37 degrees C for 1 min or 55 degrees C for 7 s).

Establishing the hypoosmotic swelling test for sperm analysis in collared peccaries (Pecari tajacu)

“…Until this moment, semen analysis in such species has been mainly based on the evaluation of classic parameters (Costa and Paula 2005;Souza et al, 2009). The hypoosmotic swelling (HOS) test was only empirically applied using distilled water as a hypoosmotic solution (Souza et al, 2009;Castelo et al, 2010).…”

“…The semen was collected using an electroejaculator (Autojac®, Neovet, Campinas, SP, Brazil) connected to a 12 V source, using the protocol previously described for the species (Castelo et al, 2010). Semen was collected in plastic tubes and immediately evaluated for color, pH and volume.…”

Protein profile of the seminal plasma of collared peccaries (Pecari tajacu Linnaeus, 1758)

“…administration of propofol (Propovan, Cristalia, Fortaleza, Brazil) on a dose of 5 mg/kg of body weight, as previously described (Souza et al 2009). Semen was collected with the aid of an electroejaculator (Autojac, Neovet, Campinas, SP, Brazil) connected to a 12 V source (Castelo et al 2010). The stimulatory cycle comprised ten stimuli in each voltage, starting from 5 V, followed by a voltage increase in steps of 1 V, up to 12 V. Each electrical stimulus lasted 3 s, with intermittent breaks of 2 s. The stimuli cycles were maintained for 10 min from the beginning of the procedure.…”

“…Sperm concentration was determined using a Neubauer counting chamber. Sperm functional integrity was analyzed by the hypoosmotic swelling test, using distilled water as the hypo-osmotic solution (Castelo et al 2010), counting 200 cells.…”

In vitro culture of somatic cells derived from ear tissue of collared peccary (Pecari tajacu Linnaeus, 1758) in medium with different requirements

“…In general, these strategies involve the cryopreservation of gametes and embryos (Andrabi & Mawxell 2007, León--Quinto et al 2009). In collared peccary, studies related to the cryopreservation of semen (Castelo et al 2010, Souza et al 2016) and ovarian tissue (Lima et al 2012) have already been developed. However, to have a complete genetic representative of the population biodiversity, it is necessary to also consider banks of somatic cells and tissues (Cetinkaya & Arat 2011, Li et al 2009, Liu et al 2014, Machado et al 2016.…”