Improved cryopreservation protocol for Blanca-Celtibérica buck semen collected by electroejaculation

Comparative ejaculatory response, fresh and frozen semen quality and fertility to artificial vagina vs electroejaculation method of semen collection in mithun (Bos frontalis) bulls

The study aimed to describe a comparative ejaculatory response, fresh and frozen-thawed semen quality and fertility of semen collected by artificial vagina and electroejaculation in mithun. Experimental bulls were divided into two groups, G-I: young bulls (n = 4; 4-5 years of age) and G-II: older bulls (n = 4; 8-10 years of age). Sixteen ejaculates were collected from each group G-I (AV₁ ) and G-II (AV₂ ) by artificial vagina method (control). Thirty-six ejaculates were collected from the same bulls from each group G-I (EE₁ ) and G-II (EE₂ ) by electroejaculation method (treatment). The study did not reveal any significant (p > 0.05) difference in the ejaculatory responses between EE₁ and EE₂ . Mann-Whitney U test indicated that salivation discomfort sign score was significantly (p < 0.05) higher in EE₁ . Fresh and frozen-thawed semen quality parameters, and motility and velocity profiles recorded by computer-assisted sperm analyser were significantly (p < 0.05) lower in electroejaculation than the artificial vagina. The conception rates (AV₁ vs EE₁ & AV₂ vs EE₂ ) at day 35-45 post insemination were nonsignificantly higher (p > 0.05) in the artificial vagina group. It concluded that, although artificial vagina method has better semen quality, nevertheless, electroejaculation has the potential for semen collection from free-range mithun bulls to incorporate in assisted reproductive technology procedures.

Effect of the Refrigeration System on In Vitro Quality and In Vivo Fertility of Goat Buck Sperm

Cooling goat sperm insemination doses to 4 °C causes a delay in their delivery. However, chilling these doses during the transportation period could expedite their delivery and the insemination process. In this study, an economical and simple apparatus for chilling goat semen doses in itinere was developed, and the in vitro quality and in vivo fertility of these doses were compared with those chilled by means of a programmable water bath in the laboratory at a rate of -0.18 °C/min. Of the tested prototypes, the one that provided an optimal combination of the chilling rate (average of -0.09 °C/min) and time required to reach 4 °C (3 h 45 min) was selected for further testing. Immediately after chilling and 24 h later, the doses chilled in the prototype were determined to be of higher quality than the samples chilled in the programmable water bath. Finally, the kidding rate was similar between the doses chilled in the programmable water bath (61.7% ± 7.1%) and in the prototype (56.1% ± 5.9%). In conclusion, successful chilling of goat sperm doses during transport is possible, thereby accelerating the delivery of insemination doses.