Reproductive performance of immobilized cryopreserved bovine semen used for timed artificial insemination

Abstract

The SpermVital technology comprises embedding of spermatozoa within an alginate gel to facilitate release of sperm cells over a prolonged period in utero after AI. The aim of this study was to examine whether the survival time of spermatozoa is extended when applying this immobilization technology in combination with cryopreservation. Sperm cell survival (acrosome and plasma membrane integrity) was studied in vitro for 48 hr at physiological temperature. One dose of SpermVital (SV) semen was compared with single doses of Biladyl (B) processed semen as well as double doses of B (B double). B double was obtained by adding a second B dose the following day, thereby mimicking double AI. Furthermore, reproductive performance applying single early timed AI (TAI) with SV following oestrus synchronization was studied in a field trial. Double insemination (TAI on two consecutive days) with B semen served as control. Number of acrosome-intact live sperm cells decreased over time in vitro for all treatments (p < .05). There was no difference between SV sperm cell survival and B double after 24 hr (p > .05). However, after 48 hr, SV sperm cell survival was higher than B double (p < .05). Moreover, multivariate analysis showed that the outcome of single early TAI with SV was not significantly different from B double (p > .05). Likelihood of pregnancy and calving in the heifer group was higher than in the cow group (p < .05). These results imply that spermatozoa immobilized in alginate gel have prolonged survival.

In vitro studies of Norwegian Red bovine semen immobilized and cryopreserved in alginate solid gel network

“…Moreover, reduction in levels of AIL spermatozoa of both C and SV semen over time was lower than for B semen. Recently, comparable fertility rates were achieved after early AI with semen processed by the SpermVital ® technology in comparison with double AI with B semen (Alm‐Kristiansen et al., ).…”

“…Although the first commercialized production line of SpermVital ® semen has shown decreased post-thaw sperm quality compared to conventionally processed semen, an equal fertility rate was achieved for the two semen types (Standerholen et al, 2015). Furthermore, early insemination with SpermVital ® was comparable with double insemination of conventionally processed semen (Alm-Kristiansen et al, 2017). The SpermVital ® technology was commercialized in 2010 and is continuously under development to meet the demands in the AI markets.…”

Relationship between post‐thaw adenosine triphosphate content, motility and viability in cryopreserved bovine semen applying two different preservation methods

“…The other aliquot was diluted in a two‐step dilution procedure in Biladyl ® (hereafter referred to as B) extender (13,500/0,004–0,006, Minitube GmbH, Tiefenbach, Germany) to a final standard concentration of 15 million per straw. All processed semen samples were cryopreserved as described by Alm‐Kristiansen et al ().…”

“…Furthermore, in an attempt to prolong spermatozoa lifespan in vivo in the female, new semen processing methods have been established. Bovine sperm cells can be encapsulated in alginate beads (Perteghella et al, ) or immobilized by the SpermVital ® technology in solid alginate gel before freezing (Alm‐Kristiansen et al, ; Standerholen et al, ). Common goal for all processing methods is to minimize sperm cryo‐injuries.…”

Studies of gel with immobilized semen by intrauterine endoscopy post‐artificial insemination

“…Timing of AI relative to oestrous signs is assumed more flexible applying SV semen compared with standard semen. Alm‐Kristiansen et al () reported similar pregnancy rates between AIs using a single AI dose with immobilized SV semen early in heat and AIs using standard processed semen inseminated on two consecutive days. Further, in vitro evaluation of SV spermatozoa quality post‐thaw and following incubation has demonstrated prolonged viability compared with standard processed semen (Alm‐Kristiansen et al, ).…”