Use of immobilized cryopreserved bovine semen in a blind artificial insemination trial

Abstract

To make timing of artificial insemination (AI) relative to ovulation less critical, methods for prolonging shelf life of spermatozoa in vivo after AI have been attempted to be developed. Encapsulation of sperm cells is a documented technology, and recently, a technology in which sperm cells are embedded in alginate gel has been introduced and commercialized. In this study, standard processed semen with the Biladyl extender (control) was compared with semen processed by sperm immobilization technology developed by SpermVital AS in a blind field trial. Moreover, in vitro acrosome and plasma membrane integrity was assessed and compared with AI fertility data for possible correlation. Semen from 16 Norwegian Red young bulls with unknown fertility was collected and processed after splitting the semen in two aliquots. These aliquots were processed with the standard Biladyl extender or the SpermVital extender to a final number of 12 × 10(6) and 25 × 10(6) spermatozoa/dose, respectively. In total, 2000 semen doses were produced from each bull, divided equally by treatment. Artificial insemination doses were set up to design a blinded AI regime; 5 + 5 straws from each extender within ejaculates in ten-straw goblets were distributed to AI technicians and veterinarians all over Norway. Outcomes of the inseminations were measured as 56-day nonreturn rate (NRR). Postthaw sperm quality was assessed by flow cytometry using propidium iodide and Alexa 488-conjugated peanut agglutinin to assess the proportion of plasma membrane and acrosome-intact sperm cells, respectively. In total, data from 14,125 first inseminations performed over a 12-month period, 7081 with Biladyl and 7044 with SpermVital semen, were used in the statistical analyses. There was no significant difference in 56-day NRR for the two semen categories, overall NRR being 72.5% and 72.7% for Biladyl and SpermVital, respectively. The flow cytometric results revealed a significant higher level of acrosome-intact live spermatozoa in Biladyl-processed semen compared to SpermVital semen. The results indicate that the level of acrosome-intact live spermatozoa in the AI dose did not affect the 56-day NRR for the two semen processing methods. In conclusion, this study has showed that immobilized spermatozoa provide equal fertility results as standard processed semen when AI is performed in a blinded field trial, although the immobilization procedure caused increased sperm damage evaluated in vitro compared to standard semen processing procedure.

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

“…Even though there were significant differences in sperm DNA integrity between the B, C and SV semen, they are not likely to affect fertility outcome after AI. Importantly, no significant differences between AIs performed with NRF semen immobilized by the first production line of SV technology (C), which showed the highest levels of sperm DFI (%) and SD DFI in the present study, and conventionally preserved semen was found in a large AI study (Standerholen et al., ).…”

“…The third part was processed by immobilization as in Standerholen et al. () to 25 million sperm per straw and served as a control (hereafter referred to as C; control immobilization; first commercialized production line of SpermVital ® Technology). All processed semen samples were cryopreserved as described by 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., ). Furthermore, early insemination with SpermVital ® was comparable with double insemination of conventionally processed semen (Alm‐Kristiansen et al., ).…”

Alginate encapsulation preserves the quality and fertilizing ability of Mediterranean Italian water buffalo (Bubalus bubalis) and Holstein Friesian (Bos taurus) spermatozoa after cryopreservation

“…Their pregnancy rate (45%) was similar to that in our study (40%). Recently, Standerholen et al [32], used 85 bovine semen doses, immobilized in an alginate-based matrix, for an in vivo trial. The authors concluded that there were no differences between the outcome of AI using encapsulated or conventionally diluted frozen sperm.…”

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

“…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.…”