B. Asadi’s scientific contributions

Objective: This study investigated the effect of adding seminal plasma to frozen-thawed sperm on the quality of sperm and pregnancy following insemination in dromedary camels. Methods: In experiment 1, the frozen-thawed semen from 9 collections (3 bulls) was further diluted with either the base extender (EXT) or Homologous seminal plasma (HSP). In the second experiment, a pooled sample of frozen-thawed semen was diluted with either seminal plasma from 3 bulls. Live percentage, total and progressive motility, functional and acrosome integrity, and sperm kinematics were evaluated at 15, 60, and 120 minutes post-thawing and compared to the non-treated control. In experiment 3, frozen semen was used to inseminate camels in the following experimental groups: 1-Single insemination with double dose undiluted frozen semen (n=9); 2-Re-insemination in 6 hours with undiluted semen(n=13); 3-Single insemination with HSP treated sperm(n=14). Results: Frozen-thawed sperm diluted in HSP or the seminal plasma from Bull C indicated an improvement in all parameters after 1 hour post-thawing incubation (P<0.05). The proportion of total and progressively motile sperm did not drop significantly at 60 minutes post-thawing when diluted with the seminal plasma of Bull C (P>0.05). Double insemination with nontreated sperm and single insemination with HSP-treated sperm resulted in similar pregnancy rates (15.3% vs. 21.4%, P>0.05). None of the camels conceived with single insemination of nontreated sperm. Conclusion: seminal plasma improves sperm longevity and motility after thawing in dromedary camel with a significant between-bull variation in effect. Low post-thaw sperm longevity might be the cause behind the low pregnancy rates in frozen semen insemination of dromedary camels.

The objectives of this study were to comparatively identify the common bacterial isolates from the uteri of camels coming from different reproductive backgrounds after standardizing the sampling method and to investigate the association of clinically measurable parameters with uterine colonization by these isolates. The uterine samples from 856 dromedary camels yielded a total of 17 different bacterial species with a higher proportion of sub-fertile camel uteri being colonized by bacteria (66.6%) as compared to nulliparous, recently calved, and those with unknown reproductive history combined (44.2%; p < 0.05). Camels with body condition scoring < 3 and those with a consistently echogenic appearance of the uterine lumen by sonography were more likely to be positive on uterine culture, while the presence of pus in uterine discharge was not associated with the odds of bacterial isolation (p > 0.05). While certain strains were more likely to be obtained from the uteri of the sub-fertile group (p < 0.05), embryo transfer to camels with a positive uterine culture in the absence of other gross reproductive pathologies did not necessarily affect the overall pregnancy rate compared to recipients with a negative uterine culture (p > 0.05). In conclusion, a relatively high bacterial load can be identified from the uteri of both sub-fertile and normal dromedary camels, with a higher frequency among the former. The uterine ultrasonography and evaluation of the body condition score can help in identifying the camels in which uterus is contaminated by bacteria.

Production of invivo embryos for transfer in dromedary camel is a well-established practice, whereas freezing of these embryos is still an ongoing challenge. A common approach in evaluation of freeze–thawing method is achieved by studying invitro development of frozen–thawed embryos. However, not much is known about the development pattern of fresh dromedary embryos during incubation. The objectives of this study were to evaluate the usefulness of commercial holding media for easy short-term culture of these embryos and to provide preliminary insights on the growth and development of hatched blastocysts with different shapes. Recovered hatched blastocysts from superovulated donors were graded as transferable and non-transferable. Embryos with significant folding or crinkliness were further categorized as collapsed, whereas those with a round or oval appearance were categorized as spherical. Culture was performed in 500-μL drops at 38.5°C, 5% O2, 0–6% CO2, and maximum humidity in groups of 2 to 4. The 4 experimental media included culture medium (CM; TCM-199, 10% fetal calf serum (FCS), 0.3mM sodium pyruvate, 2.2mg mL−1 sodium bicarbonate), serum-supplemented holding medium (SSH; Syngro+10% FCS), serum-free holding medium (Syngro) and V-Onestep (Vitromed). In experiment 1, a total of 36 embryos were assigned to 4 groups and further development of the embryos was monitored up to 96h by morphological evaluations, identifying static and degenerating embryos on daily basis. In experiment 2, a total of 16 spherical and 16 collapsed embryos were cultured in SSH and CM and two-thirds of the culture drop was replaced with fresh medium at 72h. The proportion of developing embryos and their size expansion was compared between treatments by Fisher’s test and Mann–Whitney U test, respectively. Statistically similar proportions of embryos continued to develop in all media within the first 48h despite a numeric advantage in CM group; at 72h, the proportion of growing embryos was significantly higher in CM (77.8%) and SSH (66.6%) compared with SFH (11.1%) and OneStep (22.2%) (P<0.05). None of the embryos in SFH and only 1 embryo in the V-Onestep group survived beyond 72h, whereas 3/9 embryos in SSH and 7/9 embryos in CM continued to expand. In experiment 2, the proportion of spherical embryos that developed was higher compared with their collapsed counterparts (8/8 in both groups vs. 5/8 and 4/8 in CM and SSH, respectively) at 24h. However, remaining collapsed embryos grew and expanded at similar rates to spherical ones in each group (P>0.05). Replacing the medium did not favour continuation of embryonic growth in SSH beyond 72 h; only 5/16 embryos survived to 96h compared with 12/16 in CM. In conclusion, serum-supplemented commercial holding preparations provide comparable results to culture medium for short-term incubation of invivo dromedary embryos. Natural collapsing of hatched blastocysts might be associated with lower developmental competence.