This study was conducted to evaluate various factors affecting fertility following insemination of dromedary camels. In experiment 1, camels were either bred by natural mating (NM) or inseminated in the body of uterus with whole, split (50:50) or 1 mL of undiluted ejaculate. In experiment 2, camels were inseminated with fresh diluted semen either in the body of the uterus or tip of the uterine horn and at either the time of ovulation induction (0 h), 24 or 30 h later. In experiment 3, camels were inseminated at the tip of the uterine horn with different doses of fresh diluted semen (75, 150 or 300 x 10⁶ motile spermatozoa) or with 150 x 10⁶ motile spermatozoa diluted with different extenders (Green buffer, Optixcell or Triladyl). In experiment 4, camels were inseminated in the tip of the uterine horn with diluted (Triladyl or Optixcell) liquid-stored semen or diluted (Triladyl) frozen-thawed semen consisting of either 300 or 500 x 10⁶ motile spermatozoa. The pregnancy rate in camels bred by NM was similar to camels inseminated with whole undiluted ejaculates whereas insemination with 1 mL undiluted ejaculate resulted in lower pregnancy compared to whole and split undiluted ejaculates (P < 0.05). Deposition of semen in the uterine body resulted in lower pregnancy rates compared to deposition in the tip of the horn (35.3% versus 72.2%, P < 0.05) but insemination at the time of ovulation induction and 24 h later resulted in higher pregnancy rate to camels inseminated at 30 h after induction (68.4 and 70.0% versus 23.5%; P < 0.05). Artificial insemination with 75 x 10⁶ motile spermatozoa resulted in lower pregnancy rates compared to 150 and 300 x 10⁶ motile spermatozoa doses (40.9% versus 65.2 and 70.0%, respectively) and pregnancy rate was not affected by extenders. Insemination of chilled motile spermatozoa stored in either Triladyl or Optixcell resulted in similar pregnancy rates, regardless of insemination dose, although an upward trend with increasing sperm number was apparent (Triladyl; 11.1% versus 21.1% and Optixcell; 5.9% versus 12.5%, for 300 x 10⁶ and 500 x 10⁶ groups, respectively; P > 0.05). No pregnancies were obtained with frozen thawed semen. In conclusion, this study demonstrated that the success of camel AI is highly dependent on sperm dose, location of semen deposition, timing of insemination and semen type. Further studies are required to determine the reason for the compromised fertility of preserved semen despite apparent high in vitro quality.

Spirulina platensis (SP) is a protein-rich dietary supplement that improves animal reproductive traits. This study investigated the effect of SP supplementation on puberty onset, semen characteristics, scrotal circumference (SC), libido, and hormone concentrations in Sahrawi and Jabbali bucks. The study was conducted in 36 bucks, divided into three groups (n = 6/group), for 70 days. The rations included the following: (1) Control feed (Con) with 14% crude protein and 11.97% MJ/kg DM energy; (2) Con with 2 g SP/head/day SP treatment (T1) and (3) Con with 4 g SP/head/day treatment (T2). The mean (±SEM) SC of both SP groups in the Sahrawi breed was significantly higher (p ≤ 0.05) compared to the Con. The mean of the semen volume significantly increased (p ≤ 0.05) in the SP group than in the Con group in both breeds. SP groups vs. Con groups had increased sperm concentration in Sahrawi bucks than Jabbali bucks. Mean serum luteinizing hormone (LH) and testosterone (Tes) concentrations in Jabbali bucks were significantly higher (p ≤ 0.05) in the SP groups compared to Sahrawi bucks. SP improved the SC, semen quality, libido, sperm concentration, and LH and Tes concentrations in both breeds. The results of the current study suggest that adding SP to the diet may have the ability to improve the semen quality of the local Omani bucks.

Background and Aim: Dromedary camels exhibit unique immune adaptations that enable survival in harsh environments with high microbial exposure. However, the cellular mechanisms underpinning their innate immune responses, particularly oxidative respiratory bursts, remain underexplored. This study aimed to investigate the kinetics of reactive oxygen species (ROS) production in camel leukocytes in response to selected bacterial and fungal pathogens and to assess the effect of serum opsonization on ROS generation. Materials and Methods: Whole blood from six clinically healthy female dromedary camels was stimulated with opsonized and non-opsonized Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae (three strains), and Candida albicans. Luminol-enhanced chemiluminescence (CL) assays were used to quantify ROS production over a 3-h period. Colony-forming units were evaluated to confirm microbial viability post-opsonization. Key ROS metrics included area under the curve, peak emission (relative light unit), and time to peak. Results: Camel neutrophils demonstrated distinct pathogen-specific ROS kinetics. P. aeruginosa and K. pneumoniae 1705 elicited the highest total ROS on serum opsonization, whereas S. aureus and C. albicans showed minimal ROS induction. E. coli failed to induce a measurable ROS response. Serum opsonization significantly enhanced total ROS production and shortened peak response time for K. pneumoniae strains. In contrast, it reduced total ROS output for S. aureus and C. albicans without significantly affecting their peak kinetics. Conclusion: This study provides the first comprehensive analysis of microbial-specific ROS production in camel whole blood using a luminol-based CL assay. The findings underscore the variability in camel innate immune responses to different pathogens and highlight the modulatory role of serum opsonization. These insights could inform future strategies in camel immunotherapy, vaccine development, and disease diagnostics. Keywords: Camelus dromedaries, luminol chemiluminescence, microbial pathogens, neutrophils, oxidative burst, reactive oxygen species, serum opsonization.