Artificial insemination with fresh, liquid stored and frozen thawed semen in dromedary camels

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.