Camel semen collection, viscosity, and cryopreservation: a review

Document Type : Review article


Department of Theriogenology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran


Artificial insemination in camels remains undeveloped due to the difficulties in semen collection, semen viscosity, and semen cryopreservation. The semen collection procedure has been facilitated to some extent using camel phantom and/or possibly an intravaginal condom. Main reasons for semen viscosity in camelids have been unraveled and different mechanical and enzymatic approaches were used to alleviate this problem; however, there is still no conclusive protocol to safely remove semen viscosity completely. It seems that along with the problem of semen viscosity, semen cryopreservation in camels remains unresolved. As a result, there is no convincing report on successful and repeatable pregnancies following insemination with frozen semen in camel. This review gathered most of the information that appeared in the peer reviewed journals to highlight major problems in camel semen technology, including semen collection, semen viscosity, and semen cryopreservation.


Chen, BX; Yuen, ZX and Pan, CW (1984). Factors inducing ovulation in the Bactrian camel. In: Cockrill, WR (Ed.), The Camelid and all-purpose animal. Uppsala, Sweeden, Scandinavian Institute for African Studies. PP: 387-398.
Chen, BX; Yuen, ZX and Pan, GW (1985). Semen induced ovulation in the Bactrian camel (Camelus bactrianus). J. Reprod. Fertil., 74: 335-339.
Deen, A; Vyas, S; Jain, M and Sahani, MS (2004). Refrigeratory preservation of camel semen. J. Camel Pract. Res., 11: 137-139.
Deen, A; Vyas, S and Sahani, MS (2003). Semen collection, cryopreservation and artificial insemination in the dromedary camel. Anim. Reprod. Sci., 77: 223-233.
El-Bahrawy, K; Rateb, S; Khalifa, M; Monaco, D and Lacalandra, G (2017). Physical and kinematic properties of cryopreserved camel sperm after elimination of semen viscosity by different techniques. Anim. Reprod. Sci., 187: 100-108.
Kershaw-Young, CM; Evans, G; Rodney, R and Maxwell, WMC (2017). Papain and its inhibitor E-64 reduce camelid semen viscosity without impairing sperm function and improve post-thaw motility rates. Reprod. Fertil. Dev., 29: 1107-1114.
Kershaw-Young, CM and Maxwell, WMC (2012). Seminal plasma components in camelids and comparisons with other species. Reprod. Domest. Anim., (Suppl. 4), 47: 369-375.
Kershaw-Young, CM; Stuart, C; Evans, G and Maxwell, WMC (2013). The effect of glycosaminoglycan enzymes and proteases on the viscosity of alpaca seminal plasma and sperm function. Anim. Reprod. Sci., 138: 261-267.
Keshavarz, M; Niasari-Naslaji, A; Zare, H; Ziapour, S; Mirtavoosi, M; Omidi, M; Kalantari, A and Moosavi-Movahedi, AA (2016). Effect of Ficin enzyme on semen viscosity in dromedary camel. J. Camel Pract. Res., 23: 219-222.
Mal, G; Vyas, S; Srinivasan, A; Patil, NVR and Pathak, KML (2016). Studies on liquefaction time and proteins involved in the improvement of seminal characteristics in dromedary camels (Camelus dromedarius). Scientifica 1-6.
Malo, C; Crichton, EG; Morrell, JM; Pukazhenthi, BS; Johannisson, A; Splan, R and Skidmore, JA (2018a). Colloid centrifugation of fresh semen improves post-thaw quality of cryopreserved dromedary camel spermatozoa. Anim. Reprod. Sci., 192: 28-34.
Malo, C; Crichton, EG; Morrell, JM; Pukazhenthi, BS and Skidmore, JA (2017a). Single layer centrifugation of fresh dromedary camel semen improves sperm quality and in vitro fertilization capacity compared with simple sperm washing. Reprod. Domest. Anim., 52: 1097-1103.
Malo, C; Crichton, EG and Skidmore, JA (2017b). Optimization of the cryopreservation of dromedary camel semen: Cryoprotectants and their concentration and equilibration times. Cryobiology. 74: 141-147.
Malo, C; Crichton, EG and Skidmore, JA (2020). Preservation of the spermatozoa of the dromedary camel (Camelus dromedarius) by chilling and freezing: The effects of cooling time, extender composition and catalase supplementation. Theriogenology. 153: 9-18.
Malo, C; Elwing, B; Soederstroem, L; Lundeheim, N; Morrell, JM and Skidmore, JA (2018b). Effect of different freezing rates and thawing temperatures on cryosurvival of dromedary camel spermatozoa. Theriogenology. 125: 43-48.
Malo, C; Grundin, J; Morrell, JM and Skidmore, JA (2019). Individual male dependent improvement in post-thaw dromedary camel sperm quality after addition of catalase. Anim. Reprod. Sci., 209: 106168.
Mansour, N (2022). Semen collection from dromedary camel bulls, methodology and a new patented approach. In: Proceedings of ICAR 2020+2 Satellite Meeting on Camelid Reproduction, Bologna, Italy. PP: 40-44.
Medan, MS; Absy, G; Zeidan, AE; Khalil, MH; Khalifa, HH; AbdelSalaam, AM and Abdel-Khalek, TM (2008). Survival and fertility rate of cooled dromedary camel spermatozoa supplemented with catalase enzyme. J. Reprod. Dev., 54: 84-89.
Monaco, D; Fatnassi, M; Padalino, B; Hammadi, M; Khorchani, T and Lacalandra, GM (2016). Effect of α-Amylase, Papain, and Spermfluid® treatments on viscosity and semen parameters of dromedary camel ejaculates. Res. Vet. Sci., 105: 5-9.
Morrell, JM; Warring, SK; Norrestam, E; Malo, C and Huanca, W (2021). Non-enzymatic extraction of spermatozoa from alpaca ejaculates by pipetting followed by colloid centrifugation. Livest. Sci., 251: 104627.
Morton, KM; Billah, M and Skidmore, JA (2013). Effect of sperm diluent and dose on the pregnancy rate in dromedary camels after artificial insemination with fresh and liquid-stored semen. J. Camelid Sci., 6: 49-62.
Morton, KM; Vaughan, JL and Maxwell, WMC (2008). The continued development of artificial insemination technology in Alpacas. Rural Industries Research and Development Corporation: Kingston, ACT. https://www. semanticscholar. org/paper/The-continued-development-of-artificial-in-alpacas-Morton/1becbca8d69d6513a5880d260 992e9e43 26710ca.
Mosaferi, S; Niasari-Naslaji, A; Abarghani, A; Gharahdaghi, AA and Gerami, A (2005). Biophysical and biochemical characteristics of Bactrian camel semen collected by artificial vagina. Theriogenology. 63: 92-101.
Niasari-Naslaji, A; Gharahdaghi, AA; Mosaferi, S; Bahmani, N; Abarghani, A and Gerami, A (2007a). Effect of sucrose extender with different levels of osmolality on the viability of spermatozoa in Bactrian camel (Camelus bactrianus). Pajoujesh-va-Sazandeghi. 75: 112-117.
Niasari-Naslaji, A; Mosaferi, S; Abarghani, A; Gharahdaghi, AA; Bahmnai, N; Ghanbari, A and Gerami, A (2006a). Effectiveness of tris-based extender (SHOTOR diluent) for the preservation of Bactrian camel (Camelus bactrianus) semen. Cryobiology. 53: 12-21.
Niasari-Naslaji, A; Mosaferi, S; Bahmani, N; Abarghani, A; Gharahdaghi, AA and Gerami, A (2006b). Effect of lactose extender with different levels of osmolality and pH on the viability of Bactrian camel (Camelus bactrianus) spermatozoa. Iran. J. Vet. Res., 7: 14-22.
Niasari-Naslaji, A; Mosaferi, S; Bahmani, N; Gerami, A; Gharahdaghi, AA; Abarghani, A and Ghanbari, A (2007b). Cryopreseration of semen in Bactrian camel (Camelus bactrianus) using SHOTOR diluent: effects of cooling rates and glycerol concentrations. Theriogenology. 68: 618-625.
Niasari-Naslaji, A; Mosaferi, S; Moghiseh, A; Nikjou, D; Bahmani, N; Gerami, A; Moosavi-Movahedi, AA; Gharahdaghi, AA and Abarghani, A (2008). Effects of equex on the survival of Bactrian camel (Camelus bactrianus) sperm in chilled and frozen conditions. J. Camel Pract. Res., 15: 1-8.
Panahi, F; Niasari-Naslaji, A; Seyedasgari, F; Ararooti, T; Razavi, K and Moosavi-Movaheddi, AA (2017). Supplementation of tris-based extender with plasma egg yolk of six avian species and camel skim milk for chilled preservation of dromedary camel semen. Anim. Reprod. Sci., 184: 11-19.
Perk, K (1962). Seasonal changes in the glandula bulbo-urethralis of the camel. Bull. Res. Counc. Isr., 10: 37-44.
Rateb, SA (2016). Ultrasound-assisted liquefaction of dromedary camel semen. Small Rumin. Res., 141: 48-55.
Santiani, A; Huanca, W; Sapana, R; Huanca, T; Sepulveda, N and Sanchez, R (2005). Effects on the quality of frozen-thawed alpaca (Lama pacos) semen using two different cryoprotectants and extenders. Asian J. Androl., 7: 303-309.
Sieme, H; Merkt, H; Musa, B; Hago, B and Willem, T (1990). Liquid and deep freeze preservation of camel semen using different extenders and methods. In: Proceedings of the Workshop “Is it possible to improve the reproductive performance of the camel”. Paris. PP: 273-283.
Skidmore, JA; Crichton, EG; Malo, CM; Vaughan, JL; Wani, NA and Herrid, M (2020). Reproductive technologies in camelids. In: Presicce, GA (Ed.), Reproductive technologies in animals. (1st Edn.), Rome, Italy, Academic Press. PP: 119-134. 1016/C2018-0-01374-2.
Skidmore, JA; Morton, KM and Billah, M (2013). Artificial insemination in dromedary camels. Anim. Reprod. Sci., 136: 178-186.
Tibary, A and Anouassi, A (1997). Artificial breeding and manipulation of reproduction in Camelidae. In: Tibary, A and Anouassi, A (Eds.), Theriogenology in Camelidae: Anatomy, physiology, BSE, pathology and artificial breeding. (1st Edn.), Ins. Agron. Vet. Hassan II, Rabat, Maroc. PP: 413-452.
Tibary, A and Anouassi, A (2018). Challenges in the development of artificial insemination in the dromedary camel. Rev. Mar. Sci. Agron. Vét., 6: 178-188.
Vyas, S; Goswami, P; Raj, AK and Khanna, ND (1998). Use of tris and lactose extenders in preservation of camel semen at refrigerated temperature. Indian Vet. J., 75: 810-812.
Zhao, XX; Chen, BX and Huang, YM (1996). Artificial insemination with deep-frozen semen in the Bactrian camel
(Camelus bactrianus). Research Progress in Animal Industry and Animal Products Processing. Compiled by the Chinese Association of Agricultural Sciences. Presented at the 1st China International Annual Meeting on Agricultural Science and Technology, March 19-22, 1996. Chinese Agriculture Press, Beijing, PP: 237-242.
Zhao, XX; Huang, YM and Chen, BX (1994). Artificial insemination and pregnancy diagnosis in the Bactrian camel (Camelus bactrianus). J. Arid Environ., 26: 61-65.
Ziapour, S; Niasari-Naslaji, A; Mirtavousi, M; Keshavarz, M; Kalantari, A and Adel, A (2014). Semen collection using phantom in dromedary camel. Anim. Reprod. Sci., 151: 15-21.