Emir. J. Food Agric ● Vol 30 ● Issue 4 ● 2018 335 Effect of different proteolytic enzymes on liquefaction of semen of dromedary camel Mohd. Matin Ansari 1 *, Sumant Vyas 1 , Rajesh K Sawal 1 , Sanjay K. Ravi 2 , Niteen V. Patil 1 , Mustafa. Hasan Jan 3 1 Indian Council of Agricultural Research-National Research Centre on Camel, Bikaner, India, 2 ICAR-National Research Centre on Equines sub-campus, Bikaner, India, 3 ICAR-Central Institute for Research on Buffaloes, Hisar, India INTRODUCTION Genetic progress is very slow in camel due to monotocous female having long gestation period of around 380-390 days (Vyas and Sahani, 2000). Use of assisted reproductive technology applications like artifcial insemination (AI) and in-vitro fertilization (IVF) may overcome these problems (Skidmore et al., 2013). The use of artifcial insemination is limited in camels due to diffculty in collection and handling of semen for its subsequent processing and analysis. For AI and IVF to be successful, sperms must be progressively motile. However, in the ejaculates of camelids, spermatozoa have only oscillatory or vibratory movement and no progressive or free motility is seen, due to high seminal plasma viscosity (Deen et al., 2004; 2005; Giuliano et al., 2002; Lichtenwalner et al., 1996; Vaughan et al., 2003). Therefore, in order to achieve freely motile sperm, it is essential to remove the seminal viscosity (Conde et al., 2008). Handling of camelid semen in the laboratory is diffcult due to viscous nature of semen (Tibary and Vaughan, 2006; Del Campo et al., 1994; Maxwel et al., 2008; Sansinena et al., 2007) and is diffcult to assess spermatozoal motility for further semen analysis and processing. For effcient cryopreservation, the sperm-cryoprotective and nutritive compounds ought to come in contact with sperm cell membrane during equilibration, therefore liquefaction of camelid ejaculates is necessary for improving post- thawing semen parameters (Monaco et al., 2016). Previous researchers have evaluated the effect of different enzymes for liquefaction of camelid semen and reported both benefcial and detrimental effects (Bravo et al., 1999, 2000; Ghoneim et al., 2010; Giuliano et al., 2010; Maxwel et al., 2008; Shekher et al., 2012), and marked reduction of sperm motility with 10 min (Morton et al., 2008) to 45 min (Ghoneim et al., 2010) of exposure. Sperm fuid containing Bromelain, though effective in enhancing the liquefaction of human ejaculates, could not break down the camelid’s highly viscous seminal plasma matrix. Therefore, the objective of our study was to elucidate comparative effcacy of Collagenase, Accutase and Trypsin-EDTA for In most of domestic animals, semen biology is well studied, but it is not so well studied in camelids particularly in dromedary camels. In camelids, the ejaculated semen is highly viscous, so before its evaluation and processing for preservation, it is necessary to be liquefed. Our study was designed to evaluate the effect of three different enzymes (0.1% Collagenase, 0.5 X Accutase, 0.1% Trypsin-EDTA - Ethylene- diamine-tetra-acetic acid) on seminal viscosity at different time intervals along with its effects on seminal parameters. Semen was collected from the six adult healthy male camels using female camel as dummy. Bovine artifcial vagina was used for the semen collection and ejaculate was kept at 37ºC for further processing after its collection. All three enzymes were diluted in 1x phosphate buffered saline (PBS) and the semen samples were kept at 37ºC. The samples were evaluated at different time intervals 0, 5, 10, 15, 30, 60, 120 and 240 min (T0–T240) for viscosity and it was evaluated by pipette method. Immediately after collection, the viscosity was very high, and no sperm mass motility was seen. However, after enzyme treatment viscosity was showed declining trend in all treatment groups compared to control. In trypsin treated group maximum motility was reached in 15 minutes. Live-dead percent was observed to be similar among treatment groups. Observations on liquefaction of semen revealed that use of enzymes decreasing the viscosity but with different rates. Keywords: Computer assisted semen analyzer; Dromedary camel; Liquefying agents; Sperm physiology ABSTRACT Emirates Journal of Food and Agriculture. 2018. 30(4): 335-340 doi: 10.9755/ejfa.2018.v30.i4.1670 http://www.ejfa.me/ CAMEL REPRODUCTION *Corresponding author: Mohd. Matin Ansari, Indian Council of Agricultural Research-National Research Centre on Camel, Bikaner, India. E-mail: matin.ansari1@gmail.com Received: 20 November 2017; Accepted: 24 March 2018