The
addition of a cryoprotectant is performed at the end of
the cooling period. Although ethylene glycol and DMSO
have been used for alpaca and llama semen, respectively
(Raymundo et al., 2006), glycerol (Salinas, 1999) remains
the most used cryoprotectant for semen preservation in
both species. A concentration of 7% glycerol was superior, in
terms of viability and motility, to concentrations below 4%
(Fig. 4). In general, glycerol is added in three equal volumes
given in 15 min intervals