LAUSR

In the present study, the effect of cholesterol‐loaded cyclodextrin (CLC) on the quality of low sperm doses at post‐thaw was evaluated. Twenty four ejaculates (6 from each bull) were collected and split into eight aliquots. First four aliquots were diluted up to 20‐, 15‐, 10‐ and 5‐million sperm/0.25 ml, and remaining four were treated with CLC at the rate of 1 mg/120 million spermatozoa, followed by dilution up to 20‐, 15‐, 10‐ and 5‐million sperm/0.25 ml. The diluted semen was equilibrated, cryopreserved and evaluated post‐thaw. The averages of total motility, progressive motility, average path velocity, straight linear velocity, membrane intact spermatozoa and noncapacitated spermatozoa were higher (p < .05) in CLC‐treated sperm doses compared to control ones. However, the moribund spermatozoa, capacitated spermatozoa and acrosome‐reacted spermatozoa were reduced (p < .05) in CLC‐treated spermatozoa compared to control. The curvilinear velocity and linearity did not differ (p > .05) between control and CLC‐treated sperm doses. In conclusion, treatment of spermatozoa with CLC at the rate of 1 mg/120 million spermatozoon attenuates the dilution effect and improves the quality of bovine low sperm insemination doses during cryopreservation; hence it could be a favourable cryoprotectant for preserving bovine semen at higher dilutions.