Changes in Ultrastructure of Crossbred Bovine Spermatozoa in Butylated Hydroxytoluene Supplemented Semen

Abstract

The present study was planned to observe the effect of Butylated hydroxytoluene (BHT) on ultra-structure changes in bovine crossbred spermatozoa. The sperm plasma membrane is the primary site of damage induced by cryopreservation. There are many harmful conditions such as cold shock, osmotic stress, ice crystal formation or oxidative damage etc. which cause sperm cryo-injury and loss of sperm viability and fertility during cryopreservation. At the time of cryopreservation there were considerable ultra-structure changes to the acrosomes and middle piece studied by transmission electron microscopy. Semen from two crossbred bulls were collected and extended with egg yolk tris dilutor along with addition of different concentrations of BHT i.e. 0.0mM (Control), 0.5mM (T₁) and 1.0mM (T₂), respectively. The effect of BHT on ultrastructural alterations was revealed by Transmission electron microscopy during post dilution (Stage I), post equilibration (Stage II) and post thaw (Stage III), respectively. Per cent difference in ultastructural defects between three stages (After dilution, after equilibration and after thawing) was observed. There was significantly (p<0.05) lowest number of ultrastructural defects between three stages in group T₂ compared to T₁ and control groups, respectively. The study indicated that 1.0mM BHT increases the cryosurvival of sperm.