Effect of semen dilution and equilibration time on semen quality of Pesisir bull

The process of freezing semen, a common problem, is generally caused by cold shock to frozen cells and the formation of ice crystals. One way to overcome this is to look for diluents and optimal equilibration times to reduce damaged spermatozoa during freezing. This study aims to determine the semen quality of Pesisir Bull and the interaction between the two types of diluent and the four equilibration times. The diluent used was egg yolk tris and andromed. The equilibration times were 6, 8, 10, and 12 hours. The variables observed included macroscopic and microscopic semen evaluation. This study used a factorial randomized block design with two factors and four treatment replications. Data are reported as the mean and standard deviation analyzed using analysis of variance. The average percentage of semen motility before equilibration was 80±0.00; after equilibration, 60.00±0.00 up to 72.50±0.00. The mean percentage of viability before equilibration was 89.26±2.70 after equilibration, which was in the range of 65.44±2.72 to 78.78±2.99. The average rate of abnormalities before equilibration was 3.00±0.50 after equilibration, which was in the field of 5.81±1.29 up to 11.41±1.63. The mean percentage of IPM before equilibration was 84.18±1.18 after equilibration, which was 71.37±3.72 up to 77.85±3.53. The average rate of IAC before equilibration was 87.84±3.14 after equilibration, which was 77.69±3.65 up to 83.07±2.11. The egg yolk tris diluent treatment showed highly significant (P<0.01) differences with the andromed diluent treatment in motility, viability, IPM, and IAC. We concluded that the Semen of Pesisir Bull equilibrated from 6 to 12 hours using Andromed and egg yolk tris diluent is still categorized as suitable for further processing to manufacture frozen semen or for artificial insemination (AI).