Effect of different levels of antibiotics on ram spermatozoa quality during storage at 5°C

Experiment was conducted to study the effect of different antibiotics on sperm quality of ram by a completely randomized block design using 23 factorial arrangement with 2 block and 4 observations in each experimental units. Factors include three antibiotics named Gentamycin (G), Lincomycin (L) and Ampicillin (A) that were used at two different levels including zero and, respectively 5, 10 and 2.5 μg / ml of diluents. Tris-based and skimmed milk-based diluents were considered as block1 and block2 respectively. Semen was collected from four rams in 8 times. Samples were aggregated and divided into eight equal parts. The different levels of antibiotics were added to each part. Samples temperature was reduced at a rate of 0.25° C/min t 5° C and was stored at this temperature for 72 hours. Sperms evaluations were performed at 0, 24, 48 and 72 h after storage. The interactions between antibiotics on the progressive mobility, plasma membrane integrity and viability of sperm were significant (P<0.05).After 0,24,48 and 72h of storage, progressive motility(78.19, 66.26% and 54.52%), plasma membrane integrity(85.12%,75.12% and 62.62%) and viability of sperm(86.12% 78.38% and 70.62%) in a0g0l10 (Lincomycin 10μg / ml of diluents) were significantly (P<0.05) higher than other treatments except a0g5l0 (Gentamycin 5μg / ml of diluents) at 24, 48 and 72 h after storage. However the characteristics of a0g0l10were significantly higher than a0g5l0 at time zero. From this study we concluded that using Lincomycin 10μg / ml had the most effect on quality of spermatozoa during storage at 5° C.