This study was designed to determine the effect of bacterial contamination degree and type with Proteus mirabilis alone and Staphylococcus aureus alone and mixed of them species in ejaculation samples of fertile ram semen during storage quality. Semen was collected from six healthy mature rams using electro-ejaculator method, once a week, for the period 1/12/2022 to 1/2/2023. PH, motility (mass and individual), live sperm percentage and abnormal acrosomes of sperms were studied. Isolation and identification of Proteus mirabilis and Staphylococcus aureus species viable bacterial was recorded with routine bacterial detection work and molecular using PCR technique. Semen samples were divided into four groups: Group 1 (G1) was used as control without contamination. Group 2 (G2) was contaminated with Proteus mirabilis. The third group (G3) was contaminated with Staphylococcus aureus. The fourth group (G4) was contaminated with both Proteus mirabilis and Staphylococcus aureus together. Semen was examined after three days of incubation at 4Cº. Statistically significant differences (P<0.05) group G1, G2 and G3 with G4 groups for all analysis parameters were recorded. Significant differences (P<0.05) between G1 with G2 in mass and individual motility, live percentage and abnormal acrosomes were recorded. Significant differences (P<0.05) between G1 with G3, G2 with G3 in live percentage and abnormal acrosomes were listed. Significant differences (P<0.05) between G2 with G4 in individual motility and abnormal acrosomes were noticed. We conclude that Staphylococcus aureus (alone) contamination will lower semen quality after cooling at 4Cº and it decreases further more when the semen contaminated with Proteus mirabilis, the semen quality decreases was doubled with the mixture of both bacteria.
