ABSTRAKTujuan penelitian ini adalah untuk mengetahui pengaruh pencucian semen dan kadar lesitin kacang ⁰ kedelai terhadap motilitas dan viabilitas sperma domba yang disimpan pada suhu 5 C. Semen tampung dari tiga ekor domba jantan dewasa dengan vagina buatan. Semen dievaluasi secara makroskopis dan mikroskopis. Semen dibagi dalam sepuluh tabung, semen dari lima tabung pertama tidak dicuci (W0) dan diencerkan dengan extender 0%, 1%, 2%, 3% dan 4% lesitin kacang kedelai (L0, L1, L2, L3 dan L4). Semen dari lima tabung lainnya dicuci (W1) kemudian masing-masing diencerkan dengan kadar ⁰ extender yang sama. Sampel semen yang telah diencerkan disimpan pada suhu 5 C, kemudian motilitas dan viabilitas sperma dievaluasi setiap hari. Interaksi dari pencucian semen dan kadar lesitin kacang kedelai tidak berbeda nyata (P>0.05) tetapi secara tunggal faktor kadar lesitin kacang kedelai berpengaruh nyata (P<0.05) dan faktor pencucian semen tidak berpengaruh nyata (P>0.05) terhadap motilitas progresif dan viabilitas sperma domba. Ekstender terbaik adalah 3% lesitin kacang kedelai (L3) dengan persentase motilitas progresif dan viabilitas spermatozoa masing-masing 63.18 ± 3.61% dan 71.76±2.32%. Kata kunci: domba, motilitas,lesitin kacang kedelai, pencucian semen, spermatozoa, viabilitas ABSTRACTThe objectives of this reserarch were to study the effect of semen washing and soybean lecithin ⁰ level on the motility and viability of ram spermatozoa stored at 5 C. Semen was collected from three mature rams by artificial vagina. Semen was evaluated by macroscopic and microscopic. Semen was divided into ten tubes, the semen of first five tubes was unwashed (W0) and diluted with extender 0%, 1%, 2%, 3% and 4% soybean lecithin (L0, L1, L2, L3 and L4). Semen of another five tubes were washed (W1) then each diluted with similar extender levels. The diluted semen samples were stored at ⁰ 5 C and the sperm motility and viability were evaluated each day. The interaction of the semen washing and soybean lecithin levels were no significant differences (P>0.05) but the single factor of soybean lecithin level was significant differeNces (P<0.05) and the single factor of semen washing were no significant differences (P>0.05) on progressive motility and viability of ram sperm.The best extender was 3% soybean lecithin (L3) with the percentage of ram sperm progressive motility was 63.18 ± 3.61% and viability was 71.76±2.32%.