Pengaruh pemberian berbagai konsentrasi kuning telur ayam kampung terhadap kualitas spermatozoa ikan koi (cyprinus carpio, linnaeus 1758) 48 jam pascakriopreservasi = Various effect of free range chicken egg yolk concentration to spermatozoa quality of koi fish (cyprinus carpio linnaeus 1758) 48 hours post cryopreservation