Source of milt
Milt was collected during the spring spawning in April from rainbow trout males of the Rutki strain (3 years of age). The fish were anesthetized using Propiscin (1 ppm IFI, Żabieniec, Poland) prior to milt collection. Milt samples were collected by gentle abdominal massage, taking care not to contaminate them with feces, mucus, or urine. This study was approved by the Animal Experiments Local Committee in Olsztyn, Poland.