MATERNAL IMMUNITY RESPONSE AND LARVAL GROWTH OF ANTI CYHV-3 DNA VACCINATED COMMON CARP (CYPRINUS CARPIO) AT DIFFERENT PRE-SPAWNING TIME

Abstract

This study aimed to evaluate maternal immunity response of common carp broodstock and their progenies. Vaccination of broodstock was performed by injecting GP25 plasmid as anti-CyHV-3 DNA vaccine at 30, 45 and 60 days pre-spawning (dps). Three fish were used for each treatment. Triplicates challenge test at 7, 14, 21 and 28-day-old progenies were performed for 21 days by 1hour immersion of 10-3 CyHV-3 filtrate dilution. Serum was collected six times from broodstock, and four times from larvae. The result showed that vaccination could induce the immune response of broodstock. Leukocytes count, and phagocytic activity of the vaccinated broods were significantly higher than that of control (P<0.05) at 30 days post vaccination (dpv). Furthermore, broodstock vaccination at different pre-spawning time allowed different immunity response in their larvae. Vaccination at 60 days pre-spawning (dps) had the highest antibody titer in eggs and larvae and offered higher protection on the larvae against CyHV-3 infection. Growth of larvae from vaccinated broodstocks was significantly higher than that of control (P < 0.05). This study indicated that broodstock vaccination at a proper pre-spawning time improves its immunity and protection capability is transferred to their immature immunity larvae against pathogens infection