THE EFFECT OF VITAMIN C AND AEROMONAS VACCINE ON THE IMMUNE RESPONSE AND DISEASE RESISTANCE OF GROUPER (Epinephelus fuscoguttatus)

We evaluated the effectiveness of vitamin C and Aeromonas salmonicida vaccine in grouper (Epinephelus fuscoguttatus) for increasing immune responses and protection against A .salmonicida. The vitamin C used was polyethoxylated ascorbic and tocopherol. The vaccine was prepared from formalin-killed cells and concentrated extracellular products of a single isolate A. salmonicida. Bath immersion vitamin C and vaccine trials were conducted for 60 min. Fish used had a mean weight 25 g. Control groupers were injected with tryptic soy broth. The results showed that vitamin C enhanced phagocytic activity in head kidney leucocytes of grouper 7, 14, 28 and 36 days after treatments. A significant different of the antibody titre was found between control fish and the treated fish at 42 days after treatments. In addition, at day 42, Relative Percent Survival (RPS) for control group was 53.3 %, vitamin C-treated group was 80.0 % and vaccinated group was 90.0 %. The results of this study suggest that bath immersion of vitamin C provided an increasing of phagocytic activity (non-specific immune responses), titre antibody (specific immune responses) and protection against A. salmonicida infection in grouper. A. salmonicida vaccine also en-hanced titre antibody and protection against A. salmonicida infection in grouper.

SEROLOGICAL EXAMINATION OF PARVOVIRUS INFECTION ON PIG FARMS

Porcine parvovirus (PPV) is one of the causative agents in reproductive disorders in swine that causes great economic losses. The objective of our research was to determine prevalence of this infection on farms with intensive breeding in 5 municipalities in Vojvodina. The research encompassed 19 herds with a total of 344 blood samples screened for the presence of antibodies against PPV (gilts, breeding sows and boars). Serological examination was carried out by haemagglutination inhibition test (HI test). After the analyses of the results, seropositive animals were detected on the farms and there were no PPV-free farms. The determined antibody titre against PPV ranged from 1:64 to 1:16384. Out of 344 examined animals, there were 305 (88.66%) with a high antibody titre (1:1024 to 1:16384). The highest level of antibodies (1:16384) was detected in 145 animals, what is 42.15% of total number. In 24 animals (6.97%) titre antibody was 1:512 and these animals were of low seropositivity. Simultaneously, a comparison of antibodies in blood sera was carried out on 20 gilts (Table 3, farm 2) originating from a farm where the animals were vaccinated against PPV and 20 unvaccinated gilts (Table 4, farm 1) originating from a farm without vaccination against PPV. In unvaccinated animals antibody titre was unequal and ranged from 1:256 to 1:16384, in unvaccinated animals the values were considerably higher and ranged from 1:4096 do 1:16384, and in 17 out of 20 vaccinated pigs (85%) the highest antibody titre was 1:16384.