Veterinary Research Forum

Abstract The natural polymer poly-β-hydroxybutyrate (PHB) is converted to β-hydroxybutyric acid, which is similar to short-chain fatty acids, via microbial fermentation and host enzyme breakdown. This study investigated the impact of different PHB concentrations (Control, 1.00, 3.00, and 5.00% substitution) on growth performances and fish welfare in common carp fingerlings. After a 60-day trial, fish fed on diet containing 1.00% PHB exhibited significantly higher weight gain and improved feed conversion efficiency compared to the control group. Furthermore, analysis of enzymatic activity showed elevated levels of total protease and amylase in PHB-fed treatments compared to the control. Red blood cell counts, hemoglobin, and hematocrit levels remained unaffected and a significant increase in white blood cell count was observed in fish fed on diets containing 1.00 and 3.00% PHB compared to the control group. Furthermore, fish fed on diets containing 1.00 and 3.00% PHB demonstrated significantly higher total protein levels and lower glucose concentrations as well as reduced hepatic enzyme activities (aspartate aminotransferase and alanine aminotransferase) compared to both the control and 5.00% PHB groups. Assessment of antioxidant and immune parameters revealed significantly increased complement hemolytic activity and immunoglobulin M levels coupled with decreased malondialdehyde concentrations in the plasma of PHB-fed fish compared to the control group. In conclusion, dietary supplementation with PHB, especially at the 1.00% level, enhanced growth performance and improved nutritional and health indicators in the fingerlings. These findings suggested that PHB had the potential to be a valuable dietary additive for this species.

Abstract Cell-surface proteins of Clostridium chauvoei were purified using a simple method. Bacterial cultures were centrifuged and agitated vigorously in phosphate buffered saline with or without further glycine treatment and ammonium sulfate precipitation. Rabbits were immunized subcutaneously with a blackleg disease vaccine twice with a two-week interval. Immunized sera were collected one week after the second injection. Enzyme-linked immunosorbent assay (ELISA) was performed using the proteins purified by the second method as the coating antigen. Bradford assay results showed a higher protein concentration in the second than the first method. Sodium dodecyl-sulfate polyacrylamide gel electrophoresis analysis showed multiple bands for the cell-surface proteins of C. chauvoei in the first method and a sharp band equivalent to flagellin protein in the second method. The ELISA results indicated that the purified proteins were capable of detecting antibodies against Blackleg disease vaccine. The purified protein would be an alternative antigen for indirect ELISA in order to monitor the immune response in vaccinated farm animals.

Abstract The role of immunostimulants in reducing diseases and enhancing fish performance has been proven in various studies. In this study, the effects of antioxidant procyanidin and commercial probiotic Bio-Aqua^® on some hematological and immune indices of rainbow trout (Oncorhynchus mykiss) were investigated. A total number of 525 fingerlings in seven treatments (each treatment in triplicates) with experimental diets, including (1) commercial food without supplements (CTL), (2) 400 mg procyanidin kg^-1 feed (PC400) , (3) 800 mg procyanidin kg feed^-1 (PC800), (4) 0.50% probiotic diet (PB0.5), (5) 1.00% probiotic diet (PB1), (6) probiotic and procianidin 0.50% and 800 mg kg^-1 feed, respectively (PB0.5 + PC800) and (7) probiotic and procianidin 1.00% and 400 mg kg^-1 feed, respectively, (PB1 + PC400) were fed for eight weeks. The results showed that the use of procyanidin alone did not have any significant effect on blood biochemistry and immune indices. However, the individual use of Bio-Aqua^® probiotic could affect the hematological and immune indices of fish, except for monocyte, compared to the control and procyanidin treatments. However, the combined use of the supplements improved the hematological and immune indices of fish. It was concluded that the simultaneous dietary administration of procyanidin and probiotic Bio-Aqua^® could improve the general health of rainbow trout.

Abstract Mycoplasma capricolum subspecies capripneumoniae (Mccp) is the etiological agent of caprine contagious pleuropneumonia (CCPP) disease. The CCPP is one of the most severe diseases of goats. A herd of 2,000 goats located in the countryside of Tehran city, Iran, was examined for the study in August 2021. In history taking, observation, inspection and clinical examination, high case fatality rate (46.00%) due to respiratory distress and high morbidity of pleuropneumonia (15.00%) syndrome were recorded. Accordingly, ten carcasses of goats were dissected. The epidemiological pattern of the disease, clinical examination findings and the signs of necropsy of dead patients were suspected to CCPP. Four lung samples of necropsied goats were sent to the laboratory for PCR test and in all of them, Mccp was detected and CCPP was also confirmed. The disease was controlled by two measures: (a) the whole herd was first treated with antibiotics (florfenicol and tylosin) and (b) then the Pulmovac-In vaccine was then administered. This study is the first documented report of CCPP occurrence caused by Mccp in Iran and shows the importance of availability of effective vaccines to control and prevention of CCPP.

Abstract Mastitis is the most important disease in dairy cattle industry because of its high economic losses both in herd management, milk and milk products. The aim of this study was to determine the efficacy of inactivated Parapoxvirus ovis (IPPVO) Para immune activator as a prophylaxis against mastitis and as the therapy for subclinical mastitis in dairy cattle. The prophylactic effects of IPPVO were investigated in California mastitis test (CMT). Healthy Holstein cows were divided into A1 (n = 30) and A2 (n = 30) subgroups. In addition, 90 subclinical mastitis Holstein cows were divided into subgroups of B1, B2, and B3 to investigate the efficacy of IPPVO treatment. A significant difference in CMT levels was observed (p ˂ 0.01) 30 day after treatment in A groups. The difference in somatic cell count (SCC) levels between the A groups 15, 30 day after treatment was significant (p ˂ 0.01). The results of the CMT among the B groups showed no statistically significant difference (p > 0.05). The results of the SCC tests showed no statistically significant difference (p > 0.05) among the B groups on days 0, 9 and 15 after treatment. Coagulase-negative Staphylococcus (n = 53) and Escherichia coli (n = 30) were the most prevalent bacteria isolated in this study. In conclusion, IPPVO, although had no additional effect when used in combination with antibiotics could possibly be used instead of antibiotics and to protect cattle from subclinical mastitis, however, it is not known how long this prophylaxis effect could last.