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The objective of this study was to compare an indirect ELISA, based on a purified 60 kDa envelope glycoprotein (gp51SU), with a Pourquire indirect ELISA for the detection of antibodies to the bovine leukemia virus. For conducting this research, 340 serum samples were collected from two different breeds of cows (Sarabi and Holestin) in different herds. Commercial ELISA revealed positive results in 17 (7%) Holstein cows. An appropriate ELISA cut-off was determined by receiver operating curve (ROC) analysis in comparison with commercial indirect ELISA. Results showed a relative sensitivity and specificity of 97% and 92%, respectively, for a cut-off value of 0.34 in the domestic ELISA. In conclusion, the results of the present study showed that domestic developed kit can be used for diagnosis of bovine leukemia virus with appropriate sensitivity and specificity. In addition, a comparison of the results from a native breed, Sarabi, with Holstein showed that there was no significant (P>0.05) difference in the frequency of infection with BLV between the two breeds.

Theileria species are common in tropical and subtropical regions and cause great economical losses in ruminants. Two species, T. lestoquardi and T. ovis, are suspected to cause ovine theileriosis in Iran. The epidemiological aspects of ovine theileriosis in Iran are poorly understood and further investigations by sensitive and precise techniques are required. In a previous study, a sensitive and specific PCR-RFLP method was used for the identification of Theileria spp. in sheep. In the present study, Theileria species involved in ovine theileriosis were determined in five different regions in eastern half of Iran (Zabol, Lar, Ferdows, Semnan and Gorgan). Blood samples were collected in EDTA. Of 220 blood samples obtained from sheep in different regions, 60% (132.220) were positive for Theileria spp. by nested-PCR compared with 22.27% (49.220) by microscopic examination. Using RFLP of PCR products, out of 132 positive blood samples, 55.3% (73.132) were positive for T. lestoquardi and 44.7% (59.132) were positive for T. ovis. The infection with these two Theileria species in different areas is compared in the article. This is the first report in which ovine theileriosis has been studied in different regions in Iran using molecular identification techniques.

Bovine brucellosis is a zoonotic disease distributed worldwide and characterized by abortion and reduced fertility in cows. Since brucellosis eradication programme in Iran uses vaccination, test, slaughter and quarantine as control measures, it is essential to distinguish vaccine strains from strains that cause infections among vaccinated cattle herds. We developed and evaluated a multiplex polymerase chain reaction (PCR) assay to identify and differentiate the vaccine strains from wild field isolates, including all Brucella types usually found in cattle in Iran. Two pair primers were used to amplify eri and wbo regions of DNA sequences those strain-specific targets for B. abortus S19 and RB51 vaccine strains. This multiplex PCR method evaluated with DNA from reference strains, two vaccine strains and 29 field strains of Brucella. The results showed that the multiplex PCR can differentiate Brucella isolates into three categories: strain 19 (S19), strain RB51 and field strains. This PCR assay was successfully used, compared with traditional method to differentiate of S19 and RB51 from field Brucella isolates.

The objective of this study was to compare different antigen preparations to produce monoclonal antibodies against bovine leukaemia virus gp51SU. The four antigen preparations for immunization of BALB/c mice were: CL: BLV-FLK cell lysate, UF: a fraction of CL (between 30 and 100 kDa), WVP: whole virus particles and SP: with ion exchange chromatography, gp51SU was semipurified. A total of nine successful fusions were performed which resulted in production of 23 monoclonal antibodies (mAbs) specific against gp51SU. The highest ratio of specific hybridoma colonies in each fusion was with SP preparation. Based on the reactivity of the mAbs in Western blotting, mAbs were classified into four groups: anti-gp51SU (23 mAbs), anti-gp30TM (8 mAbs), anti-Pr72 (5 mAbs) and antibodies against other viral proteins (7 mAbs). Some of the anti-gp51SU mAbs reacted with more than one band in Western blotting, suggesting that these colonies recognized not only gp51SU but also its precursors.

The effect of ascorbic acid (vitamin C) on the immune system is well-known. Ascorbic acid stimulates either humoral or cell-mediated immunity in many species. This experiment was conducted to evaluate the effect of oral administration of ascorbic acid on serum γ-globulin concentration of colostrum-fed newborn calves. During a cold winter season, 20 dairy Holstein calves from a group of 40 calves were supplemented with ascorbic acid from birth to 3 weeks of age (treatment). The other 20 calves did not receive any ascorbic acid supplementation (control). Ascorbic acid was administered per os and treatment was as follows: 3 g/day for the first week, 2 g/day for the second week, and 1 g/day for the third week. All calves were housed in elevated metal pens during the winter and at low temperature from birth to 60 days of age. Serum samples were collected immediately after birth, before taking colostrum and on the 2nd, 14th and 28th days of age via jugular vein. There was no significant difference in serum γ-globulin concentrations for the two groups before taking colostrum and at 2 and 14 days of age. The serum γ-globulin concentration of the supplemented group at 28 days of age was significantly higher than that of calves not receiving ascorbic acid. The results of the present study showed that oral administration of ascorbic acid increases γ-globulin concentration of neonatal calf serum.