Veterinary Research Forum

Abstract Antioxidant potential of different milk types and thermal-treated milks may be of interest to milk processors, consumers, and nutritionists. The objectives of this study were comparison of the antioxidant potential of milk, defatted milk, whey, and deproteinized whey from cow, sheep, and goat, and also evaluation of the effect of thermal treatments (pasteurization and sterilization) on the antioxidant activity of the milk. The antioxidant potential of different milk samples and their fractions was examined using reducing power, 2,2-diphenyl-1-picrylhydrazyl, and 2,2-azinobis-3-ethylenzothiazoline-6-sulphonicacid methods. The results showed that the antioxidant potential of sheep raw milk was significantly higher than that of cow milk and goat milk. The results also indicated that thermal processing increased the reducing power and antioxidant potential of milk, and increasing heating temperature significantly increased reducing power and 2,2-diphenyl-1-picrylhydrazyl scavenging activity of milk, especially sheep milk and goat milk. Removing of whey proteins from whey of all animal species, particularly sheep, caused a significant decrease in the antioxidant potential of whey. The results of this study showed that sheep milk and its fractions are a good source of natural antioxidants, which may have higher health promotion effects on consumers from nutritional point of view.

Abstract The genetic diversity of Brucella strains has not been fully understood. To investigate this, the genetic characteristics of 64 isolates of Brucella melitensis from sheep and goats’ milk were studied using random fragment length polymorphism (RFLP) and multiple locus variable-number tandem repeat analysis (MLVA-16) methods developed in Orsay, France (MLVA-16_Orsay). The RFLP analysis revealed that all 64 isolates were of biovar one. The MLVA-typing showed that one sample was simultaneously infected with two strains of B. melitensis and the genotype of 65 isolate was analyzed. Four genotypes (47, 42, 43, and 63) were identified using MLVA-8 (panel 1), whereas six genotypes (138, 125, 116, 108, and two unknown genotypes) were identified using MLVA11 (panels 1 and 2A). From the review of MLVA-16 (panels 1, 2A, and 2B), panel 2B showed a very high discriminatory power. Two loci of Bruc04 and Bruc30 from this panel had diversity index values higher than 0.71 and the average diversity index was 0.619. So MLVA-16_Orsay 34 showed the genotype indicating a low genetic homogeneity among the isolates. The findings of MLVA genotyping of the isolates suggest that strains of B. melitensis isolated from the milk of small ruminants in Iran are most closely related to the isolates from neighboring countries of the Eastern Mediterranean group. To the best of our knowledge, this is the first study to indicate the potential use of MLVA genotyping for simultaneous detection of specimen contamination using two different B. melitensis biovars.

Abstract Epidermal growth factor (EGF) has biological roles, including embryonic organ development, breast morphogenesis, breast cell proliferation, and mammary development. This study aimed to measure EGF concentration and evaluate its relationship with somatic cell count (SCC) in healthy water buffaloes (Bubalus bubalis) milk. The study material was constituted of 120 milk samples obtained from 30 healthy water buffaloes between the ages of 3 - 6 years, negative for California mastitis test and SCC less than 3.00 × 10⁵ cells mL^-1 milk. In milk serum samples, the EGF concentration was measured using a bovine-specific enzyme-linked immunosorbent assay kit. Epidermal growth factor concentration in the buffalo milk was ranged from 4.30 to 9.80 ng mL^-1, with a mean of 8.30 ± 1.50 ng mL^-1. Positive correlation between milk SCC values and EGF concentrations was recorded in water buffaloes. Further research is required to evaluate the content of milk EGF in different species of animals because of the EGF effective role in mammary gland and intestinal mucosa.

Abstract Bovine leukemiavirus (BLV) is one of the most important carcinogenic viruses genetically related to the human T-cell lymphotropic viruses (HTLV-1 and HTLV-2). The virus infects type B lymphocytes and creates lymph glands tumors. Recently, the association between the presence of this virus and breast cancer has been addressed in humans. Here, we studied the prevalence of BLV in the samples of raw milk of native Iranian and Iranian-foreign cows in traditional, semi-industrial and industrial dairy farms in rural and urban areas of Zanjan province. Raw milk samples of cows were collected manually in sterile tubes. The samples were tested by nested-PCR method. Forty samples (9.93%) out of 403 samples showed BLV contamination. In this study, nested-PCR was successfully applied to determine the level of contamination in raw milk samples from cows infected with BLV. Furthermore, a relatively high rate of BLV infection was found in dairy cows in Zanjan province, northwestern of Iran.

Abstract Milk samples from high and low milk producer Holstein cows, were obtained during the morning and afternoon milking over a one week period. Overall, 1064 samples were tested within 14 times sampling in Urmia, Iran. Milk macro-mineral concentrations in the morning milking and in low producers were greater than in the afternoon and in high producers. The highest and lowest concentrations were observed in Na+ and Mg++, respectively. Mean milk values between low and high producers in the morning, afternoon and daily milking times were different (p < 0.05). The individual comparison of milk parameters between both groups in the different milking times were also different (p < 0.05). The results of correlation among macro-minerals in the morning, afternoon and overall milking showed significant and positive correlations among all macro-minerals except for Na+ and K+, in which there was a significant negative correlation (p < 0.05). The highest and lowest correlations were found between Ca++ and inorganic phosphorus (IP) (r=0.37, p < 0.05) and Na+ and IP (r=0.10, p < 0.05), respectively. It is concluded that the concentration of macro-minerals in different producers varied between milking times. The sodium concentration was the highest while Mg++ was the lowest among macro-minerals. The correlation between Ca++/ IP was the highest, while Na+/K+ revealed a negative correlation. Therefore, by organizing the appropriate macro-minerals in the ration, it would be possible to achieve an optimal purpose from animal husbandry.