جستجوی مقالات مرتبط با کلیدواژه « milk » در نشریات گروه « دامپزشکی »

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Milk's healthand products are essential in human nutrition due to its high nutritional value. This nutritious snack is one of the most essential sources that microbial agents contaminate. Brucella is a Gram-negative coccobacillus whose hosts include humans, cattle, goats, and sheep. Brucella is transmitted through milk and dairy products and causes human malt fever. Serological methods for detecting Brucella do not have sufficient sensitivity and accuracy and have many false positive and negative results. This study collected 20 samples of raw milk and 20 samples of local cheese from Farsan City. Became NA of samples extracted by the DNP kit. After optimizing the first and second rounds of the test, PCR sensitivity and specificity were evaluated. Then all the samples were analyzed by optimized PCR test. Out of 20 raw milk samples, 1 sample (equivalent to 5%) was PCR positive; no PCR-positive sample was observed out of 20 local cheese samples. Since milk is widely used as a very nutritious and useful snack, the results indicate that despite the efforts made to prevent brucellosis, there is still a possibility of raw milk contamination in the areas Different, there are Brucella bacteria.

Arcobacter is Gram-negative bacteria without curved spores, distinguished from Campylobacter by growth in the presence of oxygen and low temperatures. This study evaluates Arcobacter contamination in grilled meat, ready-to-eat salads, raw milk, and water in Yasouj City. In this study, 120 samples, including 30 grilled meat samples, 30 ready-to-eat salad samples, 30 raw milk samples, and 30 drinking water samples, were randomly collected from different parts of Yasouj City and transferred to the quality control laboratory of Shahrekord Islamic Azad University. The samples were tested according to the standard method. P<0.05 was considered a significant level in the present study. The results showed that out of 120 food samples tested, 22 were contaminated with Arcobacter. There was no significant relationship between the sampled foods and the level of Arcobacter contamination. According to the results, the drinking water contamination was zero, grilled meat was 13, salad was 1, and raw milk was 8. In total, 22 out of 120 samples were infected with Arcobacter. Considering the contamination of 18/33% in all the samples of this study and the possibility of contamination to humans and causing complications such as gastroenteritis, as well as the high consumption of meat, especially grilled meat, in roadside restaurants, it seems necessary to take measures to control this contamination. Bacteria from the production cycle to the consumption of meat, salad, raw milk, cooking meat, and boiling milk before consumption must be done carefully.

Prevention, control and eradication of brucellosis in areas where the disease is endemic requires sufficient epidemiological information to apply policies. The present study was conducted with the aim of epidemiological investigation of brucellosis among the ruminant population of Lorestan province. In this cross-sectional descriptive study, all studies related to brucellosis in livestock were analyzed in Lorestan province. The results obtained from this study show that brucellosis has a high prevalence (22%) in three ruminant species (including cows, sheep and goats) of Lorestan province. The highest prevalence of brucellosis in sheep, goat, and cow milk was determined to be 25.6%, 23.5%, and 21.3%, respectively. Brucella abortus is the predominant species in milk obtained from ruminants in Lorestan province. Rev. 1 vaccine strain is excreted to a high extent (7.5%) in sheep and goats' milk. In general, unpasteurized milk is introduced as a threat to public health in Lorestan province. More extensive studies should be conducted, and existing methods of controlling and eradicating brucellosis should be modified.

In this study, the purpose of the study was to investigate the fungal flora of animal feed and the Concentration of aflatoxin M1 in the milk produced by traditional cattle ranches in Shahre-kord city, Chaharmahal and Bakhtiari province. For this purpose, since spring 2019 to spring 2020 (During one year), samples of animal feed consumed annually by twelve traditional dairy farms with the number of animals above 15 heads, located in different parts of Shahre-Kord city, the capital of Chaharmahal and Bakhtiari province, were randomly sampled. Isolation, cultivation and detection of fungi in the feed as well as the amount of aflatoxin in the produced milk in order to investigate the relationship between the composition of animal feed, mold and aflatoxin M1 in cow's milk was measured and measured using the ELISA method. The results of this study showed that the ingredients of animal feed include corn, cottonseed meal and rapeseed meal, nutritional supplements, barley, wheat bran, dry bread, fat powder and alfalfa containing contamination factors and molds of Aspergillus flavus, Clavanthos and Rhizophos stolonifer. In addition, the results of this study showed the presence of aflatoxin M1 in the milk of all farms under study during the test period. The results of statistical analysis on animal feed and aflatoxin data confirmed the existence of a strong correlation coefficient between rapeseed and soybean meal with Aspergillus molds in animal feed and milk contamination with aflatoxin. In general, according to the results of this research, it seems that controlling the contamination of animal feed with mold and fungi is the best method to prevent the contamination of milk and its products with aflatoxins, which plays an important role in improving the health of society.

Subclinical mastitis plays an important role in the economic losses of dairy cattle farms. Staphylococcus aureus is one of the most important causes of this disease. Treatment of this disease with synthetic antibiotics has complications like antibiotic resistance. Using herbal antibiotics can be an excellent way to reduce these side effects.

This study aimed to determine the minimum inhibitory concentration of alcoholic extract of olive leaf on Staphylococcus aureus isolated from milk of cows with subclinical mastitis to achieve herbal treatment.

This study was conducted on 175 Holstein female cattle. The milk samples of 60 cows were obtained with the sterilized method, and Subclinical mastitis-positive cases were determined using the California mastitis test. Staphylococcus aureus bacteria were isolated from positive samples by culture method, and the minimum inhibitory concentration of olive (Olea europaea L.) leaves alcoholic extract on isolated bacteria was determined by microdilution method.

From 175 cows under study, 60 cows had a positive California mastitis test, and Staphylococcus aureus separated from milk samples of 14 cows. The minimum inhibitory concentration of olive (Olea europaea L.) leaves extract on this bacterium was 12000 ppm.

Alcoholic extract of olive (Olea europaea L.) leaves has an antimicrobial effect on Staphylococcus aureus as a cause of mastitis. The minimum concentration required for this effect was 12000 ppm. Further studies on the impact of this plant on other bacterial causes of subclinical mammary inflammation in cows and investigation of the effective substances in the extract are needed.

Aspergillus flavus, A. parasiticus and A. nomius are the most important aflatoxin-producing species of B1, B2, G1 and G2 in food and feed. M1 and M2 Aflatoxins are the hydroxylated metabolites of B1 and B2 aflatoxins. The aim of this study was to evaluated the amount of aflatoxin B1 in animal feed and its relationship with aflatoxin M1 in raw milk. For this purpose, 20 industrial and 20 semi-industrial farms were selected and a sample of TMR ration and raw milk of each farm was sampled separately. Aflatoxin B1 in feed and Aflatoxin M1 in milk were evaluated by competitive ELISA, and the samples with values above maximum residue limit (MRL) were evaluated by high performance liquid chromatography (HPLC). The ELISA results showed that 35% of industrial farm feed and 75% of semi-industrial farm feed were contaminated with aflatoxin B1, of which 5% and 15% of industrial and semi-industrial farm had values above MRL, respectively. Also, in evaluating the amount of aflatoxin M1 in produced milk, it was found that aflatoxin M1 was observed only in the milk of farms that were positive for aflatoxin B1 and this rate was 20% and 55% in industrial and semi-industrial farms, respectively. The samples of milk with values above MRL were measured by HPLC confirmation test, which indicates that none of the samples of industrial and semi-industrial dairy production milk had higher values (0.5 ng/ml). Due to the importance of per capita milk consumption in the community diet and the dangers of aflatoxin M1 in it, extensive and accurate monitoring of milk production and supply centers as well as dairy factories is essential.

The aim of this study was to investigate the probiotic characteristics of the isolated lactic acid bacteria (LAB) in coagulated cow's milk including antimicrobial activities, acid and bile tolerance, fermentation profile, hemolytic properties, acidification and coagulation collected from some villages of Tehran province were examined. Among the 13 milk samples collected, 7 isolates were identified as lactic acid bacteria based on phenotypic and biochemical tests. In order to determine the biochemical results, their DNA was extracted and amplified by PCR with specific primer and then sequenced by PCR products and they were recorded in the NCBI database. These results definitely confirmed that the isolated strains belong to lactobacilli. The results showed all isolated LABs were positive for hemolytic activity. LABs A and C showed beta hemolysis. LAB E showed the highest resistance to acidic environments, whereas all the our isolates were resistant to bile conditions. The supernatant obtained from lactic acid bacteria had an effect on Escherichia coli and a non-growth halo was created. But it had no effect on staph and fungi. all LAB isolates exhibited the ability of acid production and coagulation at 30°C. In contrast, none of the LAB isolates presented coagulation potential at 30 °C. Based on this study results, LAB E and C isolated from coagulated cow's milk could be considered as probiotic microorganisms considering the observed properties. They can be purified and used for the production of probiotic dairy products.

Neosporosis is the main cause of abortion in cattle in Iran and other parts of the world, which is caused by a parasitic protozoan Neospora caninum . The economic effects of Neosporosis are reduced milk and meat production in cattle. Transmission of N.caninum is possible through vertical and horizontal routes. Some studies have been conducted on the importance of vertical transmission during infancy, through colostrum and milk. Most studies in Iran to investigate the incidence of N.caninum in cattle are based on the search for anti-parasitic antibodies in the blood serum and limited studies have been performed on milk. The aim of this study was to investigate the presence of N.caninum genome in raw cow milk using PCR method to evaluate the vertical transmission of this parasite. In this study, 300 samples of raw cow's milk were collected from traditional farms in Yazd province. The results of this study showed that 54 cases (18%) of 300 samples of cow milk were infected with N.caninum genome. The findings of the present study indicate a high presence of N.caninum infection and showed that infected cow's milk plays an important role in the transmission of Neosporosis in newborn calves. Based on these findings, control and eradication programs, including vaccination, are necessary to prevent and reduce the economic losses of this protozoan infection in cattle.

Enterococci are among the lactic acid bacteria with probiotic potential which are found in dairy products and especially in fermented products. The study aimed to isolate enterococci from raw milk of Jersey cows and its fermented products as well as to determine some probiotic properties of the isolates. Five specimens from each of raw milk, buttermilk, yogurt, cheese, and butter were obtained. Twelve isolates of Enterococcus faecium, Enterococcus avium, and Enterococcus faecalis were isolated. The antimicrobial effects of the isolates were investigated on indicator microorganisms. All isolates had an inhibitory effect on these microorganisms. Escherichia coli was more sensitive than the others. Pseudomonas aeruginosa and Listeria ivanovii followed, and the lowest susceptibility was observed in Listeria monocytogenes, Bacillus cereus, and Klebsiella pneumoniae, respectively. Overall, gram-negative microorganisms were significantly more sensitive than gram-positive microorganisms (p≤0.05). In the study of resistance of isolates in culture medium containing 0.3% bile, out of 12 isolates obtained from the tested samples, two isolates of E. avium (40%), three E. faecalis isolates (100%), and one E. faecium (20%) were found to be resistant. Amongst, one isolate of E. avium was resistant to acidic conditions. In general, milk and fermented products can be considered rich sources of Enterococcus species, a small number of which are resistant to the human gastrointestinal tract environment. Of course, these isolates must be further evaluated for safety.

Improper use of antibiotics, and the subsequent residues in raw animal products such as milk, can directly or indirectly cause health problems in human communities such as allergic reactions and reduce the effectiveness of antibiotic treatments. The aim of the present study was to determine the residual levels of tylosin, gentamicin, and neomycin in milk and ice cream distributed across Tehran. A total of 125 samples, including raw milk, pasteurized and sterilized milk, traditional and pasteurized ice cream. The samples were randomly obtained from retail centers in Tehran from July to September 2019. The residual levels of tylosin, gentamicin, and neomycin were determined using high-performance liquid chromatography (HPLC) method. Of the samples, tylosin, gentamicin, and neomycin were detected in 94.4%, 92.2%, and 96.6%, respectively. The highest tylosin residues in raw milk and ice cream samples was 26.72 ± 1.55 and 26.01 ± 1.55 μg/l, respectively. The highest gentamicin residues in raw milk and ice cream samples were 28.15 ± 1.29 and 28.8 ± 1.29 μg/l, respectively. The highest neomycin residues in raw milk and traditional ice cream samples were 33.46 ± 1.95 and 34.7 ±1.95 μg/l, respectively. According to the Iranian National Standard, in all tested samples the residual antibiotics were below the standard approval limit. Since most samples contained antibiotic residues, continuous monitoring of milk samples for antibiotic residues is recommended.

Mycobacterium avium subspecies paratuberculosis (MAP), the causative agent of Johne’s disease, is a very slow-growing bacterium that imposes heavy costs on livestock-related industries. Due to the similar clinical and pathological symptoms in Johne’s and Crohn’s diseases, MAP is likely to play a role in the development and progression of Crohn’s disease. Hence, the possibility of transferring MAP through milk has created many concerns. To investigate the status of MAP contamination in raw and pasteurized milk samples in Kerman province, three diagnostic methods, including culture, IS900 PCR, and IS900 nested PCR was used. The results showed that the level of contamination with MAP in raw milk was relatively high in the studied herds. Based on culture, PCR, and nested PCR assays, 4.38%, 9.16%, and 13.55% were found positive, respectively. In pasteurized milk samples, 1.12%, 3.93%, and 6.18% were found positive for MAP by culture, PCR, and nested PCR, respectively. Comparing the methods used in this study demonstrated the best capability of nested PCR to detect MAP contamination. High levels of MAP contamination in raw milk on the one hand and relatively high resistance to thermal treatments, along with its intracellular characteristics, cause more survival of this bacterium, especially in the milk pasteurization process. Therefore, food hygiene researchers should pay more attention to the public health hazard caused by this bacterium.

The current study aimed at removing aflatoxin (0.5 and 0.75 ng/mL) from the reconstituted milk by adding three probiotics Lactobacillus rhamnosus, L. plantarum and Saccharomyces boulardii in the cell concentration of 107 and 109 CFU/mL at 4°C and 37°C within 30 and 90 minutes. The highest activity of Lactobacillus rhamnosus in the removal of aflatoxin M1 was observed in the cell concentration of 107 CFU/mL and 0.75 ng/mL toxin concentration at 37°C (Figure 1) after 90 minutes exposure (64.31% ± 3.79%) and had no significant difference with the optimum value at 30 minutes exposure (63.86% ± 5.00%) (P >0.05). Regardless of aflatoxin M1 and probiotics concentrations, the highest mean marginal estimation of aflatoxin M1 removal from the milk at 4°C in the early minutes belonged to L. plantarum, which gradually became identical for all the three probiotics until the minute 90. The potential of S. boulardii in removing aflatoxin M1 from the milk (96.88% ± 3.79%) gradually increased within the initial minutes (90 minutes) with increasing the concentration of aflatoxin M1 (0.75 ng/mL) and the yeast by 109 CFU/mL at 37°C; binding affinity also decreased with decreasing the temperature. The results of the current study indicated that 107 CFU/mL of S. boulardii can efficiently remove aflatoxin M1 from milk.

The aim of this study was to evaluate the concentration of some heavy metals in the milk produced by dairy farms in Qazvin province. For this study, milk samples of 35 industrial dairy herds under the auspices of the Livestock Breeders Union of Qazvin province in different cities including Abyek, Qazvin, Takestan, Buin Zahra and Alborz were collected by direct reference in two consecutive days. Immediately after sampling, the samples were sent to a specialized laboratory for measuring levels of heavy metals including lead, cadmium, chromium, nickel and mercury. Then, the obtained data were analyzed in a completely randomized design. The results showed that the concentrations of lead, cadmium and chromium in the produced milk were 1.43± 3.77, 0.70± 2.24 and 1.07±1.27 μg / kg respectively.  There was no significant difference in the concentration of these elements among different cities. The concentrations of nickel and mercury in the produced milk were 0.63± 0.30 and 0.39± 0.37 μg / kg respectively. In terms of nickel and mercury concentrations, the difference between different cities of the province was significant and in Abyek was higher than others (P=0.02 and p=0.02 respectively). In conclusion, concentrations of heavy metals (lead, cadmium, chromium, nickel and mercury) in milk produced in dairy farms was less than the standard levels, thus milk produced in Qazvin province can be considered as a healthy product from heavy metals (lead, cadmium, chromium, nickel and mercury) for human consumption.

Early pregnancy detection is a strategic way to reduce farm costs. Nutritional and health costs resulting from the maintenance of non-pregnant animals will not be imposed on the farmer, by timely detection of pregnancy. The aim of this study was to evaluate the accuracy of early detection of estrus and pregnancy in Sannan goats by measuring of estradiol-17β and progesterone concentrations in milk. In this experiment, 22 Sannan goats with 2-3 years old, with an average calving of 1.75 and an average weight of 47.5 ± 3.45Kg were selected and kept under equal conditions. First, estrus was synchronized in goats with vaginal sponge and PMSG and prostaglandin hormones (sponge for 12 days and injection of hormones on the final day). Milk samples were taken on days 0 and 1 of the estrous cycle (for estradiol test and estrus diagnosis) and on days 19, 21, 23 and 25 after mating (for progesterone measurement and pregnancy diagnosis). The average concentration of estradiol in milk was 15.01 pg/ml on day 0 and 2.76 pg/ml on day 1 of estrus. Based on sources, animals whose milk progesterone was more than 7.5 ng/ml were assumed to be pregnant, which was evaluated 50 days later by ultrasonography. Results show that Milk progesterone can be a way to diagnose goat pregnancy from the 19th day after mating with 86% accuracy. In summary, measuring milk estradiol and progesterone can be a way to timely estrus detection and to early diagnosis of pregnancy.

Toxoplasma gondii is the causative agent of Toxoplasmosis, an obligate intracellular parasite of warm-blooded animals. This study aimed to investigate the survival rate of T. gondii tachyzoites in the traditional Lighvan cheese-making process with different concentrations in 24 hours. For this purpose, the first 2 liters of fresh sheep milk were prepared from milk collection centers and transferred to the Laboratory. The 8×107 parasites of T. gondii strain RH and rennet were added to the milk. After stirring, make slices 2 in the cheese and separate containers containing different concentrations. NaCl containing 4, 8, 12, and 16% were placed in 24 hours with three repetitions. After the mentioned periods, each Lighvan cheese treated was completely homogenized with PBS for 5 minutes with 2000 rpm centrifugation. The resulting sediment was injected intraperitoneally with three repetitions to 3 rats. At the same time, some Lighvan cheese was fed orally to each of them. Survival rates of T. gondii tachyzoites were assessed by mouse mortality. The results showed that the survival rates of mice at concentrations of 12 and 16% for 24 hours were 100%. Also, at a concentration of 4% at 24 hours, the highest mortality rate of mice was observed, which indicates the survival of the parasite at this concentration and duration. This study showed that to inactivate possible T. gondii tachyzoites in contaminated milk used in the traditional Lighvan cheese industry, it is better to place the prepared cheese in 12% and 16% salt concentrations for more than 24 hours.