2,609 research outputs found
Relationship Between Some Traits Used As Mastitis Indicators in Holstein Cows’ Milk
This study was carried out in order to identify the relations between Somatic cell count (SCC), milk temperature, milk pH and milk density in mastitic and non-mastitic Holstein Friesian cows. The animal material of the study was mastitic and non-mastitic Black and White cows which similar age and lactation number. At the end of the study, it was defined that the mastitic milk was highly corelated with SCC and pH of milk (r=0,633; r=0,570 respectively). While in healthy group (non-mastitic), there wasn’t any correlation between the SCC and the other parameters; but in the mastitic group, it was found that there was significant correlations statistically between SCC and other parameters. Keywords: SCC, cows, Milk temperature, pH, electrical conductivty, density DOI: 10.7176/ISDE/11-1-03 Publication date: January 31st 202
Escherichia coli induces apoptosis and proliferation of mammary cells
Mammary cell apoptosis and proliferation were assessed after injection of Escherichia coli into the left mammary quarters of six cows. Bacteriological analysis of foremilk samples revealed coliform infection in the injected quarters of four cows. Milk somatic cell counts increased in these quarters and peaked at 24 h after bacterial injection. Body temperature also increased, peaking at 12 h postinjection, The number of apoptotic cells was significantly higher in the mastitic tissue than in the uninfected control. Expression of Bax and interleukin-1 beta converting enzyme increased in the mastitic tissue at 24 h and 72 h postinfection, whereas Bcl-2 expression decreased at 24 h but did not differ significantly from the control at 72 h postinfection, Induction of matrix metalloproteinase-g, stromelysin-1 and urokinase-type plasminogen activator was also observed in the mastitic tissue. Moreover, cell proliferation increased in the infected tissue, These results demonstrate that Escherichia coli-induced mastitis promotes apoptosis and cell proliferation
Feeding and Housing of Dairy Calves
In an 18 mo study antibiotic containing mastitic milk was collected from infected cows and fermented naturally for a minimum of 7 days at ambient temperature. Fermentation of antibiotic containing mastitic milk increased titratable acidity from 0.209% to 0.650% and decreased pH from 7.02 to 5.48. Fermentation decreased crude protein from 3.7% to 3.5% and increased NPN (% TN) from 6.0% to 8.4%. Penicillin was detected at a concentration of 1.2 IU/ml in the first milk after treatment and 0.01 IU/ml when fermented. Species of pathogenic organisms isolated from fresh and fermented milk were Staphylococcus epidermidis, Escherichia coli, Streptococcus dysgalactiae, Proteus species, Pseudomonas species, Enterobacter species and Klebsiella species. Holstein calves were fed either fermented antibiotic containing mastitic milk or whole milk for 6 wk then fed only dry feed for an additional 2 wk. Calf growth and dry feed intake was not different between treatments for the 8 wk trial. Female calf weights at 3, 6, and 12 mo of age were similar for both treatments. During the first 4 wk of the trial feed intake, minimum, and mean temperature accounted for 25.8% of the variation in body weight gain. From 5 to 8 wk of age and overall dry feed intake accounted for 38.7% and 44.6% of the variation in body weight gain. Fermented antibiotic mastitic milk treatment calves experienced 294% more scour and respiratory problems and 50% less mortality than the control treatment. Feeding fermented antibiotic containing mastitic milk appeared to be an acceptable alternative milk source for newborn dairy calves without significant effect on weight gain or feed intake, but health problems were more frequent
Effect of somatotropin on changes in milk-production and composition during coliform mastitis in periparturient cows.
The potential protective and therapeutic effects of bST during coliform mastitis in periparturient cows were evaluated. In a first study, 19 cows, classified as moderate or severe responders based on the respiratory burst activity of blood neutrophils, were treated with recombinant bST or vehicle 48 h after intramammary inoculation of Escherichia coli. Clinical status and changes in milk production and composition were compared in the four groups. In a second study, 8 cows received bST or vehicle 7 d before bacterial challenge.
During mastitis, losses in milk production and compositional changes were most pronounced in infected glands and in severe responders. Milk production of bST cows recovered better than that of placebo cows. Recovery of milk components was accelerated in severe responders treated with bST, but not in moderate responders. Pretreatment of severe responders with bST enhanced milk production before infection, protected the mammary glands from excessive loss of milk during the subsequently induced coliform mastitis, and accelerated normalization of milk composition.
In conclusion, the beneficial effects of bST upon normalization of milk production and composition in periparturient cows suffering from coliform mastitis seem to be restricted to the severe responders. In severe responders that had been treated with bST, changes observed during mastitis resembled those in moderate responders treated with the placebo
Effect of pre-analytical treatments on bovine milk acute phase proteins
Background
Samples for diagnostic procedures often require some form of pre-analytical preparation for preservation or safe handling during transportation prior to analysis in the laboratory. This is particularly important for milk samples which frequently need preservatives to retain milk composition as close to that found in freshly collected samples as possible.
Methods
Milk samples were treated by heating at 56 °C for 30 min or preserved by addition of either potassium dichromate or bronopol respectively. Haptoglobin (Hp), mammary associated serum amyloid A3 (M-SAA3) and C-reactive protein (CRP) were measured in the various treatment groups and in control samples which were not treated, using enzyme linked immunoassays. The concentrations of each APP were compared between treated and non-treated groups using the Wilcoxon signed ranks tests.
Results
Heat treatment of samples was found to have a significant lowering effect on milk M-SAA3 and CRP but not Hp. The use of potassium dichromate and bronopol as preservatives in milk had no significant effects on milk Hp and M-SAA3 concentration but lowered milk CRP values compared to controls.
Conclusions
The observed effects of heating and preservative use on milk APP should be taken into consideration when assaying samples which have undergone heat treatment as a result of international transfer regulations involving biological samples or samples needing chemical preservation prior to transport to laboratory
Plasmin aktivering i mastitmjölk
Received 22 April 1988 Published 23 January 2021 Issue Date September 1988Peer reviewe
Influence of mastitis on curd strength of milk
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Longitudinal metagenomic profiling of bovine milk to assess the impact of intramammary treatment using a third-generation cephalosporin
Antimicrobial usage in food animals has a direct impact on human health, and approximately 80% of the antibiotics prescribed in the dairy industry are used to treat bovine mastitis. Here we provide a longitudinal description of the changes in the microbiome of milk that are associated with mastitis and antimicrobial therapy. Next-generation sequencing, 16 S rRNA gene quantitative real-time PCR, and aerobic culturing were applied to assess the effect of disease and antibiotic therapy on the milk microbiome. Cows diagnosed with clinical mastitis associated with Gram-negative pathogens or negative aerobic culture were randomly allocated into 5 days of Ceftiofur intramammary treatment or remained as untreated controls. Serial milk samples were collected from the affected quarter and the ipsilateral healthy quarter of the same animal. Milk from the mastitic quarter had a higher bacterial load and reduced microbial diversity compared to healthy milk. Resolution of the disease was accompanied by increases in diversity indexes and a decrease in pathogen relative abundance. Escherichia coli-associated mastitic milk samples had a remarkably distinct bacterial profile, dominated by Enterobacteriaceae, when compared to healthy milk. However, no differences were observed in culture-negative mastitis samples when compared to healthy milk. Antimicrobial treatment had no significant effect on clinical cure, bacteriological cure, pathogen clearance rate or bacterial load
Staphylococcus aureus in mastitic crossbreed cows and its associated risk factors in Addis Ababa City, Ethiopia
A cross sectional study was conducted in dairy farms of Addis Ababa city from November 2011 to April 2012 to estimate the prevalence of Staphylococcus aureus and its associated risk factors in mastitic dairy cows. Milk samples were collected from 153 (50 clinical and 103 subclinical) mastitic lactating crossbred cows and were subjected to laboratory examination for identification of Staphylococcus aureus. Of the 153 mastitic cows, 67 were Zebu-Holstein Frisian and 86 were ZebuJersey crossbred. Bacterial identification was based on colony morphology, gram staining characteristics, and enzymatic tests including catalase and coagulase. Staphylococcus aureus was identified in 74 (48.4%) milk samples. It was higher (n= 63, 61.1 %) in subclinical cases as compared to clinical form of the disease (n= 11, 22%). The occurrence of bovine mastitis associated with Staphylococcus aureus varied significantly (p<0.05) between breed, lactation stage, parity and age. It was higher (n= 49, 56.9%) in Zebu-Jersey than Zebu-Holstein Frisian (n= 25, 37.3%) crossbred cows. Staphyloccocal mastitis is a major health problem in dairy farm of Addis Ababa causing huge economic loss. Furthermore, Staphylococcus aureus can leads to public health hazard through consumption of raw milk or milk products from infected animals. Therefore, early diagnosis and screening of cows for mastitis is important to limit spread of the disease. Appropriate control and prevention measures should be in place to reduce Staphylococcus aureus mediated bovine mastitis. Routine pasteurization of milk should also be practiced to safeguard the public health.Keywords: Addis Ababa, Crossbred Cows, Prevalence, Mastitis, Staphylococcus aureu
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