جستجوی مقالات مرتبط با کلیدواژه « Mastitis » در نشریات گروه « علوم دام »

The transition period between late pregnancy and early lactation (also called the periparturient period) certainly is the most interesting stage of the lactation cycle and is the last 3 weeks before parturition to 3 weeks after parturition. Most infectious diseases and metabolic disorders occur during this period. Milk fever, ketosis, retained fetal membranes, metritis, and displaced abomasum primarily impact cows during the periparturient period (Drackley, 1999). Any nutritional limitation during this period has an important impact on cow efficiency and consequently, milk production decreases. Dairy cows encounter substantial metabolic and physiological adaptations during the transition period. The immune system during the periparturient period is impaired. At this time, the most important factor causing immune-suppression in highly productive cows is metabolic stress resulting from hormonal and metabolic fluctuations, a negative energy balance, shortage of proteins, minerals and vitamins which are required to meet the demands of the fetus as well as the onset of lactation (Sordillo, 2016). In the world, Cu deficiency is one of the most common problems in cattle with clinical and subclinical signs (Hill and Shannon, 2019). Even marginal Cu deficiency (6 to 7 ppm dietary Cu) depresses blood neutrophil function in dairy cattle (Torre et al., 1996). One strategy for improving immune system of transition dairy cows is mineral and vitamin supplementation. It has been reported that many minerals are enzymatic cofactors (Filappi et al., 2005). Studies showed that minerals injection would be a suitable method to improve mineral utilization, and this may be a promising alternative to improve animal performance (Collet et al., 2017). Furthermore, during this period, dairy cows need antioxidants to combat reactive oxygen species (ROS) which produce during oxidative stress. Vitamin C was identified as antioxidant and could help immune system to overcome ROS production. Hence, this experiment was aimed to study the effect of vitamin C and copper injection on the health status of transition dairy cows.

The study was carried out in a commercial farm located in Kermanshah province of Iran. Cows were enrolled from June 22, until September 22. Temperature and humidity index (THI) was calculated. It was between 72-78. The experiment was performed with 40 multiparous (twenty; second parity and twenty; third and fourth parity) Holstein lactating dairy cows which divided into four groups (10 animals/ group) in a 2×2 factorial arrangement. All cows were offered a TMR diet. Experimental treatments consisted of control (injection of 7 ml of NaCl % 0.9), Cu (injection of 75 mg Cu per cow) Vitamin C (injection of 25 mg vitamin C solution/kg BW), and Vitamin C-Cu (simultaneous injection of 25 mg vitamin C solution/kg BW and 75 mg Cu/ cow). Solutions were injected on d 20 and 40 days before expected parturition, parturition day and day 20 of postpartum. Serum concentrations of total protein, glucose, triglycerides, cholesterol, HDL-cholesterol, Ca, P and Mg were determined using autoanalyzer by Pars Azmoon Kits. Serum concentrations of Beta hydroxybutyrate (BHBA) and non-esterified fatty acids (NEFA) were measured using autoanalyzer by Randow Kits. Serum concentration of Cu was determined by atomic absorbtion. Serum concentrations of vitamin C and superoxide dismutase was measured by Elisa reader. Incidence of metabolic disorders and infection disease were recorded. Data of serum variables were analyzed based on a randomized block design with a 2×2 (Vitamin C and Cu, with or without injection) factorial arrangement using Proc Mix of SAS software. The differences among treatments were evaluated using Tukey adjustment when the overall F-test was P ≤ 0.05. Trends were declared when 0.05 < P < 0.10. In addition, percentages of metabolic disorders were reported.

Results showed that the interaction effect of vitamin C and Cu had no significant effect on serum concentration of vitamin C and superoxide dismutase activity. Cows received vitamin C had the greatest serum vitamin C concentration on d 20 prepartum, parturition day, d 10, 20 and 30 postpartum (P<0.05). Content of serum Cu were affected by the interaction of vitamin C and Cu on d 10 and d 20 postpartum (P<0.05). Copper injection increased serum Cu concentration and superoxide dismutase activity on d 20 prepartum, parturition day, d 10, 20 and 30 postpartum (P<0.05) in cows received Cu without vitamin C. Serum concentrations of P, Mg, glucose, BHBA, NEFA, triglycerides and HDL-cholesterol were not influenced by the interaction effect of vitamin C and Cu. Serum triglyceride concentration tended to decrease (P=0.06) in cows received vitamin C and on parturition day. Copper injection tended to increase (P=0.06) serum triglyceride concentration on d 20 postpartum. Serum protein concentration tended to decrease (P=0.07) in cows received vitamin C and in compared to other treatments on parturition day. Copper or vitamin C injections had no effect on serum concentrations of Ca, P, Mg, glucose, BHB and NEFA of experimental cows. Serum calcium concentration tended to increase (P=0.07) in cows received simultaneous injection of vitamin C and Cu in compared to the others on parturition day. Simultaneous injection of vitamin C and Cu tended to increase total cholesterol concentration (P=0.06) on d 10 and 30 of postpartum. Copper injection tended to increase total cholesterol concentration on d 20 prepartum, parturition day and d 10 postpartum (P=0.06). Control groups had the highest incidence rate of retained placenta and clinical mastitis.

It is concluded that vitamin C and Cu injection reduced incidence rate of retained placenta and clinical mastitis due to improving immunity system performance of transition dairy cows.

Mastitis is one of the most frequent and costly diseases of the dairy cattle industry and causes many economic losses, which negatively affects milk yield and composition, fertility, longevity and welfare of cows. The best solution for reducing the economic and biological consequences is early and accurate prediction of mastitis based on indicator factors. So far, various statistical methods have been used to predict mastitis such as linear and multiple regression, and threshold models. Machine learning is another method that has recently widely been used to predict farm profitability, reproductive traits, longevity and abortion in dairy cow. Machine learning is defined as a set of methods for automatically finding patterns in data and then using those patterns to predict possible future data.

In this research, the performance of four machine learning algorithms including random forest, decision tree, Naïve Bayes and logistic regression and two sampling methods, over-sampling and under-sampling, were compared to predict risk of clinical mastitis based on data collected in two Holstein dairy herds in Isfahan province. Final dataset included 393504 records on cows calved during 2007 to 2017 of which 13653 cases (3.47%) were infected and 379851 cases (96.53%) were healthy. Factors related to mastitis, including parity, daily milk production, calving

In the current study, the effect of source and level of copper in the diet on production and health of dairy cows using 105 multiparous pregnant Holstein cows from -21 until +15 days relative to calving in randomized complete block design with 3 treatments and 35 replications were investigated. The experimental treatments include: 1) diet containing copper at the NRC recommended levels from copper sulfate source (NRC-S), 2) diet containing copper at twice the NRC recommended levels from copper glycinate source (2NRC-Gly) and 3) diet containing copper at twice the NRC recommended levels from copper sulfate source (2NRC-S). Milk yield and composition were not affected by experimental treatments, but treatment by time interaction showed that cows fed by 2NRC-Gly had more milk than NRC-S group (P<0.05) at 60, 90,120 DIM and cow in 2NRC-Gly produced more milk at 90 and 120 days in milk compared to NRC-S (P<0.05). The somatic cells count for 2NRC-Gly cows was lower compared to NRC-S cows (P 0.05). The incidence of subclinical mastitis at 15 DIM in 2NRC-Gly was lower compared to the other two treatments (P = 0.05). No difference in body weight and body condition score changes were observed across treatments. Blood metabolites and liver enzymes were not affected by adding different Cu sources, but serum albumin postpartum was increased in 2NRC-Gly group relative to the other two groups (P 0.05). Based on the results, adding copper especially by copper glycinate source at twice the NRC recommended levels led to an increase in the serum albumin concentration, a decrease in milk somatic cells count and lower incidence of subclinical mastitis, which could indicate an improvement in health of cows during transition period.

The aim of the present study was to estimate the impact of somatic cell count on daily milk yield of Iranian dairy cows using quantile regression statistical technique. A total of 784,532 test day records belonging to 93,259 first-parity cows distributed in 660 herds and calved during 2003-2013 were used. The studied trait was test day milk yield and the model was defined as a quantile regression. All of the estimated regression coefficients were negative, which indicated a decrease in the amount of daily milk production when milk somatic cell counts increased, so that, in the spite of lactation stage, on the basis of absolute value, the lowest and highest regression coefficients observed at ninety-fifth percentile and fifth, respectively. Considering lactation stage in the seventh stage of fifth percentile, the highest decrease was 238 g milk reduction per day, for increase of 100 thousand somatic cells per ml/L of milk, and in the 95th percentile of the fourth stage, the lowest decrease was 64 grams milk reduction per day, for increase 100 thousand somatic cells per ml/L of milk. The results revealed that in high quantiles of daily milk yield, the impact of SCC on milk production decreases indicating that high-producing cows are less influenced in terms of loss of milk production as SCC increases. The difference in the amount of somatic cell count on the amount of milk production in cows with different production potential should be considered in the genetic evaluation of herds.

In the dairy industry, it is important to identify the genotypes resistant to mastitis while select high-yielding dairy cows. Bovine β-difensin gene polymorphism can be used as a molecular marker in the selection of mastitis-resistant dairy cows. The aim of this study was to investigate the relationship between point mutation of β4-difensin gene and the occurrence of clinical mastitis in the dairy cows using RFLP-PCR method and identification of superior genotype of dairy cows β-difensin gene for mastitis resistance.

blood sample (with EDTA anticoagulant) was taken from total 73 cows (32 with a history of mastitis and 41 with no history of mastitis) in an industrial dairy farm. After DNA extraction amplification of the region of bovine β-difensin gene (393 bp) was performed. PCR products were digested by endonuclease (NlaIII (Hin1II)) for rapid detection of polymorphism in the 2239 region of the β-difensin gene (C to T conversion). Statistical analysis was performed by Chi-square test.

Allele frequencies were 0.68 and 0.32 for C and T, respectively. Statistical analysis was performed by Chi-square test. The results of this study indicate the association between number of mastitis and polymorphism in the β-difensin gene. In other words, the incidence of mastitis was  numerically lower in cows with T allele than in cows without it (p=0.07).

It can be concluded that the bovine β-difensin gene can also be used as a molecular marker in the selection of dairy cows to reduce the incidence of mastitis.

To study the reaction of udder mRNA abundance of genes related to nuclear erythroid 2-related factor 2 (Nrf2) to an intramammary lipopolysaccharide (LPS) challenge with changes in blood insulin and metabolites levels, 24 dairy cows were used. Treatments included insulin infusion (HypoG, n=5), insulin and glucose (EuG, n=6), β-hydroxybutyrate (HyperB, n= 5), and saline (Control, n=8) for 56 h. At 48 h of infusions, two quarters were treated with 200µg LPS, and two control quarters were treated with physiological serum. Mammary tissue biopsies were obtained before and after the LPS challenge. The mRNA abundance of the genes was measured by the qPCR approach. In the LPS quarters, the mRNA abundance of MT1A, MT2A, and MT1E increased in all treatments. The mRNA abundance of GPX3 increased in HyperB and Control. The mRNA abundance of MGST3 and SOD1 decreased in all groups lacking EuG. Decreased mRNA abundance of NQO1 observed in HypoG. In the control quarters, the mRNA abundance of MT1A and MT2A was raised in all groups. Similarly, MT1E is up-regulated in all groups except for the HypoG. The increase of mRNA abundance of GPX3 was observed in the Control and EuG groups, and UGT1A1 in EuG. LPS decreased the mRNA abundance of MGT3, NQO1, and SOD1 in HypoG. In conclusion, LPS influenced the mRNA quantity of the investigated genes in both quarters, which indicate local and systemic reactions to endotoxin. Applying appropriate management strategies will reduce oxidative stress and susceptibility to diseases and will lead to better welfare and performance of the animal.

The aim of this study was to identify the allelic variants of C4-A and LF genes and to investigate their associations with the nunber of milk somatic cells in Holstein cows. Mastitis is one of the most common diseases in dairy cows, that reduces milk production and imposes high costs on breeders. C4-A and lactoferrin genes are amonge the genes that affect the immune system to fight pathogens, microbial agents and mastitis. 384 blood samples were prepared from Holstein cows and DNA extraction was performed using optimized salting out method. IPLEX technique was used to determine the genotype of the samples. To identify single nucleotide polymorphisms, the marker sites of 1-rs137485678; C<G and 2-rs132741478; C<T for C4- A complement gene and 1-rs384176726; A<G and 2-rs445918028; A<T were selected for the LF gene. Genotyping at 1-rs137485678; C<G locus of C4-A gene showed two C and G alleles with frequencies of 58 and 42 %, and also three genotypes CC, CG and GG with frequencies of 31, 53 and 16%, respectively. No polymorphisms were observed at the other sites. Marker-trait analysis showed a statistically significant association (P<0.05), so that cows with CG genotype had the lowest number of somatic cells. Phase software was used to identify haplotypes. Based on the results of this research, the marker rs137485678; C <G-1 of the C4-A gene can be used as a genetic marker to improve mastitis in dairy cows.

Treatment of bacterial diseases with antibiotics has problems such as antibiotic resistance and side effects. Essential oils of medicinal plants have antibacterial effect and are suitable alternatives. Lavandula stoechas and Origanum majorana are two members of lamiaceae family that have shown antibacterial effect against some bacteria. Escherichia coli, Staphylococcus aureus, and Streptococcus agalactiae bacteria are major bovine mastitis-causing bacteria. Therefore, this study examined the antimicrobial activity of Lavandula stoechas (lavender) and Origanum majorana (marjoram) essential oil against these bacteria in comparison with gentamycin and amoxicillin/clavulanate antibiotics.

Chemical compositions of essential oils were determined by GC/MS. Broth dilution testing using macrodilution was performed to determine minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of essential oils and licospectinomycin as positive control and the inhibition zones of oils, gentamycin and amoxicillin/clavulanate antibiotics were assayed by disk diffusion method. The effect of sub-MIC concentrations of essential oils on tested bacterial count was obtained at 0, 6, 10 and 24 hours and growth curve were plotted as log cfu/ml.

Main components of the Lavandula stoechas and Origanum majorana oils were 17-pentatriacontene (42.15%), linalyl acetate (26.82%), eucalyptol (18.87%), linalool (5.7%) and 3-cyclohexene-1-ol,4-methyl-1-(1-methylethyl)-,(R)-(44.84%), α-terpineol (6.83%), P-cymene (6.75%), respectively. MIC and MBC values ranged from 0.15 - 0.62% for lavender and 0.62 - 1.25% for marjoram. MIC and MBC of licospectinomycin antibiotic were 0.07 - 0.31% and 0.15 - 0.64%, respectively. The lavender and marjoram essential oils had the most effective against S. aureus and MIC and MBC values were 0.15% and 0.31%, respectively. Also, the most effective of Lincospectinomycin antibiotic was against S. aureus and MIC and MBC values were 0.07% and 0.15%, respectively. The Lavandula stoechas and Origanum majorana oils at sub-MIC concentrations significantly reduced the bacterial population at 24 h. The inhibition zone of lavender and marjoram essential oils had no significant difference against S. aureus with gentamycin and amoxicillin/clavulanate antibiotics and against E. coli with gentamycin but against S. agalactiae were significantly lower than gentamycin and amoxicillin/clavulanate.

Essential oils of Lavandula stoechas and Origanum majorana had antibacterial activity against Staphylococcus aureus, Streptococcus agalactiae and Escherichia coli bacteria in vitro. This effect had no significant difference against S. aureus with gentamycin and amoxicillin/clavulanate and against E. coli with gentamycin that show satisfactory effects of oils. Clinical studies on therapeutic effects of Lavandula stoechas and Origanum majorana oils on different diseases such as bovine mastitis are recommended.

The aim of this study was to identify regulatory genes affecting mastitis in dairy cattle using DNA microarray data. To reach this goal, the gene expression data with the largest number of arrays pertained to GPL1221 Platform with accession number GSE24560 was extracted from the GEO database. For quality control of data, ArrayQualityMetrics package and for preprocessing of data, three step function in AffyPLM, an add-in package in R environment were used. After identifying differentially expressed genes, a Tabu search algorithm was used to determine regulatory genes using bnlearn package in R environment. The results of this study revealed the causative and regulatory role for BCL2A, CCL2, S100A12, AOX1 and MGP genes on expression of other genes in mastitis of dairy cattle. Gene anthology analysis, revealed significant differences in 7 groups of molecular function, 48 groups of biological process and 11 groups of cellular components. Also, the results of the enrichment of the gene expression data set showed that most of the differentially genes expressed in this study that were significantly (P<0.05) active in metabolic pathways (GO: 0009605, GO: 0002376 and GO: 0006954) involved in response to pathogens, immune response and response to inflammation in the mammary tissue of dairy cattle.

Epigenetics is assumed as the most complex field of biological sciences. Generally, epigenetics includes mechanisms that not only affect gene expression, but also bring about functional changes in the next generation of mitotic cell division (autosomal inheritance) and meiotic cell division (generational inheritance), though DNA nucleotide structure is not changed (Barazandeh, 2016). DNA methylation refers to the enzymatic addition of a CH3 group to a cytosine residue in DNA strand, which occurs almost particularly at CpG dinucleotides (i.e., a cytosine located 5′ of a guanine) in animals. The enzymatic machinery responsible for DNA methylation includes a family of DNA methyltransferases (DNMTs), including the maintenance methyltransferase DNMT1 (responsible for copying pre-existing DNA methylation patterns to the new strand during mitosis) and the de novo methyltransferases DNMT3A/3B. DNA methylation is considered as epigenetics factor. In mammalian, DNA methylation is necessary for both embryonic development and stem cell differentiation and this phenomenon is basically occurring in CpG dinucleotide. CpG dinucleotide intends to make cluster over genome that is called CpG island. CpG islands are considered gene markers and represent an important feature of mammalian genomes. CpG islands vary greatly among mammalian genomes (Medvedeva, 2011). Some factors such as recombination rate and chromosome size might have influenced the evolution of CpG islands in the course of mammalian evolution. Whenever CpG island in gene's promoter is not methylated and suitable transcriptional factors are accessible, gene expression machine is activated and therefore gene is expressed. However, methylation of CpG islands in gene promoter with compact form of chromatin could lead to inhibition of gene expression (Shi et al., 2012). Hypermethlation of CpG islands could cause a range of diseases such as cancer. Epigenetic process could modify proteins after translation that actually refers to biochemical events inflicting on proteins. Some of these events include: methylation, phosphorylation, glycosylation, sulfation, sumoylation, and ubiquitinylation disulfide bonding. Nutrition is seen as one of the greatest environmental determinants of an individual’s health. Although nutrient quantity and quality could impart direct effects, the interaction of nutrition with genetic and epigenetic is often overlooked despite being shown to influence different biological variation in mammals (Murdoch et al., 2016). Understating and unrevealing complex traits, such as those that are nutrition-related, to determine the genetic and epigenetic contributions toward a phenotype would be a formidable job to get it done. Similar to other epigenetic endpoints, patterns of DNA methylation could be susceptible to alterations by exposing to environmental treatments, including contaminants (Head, 2014). These sort of alterations may persist in the absence of the initial treatments as cells divide, and can even be inherited over generations provided that they occur in the germ line. Although our knowledge concerning patterns of DNA methylation in animals is increasing, a big gap remains in the literature, especially when it does come to species outside of those generally used for biomedical researches. Unlike DNA, epigenetic markers could be directly influenced by the environment factors; therefore, epigenetic markers have been shown to be pivotal mediators of phenotypic responses to environmental signals. To understand how epigenetic modifications facilitate and affect gene expression, it is crucial to understand how and when the epigenome is established (Faulk and Dolinoy, 2011). While we do not fully understand how all of the complex epigenetic genome changes occur, yet some epigenetic information is sought to retain and transmit to the next generation. In this study, first of all, some articles and resources that describe candidate genes affecting mastitis were explored and some of the genes which were considered candidate genes in bovine mastitis were chosen. These genes included 14 interleukins (in exception of interleukin 8 and interleukin 9), interferon-gamma, and tumor necrosis factor (in total 13 genes). Their DNA sequences and other features of selected genes (for example exon numbering, gene length, guanine percentage and cytosine percentage) were obtained from NCBI database and saved as FASTA format. The C++ based software and Promoter 2.0 Prediction Server were used to extract characteristics of genes and detecting gene promoters, respectively. This software is generally used to predict transcription factor-biding sites of DNA sequences in vertebrata. In order to detect CpG islands, DBCAT, SMS, and Geneinfinity softwares were used. Also, primary structure of proteins derived from these genes was extracted from NCBI database and finally protein methylation was obtained by using PMeS software. Depending on the type of algorithm used to identify the CpG islands, the number and length of the CpG islands found to be different. Predicted CpGs were used as measurements to indirectly investigate the level of methylation over DNA level of genes. The investigated genes in terms of some features like total size based on number of nucleotides, number of exons, total annotated spliced exon length, and percent of GC content were quite different. The essence of gene heterogeneity from different features made grouping of these genes a cumbersome job. In this research, our overall objective was to locate the position and number of CpG in the promoter region of genes. Referencing of applied software to detect CpG islands, number and length of detected CpGs was different. Results shown that methylation was not evenly/ uniformly occurring in considered genes and in average, less than 50 % of CpG islands were in promoter region of genes and methylated CpG was located in intergenic regions. Also, the maximum amount of methylation was seen in interleukin 1, 2, and TNF gene, which are among the most important genes in circumventing mastitis. The degree of methylation in the proteins derived from the investigated genes showed fairly non-concurrence results with their DNA methylation. However, protein derived from interleukin 11 undergoes methylation in large portions of its original protein structure. It should be noted that different algorithm architectures may give different results (Barazandeh, 2016; Medvedeva, 2011). At the DNA level, this gene also had the highest CpG in its promoter. This may indicate the complexity of epigenetic process with this gene. Therefore, this gene could be considered as a suitable candidate for performing demethylation experiments and proving biological drugs to circumvent mastitis. An integrative view to gene structure, DNA methylation and methylation of proteins derived from the investigated genes in this research would provide the better idea pertaining to methylation function in circumventing the mastitis in dairy cattle. Out of the three software tested, the results of the two SMS and Geneinfinity software were almost similar and probably use a similar algorithmic architecture. It should be noted that the algorithms used in this study were not developed to identify specific CpG islands on the bovine genome. The genes under study had undergone a methylation process at many levels of their proteins. The results of this study depend on different algorithmic parameters and changing these parameters were diverse. As matter of fact that mastitis heritability is low in general, such studies could reveal a better role for single and group genes in the epigenetics process.

Generally, the causes of mastitis classified into two types of infectious factores ( eg Staphylococcus aureus ) and environmental factors such as ( Escherichia coli ). The common method to treat this disease is to use antibiotics Which can cause problems related to human health. the Peptides created in the laboratory or In living organisms from incomplete digestion of proteins and have a specific biological function called bioactive peptides. Casein contains antibacterial peptides called israchidine, Which by destroying the cell membrane or mitochondria membrane, It causes the destruction of bacterial cells. The purpose of this study, was to identify the protein and bioactive anti-bacterial peptides of alpha-s1 casein in eight different species of mammals and Comparison of the antibacterial properties of these peptides in these eight species of mammals against two major bacteria producing Staphylococcus aureus and Escherichia coli. first, genomic and protein data for eight different species of mammals ( cattle , sheep , camels, horses , humans , ewes and pigs ) was collected from the National Center for Bioinformatics Information Center ( NCBI ) And then, The prediction of bioactive peptide alpha s1 casein and its three-dimensional structure was done with the help of the online software ACCLUSTERServer, I-TASSER and Galaxy WEB. In order to evaluate protein and peptide stability under dynamic conditions ( intracellular conditions ), 3Drefine and YASARA software were used. Finally, the simulation of the interaction ( docking ) of alpha-s1 casein and the bioactive peptides of israchidine with mastitis producing bacteria inside the cell was done using ClusPro 2.0 software online. Bioinformatics analysis on The molecular interaction of this protein and its bioactive peptides in eight different species of mammals with surface proteins in the membrane of two major mastitis producing bacteria shows that milk " sheep and pig " has the highest performance in destroying Staphylococcus bacteria , " Human and ewes "also have the best performance against Escherichia coli and prevent mastitis ( mastitis ). Therefore, it seems that israchidine peptides can be used as natural factors and antibiotic substitute materials to reduce the destructive effects of mastitis on human health through the possibility of transferring resistant bacterial strains to antibiotics from livestock to humans and also increase the quality of milk consumed ( reducing the number of body cells in milk , increasing milk production and less damage to Mustache ).

Enhancing disease resistance in animal production can be achieved by genetic improvement programs. Candidate gene polymorphism is one of the potential approaches for search of association between SNP within this gene phenotype of animals, particularly in MAS for mastitis of large dairy cattle populations. Polymorphism of exon 9 of the BRCA1 gene was investigated by the PCR-RFLP method in 60 Iranian Holstein cattle. In this study, 3 different alleles were recognized. Polymerase chain reaction-restricted fragment length polymorphism method was used to amplify, digestion and electrophoresis for a 219 base pair of bovine BRCA1 gene. A polymorphism was revealed by G-A single nucleotide polymorphism in +46126 position of BRCA1 gene. Observe genotype frequencies for KK, KL, LL were 0.27, 0.43 and 0.30 respectively, and allele frequencies for observed K and L allele were 0.48 and 0.52 accordingly. For analysis of variance, normality test and transformation of raw data for SSC records was performed based on previous main reports and literature reviews. GLM and logistic regression methods was used for association study between genotype and collected phenotype. As a final message of the present report, KK genotype was showed significantly affect SCC data and has tendency for low SCC score than other two genotypes. The results of present study indicated BRCA1 gene as an effective candidate gene could be benefit for mastitis resistant in Marker Assisted Selection strategies in dairy cattle.

Mastitis is one of the most common diseases in dairy cattle, which has imposed therapy heavy costs to farmers through significant reduction in total milk production. Identification of nucleotide polymorphism of two candidate immunity response genes and its effects on SCS as a mastitis incidence indicator was carried out in this research. The genes were exons 1 and 2 of TLR2 and 3 and 4 of TNFα. For this purpose, a hundred Holstein lactating cows were selected based on their breeding values for milk production, fat and somatic cell scores. Then cows based on their residual values for somatic cell scores were divided into two resistant and susceptible groups and 5 ml blood samples were collected from each animal. Selective genotyping of two target groups of susceptible and resistant animals to mastitis was done using PCR-RFLP approach. The association between genetic polymorphisms with corrected records of somatic cell scores (residual values for somatic cell score) were analyzed using the Generalized Linear Model (GLM) procedure of SAS statistical package (version 9.2) followed by means comparison with Tukey-Kramer test. There was a significant direct relationship between TLR2 and TNFα gene polymorphisms and somatic cell score residual values (P

Identification of disease-causing genes that underlie complex traits such as susceptibility to disease not only can improve diagnosis and the prevention of illness, but also help breeder to select resistance animals against diseases. In the current study to aim the higher power of statistical analysis to identification of genes and biological pathways related to mastitis disease, we used Fisher meta-analysis to combine p-values obtained from individual analysis of datasets extracted from 6 microarray-based studies which investigate transcriptomic data of mammary gland tissue infected by Escherichia coli (E. coli) in dairy cows. Identification of genes that did not show a significant p-value in any of the independent studies may confirm the aim and lead to introduce a more complete set of biological pathways involved in this disease such as the pathways related to immune response, inflammation, proteolysis, growth, and death of cell. Positive regulation of transcription from RNA polymerase II promoter, is new pathways related to this disease which despite of the enrichment by maximum number of up-regulated genes in this study, have not been reported in previous mastitis studies.

The objectives of present study were to estimate the genetic and permanent environmental covariance components and genetic and phenotypic trends of test-day records of somatic cell score (SCS) of the first lactation Iranian Holstein cows. Dataset included the 108995 test day records were collected by the Animal Breeding Center of Iran from 2001 to 2010. The GLM procedure of SAS software was used for fitting the fixed effects in the statistical models of analysis. All analyses were performed using the AIREML algorithm of WOMBAT software. 16 different random regression models were studied and compared based on Akaike’s information criterion. Random regression model with Legendre polynomial functions of orders of 4, 4, 5 were chosen to fit fixed regression, additive genetic and permanent environmental effects, respectively, and residual variance was assumed in 4 heterogeneous levels during the lactation. Estimation of heritability was low (0.022 to 0.032) that indicated this trait mostly affected by environmental factors. Genetic and environmental correlations between daily SCS were high for adjacent tests and low between the beginning and the end of lactation. The estimated environmental correlations were lower than the genetic correlations in all stages of lactation. Annual genetic and phenotypic trends were -0.59±0.103 and -0.08±0.002, respectively, for SCS trait. Both genetic and phenotypic trends for SCS were significant (P

The aim of this study was to investigate the association of bovine leukocyte antigen-DRB3 alleles with peripheral blood mononuclear cell (PBMC) proliferation in response to Staphylococcus aureus. The animals included in this study (n=347) were approximately of same age and comprised of F2 Holstein-Friesian ´ Charolais (n = 155), Holstein-Friesian backcross (F0 Holstein-Friesian dams crossed with unrelated F1 sires, n = 60), Charolais backcross (F1 dams crossed with F0 Charolais sire, n=46) and pure Holstein-Friesian (n = 86). A sequence-based typing method was used in order to determine the genotype of the animals at BoLA-DRB3 locus and a linear mixed model was used to evaluate the association of bovine leukocyte antigen-DRB3 alleles with peripheral blood mononuclear cell (PBMC) proliferation. Beside the BoLA-DRB3 alleles, fixed effects of genetic group and gender and random effect of sires were included into the statistical model. In this research, 27 alleles were found for BoLA-DRB3 gene. The results showed that alleles BoLA-DRB3*0101 and BoLA-DRB3*0902 significantly affected on the stimulation index of S. aureus–induced peripheral blood mononuclear cell proliferation (P

Mastitis causes lots of cost annually in dairy farm enterprises of different countries. Mastitis caused by Escherichia coli is common in high-producing cows with low milk somatic cell count. The severity and effect of Escherichia coli mastitis vary between cows of the same herd and between different lactation stages in the same individual. The severe form of Escherichia coli mastitis is associated with loss of milk production and can outcome in death of the cow. As matter of fact that Escherichia coli bacterium plays enormous role in causing and expanding mastitis, in this research it was tried those DNA sequence segments of this bacterium involving in mastitis to be investigated using information theory.
In this study, first, Escherichia coli's DNA sequences related to mastitis in dairy cattle were downloaded from Genbank (NCBI) and saved in FASTA format. The DNA segment sequences were aligned. The amount of entropy, mutual information among nucleotides and Kullback – Leibler distance among DNA segment sequences were calculated using MATLAB software.
The results shown that entropy of DNA sequences were different in this bacterium but almost all of them had high amount of entropy (H(x) > 1.900). The absolute values of Kullback – Leibler distance indicated that DNA sequences investigated in this study were not similar. This might indicates that these DNA sequences could be involved in different metabolic networks, therefore, manipulating them - like silencing –might bring about unpredicted consequences. The results of mutual information turned up that DNA bases in different DNA sequence segments have different degree of association, which could transparent a type of linkage disequilibrium among different DNA bases.
In general, it was concluded that for managing mastitis, it is possible to single out those DNA sequences segments bearing up high amount of entropy as drug and biotechnological targets; since in this study it was assumed that those DNA sequence segments that exert high amount of entropy, would have higher degree of influence on mastitis in dairy cows.

Study of management and hygienic factors involved in mastitis and also offering appropriate treatment is very effective in lactating animals production.
This study was to investigate the conformity between organoleptic and microbial culture techniques to diagnose mastitis in industrial and traditional dairy herds in Daland city and to determine the kind of pathogens in milk samples and also antibiogram test for the common antibiotics.
Eight dairy cattle herds (four as industrial and four as traditional) were selected from the region. Three cows from each herd that seemed to be infected to clinical mastitis (according to visual, tactile and etc.) were selected and two morning milk samples were collected from each. Initially, samples incubated in general culture to observe colonies and then, differential tests were performed to identify Staphylococcus aureus and Escherichia coli. Antiobiogram test was performed to determine the sensitivity to oxytetracycline, chlortetracycline and gentamycine.
Results of microbal culture showed the incidence of mastitis in the most of suspected cow. Staphylococcus aureus infection was observed in all industrial herd's samples except one, and in 100% of traditional herd's samples, while Escherichia coli infection was only observed in one-fourth of industrial herd's samples and in 100% of traditional ones showing a significant difference between them (P Results demonstrated the high conformity of organoleptic method with bacteriological method to diagnose clinical mastitis. Staphylococcus aureus in both industrial and traditional herds and also Escherichia coli mainly in traditional herds are mediated in dairy cows mastitis in this region. Udder pathogens in both kinds of herd in this region are relatively resistant to oxy- and chlortetracycline while gentamycine can be effective.

The objective of this study was to estimate variance components, genetic and phenotypic trends for somatic cell score. Dataset that collected by the Animal Breeding Center of Iran was used in this study. Data file included 850,729 test day records of somatic cell counts (SCC) on 32,955 cows from lactations one to four, in 472 herds, gathered from years 2002 to 2013 in Iran. A test day repeatability animal model was used to estimate the genetic parameters and variance components using ASReml. The heritability was estimated 0.176. Estimated repeatability (± SE) for within (rwit) and between (racr) parities were 0.362 ± 0.006 and 0.230 ± 0.002, respectively. The genetic and phenotypic trend based on regression of average breeding values of SCS on year of birth, was -0.0246 and -0.047, respectively. This trend could be due to genetic improvement and mastitis management control programs that are widely being used across the dairy farms in country.