Disease In Dairy Cattle Research Articles

Polymorphisms of MASP2 gene and its relationship with mastitis and milk production in Chinese Holstein cattle

Mastitis is a deleterious disease of dairy cattle, and its incidence is closely related with the innate immune response, including the complement system. Mannose-binding lectin-associated serine protease 2 (MASP2) is a functional central enzyme in the complement system. Here, we aimed to study single nucleotide polymorphisms (SNPs) of MASP2 and its relationship with mastitis and milk production in Chinese Holstein cattle. We found three novel SNPs, namely g.14047A > C, g.14248T > C and g.14391C > T, in MASP2. The SNP g.14047 A > C (GAA (Glu)>GAC (Asp)) at position 608aa of MASP2 was correlated with the CH50 level and the protein percentage. Meanwhile, the SNP g.14248 T > C (ATT (Ile) > ATC (Ile)) at position 675aa was also correlated with the CH50 value and the milk production. The haplotype combinations H2H2 and H2H4 showed a significant relationship with the CH50, SCS and the milk production abilities, respectively. Based on the SNPs identified in this gene, several genotypes and haplotypes, respectively, were found in Chinese Holstein cattle. The genotypes AC (g.14047 A > C) and TT (g.14248 T > C) and the haplotype combinations H2H2 and H2H4 may be used as molecular markers for breeding mastitis-resistant dairy cattle. The haplotype combination H1H2 should be gradually phased out in breeding programmes.

ЗАБОЛЕВАНИЯ МОЛОЧНОЙ ЖЕЛЕЗЫ И ПОЛОВЫХ ОРГАНОВ КОРОВ В ПОСЛЕРОДОВЫЙ ПЕРИОД

Mastitis-endometritis syndrome at the beginning of lactation in cows is one of the most economically significant diseases of dairy cattle, since the measures of treatment and prevention are financially costly and, very importantly, difficult to recover. In this regard, further study of the relationship of these diseases in the postpartum period is of great practical importance. In the course of work, the percentage of cows with placenta retention, endometritis and mastitis, separately, as well as jointly occurring in the postpartum period (the first month after calving) was determined. It was found that of 590 calving cows and heifers in the first month after calving revealed 322 or 54.5% of animals with postpartum pathology, including endometritis, detention of the afterbirth and mastitis. Among postpartum diseases of cows in the surveyed economy dominated by endometritis (43.2% of the number of calving cows) with various forms of inflammation of the endometrium. Detention of placenta and mastitis amounted to 20.0% and 17.8% of the number of calving animals or 2.2 and 2.4 times less compared to endometritis. The analysis of the results found that the number of postpartum diseases averaged 0.8 per calving cow or 1.5 per sick cow (P>0.999). A direct average relationship between the diseases of cows in the postpartum period of endometritis and mastitis was established, with a correlation coefficient (r) of 0.48; a direct strong relationship between endometritis and placenta retention was 0.83 at P>0.999.

Prevalence of different dairy cattle diseases in selected dairy areas and farms of Bangladesh

The present study was designed to have a comprehensive epidemiological data of the circulating diseases in Pubna cattle in Pubna and sirajgonj districts of Bangladesh. Two sites were selected for the study as the Nucleus Breeding Hard (NBH); which is located in the BLRI-RS, Baghabari, Sahjadpur, Siragjang and the community; consists of three villages of Bera upazila of Pabna district namely Khar-bagan, Hatail-aralia and Char-sabolla. The total cattle population was 576 (506 in the community and 70 in the NBH). The overall weather was hot and humid. A total of 965 clinical cases of cattle of different age and sex were diagnosed during the period from July, 2017 to June, 2018.The descriptive statistics suggested that endo-parasites (15.67%), FMD (27.51%), non-specific diarrhea (7.73%) and post-partum anoestrus (7.78%) are the most prevailing diseases in the community and endo-parasites (21.82%), foot-rot (15.15%), non-specific fever (7.27%), dermatochalasis (5.45%) and conjunctivitis (4.85%) are the most prevailing diseases in the NBH. Population data shows that there was an endemic outbreak of FMD in the community between March to May 2018 where almost 50% cattle were affected by the disease though calf morbidity was low (2.69%) but all the affected calf died. Non-specific diarrhea was more common in older individuals (14% in over 3years old cattle) mostly in cows (14.2%) and occurred in summer (9.84%) and winter (8.81%) may be because of the ignorance of the farmers to supply clean water to their animals. Although, we routinely de-worm our cows in the community and in the NBH round the year we found many cases of parasitic gastro-enteritis in both the locations which suggested that our de-worming practice is not working. Repeated study of the same kind can provide us a large set of data on cattle disease prevailing in the area which may provides valuable insight to design and implement priority based research on specific disease and to take efficient control strategies against that disease.
 Asian Australas. J. Biosci. Biotechnol. 2018, 3 (3), 231-236

Predictive models for early lactation diseases in transition dairy cattle at dry-off

During the transition period, dairy cattle undergo tremendous metabolic and physiological changes to prepare for milk synthesis and secretion. Failure to sufficiently regulate these changes may lead to metabolic stress, which increases risk of transition diseases. Metabolic stress is defined as a physiological state consisting of 3 components: aberrant nutrient metabolism, oxidative stress, and inflammation. Current monitoring methods to detect cows experiencing metabolic stress involve measuring biomarkers for nutrient metabolism. However, these biomarkers, including non-esterified fatty acids, beta-hydroxybutyrate, and calcium are typically measured a few weeks before to a few days after calving. This is a retroactive approach, because there is little time to integrate interventions that remediate metabolic stress in the current cohort. Our objective was to determine if biomarkers of metabolic stress measured at dry-off are predictive of transition disease risk. We designed a prospective cohort study carried out on 5 Michigan dairy farms (N = 277 cows). We followed cows from dry-off to 30 days post-calving. Diseases and adverse outcomes were grouped in an aggregate outcome that included mastitis, metritis, retained placenta, ketosis, lameness, pneumonia, milk fever, displaced abomasum, abortion, and death of the calf or the cow. We used best subsets selection to select candidate models for four different sets of models: one set for each component of metabolic stress (nutrient metabolism, oxidative stress, and inflammation), and a combined model that included all 3 components. We used model averaging to obtain averaged predicted probabilities across each model set. We hypothesized that the averaged predictions from the combined model set with all 3 components of metabolic stress would be more effective at predicting disease than each individual component model set. The area under the curve estimated using receiver operator characteristic curves for the combined model set (0.93; 95% confidence interval [CI] = 0.90–0.96) was significantly higher compared with averaged predictions from the inflammation (0.87; 95% CI = 0.83–0.91), oxidative stress (0.78; 95% CI = 0.72–0.84), and nutrient metabolism (0.73; 95% CI = 0.67–0.79) model sets (p < 0.05). Our results indicate that it may be possible to detect cattle at risk for some transition diseases as early as dry-off. This has important implications for disease prevention, as earlier identification of cows at risk of health disorders will allow for earlier implementation of intervention strategies. A limitation of the current study is that we did not perform external validation. Future validation studies are needed to confirm our findings.

Assessing Financial Impacts of Subclinical Mastitis on Colombian Dairy Farms.

Bovine mastitis is a dairy cattle disease with high economic impact. Subclinical mastitis (SCM) contributes to most of the financial losses. Colombia dairy sector accounts for 2.3% of the gross domestic product (GDP) and 24.3% of the livestock GDP. Milk production reaches 6,500 million liters/year from nearly 500,000 cattle farms and is mainly based on small-scale production systems. This study evaluates the financial impact of SCM and the potential for its control in three dairy farm strata in a region in Colombia. The objectives of the study were 1) to determine the perception of farmers about the SCM problem on their farms, 2) to assess prevalence and financial impact of SCM on farms and in the “Area five” sanitary region of the Bogota plateau, and 3) to assess costs and effectiveness of control methods of SCM. Information about disease management and decision-making process was obtained through a participatory epidemiology workshop and applying a semi-structured survey. A two-stage stratified cross sectional epidemiological study was conducted on dairy cattle from a region with approximately 400 farms and 12,000 cows, with a sample size of 55 farms. Prevalence of SCM was calculated by defining a cow as positive for the disease when any quarter had a somatic cell count (SCC) higher than 250 × 103 cells/ml. The prevalence of SCM in cows was 55.2%; significant differences were found between strata. Assessment of the financial impact of SCM in terms of milk losses was conducted using spreadsheet models. Milk production losses per farm ranged from 1.3% to 13.5%, and the economic impact in the region was estimated over USD $800.000 per year. The financial impact was greater in small- and medium-sized farms than large farms, and it was associated with the severity of SCC per quarter. Principal component analysis showed interactions, irrespective of the individual effect, and suggested three main groups of control interventions: application of basic milking hygiene practices, increase in the level of hygiene practices and veterinary advice, and SCM diagnosis and dry-cow treatment. Lack of information on management and production at farms promotes intuitive decision-making. Further research for the deeper understanding of intervention costs and effectiveness is suggested.

The genetic architecture of milk ELISA scores as an indicator of Johne's disease (paratuberculosis) in dairy cattle

Johne's disease (or paratuberculosis), caused by Mycobacterium avium ssp. paratuberculosis (MAP) infection, is a globally prevalent disease with severe economic and welfare implications. With no effective treatment available, understanding the role of genetics influencing host infection status is essential to develop selection strategies to breed for increased resistance to MAP infection. The main objectives of this study were to estimate genetic parameters for the MAP-specific antibody response using milk ELISA scores in Canadian Holstein cattle as an indicator of resistance to Johne's disease, and to unravel genomic regions and candidate genes significantly associated with MAP infection. After data editing, 168,987 milk ELISA records from 2,306 herds, obtained from CanWest Dairy Herd Improvement, were used for further analyses. Variance and heritability estimates for MAP infection status were determined using univariate linear animal models under 3 scenarios: (a) SCEN1: the complete data set (all herds); (b) SCEN2: herds with at least one suspect or test-positive animal (ELISA optical density ≥0.07); and (c) SCEN3: herds with at least one test-positive animal (ELISA optical density ≥0.11). Heritability estimates were calculated as 0.066, 0.064, and 0.063 for SCEN1, SCEN2, and SCEN3, respectively. The correlations between estimated breeding values for resistance to MAP infection and other economically important traits, when significant, were favorable and of low magnitude. Genome-wide association analyses identified important genomic regions on Bos taurus autosome (BTA)1, BTA7, BTA9, BTA14, BTA15, BTA17, BTA19, and BTA25 showing significant association with MAP infection status. These regions included 2 single nucleotide polymorphisms located 2 kb upstream of positional candidate genes CD86 and WNT9B, which play key roles in host immune response and tissue homeostasis. This study revealed the genetic architecture of MAP infection in Canadian Holstein cattle as measured by milk ELISA scores by estimating genetic parameters along with the identification of genomic regions potentially influencing MAP infection status. These findings will be of significant value toward implementing genetic and genomic evaluations for resistance to MAP infection in Holstein cattle.

Validation of a handheld somatic cell count device

Mastitis is the most common and costly disease of dairy cattle. It impacts farm economics through diagnostic and treatment costs and loss of income through discarded milk, decreased milk production, and loss of milk quality premiums. It negatively affects cow comfort and increases the culling risk. Most cases of mastitis are subclinical, leading to undetected economic losses. To mitigate these losses, surveillance for subclinical mastitis (SCM) indicators can be useful. One such indicator is the somatic cell count (SCC). Elevated SCC indicates inflammation, most likely caused by bacterial infection. One barrier to early detection of SCM is the lag between sample collection and availability of test results. The objective of this study was to evaluate a novel handheld, cow-side instrument for the enumeration of somatic cells in milk, the DQI iPod Touch Cell Counter. Our goal is to determine the sensitivity, specificity, and agreement of the instrument compared to currently available laboratory methods.

Herd-level prevalence of Johne's disease and BVD, management practices and farm characteristics for positive dairy herds in Utah and Idaho

Johne's disease (JD) and bovine viral diarrhea (BVD) are expensive dairy cattle diseases causing production, infertility, and death losses. Herd-level prevalence estimates are 68% for JD and 15% for BVD. The objectives of this study were to estimate regional dairy herd-level prevalence of JD and BVD and evaluate farm characteristics, management, and control practices on farms with either disease detected.

HDAC1/2‐mediated regulation of JNK and ERK phosphorylation in bovine mammary epithelial cells in response to TNF‐α

Bovine mammary epithelial cells (MAC-Ts) are a common cell line for the study of mammary epithelial inflammation; these cells are used to mechanistically elucidate molecular underpinnings that contribute to bovine mastitis. Bovine mastitis is the most prevalent form of disease in dairy cattle that culminates in annual losses of two billion dollars for the US dairy industry. Thus, there is an urgent need for improved therapeutic strategies. Histone deacetylase (HDAC) inhibitors are efficacious in rodent models of inflammation, yet their role in bovine mammary cells remain unclear. HDACs have traditionally been studied in the regulation of nucleosomal DNA, in which deacetylation of histones impact chromatin accessibility and gene expression. Using MAC-T cells stimulated with tumor necrosis factor α (TNF-α) as a model for mammary cell inflammation, we report that inhibition of HDACs1 and 2 (HDAC1/2) attenuated TNF-α-mediated inflammatory gene expression. Of note, we report that HDAC1/2-mediated inflammatory gene expression was partly regulated by c-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK) phosphorylation. Here, we report that HDAC1/2 inhibition attenuated JNK and ERK activation and thus inflammatory gene expression. These data suggest that HDACs1 and 2 regulate inflammatory gene expression via canonical (i.e., gene expression) and noncanonical (e.g., signaling dependent) mechanisms. Whereas, further studies using primary cell lines and animal models are needed. Our combined data suggest that HDAC1/2-specific inhibitors may prove efficacious for the treatment of bovine mastitis.

Comparison of the pharmacokinetics of plant-based treatments in milk and plasma of USDA organic dairy cattle with and without mastitis

ABSTRACTOrganic dairy products are the second largest sector of the organic food market. Organic dairy products come from United States Department of Agriculture (USDA) certified organic dairy cattle that meet USDA organic standards. Organic dairy cattle in the US cannot be treated with antibiotics for mastitis, one of the costliest diseases of dairy cattle, and thus effective alternatives are needed. When any compound (medication or other non-food product) is used in a food producing animal, a withhold time for that compound that meets US Food and Drug Administration (FDA) standards for food safety must be applied to the animal and its products (like milk). However, there are no US FDA products approved for mastitis that maintain USDA certified organic dairy cattle’s organic status. Thus, we studied the pharmacokinetics of 3 compounds (garlic, thymol and carvacrol) used on organic both healthy and mastitic organic dairy cattle. We also used this information to estimate a milk withhold time using methods consistent with US FDA requirements. For thymol intra-mammary and carvacrol intra-mammary or topical administration, all compounds were partially absorbed into the body from the milk or skin. Thymol and carvacrol are measurable in plasma (at 0.0183 and 0.0202 µg/mL, respectively) after intramammary administration with similar elimination half lives of 1.7 h. Milk concentrations of thymol and carvacrol are much higher at 2.958 and 4.487 µg/mL in healthy cattle, respectively. Concentrations are not significantly different in cows with mastitis as compared to those in healthy cows. Despite these compounds being natural products, they should have a withhold time for milk of at least 24 h after administration. For garlic, levels remained below the limit of detection in milk and plasma and thus no withdrawal time appears to be needed for milk.

Cattle health monitoring system using wireless sensor network: a survey from innovation perspective

Health monitoring of dairy cattle plays a vital role for increasing the dairy products supply worldwide. Nowadays farmers are showing less interest in dairy sector as animals are suffering from various ailing health issues, unpredictable killing diseases, and advanced breeding costs. Therefore, it is necessary for farmers to adopt efficient technical methods for cattle health monitoring to increase the milk production supply. This study documented various wireless sensor network (WSN)-based automatic health monitoring systems for monitoring various diseases of dairy cattle. The main objective of WSN-based intelligent monitoring systems in farm automation is to monitor the health of dairy cattle on regular basis. This monitoring system needs to be installed in local and remote locations of farms that will assist the concerned farmers in monitoring their cattle activities from diverse locations for the whole day. All collected factors from the automated system will be stored in a database. Subsequently, with the help of farm automation, farmers can retrieve information for the execution of correct farm control strategies. Moreover, WSN is low-cost technology which is specific for the identification of diseases in dairy animals. This revolution in advanced technological farm automation will aid in improving the productivity rate with the reduction of human intervention. This review study concludes all cattle monitoring systems along with various issues and challenges.

Protective effect of chlorogenic acid on lipopolysaccharide-induced inflammatory response in dairy mammary epithelial cells

Mastitis is a major disease of dairy cattle. Given the recent emergence of antibiotics resistance to mastitis, new intramammary treatments are urgently required. In the present study, we investigated whether lipopolysaccharide (LPS) could induce the increase in the proinflammatory cytokines in bovine mammary epithelial cells (MECs), and whether a natural antimicrobial compound Chlorogenic acid (CGA) could attenuate the inflammatory responses induced by LPS and thus could be a potential therapeutic compound for bovine mastitis. Our results indicated that LPS could induce the expression of proinflammatory cytokines such as tumor necrosis factor (TNF)-α, interleukine (IL)-1β and IL-6, and the activation of NF-κB p65 and p-p65 in primary bovine MECs. Furthermore, CGA significantly inhibited not only the protein expression of NF-κB p65 and p-p65 but also the mRNA expression of TNF-α, IL-1β and IL-6 after LPS treatment in primary bovine MECs. These results suggested that CGA had anti-inflammatory role by inhibiting NF-κB activation. In conclusion, CGA could be possibly used as a potential therapeutic compound for bovine mastitis.

Effect of mastitis on lactation curves in purebred Jersey cows

Mastitis is a most frequently occurring disease in dairy cattle which causes severe losses in milk production. In our study, we had collected 9960 weekly test day milk yield (WTDMY) records over a period of five years (2010– 2015) of 130 purebred Jersey cows reared at Central Cattle Breeding Farm, Sunabeda, Odisha under Ministry of Agriculture, Government of India. To study the lactation pattern of above milk data, we used six different lactation curve models, viz. Wilmink (WK), Wood (WD), Brody (BRD), Morant and Gnanasakthy (MG), Mitscherlich × Exponential (ME) and Ali and Schaeffer (AS). It was observed that in healthy and cows affected with mastitis, Ali and Schaeffer (AS) model showed best fit giving highest value of adjusted coefficient of determination (R2 adj.= 0.963) and lowest value of root mean square of error (0.303), Akaike’s information criterion (–97.887) and Schwartz Bayesian Information Criterion (–89.081). Testing of residuals was carried out by several tests, viz. the Shapiro- Wilk’s test, the run test and the Durbin-Watson (DW). Summary measures revealed that the loss of milk production due to mastitis with respect to healthy cows was 4.43%. Lactation persistency was estimated by ratio method and Mahadevan method. Higher persistency was observed in healthy cows.

Gentisaldehyde and Its Derivative 2,3-Dihydroxybenzaldehyde Show Antimicrobial Activities Against Bovine Mastitis Staphylococcus aureus.

Bovine mastitis is a worldwide disease of dairy cattle associated with significant economic losses for the dairy industry. One of the most common pathogens responsible for mastitis is Staphylococcus (S.) aureus. Due to the development and spreading of antibiotic resistance, the search for novel antimicrobial substances against S. aureus is of great importance. The aim of this study was to evaluate two dihydroxybenzaldehydes for the prevention of bovine mastitis. Therefore we determined the minimal inhibitory concentration (MICs) of gentisaldehyde (2,5-dihydroxybenzaldehyde) and 2,3-dihydroxybenzaldehyde of a diverse set of 172 bovine mastitis S. aureus isolates using an automated robot-based microdilution method. To characterize the bovine isolates we determined the genotype by spa-typing, the antimicrobial resistance to eight antibiotic classes using the disk diffusion method and the MICs of three commonly used antiseptics (benzalkonium chloride, chlorhexidine, and iodine). Further we investigated the cytotoxicity of gentisaldehyde and 2,3-dihydroxybenzaldehyde in bovine mammary epithelial MAC-T cells using the XTT assay. The S. aureus strains showed a high genetic diversity with 52 different spa-types, including five novel types. Antibiotic susceptibility testing revealed that 24% of isolates were resistant to one antimicrobial agent and 3% of isolates were multi-resistant. The occurrence of antibiotic resistance strongly correlated with the spa-type. Both dihydroxybenzaldehydes showed antimicrobial activities with a MIC50 of 500 mg/L. The MIC of gentisaldehyde significantly correlated with that of 2,3-dihydroxybenzaldehyde, whereas no correlation was observed with the MIC of the three antiseptics. Cytotoxicity testing using bovine mammary epithelial MAC-T cells revealed that gentisaldehyde and 2,3-dihydroxybenzaldehyde show low toxicity at MIC50 and MIC90 concentrations. In conclusion, gentisaldehyde and 2,3-dihydroxybenzaldehyde exhibited antimicrobial activities against a diverse range of bovine mastitis S. aureus strains at low-cytotoxic concentrations. Therefore, both compounds are potential candidates as antiseptics to prevent bovine mastitis and to reduce the use of antibiotics in dairy cows.

The influence of BoLA-DRB3 alleles on incidence of clinical mastitis, cystic ovary disease and milk traits in Holstein Friesian cattle.

The major histocompatibility complex in cattle (BoLA) is regulated by genes that are closely related to the development of the immunological response to pathogens. The most polymorphic BoLA-DRB3.2 locus was analysed in 209 black-and-white Holstein-Friesian cows in Poland in order to a better explanation of influence of MHC on immunity to diseases in dairy cattle. A total of 23 alleles were identified, among which the *24, *16 and *22 alleles were observed with the highest frequency. These alleles were analysed in terms of their association with the occurrence of mastitis, ovarian cysts, retained placenta and uterine abscesses as well as their contribution to production traits (milk yield, protein and fat percentage in milk). It was determined that the BoLA-DRB3.2 *22 and *16 alleles were associated with a lower risk of clinical mastitis; however, a statistical significance was observed only for the *22 allele. Clinical mastitis was observed at a frequency lower by 8% in cows with one copy of the *22 allele compared to cows with 0 copies of the allele. The presence of the *22 allele in the genotype was also associated with higher milk yield, although this association was not statistically significant.

Epidemiology, Antimicrobial Resistance, and Extended-Spectrum Beta-Lactamase-Producing Enterobacteriaceae in Clinical Bovine Mastitis in Tunisia.

Bovine mastitis is a major disease in dairy cattle that causes high economic losses annually. Staphylococci, streptococci, and coliforms are among the major pathogens responsible for such infections. While data on bovine mastitis are numerous in Europe where the efficacy of farm management was monitored, those are scarce in African countries. In this study, we reported the occurrence of Escherichia coli (118/372, 31.7%) and Klebsiella pneumoniae (77/372, 20.7%), two environmental pathogens known to cause bovine mastitis. Resistance phenotypes were frequently identified for tetracycline (E. coli, 46.6%/K. pneumoniae, 20.8%), sulfonamides-trimethoprim (17.8%/11.7%), gentamicin (19.5%/14.3%), and enrofloxacin (11.0%/6.5%). No carbapenem-resistant isolate was detected. Extended-spectrum beta-lactamases (ESBLs) were detected on selective medium in three E. coli and six K. pneumoniae, all carrying the blaCTX-M-15 gene. The K. pneumoniae belonged to two highly uncommon sequence types (ST471 and ST1083), while E. coli clustered in the ST167/617 clones, which have been widely reported in humans, animals, and the environment. These data point out the necessity to improve farm management in Tunisia to reduce the occurrence of coliform-induced mastitis and to avoid the dissemination in this sector of ESBL-producing E. coli and K. pneumoniae, which are of public health concern.

A large-scale study of indicators of sub-clinical mastitis in dairy cattle by attribute weighting analysis of milk composition features: highlighting the predictive power of lactose and electrical conductivity.

Sub-clinical mastitis (SCM) affects milk composition. In this study, we hypothesise that large-scale mining of milk composition features by pattern recognition models can identify the best predictors of SCM within the milk composition features. To this end, using data mining algorithms, we conducted a large-scale and longitudinal study to evaluate the ability of various milk production parameters as indicators of SCM. SCM is the most prevalent disease of dairy cattle, causing substantial economic loss for the dairy industry. Developing new techniques to diagnose SCM in its early stages improves herd health and is of great importance. Test-day Somatic Cell Count (SCC) is the most common indicator of SCM and the primary mastitis surveillance approach worldwide. However, test-day SCC fluctuates widely between days, causing major concerns for its reliability. Consequently, there would be great benefit to identifying additional efficient indicators from large-scale and longitudinal studies. With this intent, data was collected at every milking (twice per day) for a period of 2 months from a single farm using in-line electronic equipment (346 248 records in total). The following data were analysed: milk volume, protein concentration, lactose concentration, electrical conductivity (EC), milking time and peak flow. Three SCC cut-offs were used to estimate the prevalence of SCM: Australian ≥ 250 000 cells/ml, European ≥200 000 cells/ml and New Zealand ≥ 150 000 cells/ml. At first, 10 different Attribute Weighting Algorithms (AWM) were applied to the data. In the absence of SCC, lactose concentration featured as the most important variable, followed by EC. For the first time, using attribute weighted modelling, we showed that the concentration of lactose in milk can be used as a strong indicator of SCM. The development of machine-learning expert systems using two or more milk variables (such as lactose concentration and EC) may produce a predictive pattern for early SCM detection.

Genetic variability in the humoral immune response to bovine herpesvirus-1 infection in dairy cattle and genetic correlations with performance traits

Bovine herpesvirus-1 (BoHV-1) is a viral pathogen of global significance that is known to instigate several diseases in cattle, the most notable of which include infectious bovine rhinotracheitis and bovine respiratory disease. The genetic variability in the humoral immune response to BoHV-1 has, to our knowledge, not ever been quantified. Therefore, the objectives of the present study were to estimate the genetic parameters for the humoral immune response to BoHV-1 in Irish female dairy cattle, as well as to investigate the genetic relationship between the humoral immune response to BoHV-1 with milk production performance, fertility performance, and animal mortality. Information on antibody response to BoHV-1 was available to the present study from 2 BoHV-1 sero-prevalence research studies conducted between the years 2010 to 2015, inclusive; after edits, BoHV-1 antibody test results were available on a total of 7,501 female cattle from 58 dairy herds. National records of milk production (i.e., 305-d milk yield, fat yield, protein yield, and somatic cell score; n = 1,211,905 milk-recorded cows), fertility performance (i.e., calving performance, pregnancy diagnosis, and insemination data; n = 2,365,657 cows) together with animal mortality data (i.e., birth, farm movement, death, slaughter, and export events; n = 12,853,257 animals) were also available. Animal linear mixed models were used to quantify variance components for BoHV-1 as well as to estimate genetic correlations among traits. The estimated genetic parameters for the humoral immune response to BoHV-1 in the present study (i.e., heritability range: 0.09 to 0.16) were similar to estimates previously reported for clinical signs of bovine respiratory disease in dairy and beef cattle (i.e., heritability range: 0.05 to 0.11). Results from the present study suggest that breeding for resistance to BoHV-1 infection could reduce the incidence of respiratory disease in cattle while having little or no effect on genetic selection for milk yield or milk constituents (i.e., genetic correlations ranged from -0.13 to 0.17). Moreover, even though standard errors were large, results also suggest that breeding for resistance to BoHV-1 infection may indirectly improve fertility performance while also reducing the incidence of mortality in older animals (i.e., animals >182 d of age). Results can be used to inform breeding programs of potential genetic gains achievable for resistance to BoHV-1 infection in cattle.

Inflammatory mechanism of Rumenitis in dairy cows with subacute ruminal acidosis

BackgroundSubacute ruminal acidosis (SARA) is a metabolic disease in high-producing dairy cattle, and is accompanied by rumenitis. However, the mechanism of rumenitis remains unclear. Therefore, the aim of this study was to investigate the molecular mechanism of rumenitis in dairy cows with SARA.ResultsThe results showed that SARA cows displayed high concentrations of ruminal volatile fatty acids, lactic acid and lipopolysaccharide (LPS). Furthermore, the blood concentrations of LPS and acute phase proteins haptoglobin, serum amyloid-A, and LPS binding protein were significantly higher in SARA cows than in control cows. Importantly, the phosphorylation levels of nuclear factor-kappaB (NF-κB) p65, inhibitor of NF-κB (IκB), c-Jun N-terminal kinase (JNK), and extracellular signal-regulated kinase 1/2 (ERK1/2) were significantly higher in the rumen epithelium of SARA cows than those of control cows. The ruminal mRNA and protein levels of NF-κB- and mitogen-activated protein kinase (MAPK)s -regulated inflammatory cytokines, tumor necrosis factor α (TNF-α), interleukin 6 (IL-6) and interleukin 1β (IL-1β), were markedly higher in SARA cows than in control cows. Similarly, serum concentrations of TNF-α and IL-6 were also significantly higher in SARA cows.ConclusionsThese results indicate that SARA results in high concentration of ruminal LPS, which over activates the NF-κB and MAPKs inflammatory pathways and then significantly increases the expression and synthesis of pro-inflammation cytokines in the rumen epithelium, thereby partly inducing rumenitis.

Evaluation of ionic liquids supported on silica as a sorbent for fully automated online solid-phase extraction with LC-MS determination of sulfonamides in bovine milk samples.

Sulfonamides are antibiotics widely used in the treatment of diseases in dairy cattle. However, their indiscriminate use for disease control may lead to their presence in tissues and milk and their determination requires a sample preparation step as part of an analytical approach. Among the several sample preparation techniques available, those based upon the use of sorptive materials have been widely employed. Recently, the application of ionic liquids immobilized on silica surfaces or polymeric materials has been evaluated for such an application. This manuscript addresses the evaluation of silica-based ionic liquid obtained by a sol-gel synthesis process by basic catalysis as sorbent for online solid-phase extraction with liquid chromatography and electrospray ionization time-of-flight mass spectrometry for sulfonamides determination. Infrared vibrational spectroscopy confirmed the presence of the ionic liquid on the silica surface, suggesting that the ionic liquid was anchored on to the silica surface. Other sorbents varying the ionic liquid alkyl chain were also synthesized and evaluated by off-line solid-phase extraction in the sulfonamide extraction. As the length of the alkyl chain increased, the amount of extracted sulfonamides decreased, possibly due to a decrease in the electrostatic interaction caused by the reduction in the polarity, as well as the presence of a hexafluorophosphate anion that increases the hydrophobic character of the material. The use of 1-butyl-3-methylimidazolium hexafluorophosphate as a selective ionic liquid sorbent enabled the isolation and sulfonamide preconcentration in bovine milk by online solid-phase extraction with liquid chromatography and electrospray ionization time-of-flight mass spectrometry. The limit of quantification for the method developed was 5-7, 5 μg/mL, with extraction recoveries ranging between 74 and 93% and intra- and interassay between 1.5-12.5 and 2.3-13.1, respectively.