Bovine Dairy Research Articles

B-001 Serum 25-hydroxyvitamin D and C-3 epimer concentrations throughout gestation in a bovine dairy herd

Abstract Background Serum 25-hydroxyvitamin D (25(OH)D) serves as an indicator of vitamin D status in most animal species. The recent identification of its C-3 epimer, 3-epi-25-hydroxyvitamin D3 (3-epi-25(OH)D3) remains diagnostically confounding. The appearance of this epimer in blood serum has been reported for both pregnant women and infants; however, because of its recent discovery, its physiologic role, biochemical regulation, and overall biologic importance have yet to be fully elucidated. Given its prevalence in pregnant women, it was hypothesized that 3-epi-25(OH)D3 may serve as a novel predictive biomarker of pregnancy in animals. Methods In the current study, we validated an LC-MS/MS method to measure the mono-hydroxyvitamin D metabolites 25-hydroxyvitamin D2 (25(OH)D2), 25-hydroxyvitamin D3 (25(OH)D3), and 3-epi-25(OH)D3, in bovine serum. Serum was collected from dairy cows at six stages of pregnancy (n=60 (10 per group), pre-breeding heifers, 30-40 days pregnant, 70-90 days, 120-180 days, 210-260 days, and 30-45 days post-calving). The 25(OH)D metabolites were extracted from serum by supported liquid extraction (SLE) and the eluate was derivatized with 2-Nitrosopyridine. Derivatized samples were introduced to the LC-MS/MS, ionized by electrospray ionization in positive-ion mode, and detected and quantified by multiple-reaction monitoring. Results The LC-MS/MS method was linear in the concentration range of 0.25 ng/mL to 100 ng/mL with an r2 > 0.99 for each analyte. 3-epi-25(OH)D3 and total serum 25(OH)D concentrations were calculated for each stage of pregnancy. Pre-bred heifers had serum 25(OH)D concentrations ranging from 65 - 85 ng/mL with trends toward non-significant increases with mean values approaching 100 ng/mL during pregnancy. Interestingly, 3-epi-25(OH)D3 remained near baseline (1.3 - 1.9 ng/mL) for the first 90 days and elevated 3- to 4-fold thereafter. Conclusions This study confirms that epimerization of 25(OH)D3 is a conserved biochemical process across species. While not predictive of pregnancy itself, the increase in circulating 3-epi-25(OH)D3 concentrations was consistent with mid- to late-gestational increases in estrogen concentration observed for dairy cattle. Future studies will explore the potential link between increases in gestational estrogen and epimerization.

Human health risk from co-occurring mycotoxins in dairy: A feed-to-fork approach

The presence of multiple mycotoxins in bovine dairy products can lead to potentially harmful health effects. This study examined the risk to human health from multiple mycotoxins in bovine dairy products using a feed-to-fork approach. It conducted a component-based risk assessment, using the toxicity of the most potent mycotoxin as a reference for others. The model also accounted for the influence of varying feed composition on mycotoxin contamination, considering monthly feeding pattern changes in Ireland. The probabilistic risk assessment uses Monte Carlo simulation to capture uncertainty and variability present in the model. The risk characterisation was undertaken using the Margin Of Exposure (MOE) method, where if the MOE was below 10,000, then the population's health was considered at risk. This study investigated the risk to human health from single mycotoxins and a combination of mycotoxins. The results showed that all mycotoxins were of low risk. However, the risk increased when aflatoxin was included in the co-occurring groups. Since 5% of the MOE was less than 10,000, the Irish population (male and female) was at relatively low risk of consuming aflatoxin or other co-occurring mycotoxin-contaminated milk. In comparison, the age group 8-12 years were at a relatively higher risk, with 10% of the MOE less than 10,000. The carry-over rates, the concentration of mycotoxin in feed components and the feeding composition were the most sensitive parameters. An increase in aflatoxin production in feed components can occur under climate scenarios and thus needs to be monitored, preventing any risks from aflatoxin or a combination of co-occurring mycotoxins. This study underscores the need for continuous monitoring and preventive measures, especially in feed components that are sensitive to aflatoxin-producing fungi that may contaminate bovine feed.

Molecular characterization and antibiotic susceptibility of Shiga toxin- producing Escherichia coli (STEC) isolated from raw milk of dairy bovines in Khyber Pakhtunkhwa, Pakistan.

This study investigated the virulence potential and antibiotic susceptibility analysis of non-O157 Shiga toxin-producing Escherichia coli (STEC) serogroups, which are significant cause of food borne diseases. A study collected 800 samples of dairy bovine raw milk through various sources, 500 from milk shops, 200 from dairy farms, 26 from milk collection centers, and 74 from street vendors. Using a standard method, E. coli was detected in 321 out of the 800 samples collected. Out of the 321 E. coli-positive samples isolated, 148 were identified as STEC using selective media, specifically Cefixime Tellurite Sorbitol MacConkey's Agar (CT-SMA). Out of the 148 positive samples, 40 were confirmed as STEC non-O157 strains using multiplex PCR, indicating a prevalence of 5% (40 out of 800 samples). STEC isolates were subjected to antimicrobial susceptibility testing, and all isolates were resistant to at least one or more antimicrobials tested through the disk diffusion method, revealed high resistance to Amoxicillin 100%, Ceftriaxone 50%, and Penicillin 44.5%, and notably 44% of the strains exhibited Streptomycin resistance, while Enrofloxacin 55%, Florfenicol 50% and Norfloxacin 44%, demonstrated the highest susceptibility. Out of 40 STEC non-O157, twelve were subjected to Multi Locus Sequence Typing (MLST) sequencing through Illumina Inc. MiSeq platform's next-generation sequencing technology, United States. The genome investigation evidenced the persistence of twelve serotypes H4:O82, H30:O9a, H4:O82, H16:O187, H9:O9, H16:O113, H30:O9, H32:O, H32:O, H32, H32, and H38:O187, linked to the potential infections in humans. Conclusion: STEC isolates showed resistance to multiple antimicrobials, raising concerns for both animal and public health due to widespread use of these drugs in treatment and prevention. The study contributes new insights into monitoring STEC in raw milk, emphasizing the critical role of whole genome sequencing (WGS) for genotyping and sequencing diverse isolates. Still a deficiency in understanding STEC pathogenesis mechanisms, ongoing surveillance is crucial for safeguarding human health and enhancing understanding of STEC genetic characteristics.

Embryonic and Fetal Mortality in Dairy Cows: Incidence, Relevance, and Diagnosis Approach in Field Conditions

Pregnancy loss (PL) in dairy cattle results in animal health and welfare disruption and has a great economic impact on farms, with decreases in fertility and increased culling. It can occur at any stage of embryonic or fetal development. Abortion occurring from the second half of pregnancy has a more negative impact on dairy farms. There are several infectious and non-infectious factors that can lead to PL and vary according embryonic or fetal stages. As this is a multifactorial or multi-etiological occurrence, it is important to identify the risk factors and the best diagnostic tools to approach these reproductive losses that can occur sporadically or by outbreaks. Reaching a final diagnosis can be challenging, especially when it occurs at a very early stage of pregnancy, where losses may not be detected and neonatal deaths may be related to alterations in the fetus in utero. Also, laboratorial results from animal samples should be interpreted according to the full clinical approach. This review aimed to highlight all these essential aspects, identifying the main infectious and non-infectious causes leading to PL, as well as the best veterinary practices for diagnosing it, mainly through transrectal palpation, ultrasound, and laboratory methods, in bovine dairy farms.

Advancing mastitis assessment in dairy bovines via short milking tube thermography: A seasonal perspective.

In India, where dairy production leads globally, infrared thermography (IRT) and short milking tube thermography specifically are vital for managing mastitis. Therefore, the present study focuses on thermal imaging of the udder and short milking tube (SMT) of the milking machine during the peak milking process of Sahiwal cows and Murrah buffaloes during winter, summer, rainy and autumn seasons to identify sub-clinical (SCM) and clinical mastitis (CM) cases using the Darvi DTL007 camera. The udder health was assessed using the California Mastitis Test, Somatic Cell Count (SCC) and IRT throughout the year. Log10SCC and thermogram analysis revealed a difference (p < 0.01) between healthy, SCM, and CM cases during different seasons in both breeds. Further results showed an increase (p < 0.01) in SMT thermograms of SCM and CM cases compared to healthy quarters in Sahiwal cows during winter, summer, rainy, and autumn were 4.26 and 7.51, 2.37 and 4.47, 2.20 and 3.64, 2.90 and 4.94 ºC, respectively and for Murrah buffaloes were 3.56 and 5.55, 2.70 and 3.81, 1.72 and 3.10, 3.14 and 4.42ºC, respectively. The highest degree of increase in milking udder skin surface temperature and SMT of SCM and CM cases compared to healthy quarters was observed during the winter and the least during the rainy season. Thus, regardless of the seasons examined in this study, SMT thermograms effectively assessed SCM and CM.

Impact of dietary regime on the metabolomic profile of bovine buttermilk and whole milk powder

IntroductionBovine milk contains a rich matrix of nutrients such as carbohydrates, fat, protein and various vitamins and minerals, the composition of which is altered by factors including dietary regime.ObjectivesThe objective of this research was to investigate the impact of dietary regime on the metabolite composition of bovine whole milk powder and buttermilk.MethodsBovine whole milk powder and buttermilk samples were obtained from spring-calving cows, consuming one of three diets. Group 1 grazed outdoors on perennial ryegrass which was supplemented with 5% concentrates; group 2 were maintained indoors and consumed a total mixed ration diet; and group 3 consumed a partial mixed ration diet consisting of perennial ryegrass during the day and total mixed ration maintained indoors at night.ResultsMetabolomic analysis of the whole milk powder (N = 27) and buttermilk (N = 29) samples was preformed using liquid chromatography-tandem mass spectrometry, with 504 and 134 metabolites identified in the samples respectively. In whole milk powder samples, a total of 174 metabolites from various compound classes were significantly different across dietary regimes (FDR adjusted p-value ≤ 0.05), including triglycerides, of which 66% had their highest levels in pasture-fed samples. Triglycerides with highest levels in pasture-fed samples were predominantly polyunsaturated with high total carbon number. Regarding buttermilk samples, metabolites significantly different across dietary regimes included phospholipids, sphingomyelins and an acylcarnitine.ConclusionIn conclusion the results reveal a significant impact of a pasture-fed dietary regime on the metabolite composition of bovine dairy products, with a particular impact on lipid compound classes.

Bovine dairy production and diversity of regional dairy products sold in Presidente Médici markets - RO, Western Amazon

This study investigates bovine dairy production in Rondônia, as well as the availability of bovine dairy products produced in the state available in markets in the urban area of ​​Presidente Médici - RO. To this end, the SIDRA/IBGE Municipal Livestock Survey database was used, from 2015 to 2022; To assess the availability of dairy products, visits to markets were carried out. For the period analyzed, Rondônia emerges as the largest producer in the North Region, presenting its peak in 2018, with 1,160,198 liters, the state's contribution at national level is approximately 1.9%, the municipalities with the highest milk production were: Jaru, Machadinho do Oeste and Ouro Preto, respectively; the municipality of Presidente Médici ranked 11th with production of 212,913 liters. Regarding the commercialization of dairy products produced in the state, these were found in 100% of the markets, with cheese having the greatest diversity of types and manufacturers, followed by butter, yogurt, type C milk, UHT milk and dulce de leche, respectively. Dairy production in Rondônia and the municipality of Presidente Médici may be related to the need for genetic improvement of the herd, low technology and greater technical assistance to producers. With regard to dairy products available in the markets, it is clear that entrepreneurship through agroindustrialization is one of the economic strategies that integrate several stages of the production chain, adding value to the product, increasing the use of local labor, which contributes to reducing the rural exodus and increases the well-being and comfort of the families and communities involved.

Multiple-Drug Resistant Shiga Toxin-Producing E. coli in Raw Milk of Dairy Bovine.

Raw milk may contain pathogenic microorganisms harmful to humans, e.g., multidrug-resistant Escherichia coli non-O157:H7, which can cause severe colitis, hemolytic uremia, and meningitis in children. No studies are available on the prevalence of Shiga toxin-producing E. coli (STEC O157:H7) in sick or healthy dairy animals in the Khyber Pakhtunkhwa Province of Pakistan. This study aimed to isolate, characterize, and detect antibiotic resistance in STEC non-O157:H7 from unpasteurized milk of dairy bovines in this province. We collected raw milk samples (n = 800) from dairy farms, street vendors, and milk shops from different parts of the Khyber Pakhtunkhwa Province. E. coli was isolated from these samples followed by latex agglutination tests for serotyping. The detection of STEC was conducted phenotypically and confirmed by the detection of virulence genes genotypically. An antibiogram of STEC isolates was performed against 12 antibiotics using the disc diffusion method. A total of 321 (40.12%) samples were found to be positive for E. coli in this study. These samples were processed for the presence of four virulence genes (Stx1, Stx2, ehxA, eae). Forty samples (5.0%) were STEC-positive. Of these, 38%, 25%, 19%, and 18% were positive for Stx1, Stx2, ehxA, and eae, respectively. Genotypically, we found that 1.37% of STEC isolates produced extended-spectrum beta-lactamase (ESBL) and contained the blaCTX M gene. Resistance to various antibiotics ranged from 18% to 77%. This study highlights the risk of virulent and multidrug-resistant STEC non-O157:H7 in raw milk and the need for proper quality surveillance and assurance plans to mitigate the potential public health threat.

Mycotoxins evaluation of total mixed ration (TMR) in bovine dairy farms: An update

The total mixed ration (TMR) is currently a widespread method to feed dairy cows. It is a mixture of raw fodder and concentrate feed that can be contaminated by several mycotoxins. The main aim of this paper was to provide a critical review on TMR mycotoxin occurrence and its usefulness to monitor and control them on-farm. Aflatoxins, zearalenone, deoxynivalenol, T-2 toxin and fumonisins (regulated mycotoxins) are the most prevalent mycotoxins evaluated in TMR. Nonetheless, several emerging mycotoxins represent a health risk at the animal level regarding their prevalence and level in TMR. Even when measured at low levels, the co-occurrence of mycotoxins is frequent and synergistic effects on animal health are still underevaluated. Similar to the animal feed industry, on-farm plans monitoring mycotoxin feed contamination can be developed as a herd health management program. The estimated daily intake of mycotoxins should be implemented, but thresholds for each mycotoxin are not currently defined in dairy farms.

The effects of dairy on the gut microbiome and symptoms in gastrointestinal disease cohorts: a systematic review.

Bovine dairy foods provide several essential nutrients. Fermented bovine dairy foods contain additional compounds, increasing their potential to benefit gastrointestinal health. This review explores the effects of dairy consumption on the gut microbiome and symptoms in gastrointestinal disease cohorts. Human subjects with common gastrointestinal diseases (functional gastrointestinal disorders and inflammatory bowel disease) or associated symptoms, and equivalent animal models were included. A systematic literature search was performed using PubMed, Embase and Web of Science. The search yielded 3014 studies in total, with 26 meeting inclusion criteria, including 15 human studies (1550 participants) and 11 animal studies (627 subjects). All test foods were fermented bovine dairy products, primarily fermented milk and yogurt. Six studies reported increases in gastrointestinal bacterial alpha diversity, with nine studies reporting increases in relative Lactobacillus and Bifidobacterium abundance. Six studies reported increases in beneficial short-chain fatty acids, while three reported decreases. Gastrointestinal symptoms, specifically gut comfort and defecation frequency, improved in 14 human studies. Five animal studies demonstrated reduced colonic damage and improved healing. This review shows fermented bovine dairy consumption may improve gut microbial characteristics and gastrointestinal symptoms in gastrointestinal disease cohorts. Further human intervention studies are needed, expanding test foods and capturing non-self-reported gastrointestinal measures.

The impact of heat-set milk protein gel textures modified by pH on circulating amino acid appearance and gastric function in healthy female adults: a randomised controlled trial.

Modification of dairy proteins during processing impacts structural assemblies, influencing textural and nutritional properties of dairy products, and release and availability of amino acids during digestion. By modifying only pH, acid heat-set bovine dairy gels with divergent textural properties were developed to alter protein digestion. In vitro assay confirmed faster digestion of protein from a firm gel (pH 5.65) versus a soft gel (pH 6.55). We hypothesised that firm gel (FIRM-G; pH 5.6) would result in greater indispensable amino acid (IAA) appearance in circulation over 5 h and corresponding differences in gastric myoelectrical activity relative to soft gel (SOFT-G; pH 6.2). In a randomised, single-blind cross-over trial, healthy females (n = 20) consumed 150 g of each gel; plasma amino acid appearance was assessed over 5 hours. Iso-nitrogenous, iso-caloric gels were prepared from identical mixtures of bovine milk and whey protein concentrates; providing 17.7 g (FIRM-G) and 18.9 g (SOFT-G) of protein per serving. Secondary outcomes included gastric myoelectrical activity measured by body surface gastric mapping, glycaemic, triglyceridaemic, and subjective appetite and digestive responses. Overall plasma IAA (area under the curve) did not differ between gels. However, plasma IAA concentrations were higher, and increased more rapidly over time after SOFT-G compared with FIRM-G (1455 ± 53 versus 1350 ± 62 μmol L-1 at 30 min, p = 0.024). Similarly, total, branched-chain and dispensable amino acids were higher at 30 min with SOFT-G than FIRM-G (total: 3939 ± 97 versus 3702 ± 127 μmol L-1, p = 0.014; branched-chain: 677 ± 30 versus 619 ± 34 μmol L-1, p = 0.047; dispensable: 2334 ± 53 versus 2210 ± 76 μmol L-1, p = 0.032). All other measured parameters were similar between gels. Peak postprandial aminoacidaemia was higher and faster following ingestion of SOFT-G. Customised plasma amino acid appearance from dairy is achievable by altering gel coagulum structure using pH during processing and may have minimal influence on related postprandial responses, with implications for targeting food design for optimal health. The Clinical Trial Registry number is ACTRN12622001418763 (https://www.anzctr.org.au) registered November 7, 2022.

Prevalence and Risk Factors of β-Lactamase Genes of Extended-Spectrum β-Lactamases-Producing Escherichia coli From Dairy Farm Environments of Haryana, India.

Presence of extended-spectrum β-lactamases (ESBL)-producing Enterobacteriaceae in the dairy farm environment and food chain could be a possible interface for the exchange of antimicrobial resistance genes between humans and animals. A total of 600 samples comprised of raw bovine milk, faeces, feed, environmental swabs and water samples from 20 different bovine dairy farms in and around Hisar city, Haryana, India were analysed for presence of ESBL encoding genes. Out of 240 isolates of Escherichia coli obtained, 74 isolates were found to be ESBL producers. Maximum number of ESBL isolates were found from faeces (40.5%) followed by raw milk (37.8%) and environmental swabs (17.5%). Most of the ESBL E. coli isolates were sensitive to chloramphenicol (82.4%) and gentamicin (77.0%) antibiotics. The bla CTX-M gene was found to be most prevalent (52.0%) followed by bla TEM (9.45%) while bla SHV gene alone was not detected in any sample by simplex PCR. However, the co-expression of blaCTX-M + blaTEM (21.6%) and blaCTX-M + blaSHV (4.05%) genes were also observed. The housing system, milking method and the hygienic mangement practices followed at farm level are found to be significant risk factors of ESBL-producing E. coli in dairy farms of Haryana.

Safety of a feed additive consisting of Duddingtonia flagransNCIMB 30336 (BioWorma®) for all grazing animals (International Animal Health Products Pty Ltd).

Following a request from the European Commission, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety of a feed additive consisting of Duddingtonia flagrans NCIMB 30336 (BioWorma®) for all grazing animals. The safety and efficacy of the additive have been already assessed previously, however the FEEDAP Panel could not conclude on the safety of the additive for the target species and the consumers due to the limitations in the dataset provided. For the current assessment, the applicant submitted a new tolerance trial in dairy cows and new toxicological studies. After the assessment of the new data submitted, the FEEDAP Panel concluded that the use of the feed additive in animal nutrition under the conditions of use proposed is of no concern for dairy cows. This conclusion can be extrapolated to all dairy bovines, ovines and caprines, but not to fattening and rearing animals of those species. Due to the lack of data, the FEEDAP Panel cannot conclude on the safety of the additive for other grazing species/categories. The FEEDAP Panel concluded that the additive is safe for the consumers.

Comparison of 2 PCR assays on environmental samples cultured for Mycobacterium avium subsp. paratuberculosis.

Mycobacterium avium subsp. paratuberculosis (MAP) is the causal agent of paratuberculosis, a chronic, contagious, and incurable enteric disease of ruminants. An in-house IS900 PCR assay validated for MAP detection in sheep has been shown to have a higher sensitivity than a commercial PCR and fecal culture. We have now compared the performance of this in-house IS900 PCR assay with a commercial ISMap02 PCR assay for the detection of MAP DNA in bovine dairy farm environmental samples. We purposefully selected 30 culture-positive, 62 culture-negative, and 62 non-interpretable environmental samples. We applied the IS900 PCR assay directly to the frozen inoculum of these samples. Inocula were incubated in an automated system, and growth was confirmed by an acid-fast bacilli stain and the IS900 PCR assay. Among culture-positive samples before incubation, the IS900 PCR assay yielded significantly more positive results than the ISMap02 PCR assay; however, among culture-negative samples, the IS900 PCR assay yielded positive results both before and after incubation. The ISMap02 PCR assay did not flag positively among the culture-negative samples either before or after incubation. The IS900 PCR assay is a sensitive method that can be used to detect MAP DNA in environmental samples before incubation. The ISMap02 PCR assay is a specific method used to detect MAP DNA in environmental samples both before and after incubation.

Monitoring bovine dairy calf health and related risk factors in the first three months of rearing

BackgroundRearing replacement heifers is pivotal for the dairy industry and is associated with high input costs for the preweaned calves, due to their higher susceptibility to diseases. Ensuring calf health and viability calls for systematic approaches in order to mitigate the costs induced by managing sick calves and to ensure animal welfare. The objective of this study was to develop a systematic and feasible health-monitoring tool for bovine dairy calves based on repeated clinical observations and diagnostic results of calves at three time points; the 1st (T0), the 3rd (T1) and the 12th (T3) week of age. The study included observations from 77 dairy heifer calves in nine Danish commercial dairy herds. Immunisation status was assessed by serum Brix% at T0. Clinical scoring included gastrointestinal disease (GD) and respiratory disease (RD). The average daily weight gain (ADWG) was estimated from heart-girth measurements. Pathogen detection from nasal swabs and faecal samples were analysed for 16 respiratory and enteric pathogens by means of high-throughput real time-PCR. All measures obtained in each herd were visualised in a panel to follow the health status of each calf over time.ResultsThe individual clinical observations combined with diagnostic information from immunisation and pathogen detection form each enrolled calf are presented in a herd dashboard illustrating the health status over the study period. This monitoring revealed failure of passive transfer (Brix% < 8.1) in 31% of the 77 enrolled calves, signs of severe GD peaked at T0 with 20% affected calves, while signs of severe RD peaked at T2 with 42% affected calves. ADWG over the first eight weeks was estimated to be 760 g (± 190 g). Pathogen profiles varied between herds.ConclusionsThe large variation in both clinical disease and pathogen occurrence across herds emphasizes the need for herd specific monitoring. Combining the results of the present study from measures of immunisation, health and growth from individual calves in one visualisation panel allowed for the detection of patterns across age groups in the specific herds, showing promising potential for early detection and interventions that can lead to enhanced calf health and welfare.

Genomic Insights into Methicillin-Resistant Staphylococci and Mammaliicocci from Bulk Tank Milk of Dairy Farms in Serbia.

The potential risk to human and animal health provides a rationale for research on methicillin-resistant staphylococci (MRS) and mammaliicocci (MRM) in dairy herds. Here, we aimed to estimate their occurrence in the bulk tank milk (BTM) samples collected in 2019-2021 from 283 bovine dairy farms in the Belgrade district. We used whole-genome sequencing to characterize the obtained isolates and assess their genetic relatedness. A total of 70 MRS/MRM were recovered, most frequently Staphylococcus haemolyticus and Mammaliicoccus sciuri. Five clusters of 2-4 genetically related isolates were identified and epidemiological data indicated transmission through, e.g., farm visits by personnel or milk collection trucks. Most MRSA isolates belonged to the typical livestock-associated lineage ST398-t034. One MRSA isolate (ST152-t355) harbored the PVL-encoding genes. Since MRS/MRM isolates obtained in this study frequently harbored genes conferring multidrug resistance (MDR), this argues for their role as reservoirs for the spread of antimicrobial resistance genes. The pipeline milking system and total bacterial count >100,000 CFU/mL were significantly associated with higher occurrences of MRS/MRM. Our study confirms that BTM can be a zoonotic source of MRS, including MDR strains. This highlights the urgent need for good agricultural practices and the continuous monitoring of MRS/MRM in dairy farms.

Seroprevalence and associated risk factors of leptospirosis in bovine dairy farms in Telangana state, India.

The current cross-sectional study aimed to determine the seroprevalence of Leptospira infection in bovine dairy farms in the Telangana state of India, as well as the associated risk factors, in order to implement effective preventive measures for disease control. A total of 469 blood samples were collected from 67 herds/farms in different areas, covering 20 administrative districts in the state. These samples consisted of 253 from cattle and 216 from buffaloes. Questionnaires were used to collect data on host and epidemiological factors. The collected sera were tested using the gold standard serological test, the Microscopic Agglutination Test (MAT), which employed a panel of 18 reference serovars for Leptospira exposure. The statistical analysis of epidemiological data was carried out to identify the risk factors associated with Leptospira exposure. The overall observed seroprevalence at the animal and farm levels was 41.4% and 77.6%, respectively. The most prevalent anti-leptospiral antibodies were observed against the serogroups Icterohaemorrhagiae (32.4%), Pomona (22.2%), Javanica (19.1%), Australis (17.0%), Bataviae (15.5%), Autumnalis (12.9%), Hebdomadis (12.9%), and others, in the total reacting samples. At the animal level, the significant risk factors associated with exposure to Leptospira species were breed (p = 0.03) and health status (p = 0.03). Furthermore, the multivariate statistical analysis of farm factors revealed that farm size (p = 0.05), presence of dogs (p = 0.04) and rodents (p = 0.01) on the farm, use of fodder from wet soils (p = 0.04), and proximity to water bodies (p = 0.04) were significantly associated with exposure to Leptospira in the studied region. This study provides the first report from India highlighting the important risk factors at the herd/farm and animal level associated with Leptospira infections in cattle and buffaloes. The findings contribute to strengthening the one-health strategy by facilitating the design and planning of appropriate control measures to alleviate the burden of leptospirosis in bovines.

Prevalence and risk factors associated with subclinical mastitis in peri-urban bovine dairy farms of Ouagadougou and Bobo Dioulasso in Burkina Faso, West Africa.

Prevalence and risk factors associated with subclinical mastitis in peri-urban bovine dairy farms of Ouagadougou and Bobo Dioulasso in Burkina Faso, West Africa.

Molecular and serological prevalence of Coxiella burnetii in bovine dairy herds in southern Chile: A PCR and ELISA-based assessment of bulk tank milk samples

Coxiella burnetii (C. burnetii) is a highly resilient zoonotic bacterium responsible for Q fever, a disease which occurs worldwide, with the exception of New Zealand. However, in Chile, the prevalence and impact of C. burnetii in cattle herds remain poorly understood due to limited research. This study aimed to assess the presence of C. burnetii in dairy cattle herds in southern Chile, using two diagnostic methods on bulk tank milk samples. The results of the study revealed a high prevalence of C. burnetii infection in the analyzed herds. Of the 271 milk tank samples tested, 76% (208/271, CI: 71.1–81.5) tested positive using ELISA, while 73% (200/271, CI: 68.0–78.8) tested positive using qPCR. These findings indicate a significant presence of C. burnetii in the cattle herds studied. Despite the high prevalence observed, no new Q fever outbreaks have been reported in the study area. This discrepancy highlights the need for further research to better understand the transmission dynamics, environmental factors, and livestock management practices associated with C. burnetii infection. These studies will contribute to the development of effective prevention and control strategies and promote public health regarding Q fever.

Productive Indicators of a Dairy Farm in the Center-West of The Province of Chaco-Argentina

The objective of the work was to generate productive indicators of a dairy system in the centre-west of the province of Chaco-Argentina. The work was carried out between December 2021 and December 2022 on a dairy farm belonging to the U.E.G.P. School. N°40-Agrotechnical High School, located in the town of Coronel Du Graty, department of Mayor Luis Jorge Fontana, province of Chaco, Argentina. The averages and standard deviations of productive variables were obtained. The aggregate indicators showed a milking cow/dry cow ratio of 60/40, the conversion efficiency of pasture in the milk of 0.938 milk per kg of DM and 1719 litres/ha/adjusted year. The values obtained make it possible to start having own and zonal data that will allow a constant evaluation as the data record is consolidated over time. The information obtained will be a tool that, in the medium term, will indicate the productive floor or ceiling of the analysed system and, based on this, be able to plan. It is concluded that productive indicators were generated showing the potential of the analysed region, and these should serve as a basis to implement programs to increase the adoption of input and process technologies in the bovine dairy sector of the centre-west of the province of Chaco- Argentina.