Background and Aim: Cattle are the reservoir host of Coxiella burnetii, a causative agent of Q fever. Pooling herd-level prevalence data from individual studies would help determine the global prevalence of C. burnetii in cattle herds. This study aimed to estimate the global herd-level seroprevalence and molecular prevalence of C. burnetii in cattle, explore sources of heterogeneity, and determine trends and cumulative evidence of the pooled prevalence over time. Materials and Methods: Relevant studies were retrieved from PubMed, Scopus, and Web of Science and then screened for possible inclusion. A random-effects model was used for all meta-analyses. Subgroup meta-analysis and meta-regression were used to explore some sources of heterogeneity associated with the pooled prevalence and to determine the trends of C. burnetii in cattle herds over the study years (1961–2020). A cumulative meta-analysis was used to determine the cumulative evidence of the pooled prevalence over the publication years. Results: Of the 1541 citations, 86 studies with 38,057 cattle herds from 42 countries on six continents were included in the meta-analysis. The global herd-level seroprevalence of C. burnetii in cattle was estimated to be 44.4% (95% confidence interval [CI], 37.9%–51.1%), with high heterogeneity among the included studies. The herd-level seroprevalence was significantly higher in dairy than in beef cattle herds (49.0% [95% CI: 41.9%–56.2%] vs. 14.5% [95% CI: 5.8%–32.1%], respectively). The global herd-level molecular prevalence of C. burnetii in cattle was estimated to be 32.3% (95% CI: 25.3%–40.01%), with high heterogeneity among the included studies. Herd-level molecular prevalence was significantly different among continents. The herd-level molecular prevalence ranged from 12.8% (95% CI: 7.1%–21.9%) in Asia to 70.0% (95% CI: 36.3%–90.5%) in North America. Regarding trends, the herd-level seroprevalence of C. burnetii in cattle did not change significantly over the study years. Conclusion: The global herd-level seroprevalence and herd-level molecular prevalence of C. burnetii in cattle were high, estimated at 44% and 32%, respectively. The herd-level seroprevalence trend did not significantly change over time. This result indicates that cattle remain a major reservoir host for C. burnetii and pose a potential risk to human health. Keywords: cattle, Coxiella burnetii, herd, prevalence, Q fever.

The investigation aimed to study the effect of vegetable oil sources on feed intake, nutrient digestibility and biohydrogenation bacterial population in Thai Friesian dairy cows. Three fistula Thai Friesian cows with mean body weight (BW) of 600±100 kg were assigned to receive three vegetable oil sources i.e. palm oil (PO), soybean oil (SBO) and sunflower oil (SFO) included at 4 %DM in commercial concentrate. All cows were fed on different diets that contained concentrate of 1 %BW and rice straw of 1 %BW according to a 3×3 latin square design (LSD). The results revealed that dry matter digestibility (DMD) and organic matter digestibility (OMD) tended to be higher in cows fed on SBO and SFO (P=0.06). Moreover, the DNA copy numbers (copies/ml) of biohydrogenation bacteria (Ruminococcus albus) and cellulolytic bacteria (Ruminococcus flavefaciens and Prevotella ruminicola) were higher in cows fed on SBO (P<0.05). In summary, supplementation of SBO in diet resulted in a higher nutrient digestibility and rumen biohydrogenation bacteria population.

Background and Aim: Bovine anaplasmosis (BA) is one of the most important diseases of ruminants worldwide, causing significant economic losses in the livestock industry due to the high morbidity and mortality in susceptible cattle herds. Anaplasma marginale is the main causative agent of BA occurring worldwide in tropical and subtropical regions. This study aimed to investigate the first molecular detection and genetic diversity of A. marginale in dairy cattle in Khon Kaen Province, Thailand. Materials and Methods: Blood samples were collected from 385 lactating cows from 40 dairy farms in five districts of Khon Kaen, regardless of age and health status. To detect A. marginale, all DNA preparations were used for molecular diagnosis using a single polymerase chain reaction with the msp4 gene target. A phylogenetic tree was constructed from the msp4 gene sequences using molecular genetic characterization. Genetic diversity was calculated as haplotype diversity, haplotype number, number of nucleotide differences, nucleotide diversity, and average number of nucleotide differences. Results: The overall prevalence of A. marginale was 12.72% (49/385). The highest prevalence (17.19%) was found in Ubolratana district, followed by Muang, Kranuan, Khao Suan Kwang, and Nam Phong districts (14.94%, 14.74%, 13.79%, and 3.70%, respectively). Phylogenetic analysis showed that A. marginale was closely related to isolates from Australia (98.96%), China (99.68%), Spain (99.74%), and the USA (99.63%). Conclusion: The molecular prevalence of BA in dairy cattle is the first to be observed in this area, and the genetic variability with separated clusters shown in the msp4 gene of A. marginale revealed species variation in dairy cattle. This significant genetic diversity contributes to the understanding of the diversity of A. marginale and will be important for the control and prevention of A. marginale in dairy cattle. Keywords: Anaplasma marginale, bovine anaplasmosis, dairy cattle, molecular prevalence.

The diagnosis of Anaplasma is typically carried out through morphological identification based on the presence of inclusion bodies located at the margins of erythrocytes. Microscopic examination of blood smears stained with Wright’s–Giemsa is generally suitable for detecting acute anaplasmosis in clinically suspected animals. This study aimed to compare the diagnostic accuracy of microscopic examination and conventional polymerase chain reaction (PCR) for detecting A. marginale in asymptomatic (carrier) cattle. A total of 385 blood samples were collected from cows without clinical symptoms. The sensitivity and specificity of microscopic detection were evaluated against conventional PCR results. The sensitivity and specificity of microscopic results were compared with A. marginale by conventional PCR. The results revealed 3.40% and 12.73% positive animals by microscopy and conventional PCR with significant differences (P=0.03). The value of Kappa between microscopic examination and conventional PCR has indicated a fair level of agreement (0.32). Microscopic examination showed 6.10% sensitivity and 97.40% specificity compared to conventional PCR's 100% sensitivity and specificity. These results indicate that conventional PCR is a more accurate and reliable method for detecting A. marginale in asymptomatic cattle. The limitations of microscopy, particularly in carrier animals, include the very low number of infected erythrocytes, difficulty in identifying well-stained Anaplasma organisms, and challenges in distinguishing A. marginale from A. centrale.