No abstract

Purpose Mastitis is a disease known to cause a great deal of loss of production and has a major economic impact. In the study area, there is little current information on bovine mastitis. Therefore, this study aimed to determine the overall prevalence of bovine mastitis and its associated risk factors and isolate the major pathogenic bacteria. Methods A cross-sectional study was conducted from February 2020 to September 2020 in selected dairy farms of Gamo Zone, southern Ethiopia. A total of 422 lactating cows were diagnosed for mastitis using the California mastitis test, clinical examination, and bacteriological methods. Results The overall prevalence of bovine mastitis determined in the area was 17.1% (72 of 422), of which 1.9% (eight of 422) was clinical and 15.2% (64 of 422) subclinical. Of 1,662 quarters examined, 7.94% (132) were positive. Bacteriological methods were also used to isolate the major pathogenic bacterial species associated with bovine mastitis. From 72 composite milk samples, growth of six different groups of bacteria was recorded in 64 (88.9%) samples. The most predominant bacterial pathogens isolated were Staphylococcus aureus (42.6%), ahead of Streptococcus spp. (26.2%), non-aureus staphylococci (14.8%), and Escherichia coli (11.5%). Salmonella spp. (3.3%) and Klebsiella pneumoniae (1.6%) were the least isolated bacterial pathogens. Among risk factors, breed, parity, udder depth, and tick infestation of the udder showed statistically significant differences ( P <0.05) regarding the occurrence of mastitis. Conclusion The current study revealed that mastitis is one of the health problems affecting dairy cows in Gamo. Enhancing the awareness of dairy farmers, regular screening, and improving hygienic conditions are critically important to control and prevent bovine mastitis in the study area.

Background Bovine mastitis is the commonest episode of infection in the dairy industry, which often occurs after damage of epithelial cells lining the teat duct. It is ranked as the second most important cause of milk production loss directly and a devastating disease with a higher incidence leading to the culling of dairy cows. Thus, this systematic review and meta-analysis is aimed to quantitatively estimate the current status of mastitis in general and bacterial mastitis particular in Ethiopia. Methods A literature search was carried from major databases and indexing services including PubMed, Google Scholar, Science Direct. Also, local institution repositories were searched to retrieve unpublished MSc and PhD theses. All studies were included addressing the prevalence of mastitis and bacterial isolates conducted in Ethiopia. Microsoft Excel was used to extract data and was imported to R Studio for the analyses. The random-effects model at a 95% confidence level was used for pooled estimates of outcomes. The degree of heterogeneity was computed by Higgins’s I2 statistics. Publication bias was checked by using the funnel plots of standard error augmented by Begg’s and Egger’s tests. Results A total of 46 studies with 15,780 cows were included in this study. All studies have collected 18,478 suspected samples for bacterial isolation. While pooled prevalence estimate of mastitis was 47.6%, the bacterial isolates pooled prevalence was 33.1%. The bacterial mastitis was 6.5% in cows infected by clinical patients and was 28.3% subclinical patients. The common isolates were Staph aureus, Strep species, Staph epidermis, Escherchia coli, Corynebacterium bovis, Coagulase Negative Staphylococcus and Klebsiella species. A univariate meta-regression analysis evidenced that the type of mastitis and management system was a possible source of heterogeneity (P-value = 0.001). Conclusion The pooled prevalence of bacterial mastitis in Ethiopian dairy cattle was high. The analysis showed bacterial pathogens like Staphylococcus aureus, Staph epidermis, Strep species and Coagulase Negative Staphylococcus are majorly accounted for bovine mastitis in Ethiopia. Therefore, the highly prevalent and commonly isolated pathogens cause contagious mastitis which require immediate attention by dairy producers to put under control by devising robust mastitis prevention and control interventions.