Sana FERROUDJAli ELAFRIIsmahen HALASSI2024-02-272024-02-272021-05-06http://dspace.univ-khenchela.dz:4000/handle/123456789/2174In order to complete the national picture of livestock disease caused by bovine mastitis, a cross-sectional study design was conducted in a large dairy farm in the northeastern region of Algeria. Between November 2019 and September 2020, a total of 154 lactating cows were sampled from 11 randomly chosen dairy farms. Milk samples were examined for subclinical mastitis using the California Mastitis Test (CMT: Teepol® vial, opaque blister packs), and binary logistic regression was performed to test the influence of several risk factors (management type, herd size, breed, age of animal, and stage of lactation) on cow mastitis status (0 = negative and 1 = positive). Our examination revealed that 90.91% (almost all) of the herds observed had at least one cow suffering from subclinical mastitis. At cow level, the frequency of mastitis in the present study was 12.9%. This prevalence value is the lowest in the country, since it is positioned under the range of cow recently published studies. The presence of mastitis was significantly influenced by the lactation stage and its connection with the animal’s age. The odds of finding a cow with a positive CMT result was 15.9-fold more in the late stage of lactation than in the first stage. Moreover, cows in the mid-lactation stage were significantly more likely to have mastitis than cows in the early lactation stage. The Hosmer–Lemeshow goodness-of-fit test suggested that the model fit the data (χ   = 3.62; p  = 0.92), and explained 23.5% of the deviance in the mastitis occurrence and 20.5% of the variance. Thus, we can say that poor hygiene practices, the age of cows, and the lactation stage are the greatest risk factors and are the focal issues for which preventive veterinary programs and control measures could be developed and implemented. 2 level mastitis prevalence (26–55.16%) recorded by the mostenArticle