Effect of major reproductive disorders on reproductive performance and their association with seroprevalance of brucellosis in dairy cows in Enderta district, Tigray, Ethiopia

Reproductive disorders significantly impact the reproductive performance and economic efficiency of dairy cows. This cross-sectional study aimed to investigate major reproductive disorders, assess reproductive performance, identify associated risk factors, and determine the seroprevalence of brucellosis in relation to reproductive disorders in Enderta district from January to December 2024. A total of 384 dairy cows (267 crossbreed and 117 local) from randomly selected farms were sampled. Data were collected from 96 dairy owners using a structured questionnaire. The study found that 68.23% (n=262) of dairy cows were affected by reproductive disorders. The most prevalent conditions were retained fetal membranes (26.82%), abortion (17.71%), repeat breeding (10.68%), and anestrus (7.03%). Reproductive performance parameters showed that the mean age at first service was 38.82±3.43 months (local) and 26.57±2.07 months (crossbreed); mean age at first calving was 47.71±4.49 months and 35.20±6.20 months; mean calving interval was 16.02±1.76 months and 14.15±1.45 months; mean days open were 132.11±6.83 and 118.88±3.09 days; and the number of services per conception was 1.85±0.55 and 1.70±0.71 for local and crossbreeds, respectively. Bovine brucellosis was tested using the Rose Bengal Plate Test on all serum samples, with no positive cases detected. Reproductive disorders were significantly associated with production system, age, body condition score, hygiene, and mating system (p<0.05). Additionally, cows affected by reproductive disorders exhibited significantly poorer reproductive performance than healthy cows. The study highlights the importance of improving management practices such as heat detection, veterinary care, nutrition, hygiene, and owner awareness to enhance reproductive health and productivity in dairy cows.