Prof. Fikadu RegassaProf. Gebeyehu GoshuGizaw Mekonnen2023-12-092023-12-092023http://etd.aau.edu.et/handle/123456789/522A cohort study using retrospective data from 2020 to 2022 was conducted to determine the impact of periparturient disorders, mastitis, and lameness on the reproductive performance of dairy cows in selected districts of Wolaita Zone, Southern Ethiopia, from November 2022 to April, 2023. The retrospective cross-sectional study was conducted to determine the prevalence of disorders. Multi-stage purposive sampling was used to select districts and dairy farms. Retrospective data on 1326 dairy cows was collected from 40 dairy farms. Logistic regression, chi-square, and t-test were used to analyze the data. Based on the analyzed data, 40.20% (533/1326) of dairy cows were affected by at least one disorder. The prevalence of the disorders that include endometritis, retained placenta, dystocia, hypocalcemia, mastitis, and lameness accounted 14.33%, 9.58%, 9.58%, 8.60%, 13.12%, and 10.56%, respectively. The occurrence of periparturient disorders, mastitis, and lameness showed statistically significant difference (p <0.05) with regard to body condition, parity, age, and calving season. Although the location of the farm had no significant effect on the occurrence of mastitis and lameness, it was a significant environmental factor for the occurrence of periparturient disorders. Dairy cows calving from June to August had a high probability of being affected by periparturient disorders and mastitis. Lameness was more common from September to November. In the current study; periparturient disorders, mastitis, and lameness had a strong negative impact on the calving-to-conception interval, calving-to-first service, and number of services per conception, but dystocia had no significant impact on the calving-to-first-service interval. Moreover, lameness had a significant impact on age at first calving, but it had no impact on age at first service. The first-service conception rate was higher in normal dairy cows than diseased cows (p<0.05). Thus, Periparturient disorders, lameness, and mastitis had an impact on the reproductive performance of dairy cows in the study area. It is recommended that proper feeding, husbandry, udder health, and foot care of dairy cows during the transition period need to be implemented. Early detection of disorders is essential to minimize the reproductive consequences of health problems.enDairy Cows, Lameness, Mastitis, Periparturient Disorders, Reproductive Performance, Southern Ethiopia, Wolaita ZoneThesis