The objective of this study was to investigate the criteria for cow culling and the methods used for semen selection in small and medium dairy farms in Thailand. Dairy cows on small and medium farms are culled for many different reasons. Methods of selection and culling were examined using data collected from a questionnaire asking about the number of milking cows, farm experience in raising dairy cows, criteria used for culling cows, selection of new cows, replacement cattle, and semen for breeding. Ninety-one farms were randomly selected using a snowball technique from dairy cooperatives in Khon Kaen, Maha Sarakham, and Sakon Nakhon Provinces, Thailand, with data analyzed using ANOVA and Chi-square statistics. The results showed that most farmers did not cull cows due to low milk production or aging (71.43%, 72.53%) and used 5 to >12 insemination events as a criterion for involuntary culling (50.55%). Chronic mastitis was the highest health reason for culling cows (52.10%). Farmers usually kept on-farm female calves as replacement cows (41.67%), chosen by considering their dams’ milking ability. Most farmers (67.00%) let an artificial inseminator select suitable semen for their cows. When selecting pregnant heifers for replacement, the farmers considered body conformation, udder characteristics, and cow price. Farmers with small and medium farms conducted low levels of voluntary culling and paid less attention to the genetic information of the semen. In summary, this study explains various factors influencing the selection and culling of dairy cows. Challenges leading to cattle culling included mastitis and infertility. Educating farmers on hygiene, reproductive systems, and household accounting is imperative as it facilitates sustainable cattle rearing practices.
