Most of the metabolic problems of the dairy cow happen during the first two weeks of lactation. In a review of several experiments, researchers found that approximately one out of three fresh cows have at least one clinical disease during the first 3 weeks of lactation. Consequently, culling rate increases during early lactation. It has been reported nearly 25% of the cows that leave herds do so during the first 60 days in milk (DIM).
A recent study conducted in a 5,000-cow dairy from Florida evaluated the effects of clinical diseases during the fresh period (21 DEL) on milk production, reproduction, and culling rate of Holstein cows through the entire lactation (305 DIM).