Evaluation of a standard protocol for drying off and drying off therapy in dairy cows based on the comparison of two different commercial antimicrobials

This study aims to evaluate two commercial antibiotics for dry-off. Ninety-five Friesian cows and 380 quarters were included. Cows were classified as Control and Subclinical Mastitis based on somatic cell count. The California Mastitis Test and the teat end score have been performed. Quarters were randomly treated with Cloxacillin and Ampicillin (TA) and Cephalexin (TB). The effect of the therapy (TA vs TB) was estimated by X2 analysis based on the Wald test. The preservative and therapeutic action of TA vs TB were evaluated by the Kruskall-Wallis test. TB showed a statistically significant therapeutic effect in the control group, that might be related to the pharmacological activity of the two antibiotics. Also, the subclinical mastitis group most commonly presented more quarters affected compared to the control group, leading to a worse improvement despite proper therapy. In conclusion, an abruptly dry off, the California mastitis test, teat end score and somatic cell count evaluation, as long as microbial herd data might represent key concepts for an efficient drying off standard protocol in a dairy farm. In line with the herd bacterial population, both TA and TB might be employed for drying off therapy