TREATMENT OF SUB-CLINICAL MASTITIS IN LACTATING COWS EVALUATION OF A NEW PROTOCOL CALLED "SIMULTANEOUS TREATMENT"

The efficacy of a cephalexin-based intramammary preparation was evaluated for treating sub-clinical mastitis (SCM) during lactation. Simultaneous treatment (ST) consists of treating simultaneously the clinical mastitis (CM) and quarter(s) affected with SCM. Using a cow-level economic model, SCM treatment alone proved to be unprofitable whatever the stage of lactation. Conversely, with the same model, the ST protocol proved to be profitable during the first 6 months of lactation when the expected cure rate was 50 % higher than the spontaneous cure rate. Its value was more limited with a lower cure rate. The efficacy of ST was investigated during two field trials in France. Cows with CM and SCM (detected by CMT) were included, then randomly assigned to two groups. In the control group (C), the treatment with 200 mg of cephalexin for 4 consecutive milkings was restricted to quarters with CM. In the ST group, the same treatment was applied to SCM and CM quarters. In the first trial, the individual somatic cell count was significantly reduced in the ST group 2 months after treatment. In the second trial, the bacteriological cure rate for CM did not differ between C (63%) and ST (62%) groups whereas a statistically significant difference (p = 0.02) was observed between C (27%) and ST (63%) groups regarding the SCM bacteriological cure rate. The ST protocol should be considered as a tool for SCM treatment in lactating cows and a valuable procedure in mastitis control