Efficacia della somministrazione per via endomammaria di cloxacillina benzatina per il trattamento delle infezioni intramammarie dell'ovino nel corso dell'asciutta

The efficacy of the administration at drying off in Sarda ewes of an intramammary suspension containing cloxacillin
(300 mg) as benzatine was evaluated in n.7 farms. The trial was conducted in each farm on treated (T) and untreated
(U) groups including n. 142 and n. 136 half-udders (=experimental unit) respectively. All half-udders were affected with
sub-clinical mastitis (positive bacteriological examination and SCC/ml over >300.000). Five milk samplings were carried
out from each half-udder.
2 samplings were done before treatment and 3 after.
Bacteriology and somatic cells
count
(SCC/ml) was performed
on each sample. Before treatment the Coagulase Negative Staphylococci accounted for
91,6% of the isolates. The duration of the treatment (62±22,8 days) was equivalent to the drying period. The last 3
samples were carried out 3,8±2,9, 11,0±3,2 and 58,8±16,5 days after parturition. Overall average bacteriological cure
rate observed for the 3 samplings after parturition was respectively in the T and C groups 82,3% and 36,8% (3
sampling);
81,2% and 48,1% (4
th
sampling); 61,3% and 33,3%. The SCC(x10
)/ml (geometrical mean) in groups T and C
was respectively 367 and 1,903 (3
rd
sample); 288 and 846 (4
th
3
sample); 393 and 960 (5
sample). The differences
between the groups T and C for the bacteriological cure and the SCC values were statistically significant (P<.001) for
the 3 samplings.