Semina: Ciências Agrárias (Jun 2022)
Ceftiofur efficacy in the intramammary extended treatment of staphylococcal subclinical mastitis in primiparous cows
Abstract
Extended therapy is an alternative approach to treat nonresponsive staphylococcal mastitis, although has been used mainly in adult cows. This study investigated the efficacy of intramammary ceftiofur in the treatment of staphylococcal subclinical mastitis in heifers. Sixty heifers Holstein were divided into four groups (G1 = Group negative to staphylococci infection, G2 = positive to staphylococci infection untreated Group, G3 = Group treated early lactation, G4 = treated late lactation group) with milk samples collected at five moments (M0 = diagnosis of subclinical mastitis, M1 = 7 days after diagnosis of subclinical mastitis and early extended therapy, M2 = 14 after the diagnosis of subclinical mastitis, M3 = 21 days after diagnosis of mastitis) and M4 = 28 days after diagnosis of mastitis). In the two groups G3 and G4, treated with intramammary ceftiofur, the microbiological cure was evidenced by a reduction in SCC 73.3% and 46.7%, respectively. Thus, in the treated groups (G3 + G4) and untreated (G2), cure rates were respectively 60.00% and 26.66% (P <0.05). Isolated 45 strains of Staphylococcus spp, e.g., S. aureus (51.1%) and S. intermedius (48.8%). The in vitro antimicrobial susceptibility profile showed higher sensitivity indices of isolates for oxacillin (80%), ceftiofur (77.8%), cephalexin (77.8%), ciprofloxacin (66.7%), and gentamicin (60%). In contrast, cloxacillin (24.4%), penicillin (35.6%), and tetracycline (44.5%) were the least effective antimicrobials for staphylococci isolates. Among the milk samples taken when M0 and M1 (7 days after isolation), 13.3% were positive for the detection of the inhibiting substance in Delvotest™ and all negative in the Snap test™, whereas, in the M2 (14 days after isolation), 55% were positive in Delvotest™ and 46.7% in the Snap test™. Twenty-one days after diagnosis (M3), 16.66% revealed positive results in Delvotest™ and 11.66% in the Snap test™. For the M4 (28 days after isolation), 11.66% showed positive results in Delvotest ™ and 8.33% in the Snap test™. There was a reduction in SCC among all healed animals as G2 in M0, M4 for G3 in M0, M4, and G4 in M0, M4, with p<0.05. Significant results were identified for milk production in the MO, so G1 produced more milk compared to the other three groups G2, G3, and G4. Extended intramammary therapy with ceftiofur in bovine primiparous subclinically affected by staphylococcal mastitis is effective mainly in cases treated at the beginning of lactation, showing microbiological cure and reduction in SCC.
Keywords
