A non-inferiority study evaluating a new extended-release preparation of tilmicosin injected subcutaneously vs.ceftiofur administered intramammary, as dry-cow therapy in Holstein Friesian cows
- Author:
Esteban ORTEGA
1
;
Edgar ALFONSECA-SILVA
;
Eduardo POSADAS
;
Graciela TAPIA
;
Hector SUMANO
Author Information
- Publication Type:Original Article
- From:Journal of Veterinary Science 2020;21(6):e87-
- CountryRepublic of Korea
- Language:English
-
Abstract:
Background:A new, extended long-acting tilmicosin (TLAe) preparation was tested against intramammary ceftiofur (CEF) using a non-inferiority trial model during dry-cow therapy (DCT) in a farm with high bovine population density and deficient hygiene application.
Objectives:To evaluate the possibility that TLAe administered parenterally can achieve noninferiority status compared to CEF administered intramammary for DCT.
Methods:Cows were randomly assigned to TLAe (20 mg/kg subcutaneous; n = 53) or CEF (CEF-HCl, 125 mg/quarter; n = 38 cows) treatment groups. California mastitis testing, colonyforming unit assessment (CFU/mL), and number of cases positive for Staphylococcus aureus were quantified before DCT and 7 d after calving. A complete cure was defined as no bacteria isolated; partial cure when CFU/mL ranged from 150 to 700, and cure-failure when CFU/mL was above 700.
Results:TLAe and CEF had overall cure rates of 57% and 53% (p > 0.05) and S. aureus cure rates of 77.7% and 25%, respectively (p < 0.05). The pathogens detected at DCT and 7 days after calving were S. aureus (62.71% and 35.55%), Staphylococcus spp. (22.03% and 35.55%), Streptococcus uberis (10.16% and 13.33%), and Escherichia coli (5.08% and 15.55%). Noninferiority and binary logistic regression analyses revealed a lack of difference in overall efficacies of TLAe and CEF. Apart from S. aureus, S. uberis was the predominant pathogen found in both groups.
Conclusions:This study is the first successful report of parenteral DCT showing comparable efficacy as CEF, the gold-standard. The extended long-term pharmacokinetic activity of TLAe explains these results.
