Efecto del ácido hipocloroso como alternativa terapéutica en el control de mastitis subclínica en vacas lactantes

Abstract

The objective of this research was to determine the effect of hypochlorous acid as a therapeutic alternative in the control of subclinical mastitis in lactating cows. The study was carried out at the "Santa Clara" farm, in a dairy herd of 340 Holstein lactating cows, a total of 150 animals were sampled, of which 36 were selected for the experiment. An experimental design based on a completely random statistical model (D.C.A) was used to evaluate the efficacy of 3 doses of hypochlorous acid (HClO): T1= 10 ml of HClO, 450 ppm, intramammary route, for 5 days; T2= 20 ml of HClO, 450 ppm, intramammary route, for 5 days and T3= 30 ml of HClO, 450 ppm, intramammary route, for 5 days) compared to a conventional or control treatment (T0= 10 ml of Cephalexin 200 mg + Kanamycin 100,000 IU, intramammary route for 3 days) in lactating cows that presented three different degrees of subclinical mastitis, with 3 repetitions for each treatment. The variables analyzed were: the somatic cell count (Ccs/ml) as an indication of inflammation, the Colony Forming Units count (CFU/ml) and the antimicrobial action of the applied treatments. When doses of 30 ml of HClO (T3) were administered intramammary, after the application of this product, a cell count of less than 200,000 Ccs/ml was recorded in the three degrees of subclinical mastitis. Three types of bacterial agents were identified: Staphylococcus aureus in 66%, Streptococcus spp. 24% and Escherichia coli 10%. In relation to the antimicrobial action of hypochlorous acid, a better response was obtained in the reduction of Staphylococcus aureus colonies with a dose of 30 ml, sharing levels of antimicrobial response of 100% in cows with grade I and II subclinical mastitis with a slight reduction in the control of S. aureus for grade III cows. For Streptococcus spp. the antimicrobial response was 100% in the three doses of HClO and with the conventional treatment in grade II and III cows. However, an isolated case was recorded where the T2 response decreased slightly (91.8%), which could be attributed to handling situations unrelated to the experiment. Finally, the bactericidal effectiveness in E. coli colonies was the same in all the applied treatments (100%).