Teat dip disinfectant formulation for dairy cows based on Melaleuca armillaris essential oil

BULDAIN, DANIEL; ALIVERTI, FLORENCIA; DI FILIPPO, JULIA; HONOR IRALA, FEDERICO; JULCA LOZANO, KAREN; BESADA, JULIAN; MESTORINO, NORA

Brujas

Congreso; 15th International Congress of the European Association for Veterinary Pharmacology and Toxicology; 2023

European Association for Veterinary Pharmacology and Toxicology

Introduction: Teat disinfectants is a routine milking practice that reduces the new intramammary infections occurrence in bovines and is widely accepted as a fundamental tool of a successful mastitis control program. Essential oils (EO) have great antimicrobial activity and represent an environmentally friendly alternative to conventional disinfectants. The objective was to evaluate and develop a phytotherapeutic topical formulation containing Melaleuca armillaris EO as a post-dipping solution.Material and Methods: Minimum inhibitory and bactericidal concentrations (MIC and MBC, respectively) of EO against S. aureus ATCC 29213 were determined. Two formulations containing different EO concentrations (MBC and 2×MBC, respectively) were prepared. An inoculum of 107 CFU/mL was added to formulations to make bacterial count at 30, 60, 90, and 120 s. Then formulations were evaluated using excised teats from cows. Teats were grouped into 7 groups: control without treatment (G1); EO 1.2% and 2.4% with and without 4% carboxymethylcellulose (G2–G5, respectively); lactic acid-hydrogen peroxide (G6); povidone-iodine (Iodine 5000 ppm) (G7). Teats were hung on a horizontal rod and immersed in the inoculum (1 × 108 CFU/mL) for 10 s, then treatment was applied for 30 s, and finally, a wash was performed for 10 s with sterile saline solution for the bacterial count. Also, 4 lactating cows received post-dipping treatment with 1.2% and 2.4% EO (thickened with carboxymethylcellulose), povidone-iodine, and control. Organoleptic characteristics (aroma, taste, and texture) of milk and its by-products (cream, ricotta, caramel, cheese, and whey cheese) were evaluated through 40 volunteers. Somatic cell count (SCC) was recorded pre-and post-treatment.Results: 6.25 and 12.5 μL/mL, were the EO MIC and MBC, respectively, that is, the MBC/MIC ratio was equal to 2 (bactericidal effect). Formulation performed at 1 and 2×MBC killed completely inoculum in less than 30 s. All the treatments presented a reduction of 90% (EO 1.2%: 89.6%; EO 2.4%: 90.4%; EO 1.2% thick formulation: 93%; EO 2.4% thick formulation: 98.9%; lactic acid-hydrogen peroxide: 95.9%; povidone-iodine: 99.6%) respect to the control. Milk and its by-product´s organoleptic characteristics were not altered by post-dipping treatment with EO and the SCC decreased from grade 3 to trace.Conclusions: The M. armillaris formulated as post-dipping has a quick antimicrobial activity against S. aureus and a thicker formulation result in more effectiveness. Likewise, post-dippingformulations with EO 1 do not affect the odor, or taste or texture of milk and its by-products, constituting an interesting phytotherapeutic alternative for the disinfection of bovine teats in dairy farms.