Unveiling antibiotic residue contamination: assessing yak, dzomo, and hill cattle milk from himalayan region through QuEChERS-HPLC approach and health risk assessment

Milk obtained from Yaks, yak hybrid (Dzomo) and hill cattle (Gauri) is major source of nutrients for people inhabiting Himalayas. In present study, QuEChERS approach together with HPLC-UV was used for detection and quantification of tetracycline residues in 170 raw milk samples of hill cattle (60), dzomo (58) and yaks (52) collected from high altitude regions of Himachal Pradesh, a Western Himalayan state of India. The method validated as per European Commission’s guidelines was found to be linear (R² > 0.99), accurate (recoveries: 80%~90%) precise (RSD ~ 10%) with LOD of 0.55 and 1.37 ng/mL for tetracycline and oxytetracycline, respectively. Antibiotics were detected in 8 samples, with only 3 samples exceeding MRLs. Hazard Index values for exposure to detected antibiotic residues in milk were below 1 suggesting that the population is likely protected from acute health risks associated with such exposure. However, for children, % contribution to acceptable daily intakes of antibiotics only through milk was found to be high indicating probable risks. Therefore, ongoing monitoring and adherence to regulatory standards are important to ensure the safety of milk and other food products. There is also a need to educate farmers and improve their perception about antibiotics and their usage to safeguard consumer’s health.