Production and destination dynamics of waste milk and its relationship with raw milk production in a semi‐intensive dairy cattle system in South America—A case report

Background Waste milk (WM), defined as milk unfit for human consumption due to contamination with pharmaceuticals or high microbial load, poses economic and public health challenges. Aim(s) This case study aimed to describe the production of WM on a South American dairy farm, including the volume of WM generated and its disposal. Methods In this case report, we used records and management data from a semi‐intensive dairy farm in Minas Gerais, Brazil, from 2020 to 2023, to estimate the total volume of WM produced, its proportion relative to raw milk (RM), and its primary destinations. Major Findings The results indicate that 148 651 L of WM were produced over the 4 years, representing approximately 9.85% of total RM production. On average, the RM‐to‐WM ratio was 10.15:1 (or 1 L of WM was generated per 10.15 L of RM). Most WM (74.9%) was used for calf feeding, a common but controversial practice due to its potential to promote antimicrobial resistance (AMR). Literature review and comparative international data highlight the prevalence of this practice and its associated risks. Scientific Implications Reporting, for the first time, the ratio of WM to RM in a southern country, this study also underscores the importance of improved management strategies and further research on the long‐term implications of WM use, particularly regarding AMR and food safety.