Trend analysis of bacterial counts, somatic cell counts, and milk composition in raw milk in Korea from 2014 to 2024

This study analyzed nationwide trends in raw milk quality in Korea from 2014 to 2024, focusing on bacterial counts, somatic cell counts (SCC), and milk composition, and evaluated the influence of policy developments and revisions to the national hygiene grading system.Nationwide monitoring data were obtained from the Dairy Statistics Management System operated by the Korea Dairy Committee.The total number of dairy cattle, milking cows, and dairy farms steadily declined between 2014 and 2024, while the proportion of discarded milk remained low at 0.020.04%.The proportion of 1st grade samples increased markedly, with Grade 1A bacterial counts (<310 4 CFU/mL) consistently exceeding 90% and 1st grade SCC (<2010 4 cells/mL) rising from 50.5% in 2014 to 69.1% in 2024.The mean bacterial count significantly decreased from 1710 4 to 1110 4 CFU/mL, and the mean SCC declined from 22310 4 to 19010 4 cells/mL (P<0.05).The average milk fat content increased from 3.96% to 4.06%, and milk protein content from 3.26% to 3.34%, although these changes were not statistically significant (P>0.05).Despite structural contraction in the Korean dairy sector, raw milk quality has improved substantially over the past decade.These improvements are closely linked to strengthened farm-level management practices and the progressive evolution of the national hygiene grading system.The current integrated grading system provides a solid basis for refining milk pricing policies and supporting the sustainable development of the dairy industry in Korea.