Environmental and herd management factors affecting the mineral profile of bovine milk

This study investigated how animal, environmental, and management factors influence milk mineral composition (Ca, P, Mg, S, K, Cl, and Na) of Brown Swiss cows. A total of 1,060 individual milk samples were collected from 53 herds located in Emilia-Romagna, Lombardia, and Toscana regions (Italy) between February 2021 and April 2022, representing a wide range of production environments and management systems. Information on DIM, parity, and milk yield (MY, kg/d) was combined with herd-level data on altitude, season, temperature-humidity index (THI), ventilation, and feeding system. Milk Ca, P, Mg, S, K, Na, and Cl (mg/kg) were determined using wavelength-dispersive x-ray fluorescence. A linear mixed model was used to estimate the effects of fixed animal-related, environmental, and herd management factors while accounting for herd as a random effect. Season significantly affected Ca, P, Mg S, and K; THI was associated with Mg and Cl, particularly beyond the thermal stress threshold; altitude showed a tendency to be associated with K concentration; ventilation showed tendency of association with P and K, whereas feeding system was associated with P and S. These results demonstrate that, although the animal factors exerted the strongest influence, environmental and herd management factors can still modulate the mineral variability. These findings refer to the studied Brown Swiss population and indicate that accounting for these factors is relevant to optimize milk quality, enhance cheese-making efficiency, and support precision management strategies in Italian dairy system.