Identification of management in dairy cattle by stable isotope analyses of carbon and nitrogen in milk

A promising alternative to identify the origin and quality of animal or plant products is the stable isotope technique which it is been used in traceability studies. However, studies on ruminants are scarce, being more common in broilers and products of vegetal origin. Therefore, stable isotopes are potential tracers in milk, not only for the traceability of diets containing animal by-products in dairy cattle feed, but also by isotopic analysis of milk and dairy products. The carbon (δ¹³C) and nitrogen (δ¹⁵N) isotopes are considered excellent indicators for correlating animal products with the environment they came. Based on that, our goal was to determine if isotopic compositions can be used as 'fingerprints' to identify by raw milk characteristics the differences among types of management in dairy cattle in the Mid-West State of Sao Paulo. The experiment was conducted in 145 dairy farms (57 small farmer, 47 intermediate farmers, and 41 big farmer) collected in June-September/2018. Isotopic measurement by continuous flow system in an isotope ratio mass spectrometer. In conclusion, there are significant differences in isotopic values of δ¹³C related to feeding regime changes during the months. Thus, in the farmer's category was observed the smaller the producer, the higher the isotopic value of δ¹⁵N. (author)