Variation of casein and fatty acids milk contents in Italian Browns Swiss cows

The interest in functional foods has considerably enlarged and the development of products with particular features for the food market has been encouraged. The aim of this study was to evaluate the variations of protein, casein, saturated (SFA), unsaturated (UFA), monounsaturated (MUFA) and polyunsaturated (PUFA) fatty acids contents in the milk of two groups of Italian Brown Swiss cows, either conventionally reared in indoor period of housing or consuming pasture during summer. Milk components were obtained from samples collected during the national routine (conventionally reared) and ‘extraordinary’ (mountain pasture period) milk recording scheme in 2008 and 2013 in herds located near Sondrio. Milk samples were processed with the MilkoScanTM FT6000 (Foss Electric, Hillerød, Denmark) for the identification of milk casein, SFA, UFA, MUFA and PUFA composition. The groups were analyzed separately per year and the environmental factors (pasture/indoor, parity, data of sampling, days in milk, days from collection collection to analysis) affecting milk protein, casein, and fatty acids contents were included in the GLM and MIXED procedures of SAS 9.3. A total of 778 milk samples were available, including 234 records from indoor and 544 observations from pasture feeding. Pasture intake affected the content of casein (%) and the proportion of fat in milk (g/100g) through its direct effect on energy and protein intake, enhancing milk casein levels (from 2.90 to 3) and reducing the concentration of milk SFA in milk from grazing cows (from 2.32 to 1.88). This study has confirmed in a field study conducted in different locations and time, that in a low input grazing system the total production exhibits a higher true casein content and a minor amount of SFA in milk: pasture intake affects the proportions of fat and casein fractions in milk through their direct effect on energy intake. Additionally, as milk was transformed in cheese, the cheese yield was calculated as ‘kg of cheese per 100 kg of milk’ resulting to be 10.4 from cows reared indoor resulted 10.4, while this value increased to 12 from milk of pasture based diet cows. The farmers and breeders producing Bitto, “Similar Bitto”, and “Latteria” cheeses may disclose to consumer the better nutritional properties of pasture milk (i.e. less SFA) respect to indoor milk to raise awareness of the quality of marketed productions. Acknowledgments: This study was funded by Regione Lombardia projects n705 (BruCa) n. 1328 (LattOmega).