Milking system and diet's forage type impact on milk quality of Italian Holstein-Friesian.

Moving from conventional (CMS) to automatic (AMS) milking systems could impact milk quality. Moreover, the type and preservation methods of the forages used in the total mixed ration (TMR) (such as alfalfa hay -HTMR- or corn silage -STMR-) have been demonstrated to modify milk composition. Thus, this study investigated the effect of implementing AMS and different diet forage types on the quality of Italian Holstein-Friesian bulk milk. Milk samples (n = 168) were collected monthly from 21 commercial farms in northern Italy during a period of 8 mo. Farms were categorized into 4 groups according to their milking system (CMS vs AMS) and diet's forage type (HTMR vs STMR). Milk quality data were analyzed through the mixed procedure for repeated measurement of SAS with the milking system, diet's forage type, and sampling day as fixed effects. Milking through the AMS led to lower milk fat, freezing point and ß-lactoglobulin A, longer coagulation time, and higher K content, pH and ß-lactoglobulin B than CMS. Cows fed STMR produced milk with greater fat, protein, casein, Mg content, titratable acidity and ß-lactoglobulin A, while reduced curd firming time, freezing point and ß-lactoglobulin B than those fed with HTMR. In conclusion, milk quality is not only altered by the diet's forage type and characteristics but also by the milking system.

Comparison of near and medium infrared spectroscopy to predict fatty acid composition on fresh and thawed milk.

Near (NIR) and medium (MIR) infrared reflectance spectroscopy (IR) predictions of fatty acid (FA) composition, expressed as g/kg of milk or g/100g of FA, on fresh and thawed milk were compared. Two-hundred-and-fifty bulk cow milks, collected from 70 farms in northwest Italy, were scanned by MIR in liquid form and by NIR in liquid and oven-dried forms. MIR and NIR FA (g/100g FA) predictions on oven-dried milk were similar for the sum of even chain-saturated FA (ECSFA), odd chain-FA (OCFA), unsaturated FA (UFA), conjugated linoleic acid (CLA), n-3 FA, and C18:1cis9 to C16 ratio. The monounsaturated FA (MUFA), n-6 to n-3 ratio, polyunsaturated FA (PUFA), and n-6 FA were predicted better by NIR on oven-dried milk. The NIR showed worse predictions than MIR for almost all FA, when expressed as g/kg of milk. The NIR predictions on fresh liquid and oven-dried milk were similar, but the reliability decreased for thawed liquid milk. The high performance shown by NIR and MIR allows their use for routine milk FA composition recording.