Can dietary palmitic supplementation and milking frequency modify the cheesemaking properties of milk?

Abstract

Palmitic acid (PA) supplementation and greater milking frequency can increase milk production and fat yield in dairy cows. However, the technological effects of those practices on cheesemaking still need to be determined. This work aimed to evaluate, with Holstein dairy cows, the effects of dietary PA, thrice-daily milking frequency, and their interaction on cheese yield and composition. Before cheesemaking, milks were standardized to a casein-to-fat ratio of 0.78% (SE: 0.02) and targets of 3.27% (SE: 0.03) and 4.20% (SE: 0.05). Rennet coagulation properties of standardized milk, cheese composition, curd draining properties, free fatty acid (FFA) content, and proteolysis during ripening were analyzed. Dietary PA supplementation modified the milk fatty acid profile but did not affect coagulation and draining properties, cheese composition, or proteolysis. The moisture-adjusted yield and fat and protein recoveries were also similar between treatments. The greater milking frequency did not affect process performance. However, increasing milking frequency led to a significantly higher FFA content in cheese at the end of ripening of 1.4 (SE: 0.2) mEq/kg versus 0.8 (SE: 0.2) mEq/kg of cheese fat for thrice- and twice-daily milkings, respectively. Consequently, dietary supplementation of PA to dairy cows had only a limited effect on the cheesemaking process under the standardized conditions tested. However, the effects of FFA on cheese sensory properties should be considered if the milking frequency is increased.