Cheese-making properties and cheese yield of milk from Holsteins and 3-way rotational crossbred cows

Crossbreeding is regarded as a viable strategy to counterbalance the declining fertility, resilience and longevity of purebred Holstein (HO) cows, but knowledge about cheese yield properties of milk from crossbred (CROSS) cows is still scarce. The aim of this study was to investigate the effects of a 3-way rotational crossbreeding (ProCROSS) of Holstein (HO) cows with Viking Red in first (F1, VR×HO), Montbéliarde in second [F2, MO×(VR×HO)], and again HO sires in third generation {F3: HO×[MB×(VR×HO)]} on milk coagulation (MCP), curd firming and curd yield (CY) traits. Milk samples (n=333) were collected once during the morning milking from HO (n=194) and CROSS (n=139: 37 F1, 44 F2, 58 F3) cows reared in a commercial farm located in Northern Italy. Individual milk samples were analyzed for assessing milk composition, single-point MCP and modeling curd-firming over time (CFt) traits, and CY measured through a laboratory cheese-making procedure. Data were analyzed using a linear model including the fixed effects of parity, DIM class and breed combinations. No difference between HO and CROSS was found for milk yield (34.8 kg/d), fat (3.91%), lactose (5.09%), urea (20.6 mg/dl) and pH (6.59). Milk from CROSS cows showed a greater content of protein (3.71 vs 3.60%) and casein (2.89 vs 2.79%) and a smaller SCS (2.81 vs 3.34), without differences among generations. Milk from CROSS cows was also characterized by a more favorable firming time (8.3 vs 9.8 min) and curd firmness at 30 min (20.2 vs 14.8 mm) than HO, whereas some differences in favor of F2 and F3 generations respect to F1 were found for coagulation time and curd firmness after 30 min. The recovery of milk protein in the curd was greater for CROSS cows (80.4 vs 79.4%), whereas recovery of fat and total solids, and CY were not different. Also the daily production of fresh cheese per cow was not different between HO (6.2 kg/d) and CROSS (6.1 kg/d) cows. In conclusion, the 3-way rotational crossbreeding scheme considered allows to obtain daily milk and cheese yield similar to purebred HO breeding and some advantage for milk quality and technological properties. The trial is currently in progress to increase cow sample size and number of herds involved.