Lactation curves of Montbéliarde-sired and Viking Red-sired crossbred cows and their Holstein herdmates in commercial dairies.

In recent years, the Montbéliarde (MO), Viking Red (VR), and Holstein (HO) breeds have been marketed for three-breed rotational crossbreeding. The MO and VR breeds have placed more selection emphasis on fertility, health, and longevity for decades than has the HO breed, while maintaining substantial selection emphasis on increased milk solids. Research on lactation-curve characteristics of crossbred dairy cows is however limited. Also, the persistency of production for MO-sired and VR-sired crossbred cows compared with their HO herdmates has not been studied. Therefore, the objective of the study cited was to compare the lactation-curve characteristics and persistency of production for MO-sired and VR-sired crossbred cows compared with their HO herdmates, as estimated from test-day observations.

The test-day observations from milk recording for crossbred cows and their HO herdmates were analysed in first, second, and third lactations. The data included 8 020 lactations. Lactation curves were estimated for MO × HO and VR × HO two-breed crossbred cows and for MO × VR/HO and VR × MO/HO three-breed crossbred cows and their HO herdmates from test-day observations in seven high-performance herds that participated in a designed study. Test-day observations from milk recording were used to fit the lactation curves of cows in their first three lactations. Lactations of cows were required to have at least 250 days in milk (DIM). Lactation curves from random regression (RR) were compared for 305-d production (kg), peak production (kg), peak day of production, and production from four to 103 DIM (kg), from 104 to 205 DIM (kg), and from 206 to 305 DIM (kg) for milk, fat, and protein. Also, the persistency of production was compared. First-lactation versus second- and third-lactation cows were analysed separately for both the two-breed and three-breed crossbred cows and their respective HO herdmates.

The lactation curves as estimated from RR are shown in the Figure below. The statistically analysed results showed the following: For milk production of first-lactation cows, the MO × HO two-breed crossbreds were not significantly different from their HO herdmates for any of the lactation-curve characteristics, except persistency. However, the VR × HO two-breed crossbreds had significantly less milk production compared with their HO herdmates. For first lactation, the MO × HO two-breed crossbreds and the first-lactation MO × VR/HO three-breed crossbreds had more persistency of milk production compared with their HO herdmates. For second and third lactations, both the MO × HO and the VR × HO two-breed crossbreds had higher fat production compared with their HO herdmates. Furthermore, the MO × HO two-breed crossbreds had more protein production (kg) in all three periods of lactation compared with their HO herdmates.

Conclusions: The two-breed crossbreds generally had more persistency of production compared with their Holstein herdmates, and more persistency of production is often preferred by dairy producers. Although in this study only cows from the first two generations of a continuous two-breed rotation for crossbreeding were considered, the results suggest crossbred cows of the Montbéliarde, Viking Red, and Holstein breeds may have advantages over Holstein cows for persistency of production in high-performance herds. This is of significance, bearing in mind that the Montbéliarde and Viking Red breeds have also placed more selection emphasis on fertility, health, and longevity than the Holstein breed, while maintaining substantial selection emphasis on increased milk solids.