Rotational 3-breed crossbred cows of Montbeliarde, Viking Red, and Holstein (ProCROSS) were compared with Holstein cows for feed efficiency and residual feed intake (RFI) during the first 150 d of first, second, and third lactation. Primiparous and multiparous crossbred (n = 63 and n = 43, respectively) and Holstein (n = 60 and n = 37, respectively) cows were fed the same TMR twice daily with refusals weighed once daily. Feed was analyzed for dry matter, net energy of lactation, and crude protein content. Fat and protein production were estimated from monthly test days with Best Prediction. Body weight was recorded twice weekly. Measures of 150-d efficiency were fat plus protein production (F+P) per unit of DMI, ECM per unit of DMI, DMI per unit of BW, ECM per unit of net energy of lactation intake (NEI), protein production per unit of crude protein intake (CPI), and income over feed cost (IOFC), which was revenue from F+P minus feed cost. The RFI for each lactation was the residual error remaining from regression of DMI on milk energy output (mcal), metabolic BW, and change in body energy (mcal). Statistical analysis of feed efficiency and RFI for primiparous cows included the fixed effects of year and breed and, for multiparous cows, breed was a fixed effect and cow was a repeated effect. Both primiparous and multiparous crossbred cows had higher mean F+P, ECM, and protein per unit of DMI, NEI, and CPI, respectively, compared with primiparous and multiparous Holstein cows (Table 1). Also, both primiparous and multiparous crossbred cows had higher mean IOFC compared with Holstein cows (Table 1). Mean RFI was significantly lower (more desirable) for both primiparous and multiparous crossbreds compared with Holsteins. Table 1. Feed efficiency between primiparous and multiparous crossbred and Holstein cows

Item	Primiparous			Multiparous
Holstein	Crossbred	Holstein	Crossbred
F+P/DMI	0.11	0.12**		0.12	0.13**
ECM/DMI	1.70	1.77**		1.89	2.01*
ECM/NEI	1.05	1.09*		1.16	1.23*
Protein/CPI	0.30	0.32**		0.32	0.35**
DMI/BW	5.31	5.03**		5.57	5.31*
IOFC	$825	$875**		$1208	$1296*
RFI	68.8	−65.5**		75.0	−64.5*

**P<0.01, *P<0.05 for differences between breed groups.