Table 2.

Effect of concentrate supplementation and cow strain and their interactions on milk production performance and feed intake

	Conc0		Conc6			P-value
Items	HCH	HNZ	HCH	HNZ	SD	Treatment	Cow strain	Interaction
Milk production performance
Milk yield (kg/d)	24.9A	23.0B	30.0C	26.0D	4.8	<0.001	0.04	0.02
Milk yield concentrate 1 (kg/kg)			0.84a	0.50b	0.30		0.04
ECM 2 (kg/d)	22.8A	22.6A	25.3B	23.9B	3.8	<0.001	0.41	0.16
Fat (%)	3.7A	4.0A	3.0B	3.4B	0.6	<0.001	0.08	0.50
Protein (%)	3.2A	3.4B	3.2A	3.5B	0.3	0.13	<0.01	0.96
Lactose 3 (%)	4.4	4.4	4.5	4.5	0.3	0.39	0.50	0.74
Acetone (mg/l)	2.87A	2.53A	1.52B	1.36B	0.79	<0.001	0.27	0.68
Urea (mg/l)	239A	226A	178B	176B	30.0	<0.001	0.49	0.34
Feed intake
Pasture DMI (kg DM/day)	12.5A	11.7A	9.7B	9.0B	1.7	<0.001	0.09	0.83
Total DMI (kg DM/day)	12.5A	11.7A	15.0B	14.3B	1.7	<0.001	0.09	0.83
Calculated pasture DMI 4 (kg DM/day)	17.3A	16.9A	12.0B	11.0B	2.4	<0.001	0.23	0.17
Calculated total DMI 5 (kg DM/day)	17.3	16.9	17.3	16.3	2.4	0.23	0.23	0.17

Conc0=cows without concentrate supplementation; Conc6=cows with concentrate supplementation; HCH=Swiss Holstein-Friesian; HNZ=New Zealand Holstein-Friesian; DMI=dry matter intake; DM=dry matter.

^A,B,C,DMeans with different superscript letters within the same row differ (P<0.01).

^a,bMeans with different superscript letters within the same row differ (P<0.05).

¹ Milk yield per ingested concentrate (kg/kg).

² ECM=energy-corrected milk yield (Agroscope, 2013).

³ Log₁₀ transformed for statistical analyses.

⁴ According to Agroscope (2013) and Baker (2004) without BW changes and activity.

⁵ According to Agroscope (2013) and Baker (2004) without BW changes and activity plus 5.3 kg DM of concentrate.