Table 2. Milk and ECM from high-yielding and low-yielding dairy cows during the entire sampling period¹.

Items	LY	HY	SEM	P-value
DMI (kg/d)	23.4	25.6	0.43	0.0347
Milk production (kg/d)	19.3	31.9	1.76	<0.0001
4%FCM production (kg/d)2	18.95	29.20	1.73	<0.0001
ECM production (kg/d)3	21.07	32.09	1.93	<0.0001
Milk composition
Fat %	4.02	3.48	0.28	0.0788
Fat yield (kg/d)	0.75	1.10	0.07	0.0004
Protein %	3.50	3.07	0.11	0.0023
Protein yield (kg/d)	0.66	0.98	0.06	0.0002
Lactose %	4.87	5.05	0.14	0.2127
Lactose yield (kg/d)	0.92	1.61	0.10	<0.0001
Total solid content %	13.15	12.30	0.38	0.0417
SCC (log10)	2.46	3.10	2.78	0.1339

¹Data are presented as least squares means.

SCC = somatic cell count.