Table 2. Effect of prepartum control or conjugated linoleic acids (CLA) supplementation on postpartum milk yield, milk component yield and milk composition for dairy cows.

	Treatmentsa			P-value
Itemb	Control	CLA	SEM	Trtc	Time	Trt x timed
Milk yield, kg/d	46.6	47.6	0.45	0.09	<0.01	0.67
Milk component yield
Protein, kg/d	1.38	1.43	0.015	0.01	<0.01	0.69
Fat, kg/d	1.94	2.00	0.026	0.07	<0.01	0.33
Lactose, kg/d	2.28	2.33	0.022	0.12	<0.01	0.71
Milk energye, Mcal/d	35.35	36.36	0.378	0.03	<0.01	0.51
Milk composition
Protein, %	2.98	3.03	0.017	0.01	<0.01	0.75
Fat, %	4.23	4.25	0.039	0.63	<0.01	0.51
Lactose, %	4.82	4.84	0.012	0.29	<0.01	0.22
SCCf, Log10 cells x 1000/mL	1.70	1.68	0.047	0.64	<0.01	0.71

^a Treatments: Control (n = 141) cows supplemented with 78 g of Energy Booster 100 (Milk Specialties Global, Eden Prairie, MN) and CLA (n = 143) cows supplemented with 100 g/day of Lutrell Pure (BASF, Ludwigshafen, Germany). Supplementation was by individual topdress of product mixed with 200 g corn gluten feed for 16 days prepartum.

^b Data from calving to 60 days postpartum, averaged weekly.

^c Treatment.

^d Interaction treatment x time.

^e Energy content of milk was determined using the following equation as described by [14]: [(0.0929 x % milk fat) + (0.0547 x % milk true protein/0.93) + (0.0395 x % milk lactose)] x milk yield.

^f Somatic cells count.