Table 3.

Effects of feeding medium-chain fatty acid on milk composition of early lactation and peak lactation cows².

Variable	Treatment1		SEM	P-value
	CON	MCFA		Treatment	Time	Treatment ×Time
Early lactation
Milk fat percentage (%)	4.62	5.07	0.152	0.09	<0.01	0.49
Milk protein percentage (%)	3.28	3.11	0.063	0.13	<0.01	0.43
Mile lactose percentage (%)	5.17	5.18	0.034	0.94	0.37	0.76
Milk fat yield (kg/d)	1.71	1.62	0.053	0.42	0.27	0.72
Milk protein yield (kg/d)	1.24a	1.03b	0.044	<0.01	0.03	0.24
Milk lactose yield (kg/d)	1.98a	1.76b	0.071	0.03	<0.01	0.62
MUN3 (mg/dL)	19.76	17.63	1.014	0.32	0.36	0.88
SCC3 (×1000/mL)	197.07	43.00	41.458	0.32	0.09	0.72
Peak lactation
Milk fat percentage (%)	4.36	4.61	0.142	0.31	0.01	0.07
Milk protein percentage (%)	3.24	3.22	0.038	0.85	0.26	0.59
Milk lactose percentage (%)	5.28	5.25	0.022	0.48	0.61	0.01
Milk fat yield (kg/d)	1.90	2.01	0.059	0.32	0.01	0.26
Milk protein yield (kg/d)	1.48	1.42	0.034	0.46	0.88	0.42
Milk lactose yield (kg/d)	2.46	2.28	0.056	0.11	0.56	0.13
MUN (mg/dL)	19.29	18.88	0.795	0.80	0.32	0.29
SCC (×1000/mL)	69.00	57.18	13.909	0.12	0.52	0.22

SEM, standard error of mean.

^a-bMeans within a row with unlike superscripts differ (P ≤ 0.05).

¹CON, control treatment, basic diet with no medium chain fatty acids, n = 9. MCFA, MCFA treatment, basic diet and medium chain fatty acids 20 g/d, n = 9.

²Early lactation = from 1 d to 28 d after calving, Peak lactation, from 29 d to 70 d after calving.

³MUN, milk urea nitrogen, SCC, somatic cell count.