Table 2.

Effect of feeding sodium acetate (NaAc) and an equal carbon mass of calcium butyrate (CaBu) on milk fatty acid composition.

FA, g/100g	Treatment1			SE	P-value
	NaHCO	NaAc	CaBu		trt	time	trt*time2
C4:0	4.24	4.21	4.26	0.065	0.75	<0.001	0.29
C6:0	2.17	2.17	2.21	0.027	0.31	<0.001	0.82
C8:0	1.18	1.19	1.20	0.022	0.37	<0.001	0.34
C10:0	2.58	2.64	2.62	0.057	0.34	<0.001	0.05
C11:0	0.042	0.042	0.042	0.002	0.66	<0.001	0.85
C12:0	2.92	3.00	2.98	0.068	0.18	<0.001	0.03
iso C13:0	0.021	0.020	0.021	0.001	0.77	0.68	0.41
ante-iso C13:0	0.056	0.056	0.059	0.001	0.16	<0.001	0.02
iso C14:0	0.102	0.091	0.082	0.004	<0.001	<0.001	0.06
C14:0	10.1	10.4	10.1	0.12	<0.01	0.12	<0.001
iso C15:0	0.199	0.201	0.202	0.003	0.39	<0.001	0.03
ante-iso C15:0	0.36	0.35	0.35	0.004	0.04	0.35	0.04
C15:0	0.85	0.83	0.85	0.012	0.22	<0.001	0.75
iso C16:0	0.22	0.22	0.19	0.010	0.04	<0.001	0.01
C16:0	25.7	26.6	25.3	0.13	<0.001	0.01	<0.001
iso C17:0	0.26	0.26	0.27	0.005	0.04	<0.001	<0.001
ante-iso C17:0	0.34	0.33	0.34	0.004	0.12	0.002	0.002
C17:0	0.46b	0.45c	0.47a	0.006	0.001	<0.001	0.22
C17:1	0.128b	0.124b	0.133a	0.002	0.01	0.001	0.11
C18:0	12.7	13.0	12.9	0.17	0.42	<0.01	<0.001
trans−9 C18:1	0.33	0.32	0.34	0.011	<0.001	0.18	<0.001
trans−10 C18:1	0.59	0.59	0.66	0.020	<0.001	0.04	<0.01
trans−11 C18:1	1.27a	1.2b	1.27a	0.035	0.01	<0.001	0.25
cis−9 C18:1	19.5	18.8	19.4	0.56	<0.01	<0.001	<0.001
C18:2 n-6	3.12	2.95	3.17	0.097	<0.001	0.06	<0.01
C18:3 n-3	0.47	0.44	0.47	0.017	<0.01	0.25	0.01
cis-9,trans C18:2	0.54a	0.51b	0.53a	0.014	0.01	<0.001	0.12
Σ OBCFA3	3.05a	2.96b	3.03a	0.026	<0.001	<0.001	0.32

¹Treatments were on a dry matter basis: 3.2% NaHCO₃ (control), 2.9% NaAc, and 2.5 % CaBu (carbon equivalent to acetate treatment), n = 12 per treatment. Least-square means that do not share a superscript are significantly different (P < 0.05).

²Main effects of treatment when a treatment by time interaction was detected are described in the text and shown in Supplemental Table S1.

³Odd and branched chain FA.