Table 5.

Fatty acid profile of milk of dairy cows grazing grass, forb, and legume-based pastures in period 1 (April 29 to May 19) and period 2 (May 19 to June 6)

							P-values*
Milligrams/100 mg	Grass	Forb	Legume	Period 1	Period 2	SEM	Pas	Per	P × P
C10:0	0.71	0.95	0.94	0.49b	1.24a	0.11	0.21	0.01	0.49
C12:0	2.30b	2.91a	2.57ab	2.30b	2.90a	0.17	0.05	0.01	0.72
C14:0	11.5	11.6	11.5	11.8	11.4	0.25	0.88	0.18	0.45
C14:1	2.31	2.28	2.25	2.32	2.24	0.06	0.76	0.21	0.72
C16:0	34.8	34.0	35.2	35.9a	33.5b	0.64	0.45	0.01	0.17
C16:1	2.33a	1.93b	2.09b	2.18	2.05	0.08	0.01	0.17	0.09
C18:0	15.0a	14.1b	14.1b	14.4	14.4	0.21	0.01	0.97	0.20
C18:1n9t	2.69	2.20	2.40	2.19b	2.67a	0.20	0.21	0.05	0.20
C18:1n9c	21.8	20.8	20.9	21.7	20.7	0.48	0.29	0.10	0.33
C18:2n6c	1.17c	2.41a	1.77b	1.91a	1.66b	0.09	0.01	0.02	0.11
C20:0	0.68	0.86	0.78	0.85a	0.70b	0.06	0.11	0.03	0.01
Other FA	4.74b	5.88a	5.49a	4.09	6.65	0.24	0.01	0.01	0.22
SFA1	65.0	64.5	65.1	65.6	64.0	0.76	0.85	0.08	0.11
MUFA2	29.1	27.2	27.7	28.3	27.7	0.63	0.09	0.34	0.22
De novo3	37.1	38.7	38.6	37.9	38.4	0.87	0.31	0.66	0.37
Preformed3	61.6	61.3	61.4	62.1a	60.7b	0.44	0.87	0.02	0.22
Δ9 14:04	0.17	0.16	0.16	0.16	0.16	0.004	0.78	0.82	0.23
Δ9 16:04	0.062a	0.054b	0.056b	0.057	0.058	0.002	0.01	0.43	0.03
Δ9 18:04	0.59	0.60	0.59	0.60	0.59	0.01	0.78	0.41	0.37
Δ94	0.30	0.29	0.29	0.30	0.30	0.01	0.57	0.94	0.14

¹Sum of saturated fatty acids.

²Sum of monounsaturated fatty acids.

³De novo synthetized fatty acids = sum of fatty acids with chain-length <16 + 50% of C16:0 and 50% of unknown fatty acids; preformed is all fatty acids – de novo fatty acids.

⁴Delta 9 desaturase indexes calculated as the sum of delta-9 unsaturated fatty acid/[delta-9 unsaturated fatty acid + saturated fatty acid] for C14:0, C16:0, and C18:0 separated and as a sum of the three (Δ9).

^a,bMeans within a row and category with different superscripts differ (P < 0.05).

*Pas, pasture; Per, period; P × P, pasture and period interaction; SEM, standard error for interaction.