Fatty Acids
(%)

 

June

 

July

 

September

Main Effects

Breed

Lactation

Time

Breed x
Time

Lacation x Time

ΣSFAy

61.42 ±   0.55b

61.19 ±   0.58b

64.04 ±   0.47a

NS

NS

0.0055

NS

NS

  C10:0

1.72 ±   0.08b

2.20 ±   0.11a

2.18 ±   0.11a

NS

0.0012

0.0129

NS

0.0417

  C12:0

2.68 ±   0.10b

3.20 ±   3.24a

3.24 ±   0.08a

NS

NS

0.0013

NS

NS

  C14:0

10.35 ±   0.22

10.72 ±   0.46

11.34 ±   0.13

NS

NS

NS

NS

NS

  C15:0

1.25 ±   0.04

1.35 ±   0.04

1.29 ±   0.03

0.0457

NS

0.0317

NS

NS

  C16:0

26.90 ±   0.42b

25.44 ±   0.52b

29.61 ±   0.39a

0.0215

NS

0.0001

NS

NS

  C18:0

10.72 ±   0.46a

10.53 ±   0.4a

8.90 ±   0.29b

NS

NS

0.0455

NS

NS

  C20:0

0.69 ±   0.05a

0.69 ±   0.01a

0.24 ±   0.06b

NS

NS

<0.0001

NS

NS

ΣMUFA

26.39 ±   0.63

24.99 ±   0.54

24.06 ±   0.42

NS

NS

NS

NS

NS

  C14:1

0.98 ±   0.05

1.07 ±   0.07

1.12 ±   0.07

NS

0.0130

NS

NS

NS

  C16:1n9

0.94 ±   0.05b

1.11 ±   0.05a

1.21 ±   0.07a

NS

NS

0.0023

NS

NS

  C18:1n9

19.20 ±   0.62

17.97 ±   0.53

18.54 ±   0.36

NS

0.0455

NS

NS

0.0433

  C20:1n9

0.40 ±   0.04a

0.50 ±   0.03a

0.19 ±   0.01b

NS

NS

<0.0001

NS

NS

ΣPUFAx

4.24 ±   0.11

4.18 ±   0.11

4.44 ±   0.13

NS

NS

NS

NS

NS

  C18:3n3

0.25 ±   0.04b

0.15 ±   0.01b

0.80 ±   0.06a

NS

NS

<0.0001

NS

NS

Σn-9

20.14 ±   0.63

19.08 ±   0.52

19.75 ±   0.35

NS

0.0323

NS

NS

NS

Σn-6

2.39 ±   0.09

2.30 ±   0.09

2.34 ±   0.09

NS

0.0061

NS

NS

NS

Σn-3

0.25 ±   0.04b

0.15 ±   0.01b

0.80 ±   0.06a

NS

NS

<0.0001

NS

NS

zMeans ± SEM, n=39. Different superscript letters indicate differences over time by contrasts (p<0.05); NS=not significant; %=g/100 g fatty acids. Only fatty acids< >0.5% reported. Means for significant main effects of breed and lactation are provided in the text.
yTotal SFA includes estimates for C4:0, C6:0 and C8:0 (3.0%, 2.0% and 1.5%, respectively) as explained in the methods.
xData for vaccenic acid, conjugated linoleic acid and linoleic acid are shown in Figure 1
Table 3: Milk fatty acid composition during the grazing periodz.