Table 3 Total VFAs (mg/100 ml) and individual VFAs expressed as a percentage (%) of total VFAs in the different intestinal compartments of the equine digestive tract according to the dietary treatment received (HS vs. HF)

SI

Total VFAs

182.82 (130.20–235.04)

176.81 (142.89–238.49)

0.99

0.52

0.90

Succinic

11.09 (3.00–14.29)

3.86 (0–16.87)

0.29

0.47

0.80

Lactic

5.23 (3.60–7.83)

5.62 (2.96–26.27)

0.76

0.19

0.46

Formic

0 (0–1.04)

0 (0–2.59)

0.92

0.05

0.92

Acetic

55.37 (4.15)

51.32 (5.44)

0.63

0.54

0.65

Propionic

0 (0–0)

0 (0–0)

0.74

0.26

0.74

Iso-butyric

24.84 (11.05–32.57)

16.41 (11.63–24.66)

0.55

0.02*^a

0.50

Butyric

0 (0–0)

0 (0–0)

1.00

1.00

1.00

Iso-valeric

0 (0–0)

0 (0–0.80)

0.38

0.38

0.38

Valeric

0 (0–0)

0 (0–0.88)

0.59

0.64

0.75

CAE

Total VFAs

510.72 (261.05–771.56)

389.17 (290.76–462.55)

0.57

0.95

0.30

Succinic

0 (0–0)

0 (0–0)

0.84

0.36

0.84

Lactic

5.90 (2.43–6.84)

3.57 (2.79–6.65)

0.55

0.74

0.66

Formic

0.50 (0.22–0.91)

0 (0–0.99)

0.10

0.01*^b

0.97

Acetic

20.19 (14.00)

30.16 (1.07)

< 0.01*

0.88

0.53

Propionic

4.19 (3.69–5.31)

9.05 (6.91–10.72)

< 0.01*

0.32

0.79

Iso-butyric

45.09 (43.05–52.16)

51.84 (47.31–56.48)

< 0.01*

0.11

0.90

Butyric

2.01 (1.66–2.18)

3.79 (2.85–4.23)

< 0.01*

0.31

0.54

Iso-valeric

0 (0–0)

0 (0–0)

0.38

0.38

0.38

Valeric

19.26 (15.00–27.36)

0 (0–0)

< 0.01*

0.64

0.64

SF

Total VFAs

838.11 (622.74–1054.03)

436.14 (381.38–489.42)

< 0.01*

0.87

0.09

Succinic

0 (0–1.21)

0.50 (0.31–0.95)

0.19

0.35

0.79

Lactic

5.70 (0.10–6.66)

6.73 (4.88–12.33)

0.06

0.62

0.36

Formic

0.32 (0.27–1.11)

0.65 (0–1.48)

0.74

0.58

0.47

Acetic

17.71 (1.51)

33.42 (1.73)

< 0.01*

0.29

0.08

Propionic

3.80 (2.55–4.44)

8.67 (7.01–9.74)

< 0.01*

0.40

0.63

Iso-butyric

39.29 (37.77–42.78)

43.90 (36.91–49.68)

0.31

0.34

0.95

Butyric

2.72 (2.54–3.26)

6.19 (5.35–7.29)

< 0.01*

0.52

0.29

Iso-valeric

0 (0–0.14)

0 (0–0)

0.51

0.37

0.69

Valeric

30.74 (26.19–36.94)

0 (0–0)

< 0.01*

0.06

0.06

PF

Total VFAs

897.97 (804.56–1121.135)

303.72 (235.53–342.82)

< 0.01*

0.30

0.50

Succinic

0 (0–0.68)

0.47 (0–1.42)

0.50

0.52

0.17

Lactic

1.94 (0.23–3.92)

1.93 (0.90–2.44)

0.92

0.96

0.21

Formic

0 (0–0.65)

0.23 (0–1.19)

0.51

0.68

0.25

Acetic

13.93 (1.58)

36.61 (0.75)

< 0.01*

0.27

0.49

Propionic

2.48 (2.23–3.64)

9.60 (8.08–10.82)

< 0.01*

0.22

0.75

Iso-butyric

36.44 (32.23–42.31)

47.17 (43.81–48.63)

< 0.01*

0.28

0.04*^c

Butyric

2.04 (1.31–2.30)

4.10 (2.54–5.45)

< 0.01*

0.13

0.72

Iso-valeric

0 (0–0.20)

0 (0–0.47)

0.88

0.94

0.99

Valeric

43.34 (36.43–43.32)

0 (0–0)

< 0.01*

0.33

0.33

RDC

Total VFAs

835.54 (672.89–1090.51)

284.62 (202.24–340.58)

< 0.01*

0.58

0.41

Succinic

0.10 (0–0.56)

0 (0–0.60)

0.46

0.10

0.88

Lactic

0.25 (0–3.29)

3.03 (1.40–3.80)

0.07

0.58

0.60

Formic

0 (0–0.19)

0 (0–0.21)

0.76

0.63

0.25

Acetic

15.93 (1.86)

36.31 (2.29)

< 0.01*

0.16

0.72

Propionic

3.40 (2.73–3.84)

8.92 (6.84–9.46)

< 0.01*

0.40

0.52

Iso-butyric

39.10 (25.67–41.05)

46.62 (41.49–56.17)

< 0.01*

0.14

< 0.01*^d

Butyric

1.78 (1.44–4.16)

3.20 (2.35–4.16)

< 0.01*

0.56

0.98

Iso-valeric

0.18 (0–0.59)

0 (0–0)

0.06

0.13

0.43

Valeric

39.25 (36.39–52.21)

0 (0–0)

< 0.01*

0.33

0.33

RE

Total VFAs

605.76 (585.70–916.29)

195.39 (134.52–295.35)

< 0.01*

0.21

0.83

Succinic

0 (0–1.02)

0 (0–0)

0.08

0.58

0.58

Lactic

3.04 (0.34–5.89)

3.32 (2.14–4.13)

0.61

0.08

0.28

Formic

0 (0–0.23)

0 (0–1.06)

0.70

0.08

0.70

Acetic

13.13 (1.37)

28.82 (1.69)

< 0.01*

0.05

0.71

Propionic

2.08 (1.93–3.72)

6.61 (5.89–8.80)

< 0.01*

0.49

0.31

Iso-butyric

37.12 (30.67–52.77)

62.16 (53.42–64.11)

< 0.01*

0.29

0.03*^e

Butyric

1.45 (0.79–2.11)

2.00 (0.93–2.60)

0.92

0.17

0.95

Iso-valeric

0 (0–0)

0 (0–0)

0.26

0.26

0.26

Valeric

44.59 (19.98–51.79)

0 (0–0)

< 0.01*

0.11

0.11