Table 4.

Determined and predicted digestibility of DM, digested, excreted, absorbed, and available energy in gastrointestinal segments of growing pigs fed the control, flaxseed meal, and oat hulls diets (n = 8)

Item	Diet1			SEM	P
	Control	FM	OH
Determined and predicted DM digestibility2
Determined AID, % (in vivo)	72.4a	59.9b	58.0b	3.10	0.008
Determined ATTD, % (in vivo)	90.6a	86.3b	83.2c	1.55	0.001
Predicted ATTD, % (in vivo–in vitro)	91.2a	88.6a	80.5b	1.05	0.002
Determined and predicted hindgut DM disappearance
Determined disappearance, % (in vivo)	29.3c	39.1a	35.2b	1.12	0.035
Predicted disappearance, % (in vivo–in vitro)	20.1B	33.1A	28.3A	3.06	0.060
Digested energy, kcal/kg DM feed
Stomach and small intestines	3,178.4a	2,805.7b	2,497.7c	60.68	<0.001
Cecum and colon	385.9b	873.2a	386.9b	47.73	0.001
Energy produced from VFA	156.3c	427.8a	215.9b	8.68	<0.001
In vitro production from ileal digesta contents, kcal/kg DM feed
Fecal excretion	5.45b	7.04ab	8.32a	0.687	0.023
Quantity absorbed	154.9c	417.9a	212.2b	7.075	<0.001
Available energy from fermentation, %3	4.5c	14.5a	7.8b	0.426	0.011
Comparison of determined and predicted DM digestibility and disappearance4
P ATTD	0.013	0.082	0.011
SEM	5.67	7.12	5.45
P Hindgut disappearance	0.841	0.101	0.213
SEM	7.16	1.73	4.24

^a,b,cMean values within a row with unlike superscripts differ (P < 0.05). ^A,B,CMean values within a row with unlike superscripts tended to differ (0.05 < P < 0.10).

¹FM = Flaxseed meal-containing diet; OH = Oat hulls-containing diet.

²AID = Apparent ileal digestibility; ATTD = Apparent total tract digestibility.

³Percentage of total available energy (total available energy is the sum of energy digested at the end of ileum and energy absorbed as VFA). Energy absorbed as VFA is the difference between energy produced in vitro from VFA and that excreted in the feces (Iyayi and Adeola, 2015).

⁴ P _ATTD and P_{Hindgut disappearance} are the P values for comparing the determined and predicted ATTD and Hindgut disappearance of DM, respectively.