Table 6.

Effects of the experimental diets and age on intestinal morphology and enzyme activity

	Diets				Age			SEM1					P-value2
	C	Arg	Gln	Arg + Gln	6	25	35	Arg and Gln	Arg × Gln	Age	Arg × Age and Gln × Age	Arg × Gln × Age	Arg	Gln	Arg × Gln	Age
Arginine	0	0.4	0	0.4
Glutamine	0	0	0.4	0.4
N	31	32	32	32	48	40	39
Villous height, μm	609	580	577	575	620b	510a	626b	13.6	19.2	16.6	23.5	33.2	0.44	0.34	0.48	< 0.001
Crypt depth, μm	68.5	67.4	67.8	66.4	38.1a	80.2b	84.2c	0.71	1.01	0.87	1.23	1.74	0.21	0.42	0.86	< 0.001
Ratio villous/crypt	10.2	10.0	9.94	9.96	16.3c	6.36a	7.38b	0.22	0.31	0.27	0.38	0.53	0.76	0.61	0.71	< 0.001
Goblet cells, no/villi	13.7	12.8	12.7	12.7	2.94a	14.5b	21.6c	0.38	0.53	0.46	0.65	0.92	0.41	0.30	0.42	< 0.001
Mucose protein, mg/g of tissue3	103	105	102	105	–	102	106	2.80	3.96	2.79	3.95	5.59	0.51	0.86	0.80	0.36
Sucrose activity, μmol of glucose/mg of protein1	390	386	314	352	–	116	605	37.8	53.4	37.7	53.4	75.5	0.76	0.31	0.70	< 0.001

¹SEM standard error of the mean

²No significant differences (P ≥ 0.22) were found for Arg × Age and Arg × Gln × Age interactions. However, a significant (P = 0.019) interaction Gln × Age was found for villous height and it is represented in Fig. 1

³N = 9 at 25 d of age and N = 10 at 35 d of age

^a-cDiet mean values in the same row with a different superscript differ P < 0.05