Table 11.

Morphology and crypt cell proliferation in the jejunum of nursery pigs fed diets with increasing levels of xylanase

Item	Xylanase, XU per kg feed					SEM	P-value
	0	220	440	880	1,760		Linear	Quad1	0 vs. Xyl2
Villus height, μm	314	350	357	355	363	20	0.169	0.310	0.073
Villus width, μm	96	97	108	107	104	5	0.197	0.060	0.114
Crypt depth, μm	110	108	109	114	121	7	0.107	0.736	0.659
VH:CD ratio3	2.95	3.27	3.29	3.17	3.03	0.21	0.774	0.324	0.323
Ki-67 positive, %4	37.2	37.3	39.5	37.1	33.5	2.5	0.123	0.289	0.862

Quadratic.

Xylanase (220 + 440 + 880 + 1,760 XU per kg feed).

Villus height to crypt depth ratio.

Ratio of Ki-67 positive cells to total cells in the crypt.