Supplementation of vitamin E or a botanical extract as antioxidants to improve growth performance and health of growing pigs housed under thermoneutral or heat-stressed conditions

Table 3 Intestinal histology and immunohistochemistry in pigs exposed to thermo-neutral and heat-stressed environments and provided antioxidants in feed or water^a

Item	Environment^b								SEM	P-value^c
	Thermo-neutral				Heat-stressed					P-value^c
	CON	VEW	VEF	POL	CON	VEW	VEF	POL		E	S	E × S
Villus height, μm
Jejunum	425	381	464	402	368	359	378	394	28.9	0.119	0.368	0.514
Ileum	337	333	326	313	310	295	332	318	32.9	0.638	0.968	0.870
Villus width, μm
Jejunum	167	155	174	168	166	153	163	156	8.3	0.391	0.314	0.882
Ileum	156	175	160	163	152	162	176	182	11.0	0.686	0.253	0.286
Crypt depth, μm
Jejunum	148	134	138	150	130	134	106	131	11.0	0.133	0.300	0.516
Ileum	158	126	137	158	134	128	114	161	17.7	0.493	0.204	0.788
Villus:crypt ratio
Jejunum	2.92	3.08	3.39	2.77	2.90	2.81	3.66	3.08	0.233	0.652	0.046	0.645
Ileum	2.53	3.03	2.34	2.13	2.49	2.48	3.06	2.35	0.337	0.889	0.590	0.455
Enterocyte proliferation, Ki67^d
Jejunum, %	43.7	38.4	41.9	41.2	48.1	47.7	48.1	45.6	2.31	0.037	0.534	0.660
Ileum, %	47.5	44.5	43.5	47.5	47.9	49.8	52.2	44.7	2.14	0.150	0.831	0.043

^aValues are least square means of 8 pigs. Dietary treatments consisted of control diets (CON), vitamin E supplementation in water (VEW), vitamin E supplementation in feed (VEF), and botanical extract supplementation in feed (POL). Dietary and water treatments were provided starting on d −7 and environmental treatments started on d 0 until d 28
^bTemperatures were set at the following time points: 2400, 0200, 0400, 0600, 0800, 1000, 1200, 1400, 1600, 1800, 2000, and 2200 h. Temperatures for the thermo-neutral room were 18.9, 18.9, 20.0, 20.0, 21.1, 21.1, 22.2, 22.2, 21.1, 21.1, 20.0, and 20.0 °C, and for heat-stressed room they were 28.3, 29.4, 29.4, 31.1, 32.8, 33.3, 34.4, 35.6, 34.4, 31.7, 29.4 and 29.4 °C
^cEffects abbreviations: E = environment, S = supplementation, E × S = environment × supplementation
^dProliferation was evaluated by staining crypt cells with Ki67 antibody. Ki67 is a protein in the nucleus of proliferating cells

ISSN: 2049-1891