Table I.

Lymphocytes blastogenesis (mean ± SE) in response to 2 concentrations of Con A at study start, 1 and 3 mo after dietary assignment, in adult horses (n = 5 per group) receiving supplementary inorganic selenium (0.3 ppm DM, as sodium selenite), organic selenium (0.3 ppm DM, as Se yeast), or receiving no supplementary selenium (< 0.05 ppm DM)

	Study start	1 month	3 months
Con A 5 μg/mL
No Se	28.2 (3.0)	12.2 (1.8)	42.0 (7.5)
Inorganic Se	35.4 (7.9)	15.6 (3.3)	38.2 (8.9)
Organic Se	33.4 (8.6)	10.6 (2.6)	47.4 (21.0)
Con A 2 μg/mL
No Se	59.6 (8.3)	67.2 (12.2)	70.6 (13.0)
Inorganic Se	78.2 (22.2)	80.4 (17.6)	91.2 (26.6)
Organic Se	84.2 (20.7)	67.4 (7.0)	79.0 (13.9)