Effect of Dietary a L F a L F a on Zearalenone Toxicity and Metabolism in Rats and Swine 1'2

Experiments were conducted with rats and swine to determine the potential of dietary alfalfa as a t rea tment for zearalenone (Z) toxicosis. Ninety-six female weanling Wistar rats were fed a casein-based semipurified diet containing 0, 15 or 25% alfalfa and 0 or 250 /~g Z/g feed. Exposure to Z for 14 d resulted in reduced growth, feed consumption and feed efficiency as well as kidney and liver enlargement and reduced activity of 30ehydroxysteroid dehydrogenase (3~HSD). Z had no effect on uterine weight. Including alfalfa in these diets reduced the inhibitory effects of Z on growth and feed consumption, minimized Z-induced liver enlargement and increased hepatic 3~-HSD activity. Dietary alfalfa also reduced concentrations of residual Z and zearalenots (Z1) in liver. In a second experiment, 108 Yorkshire gilts weighing 8 to 11 kg were fed diets containing 0, 15 or 25% alfalfa and 0, 10, 20 or 40/~g Z/g feed for 4 wk. Z caused uterine enlargement when fed as low as 10/~g/g feed, although no effects were seen in growth rate, feed consumption or feed efficiency. Alfalfa decreased uterine enlargement (P<.05), but caused a depression in feed efficiency (P<.05). Hepatic 3~HSD activity was five times lower in swine than in rats, although activity still tended to decrease with Z and increase with alfalfa feeding. Residues of Z and Z1 in pig liver indicated species