A diet containing 20 ppm (micrograms/g) of purified deoxynivalenol (DON) was fed to male and female Sprague-Dawley rats for 60 and 15 days, respectively, before breeding. Rats consuming feed amended with DON throughout pregnancy and lactation showed no clinical signs of toxicity, nor did the control or pair-fed control groups. Male rats in the DON treatment group showed no feed refusal but were less efficient than males in control groups in converting feed into body mass. Feed refusal in female rats varied with stage of pregnancy. Before breeding, overall feed consumption was similar in all groups, but in the DON treatment group there was significant feed refusal for the first 2 days. Feed conversion efficiency was reduced in the DON treatment group. Pregnant and lactating rats fed DON-treated feed ate 6% less than did control rats fed solvent-treated feed. Although pair-fed control rats ate 14 to 21% less than rats in the DON treatment group, their body weights were greater than those of the DON group rats throughout most of the feeding trials, indicating that DON has a toxic effect. Only 50% of the matings between DON group rats resulted in pregnancy, compared with 80% in the control groups. There were no differences detected among groups in ratio of male to female pups, survival rate, or average litter number and weight. Pup weight gains in all groups were comparable through postnatal day 14.(ABSTRACT TRUNCATED AT 250 WORDS)