Adult female mink were fed diets containing 0 (control), 6.25, 12.5, and 25 ppm (micrograms/g) technical grade
heptachlor prior to and throughout the reproductive period (181 days) to evaluate the effects of
heptachlor consumption on reproduction and offspring viability and to assess the extent of placental and mammary transfer of
heptachlor epoxide to mink offspring. Feeding 12.5 and 25 ppm resulted in significant reductions in feed consumption and
body weights of female mink. Mortality was 0, 8, 67, and 100% for the control, 6.25, 12.5, and 25 ppm groups, respectively. All females in the 25 ppm group died within 88 days. Mink fed the two higher
heptachlor diets displayed clinical signs indicative of central nervous system involvement just prior to death. Females were mated with males on the same dietary treatments. Whelping success rates were 67, 83, 27, and 0% for the control, 6.25, 12.5, and 25 ppm groups, respectively. High mortality in the 12.5 and 25 ppm groups accounted for the lack of reproductive success. Gestation length, litter size and
birth weight of kits were not significantly affected by adult female consumption of 6.25 ppm
heptachlor while kits helped by females on the 12.5 ppm diet weighed significantly less than control kits at birth. Survival of kits in the 12.5 ppm group from birth to three weeks of age was also adversely affected. At three and six weeks of age, kit
body weights in both the 6.25 and 12.5 ppm groups were significantly less than
body weights in control kits.(ABSTRACT TRUNCATED AT 250 WORDS)