Chronic toxicity of dietary fluorine to mink

Seventy-two 3-mo-old pastel mink were fed diets that contained 0, 33, 60, 108, 194 or 350 ppm supplemental fluorine (F), as NaF, for 382 d to assess its effects on growth, fur quality, reproduction and survivability. The basal diet contained 35 ppm F as fed. No significant differences were observed in body weight gains or fur quality between the controls and any of the F-treated groups (P greater than .05). Some males fed 350 ppm supplemental F for a 4-mo period prior to pelting had weakened frontal, parietal and femoral bones that fractured during the pelting process. The F treatments had no measurable adverse effects on breeding, gestation, whelping or lactation, although only 14% of the kits whelped by females fed 350 ppm F survived to 3 wk of age. The survivability of the adult mink was adversely affected only at 350 ppm supplemental F. At the termination of the study, no differences were observed in hematologic parameters or serum calcium concentrations between the controls and treated mink (P greater than .05), but serum alkaline phosphatase activities were increased (P less than .05) by the two highest dietary F levels. Serum F levels were elevated (P less than .01) only in mink fed 194 and 350 ppm F, and urinary and femoral F concentrations in the treated animals were generally greater (P less than .05; P less than .01) than control values and were closely related with dietary F levels. Femoral ash contents of the 194 and 350 ppm F-treated mink were less than the control values (P less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)