EFFECT OF SUPPLEMENTAL BORON ON NUTRIENT UTILIZATION, MINERAL STATUS AND BLOOD BIOCHEMICAL-CONSTITUENTS IN LAMBS FED HIGH FLUORINE DIET

To investigate the effect of supplemental boron (B) as an antidote of fluorine (F), on nutrient utilization, mineral status and blood bioche mical constituents in lambs, two experiments were conducted: the first with 20 male lambs (about 4 months old) over 190 days, the second wit h 24 male lambs of similar age over 120 days. In both experiments the lambs, divided into four equal groups, were fed conventional concentra te mixtures and gram straw, to which were added F (sodium fluoride) fo r Groups 2, 3 and 4, and B (sodium tetraborate) for Groups 3 and 4. F intakes were similar in both experiments, but B supplementation of Gro ups 3 and 4 was higher in Experiment II (0.56 and 0.79 mg/mgF) than in Experiment I (0.40 and 0.50 mg/mgF). Body weights, dry matter intakes , mineral status and blood biochemical constituents were recorded. The results indicate that supplemental B increased faecal F excretion, an d might also reduce the blood F level, but could not overcome the adve rse effect of F on dry matter intake. However, the reduction in body w eight gain caused by F was improved by increasing levels of dietary B. Absorption of F was greater with high F diets, but supplemental B red uced the absorption of F by increasing its faecal excretion. Faecal ex cretion of copper increased with increased F intake, but appeared to b e counteracted by B supplementation. The dietary treatments had no app arent adverse effects on blood mineral status and blood biochemical co nstituents. Supplemental B had a beneficial effect in counteracting ad verse effects of F on body weights and feed efficiency.