The effect of furazolidone on fertility of male chickens.

In mature chickens, furazolidone (0.4% w/w, 10 days) decreased the weight of the testes, but did not affect significantly the concentrations of testosterone in testes and plasma, nor the concentrations of ascorbic acid, protein or cholesterol in the testes. Feeding furazolidone at a concentration of 0.08% w/w for 10 days decreased significantly the weights of the testes, wattles and combs. Treatment also produced significant reductions in the concentration of testosterone in plasma and testes, and some reductions in ascorbic acid, protein and cholesterol concentrations in the testes. Administration of furazolidone by crop tube at doses of 40 or 80 mg/kg for five days caused significant decreases in the concentrations of testicular and plasma testosterone, and reductions in ascorbic acid, protein and cholesterol concentrations in the testes. The sizes of the testes, wattles and combs were also significantly reduced. Monoamine oxidase activity in the testes was significantly inhibited by furazolidone. In all the treated birds testicular concentrations of 5-hydroxy-tryptamine were significantly raised, except in those fed the drug at a dose of 0.04% w/w for 10 days.