Nutrient utilization and growth performance of guinea pigs (Cavia porcellus) exposed to different levels of dietary cadmium

The experiment was aimed to study the effects of dietary cadmium (Cd) concentration on growth and nutrient metabolism in guinea pigs. Forty-eight healthy guinea pigs (30-35d old, mean body weight 297.4±2.76 g) were divided into four dietary groups (n=12 per group) and fed diets added with 0, 1.5, 3.0 and 4.5 mg Cd/kg for 91 days including a metabolism trial which lasted for 4 days. Intake and digestibility of nutrients and balance of calcium and phosphorus were not affected by dietary Cd concentration. However, nitrogen balance decreased and feed conversion efficiency was deteriorated in all the Cd supplemented groups, with significantly (P<0.05) lower values in group fed diet having 4.5 mg Cd/kg as compared with the control group. The average daily gain was also reduced in a linear manner as dietary cadmium content increased (r²=0.98), with significantly (P<0.05) lower values in the groups supplemented with 3.0 and 4.5 mg Cd/kg diet as compared to control group. Results indicated that addition of Cd even at 3 mg/kg level (which is below the presently recommended safe level of 5 mg Cd/kg) in the diet had an adverse effect on growth performance, feed conversion efficiency and N metabolism in the guinea pigs. On the basis of these results it may be deduced that prolonged exposure of dietary Cd even at 3 mg/kg is not safe for the animals.