EFFECTS OF RARE EARTH NITRATE ON INTERNAL ORGANS AND MINERAL ELEMENTS IN THE SERUM OF BROILER CHICKENS

This paper reports the effects of rare earth nitrate (REN) on the growth of internal organs and mineral elements in serums of broiler chickens. The REN used is mixture of light RE containing mainly La, Ce, Pr and Nd 4 elements. 40 eight-week old AA broiler chickens were divided randomly into four groups that their treatments were respectively 0, 20, 200 and 2000 mg REN/kg feed and the duration of the experiment was 60 days. Responses were measured in terms of internal organic weight and tissue, contents of mineral elements in serums. There were no significant differences between the organ ratios and tissue changes of the 20, 200 mg REN/kg groups and the control group. The organs included the heart, liver, kidneys, lungs, testicles, thyroids, adrenal glands, pancreas, tonsies of caecum, stomachus glandularis, duodenum, ileum and bursa of Fabricius. The liver and thyroid indices of 2000 mg REN/kg group were significantly higher than those of the control group (p < 0.01, p < 0.05) and the adrenal gland index lower (p < 0.05). The pathlolgic changes in the heart, kidney and thyroid were more serious than that of the control group. No significant differences occurred between the contents of K, Na, Mg elements in the serum of all groups, with the exception of the content of Ca, which was higher in the 2000 mg/kg group (p < 0.05). The contents of all trace elements including Mn, Zn and Cu, but except Fe, in the serums of all the treated groups were significantly higher than those of the control group (p < 0.01).