The effect of various copper sources on the trace elements profile in the hair, plasma and faeces and copper activity in the organism of horses

Abstract

In our experiment with 20 mares (3.6–19.8 years old) divided into 3 groups we evaluated the effect of supplementation with various sources of copper on the trace elements profile in the hair, blood plasma and faeces and copper activity in the organism of horses. The horses were stabled in box stalls (similar dimension) with feeding pump, with the access to a paddock or walker. All mares received the same basic feed ration that was supplemented with various form of copper (Cu in the organic form – proteinate - Bioplex Cu vs. Cu in the inorganic form – CuSO4.5H2O) in amount of 120 mg per day for the mares in experimental groups. The contents of trace elements in hair and faeces were established using the atomic absorption spectrometry; in the plasma using direct colorimetric determination.Significant difference between mares receiving copper in organic and inorganic form (P < 0.05) was detected in the blood levels of copper and iron. In both experimental groups a supplement of copper increased its level in the hair as compared to the control group; however this increase was statistically significant (P < 0.01) only if the inorganic form of copper was supplemented. The iron content of mares hair apparently varied not only with minerals intake, but also with the condition of kept. The differences of copper concentration in the faeces among the mares of experimental groups with regard to control group were significant (P < 0.01). An excessive amount of copper evidently reduced the absorption of zinc and iron in mares with addition of copper sulphate.The mares receiving Bioplex-Cu excreted lower amount of copper in the faeces. These had well-balanced levels of Cu in the plasma and deposited less Cu in the hair than the mares with addition of copper sulphate. In our experiment, it seems to be better available copper in the organic form than in the inorganic form for the organism of horses.Nevertheless, interpretation of these results is very difficult. Evaluation the impact of various sources of copper on the elements profile; assessed using skin derivates, plasma or other parameters should be subjected to further observation.