EVALUATION OF COPPER CONCENTRATION IN SOME DAIRY COW FEEDING RAW MATERIALS

Aida Albu, Cecilia Pop, Felicia Târca, I.M. Pop

Abstract
Copper is a metal that occurs naturally the environment and an essential nutrient for plant growth and development; ingested in food by high concentrations, copper is potentially toxic to both humans and animals.
The aim of this study was to evaluate copper concentration in some raw materials used in feeding dairy cows during 2006-2007 period.
Fifty-five samples of grass, vetch, alfalfa, Sudan grass, alfalfa hay, grass hay, corn silage, maize, wheat bran, sunflower meal and brewery dregs were analyzed to evaluate copper concentration in feeds. Copper concentration was assesed using atomic absorbtion spectrofotometry method in flame.
Results (expressed in mg/kg related to dry matter) shown that all analyzed samples contained copper residues in detectable amounts.
For samples harvested in 2006 year, the average concentration of copper ranged from 1.27 mg/kg D.M. in sunflower meal at 3.70 mg/kg D.M. in wheat bran, while samples of feed from 2007 year, values were between 0.30 mg/kg D.M. in brewery dregs and 3.89 mg/kg D.M. in alfalfa.
Values obtained in this research as regards the contents of copper were lower compared with results of other researches conducted and data from literature.

Key words: minerals, copper, raw materials, dairy cows