Effect of Rations on Trace Elements Concentration in the Body of Dairy Cattle

Abstract

The objective of this study was to clarify the effect of trace elements level in rations on the trace elements status of Holstein cattle. Zn, Cu, Se and Co intake by the cattle fed mainly roughage in this study was marginally inadequate, since most of those content in roughage was below dietary requirement for dairy cattle (NRC). It seems likely that Cu and Se deficiency in the cattle may occur after long periods of feeding low those diets, since those concentration in the liver and blood was decreased with the decreased dietary those level. Also, there may be the possibility of a borderline Zn deficiency for the cattle fed rations of low Zn contents as roughage, because Zn concentration in the liver of the cattle fed low Zn diets was lower than for the cattle fed mainly concentrate. Furthermore, there may be the possibility of the simultaneous occurrence of Zn, Cu and Se deficiency for the cattle fed mainly roughage, since the correlation among those elements in the liver was significant. However, most of dietary trace elements seems to be excreted in the feces, since those concentration in the feces was increased with the increase in dietary those level. Therefore, further study should be provided for much needed refinement in requirement and tolerance level which will allow for more effective mineral supplementation of dairy cattle.