Variation of zinc and copper concentrations in the plasma of Nubian goats according to physiological state

Abstract

The association between the combination of age and physiological status of dairy Nubian goats, pregnancy or lactation and blood concentration of zinc (Zn) and copper (Cu) was investigated. The animals were divided into (a) young (4±6 months old), (b) adult (9±12 months old), (c) pregnant (within 50 days of their ®rst pregnancy and (e) lactating animals grouped according to parity (up to 50 days after ®rst, second or third kidding). Each group or sub-group consisted of ®ve animals. The data analysis revealed that plasma Zn concentration decreased (3.91±1.12 mg/l) signi®cantly with increase in age. There was a signi®cant increase in Zn levels in high yielders compared to low ones (2.00±6.59 mg/l). Cu plasma levels increased (5.01± 3.17 mg/l) signi®cantly in adult compared to young animals but decreased (5.01±4.13 mg/l) signi®cantly after ®rst kidding compared to second and third kidding as well as in pregnant animals. It can be shown that the different physiological states would impose certain demands on animal needs for these trace elements and hence adequate amounts in the diet should be accounted for to achieve the best animal performance.