Macromineral profile in the plasma of Nubian goats as affected by the physiological state.

A total of 65 Nubian dairy goats were selected to represent a combination of age and physiological status. Changes in some plasma concentrations underlying different physiological states were monitored. There were young and adult animals, pregnant animals, all with more than 50 days after kidding, divided into subgroups according to gestation, first, second or third pregnancy. Lactating animals up to 50 days after kidding were divided into subgroups according to parity (first, second or third) and stage of lactation (early or mid). The last category consisted of animals grouped according to yield (high or low). Data analyses have shown that calcium (Ca) levels were lowest (P<0.05) during first early lactation, while those of phosphorous (P) were lowest (P<0.05) in second pregnancy and also in early lactations compared with mid-lactations (P<0.05). Magnesium (Mg) levels increased (P<0.05) with age and number of pregnancies. The order was second, third and first. Irrespective of parity, mid-lactations showed higher (P<0.05) Mg levels than early ones. Sodium (Na) plasma levels decreased (P<0.05) progressively with age and from first to third pregnancy; and decreased (P<0.05) during first and third mid-lactations compared with first or second early lactation, and as well as with second mid-lactation. Potassium (K) plasma levels were lower (P<0.05) in early than mid-lactations. Except for Mg, the type of milk yield had no significant effect on minerals under study. Minerals in the diet of animals kept under different management practices must be regarded among other essential nutrients. Physiological status might modify its requirement to these elements.