<b>Net requirements of zinc, copper and iron to grazing lambs in semiarid</b> - doi: 10.4025/actascianimsci.v32i3.5883

Abstract

This work had as an aim determine the net requirements of Zinc (Zn), Copper (Cu) and Iron (Fe) of Santa Inês lambs raised grazing in the semi-arid area. Animals with body weight between 20 e 30 kg showed corporea contents in empty body weight (EBW) in these minerals from 60.26 to 76.37 mg kg^-1, 10.78 to 16.72 mg kg^-1 and from 133.44 to 126.98 mg kg^-1, respectively. It was observed that increasing the PCV increased Cu and Zn concentration but decreased the Fe concentratiêson. The net requirements for lambs under pasture varied from 1.69 to 7.86 mg day^-1 for Cu and from 7.20 to 27.4 mg day^-1 for Zn. The results obtained in the present experiment suggest that the dietary requirements in Cu and Zn are higher than those recommended by NRC (1985), between 7 and 11 mg, with a maximum value of 25 mg for Cu and between 20 and 30 mg, with a maximum of 750 mg kg^-1 of food for Zn, respectively. The net requirements for Fe varied from 8.46 to 26.66 mg day^-1 and were lower than that recommended by NRC (1985) for this mineral, from 30 to 50 mg kg^-1 of diet.