干旱区生态环境知识资源中心

A study was conducted to determine the trace mineral status of forage and soils on a goat ranch in the semi-arid region of South western Punjab, Pakistan. Forage and soil samples were collected twice a year during winter and summer from three different sites within the ranch. Site I represented land characterized by natural pasture with low intensity forage accessible to animals. Site II represented land site within proximity of main experimental station where small ruminants were provided hay, crop wastes and also by-products. Site III was grazing reserves characterized by the availability of sown pastures including different improved forage varieties. Seven composite samples from each of the three grazing sites of the pasture were collected during each sampling. Higher forage values of Cu and Mn were found in winter than those during summer. However, Fe and Zn were higher in summer. In general, higher trace elements values were found in grazing site II. Of all forage trace minerals, only Mn was adequate. Concentrations of Cu, Fe and Zn in forage from all three grazing sites during both seasons were below the critical level. All soil elements were higher in grazing sites III than those in other grazing sites. Concentrations below the critical level were found for Soil Cu during both seasons in grazing site II and during summer in site I, and for Mn in both seasons in all sites within the pasture.