Mineral deficiency in cattle in Roraima, Brazil. II. Iron and manganese

Abstract

An experiment to determine mineral deficiencies in cattle in northeast Roraima Federal Territory (Brazil) was conducted using soil, forage and bovine tissue (liver) samples collected during the wet and dry seasons of the year. Liver biopsy of lactating cows and yearling animals showed Fe means ranging from 380 ppm to 529 ppm and 286 ppm to 555 ppm, respectively. Liver Mn means ranged from 21.9 ppm to 28.7 ppm in lactating cows, and from 23.2 ppm to 27.4 ppm in yearling animals. Iron and Mn were at normal levels. Forage Fe means ranged from 52 ppm to 137 ppm and Mn from 65 ppm to 143 ppm; both were at normal levels for beef cattle diet. Soil Fe means ranged from 114 ppm to 275 ppm, and Mn from 6 ppm to 71 ppm. Even with soil Mn at borderline deficiency for cultures, forage Mn was at adequate level for ruminants.