| Abstrakt: |
An experiment was conducted to determine the trace mineral status of grazing cattle from four selected soil type regions in Florida. Animal tissue, forage and soil samples were collected during the wet (September-October) and dry (February-March) seasons from nine ranches located in four different regions. On the basis of reported critical forage levels, mean forage Co (<.1 ppm), Zn (<30 ppm) and Se (<.1 ppm) and liver and hair Se (<.25 ppm), were low during both seasons. Soil Se (<.50 ppm) and extractable soil Zn (<1.5 ppm) were low in all regions except the southeast. Mean forage Se was low in all regions. Of all animals studied in the wet season, 36 and 32% had low liver Cu (<75 ppm) and Se (<.25 ppm) concentrations, respectively. In the dry season, 20 and 39% of the animals had low liver Cu and Se concentrations, respectively. Hair Se was low (<.25 ppm) in 90% of the samples during the wet season and in 100% during the dry season. During the wet season, forage Zn, Mn, Co and Se were low in 89, 26, 63 and 84% of the samples, respectively, while extractable (double acid) Zn, Mn, Co and total Se were low in 57, 79, 63 and 100% of the soils, respectively. In the dry season, 80, 20, 40 and 80% of forages were low in Zn, Mn, Co and Se, respectively. Of the seven trace minerals studied, Se and Zn are most likely to be deficient, with Co and Cu insufficiency probable in selected areas. |
