摘要：

The nutrient status of grazing beef cattle from four selected soil order regions of Florida was examined. Liver, blood, hair and feces samples from 14 heifers and 14 cows, plus forage samples, were collected during two periods of the year from nine ranches located in four different regions. Soil samples were collected during one period. The soil order regions were the Histosol (southeast), Spodosol (southwest), Entisol (central) and Ultisol (northwest). Mean forage P values were higher (P less than .05) in the wet season, while mean hair P levels were higher (P less than .05) during the dry season. Mean forage, plasma, liver and hair Mg values were higher (P less than .05) in the wet season. Plasma vitamin E, liver vitamin A and forage carotene levels were higher (P less than .05) during the wet season. Mean forage P content was deficient (less than .25%) during both seasons and varied from .10% in the dry season to .16% during the wet season. Mean forage Mg (less than .18%) and K (less than .60%) concentrations were deficient in the dry season. Forage protein was deficient (less than 7.0%) in five of seven ranches during the dry season. Extractable soil Ca, exchangeable soil Ca, Mn, Al, H+, soil organic matter and effective cation exchange capacity were higher (P less than .05) in the Histosol region. Extractable soil K was low (60 ppm) in all regions, except the northwest. Forage P was critical (less than .25%) during the dry season in all regions and varied from .08 to .15%, while plasma P was deficient (4.5 mg/100 ml) in animals from the southeast during the dry season only.

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