Diet Quality of Steers Grazing Three Range Sites in South Florida

Abstract

Crude protein and in vitro organic matter digestibility (IVOMD) were studied in diets of 4 or 5 esophageally fistulated steers grazing pine-palmetto (PP), fresh-water marsh (FM), or transition (T) sites. Crude protein in summer diets on FM (10.6%) was higher (P>0.05) than that on PP (7.3%) and T (7.3%). There were no differences among sites for diet crude protein content (7.1%) during winter. There were no differences (P>0.05) in diet IVOMD among 3 range sites in summer (46.8%) or winter (33.7%). Data suggest that diets selected on PP and T sites could meet protein requirements for dry cows in summer but not winter. Diets from the FM site could meet protein needs of lactating cows in summer, but in winter crude protein would be deficient for dry cows because of senescence of the major grass, Panicum hemitomon. Energy from the 3 sites in summer would be marginal for maintenance of dry cows, but in winter none of the sites would be adequate without energy supplementation.