Seasonal Nutrient Content in Food Plants of White-tailed Deer on the South Texas Plains

Abstract

From September 1976, through August 1978, 34 white-tailed deer food plants were collected during the months they were eaten by deer on the H.B. Zachry Randado Ranch in south Texas and analyzed for crude protein (CP), P, Ca, K, Mg, and Na. In vitro dry matter digestibility (DMD) was measured on foods collected only during the first year of the study. Mean levels of CP, Ca, K, and Mg were adequate for deer throughout the year. The P levels were generally inadequate except during spring, whereas Na levels probably were deficient throughout the year. However, these may not be as deficient as indicated because deer select higher quality plants and plant parts. Crude protein content of browse species was generally higher than that of forbs and cacti. Forbs were generally higher in P and Na than were browse and cacti. Although pricklypear cactus generally had low levels of CP, P, and Na, it had a higher DMD (greater than or equal to 76%) than all other species. However, because of its high soluble ash content (20%), pricklypear cactus averaged about 56% in vitro digestible organic matter. Our data indicated that range managers should provide a diversity of plant species to provide an optimum habitat for deer.