Macro and Trace Mineral Content of Selected South Texas Deer Forages

Abstract

White-tailed deer (Odocoileus virginianus) derive the majority of their dietary mineral intake from range forages which may be deficient in one or more essential minerals. We have described the macro and trace mineral concentration of 18 shrub, 26 forb, 7 grass, and 1 cactus species, known to occur in south Texas deer diets, collected from the Chaparral Wildlife Management Area in 1974 and 1975. Within each forage class, there were no seasonal differences in calcium (Ca), sodium (Na), potassium (K), or magnesium (Mg) concentrations. Phosphorus (P) concentrations in browse were higher (PI0 051 durinn the snrinn (0.20%) thnn dur-_~ _~~~~ _ __e__, ______ _ _..-=_____ \_ .__, ",-__-ing other seasons(O.U-0.16%). Forb P concentrations were greatest during the spring and winter periods (0.26 and 0.2970, respectively), and P levels in grasses (0.24-0.14%) decreased as the forage matured and reached senescence. Shrubs contained less P and K (p10.01) than either grasses or forbs; whereas, grasses contained lower concentrations of Ca and Mg (EO.01) than shrubs or forbs. Sodium concentrations did not diier among forage classes. Forbs contained greater (fiO.01) levels of copper (Cu) and zinc (Zn) than erasses or browse-nnd hr~wm c~n!ri~ed 1~9s ire" (Fe! m-I-(%0.01) than forbs or grasses. Manganese concentrations did not differ among forage classes. There were differences in mineral concentrations among species within forage class. Results suggest concentrations of all minerals except P met or exceeded minimum domestic animal requirements. Managers should provide a diversity of plant species and encourage practices that promote forb growth to provide optimum and nutritional benefits for deer.

Chemical composition and dry matter digestion of some native and cultivated grasses in Mexico

“…It seems that all grasses, in all seasons, had insufficient Cu to meet the requirements of growing beef cattle (10 mg/kg DM; McDowell, 2003). Low Cu concentrations were also found in native grasses growing in semiarid regions of south Texas, USA (Barnes et al, 1990) and northeastern Mexico (Ramírez et al, 2004). Low Cu in evaluated grasses may be caused by the high pH (7.5-8.5) in soils (Spears, 1994) of these regions.…”

Was it the deer or the fox?

“…Herbivores, in a nutrient-deficient environment, have been observed to chew and consume bones and antlers to obtain minerals lacking in their diet (Fish, 1950;Gordon, 1970;Barrette, 1985;Barnes et al, 1990;Johns and Duquette, 1991;Grasman and Hellgren, 1993;Richard and Juliá, 2001;Mitchell et al, 2005;Bredin, 2006;Bredin et al, 2008). This is defined as a non-nutritional behavior, in which access to bones occurs when fat is gone and bone is dry (weathered), a behavior that may be innate in herbivores (Denton et al, 1985).…”

Mineral Composition of Soils and Vegetation from Six Mountain Grassland Communities in Northern Spain

“…The availability of the minerals in the soil, the plant species and its genetic requirement for speciÐc quantities of nutrients for its growth and reproduction a †ect the concentration in the plants (Beeson and Matrone 1976). The concentration of an element depends also on the age of the plants (Pegtel 1987 ;Georgiadis and McNaughton 1990), on the environmental conditions in which the plants grow (Montalvo et al 1975) and on the part of the plant analysed (Barnes et al 1990). Nevertheless, very little data are available to date on the mineral status of soil and plants and the relationships between them in mountain grasslands.…”