Seasonal dynamics of nutritional quality during a drought of four browse species preferred by white-tailed deer (Odocoileus viginianus) in the Rolling Plains of Texas.

Woody plant encroachment is a constant issue that must be addressed by ranchers and landowners on the Rolling Plains of Texas. While many consider any type of woody vegetation on rangeland to be noxious, certain species provide a valuable and dependable source of quality forage for wildlife such as white-tailed deer. The purpose of this research was to identify four species of browse preferred by white-tailed deer and test certain nutritional parameters throughout each season during a drought. Application of fertilizer was added as one of the treatments to evaluate forage quality.
The four browse species selected for evaluation were: fourwing saltbush [Atriplex canescens (Pursh.) Nutt.], ephedra (Ephedra antisyphilitica Berl. ex.C.A. Mey.), netleaf hackberry (Celtis reticulata) and redberry juniper (Juniperus pinchotii Sudw.). Each species were divided into a control or fertilizer treatment group. Crude protein and in vitro dry matter digestibility were evaluated for forage quality. Netleaf hackberry and redberry juniper were analyzed for condensed tannins. Fourwing saltbush and redberry juniper did not show a response to the addition of fertilizer. The response from ephedra between control and fertilizer was significant in all seasons for crude protein content (spring +1.66%, summer +3.14%, fall +2.09% and winter +1.63%). Netleaf hackberry showed a statistically significant increase in crude protein for summer (+1.05%) and fall (+0.35%). Dry matter digestibility was generally the same between control and treatment for all species. There was no significant difference between control and treatment for condensed tannin concentrations. Redberry juniper exhibited high levels concentrations of condensed tannins throughout the year (spring 36.20 mg CE/gDM, summer 50.59 mg CE/gDM, fall 61.27 mg CE/gDM and winter 60.36 mg CE/gDM). Netleaf hackberry contained smaller amounts of condensed tannins (spring 6.06 mg CE/gDM, summer 15.31 mg CE/gDM and fall 3.51 mg CE/gDM).