Use of Plants in Seasonal Grazing Trials on Chihuahuan Desert Rangeland
Short-term grazing trials were conducted to determine seasonal diet differences and forage plant use patterns on mesa dropseed (Sporobolus flexuosusThurb. ex Vasey) and snakeweed (Gutierrezia sarothrae[Pursh] Britt. Rusby) rangelands.
As preferred species disappeared (e.g., hog potato [Hoffmanseggia glauca(Ort) Eifert] and paperflower [Psilostrophe tagetina(Nutt.) Rydb.]), other plants became important in the diets, such as fluffgrass [Dasyochola pulchella(Kunth) Muell.-Arg.] and desert zinnia (Zinnia grandifloraNutt.)
with abundant available forage, cows selectively graze the most desirable plant parts, usually leaves
Evaluating several studies on range grasses, Briske and Richards (1994) reported that plant growth was more dependent on current photosynthesis than on carbohydrate reserves unless soil water and temperature were unfavorable. However, in arid envi-ronments like southern New Mexico, it is probable that carbohydrate reserves are important for regrowth and necessary for plants to be effective competitors.
Grasses were the major forage component for cattle in all 4 grazing trials, followed by forbs and then shrubs