Browsing Journal of Range Management, Volume 33, Number 6 (November 1980) by Subjects
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Nutritional Characteristics of High Yielding Exotic Grasses for Seeding Cleared South Texas BrushlandThree exotic grasses potentially useful converting south Texas brush rangeland to permanent pasture were evaluated in 1976 and 1977. Yearling cattle required 16.6, 23.1, and 34.8 kg of forage per kg of gain for coastcross-1 bermudagrass, kleingrass-75, and Bell rhodesgrass, respectively. Cattle gained 0.68, 0.56, and 0.33 kg/head daily grazing these species. They ate (forage disappearing) about 12 kg/head daily regardiess of species, so daily gains directly reflected differences in quality among the forages. Our data suggest that the quality measure most nearly deficient was the factor most limiting animal performance, e.g., correlation between average daily gain and P content was r = 0.89 for cattle grazing Bell rhodesgrass. Its P content varied from 0.16 to 0.06% from spring to fall compared to 0.24 to 0.15% from spring to fall for the other two forages. Overall, 24-hr IVDMD (fermentation only) best correlated with animal daily gain. Generally, Bell rhodegrass had lowest, coastcross-1 bermudagrass highest, and kleingrass-75 intermediate quality values, particularly for digestibility, crude protein, and digestible energy. Dry matter yields were 9.6, 11.6, and 11.8 thousand kg/ha for coastcross-1 bermudagrass, kleingrass-75, and Bell rhodesgrass in 1976.
Nutritive Content of Sheep, Goat, and White-tailed Deer Diets on Excellent Condition Rangeland In TexasA one-year study was initiated in August, 1975, to examine the nutritive content in diets of four kinds of sympatric ruminants on excellent condition rangeland of the Edwards Plateau in Texas. Sheep, Angora goat, and Spanish goat diets were collected from animals fitted with permanent esophageal cannulae. Nutritive content of white-tailed deer diets was estimated by hand-plucking representative forages as the deer were observed grazing them. Mean, annual levels of crude protein (CP) were similar among the four kinds of animals. All diets were lowest in CP during January and February, with livestock diets showing higher levels than deer. However, deer diets were higher in CP than sheep and goat diets during spring and summer. During January and February, the livestock diets warranted only minimum protein supplementation while deer diets were significantly below recommended levels. Digestible energy (DE) levels were higher for sheep diets than for diets of either goats or deer. Similarly, the goat diets were higher in DE than deer diets. The DE levels were generally adequate for sheep but critically low for Angora goats during late gestation. Deer diets were very low in DE during winter and again in early summer, coinciding with the period of peak lactation. Energy would appear to be more limiting for animal production than protein under the conditions of this research.