While-tailed Deer Food Habits and Nutritional Status as Affected by Grazing and Deer-Harvest Management

White-tailed deer were collected in 1979 and 1980 from two areas in central Texas to determine differences in diets and nutritional status between years, sexes, and areas. Area 1 was more heavily populated with white-tailed deer, exotic big game, and domestic livestock than Area 2. Differences in summer and fall precipitation levels between years were reflected in altered forb and browse consumption by deer as determined from rumen contents. Differences in forb selection, oak mast consumption, and juniper browse consumption were detected between areas and were considered evidence of differences in range condition between areas. White-tails obtained from Area 1 were older than those from Area 2, but were not significantly larger in carcass weights, which also reflected the lower range condition of Area 1. Crude protein levels of rumen contents were greater in females than males and were greater in deer obtained from Area 1 than Area 2. These differences in rumen protein resulted from differences in consumption of acorns, a highly preferred, but low protein food item. Kidney fat indices reflected differences in rainfall patterns between years. Native and exotic big game populations and livestock grazing must be controlled to maintain a high level of nutritional status in the economically important white-tailed deer of central Texas.This material was digitized as part of a cooperative project between the Society for Range Management and the University of Arizona Libraries.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202

Estimation of Fecal Output and Particulate Passage Rate with a Pulse Dose of Ytterbium-Labeled Forage

Twelve rumen-cannulated lambs (avg. wt. 40 kg), fed long-stem alfalfa or prairie hay in a crossover design (two, 15-day periods) were used to compare estimates of fecal output from a pulse dose of ytterbium (Yb)-labeled forage and fecal collection bags. Estimates of fecal output (g/day) with Yb-labeled forages were not different (P>.05) from total collection values for lambs fed either alfalfa or prairie hay. Fecal output from a pulse dose of Yb was 100 +/- 2% of total collection for lambs fed alfalfa and 103 +/- 3% for lambs fed prairie hay. Particulate passage from the rumen was faster (P<.01) in lambs fed alfalfa (7.0%/hr) then in lambs fed prairie hay (3.9%/hr). A pulse dose of Yb-labeled hay appears to prove reliable estimates of fecal output as well as passage rate estimates, but validation of techniques in free-grazing ruminants is needed.This material was digitized as part of a cooperative project between the Society for Range Management and the University of Arizona Libraries.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202

Cattle Grazing Blue Grama Rangeland. I. Seasonal Diets and Rumen Fermentation

Four field trials were conducted from early August to late October, 1982, on blue grama (Bouteloua gracilis) rangeland in south-central New Mexico to examine relationships among grazing season, diet botanical and chemical composition, and rumen fermentation in beef steers (Bos taurus). Diets contained an average of 83% grasses and 17% forbs from early August through late September and 77% forbs in late October. Cell wall content of the diet decreased from the early growing season (74.9%) through the onset of dormancy (64.9%) while acid detergent fiber and lignin increased (41.9 to 52.9% and 5.2 to 12.7%, respectively) and crude protein content declined from 18.4 to 11.7%. Soluble and insoluble nitrogen (N) fractions of the diet reflected crude protein; from 13 to 36% of N was in unavailable forms. The extent of in vitro organic matter digestion declined from the early growing season (66.5%) through onset of dormancy (47.9%). Ruminal ammonia concentrations declined as season progressed: 6.0 mg/100ml was the lowest concentration observed. Declining diet quality was accompanied by an upward shift in digesta pH and altered proportions of volatile fatty acids (VFA) in rumen contents. Total VFA concentration was highest in late August (106.3 mmoles/liter). Ruminal measures generally reflected changes in dietary protein and digestibility but concentrations could also reflect changes in digesta flow rates. Finally, data suggest that crude protein may not be a good measure of protein supply to livestock grazing on ranges with diverse forage types.This material was digitized as part of a cooperative project between the Society for Range Management and the University of Arizona Libraries.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202

An Updated Procedure for Cecal Cannulation in Sheep and Cattle

Fifteen cattle (236-500 kg) and 38 sheep (36-55 kg) were fitted with 2 types of indwelling cecal cannulae. Cannulae were made of either clear silicone or plastic tubing. The surgery was conducted in a one-step procedure that involved pharmaceuticals and equipment that were readily available. Results indicated a success rate of 67% (33% failure due to inability to locate the cecum at the time of surgery) in cattle and 100% in sheep. Both cannula types tested were acceptable, but the cannula made from plastic tubing was more desirable because it was less bulky, more durable, and easier to construct. Animals fitted with cecal cannulae appeared to be healthy and to have normal life spans.This material was digitized as part of a cooperative project between the Society for Range Management and the University of Arizona Libraries.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202

Passage Rates, Rumen Fermentation, and Weight Change in Protein Supplemented Grazing Cattle

Protein supplementation is widely used to enhance the nutritional status of cattle on rangeland. The effects of protein supplementation on particulate and fluid passage rates, rumen fermentation, and weight gain were evaluated on cattle grazing dormant blue grama rangeland. Twelve rumen-cannulated steers were randomly allotted to 3 equal supplement groups (4/treatment): cottonseed cake (CSC), pelleted alfalfa (ALF), or no supplement (CON). Supplements were individually fed every other day at isonitrogenous levels (1.7 kg/hd CSC vs 3.6 kg/hd ALF). Particulate passage rate was measured during 2 collection periods. Concurrently, 102 yearling heifers were allotted to the same treatment groups for measurement of average daily gain. Cattle were fed these treatments from January through April 1983. In a second trial, 9 rumen-cannulated steers were randomly allotted to the same treatment groups as trial 1. An intraruminal dose of Co-EDTA was used to estimate fluid passage rates. Rumen ammonia, volatile fatty acids, and pH were also measured. In trial 1, average daily gain did not differ between ALF and CSC supplemented heifers; however, both ALF and CSC gained more than CON heifers. Passage rate estimates were not different among treatment groups. In trial 2, rumen fluid dilution rate, volume, and outflow rate were not different among treatments. Rumen ammonia-N was different at 11 h postsupplementation when the CSC steers had higher levels than steers in other treatment groups. Rumen pH was not influenced by supplementation. Molar proportions of acetate and propionate at 8 and 11 h after supplementation differed among treatment groups. Acetate was lowest in ALF, intermediate in CSC, and highest in CON supplemented steers. Propionate followed the reverse trend. Overall, protein supplementation improved livestock performance but the mechanism involved was not elicited. The current data suggest shifts in fermentation patterns and meeting dietary demands for gain are the factors involved in improving performance.This material was digitized as part of a cooperative project between the Society for Range Management and the University of Arizona Libraries.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202