• Particle Size Changes in Rumens of Cattle Grazing Kansas Flint Hills Range

      Forwood, J. R.; Owensby, C. E.; Towne, G. (Society for Range Management, 1985-03-01)
      A ruminally fistulated Hereford steer and heifer grazing Kansas Flint Hills range were used with the objective of determining forage particle breakdown and distribution in different rumen sites over several hours post feeding during seasons of differing forage quality. During the first year, samples were taken after an overnight fast from 3 rumen sites and from feces early on the sample morning (AM sample). The cattle were fed and sampled again 12 hours later (PM sample). During year two, the cattle were sampled immediately as they came from the native pasture (PRE sample) in addition to the 2 other sample times. Samples were wet-sieved through a series of 5 screens to separate particle sizes. Material from each screen was dried, weighed and expressed as a percentage of the total of all screens. In the rumen, relative amounts of coarse particles generally decreased while amounts of smaller particles generally increased with advancing season. Forage maturity had similar effects on fecal particle sizes. Particles in the feces were more uniform in size than particles in the rumen.
    • Performance and Phosphorus Status of Range Cows with and without Phosphorus Supplementation

      Judkins, M. B.; Wallace, J. D.; Parker, E. E.; Wright, J. D. (Society for Range Management, 1985-03-01)
      Performance and phosphorus (P) status were studied in 2 groups of range cows, one of which had free access to salt alone (control) and the other to a mineral mix (P-supplemented). The mineral mix contained 50% dicalcium phosphate, 45% salt, and 5% cottonseed meal. Performance traits (birth date, calving interval, weaning weight, suckling gain, and percent calf crop) were compared over 5 years (1979-83), one of which was considered a drought year (1980). Cows involved in the study received no supplemental protein or energy during the experiment. Lack of P supplementation had a detrimental effect on cow performance only when coupled with the effects of drought. This apparent combined effect delayed postpartum estrus in control cows during the 1980 drought, thus causing them to calve later (7 April vs. 11 February; P<.05) and wean lighter (226 vs. 253 kg; P<.05) calves in 1981 as compared to P-supplemented cows. Percent calf crop did not differ (P>.05) between the 2 groups during any year of the study, although in both groups, this trait was considerably lower in 1981 than in other years because of the 1980 drought. These results suggest that rainfall or P supplementation before and during the breeding season may be critical in maintaining early calving dates and heavier weaning weights but, even with P supplementation, lower conception rates may occur under drought conditions. Phosphorus status of cows was estimated from fecal, saliva, and rib bone biopsy samples collected at 6 intervals from April 1981 to January 1982. Fecal P varied (P<.05) among sampling dates and was higher (P<.05) for P supplemented cows than for control cows when averaged over sampling dates. Levels of fecal P were higher (P<.05) during the period of active forage growth than during dormancy. Salivary P peaked concurrently with fecal P; however, across sampling dates, response to supplemental P was inconsistent as evidenced by a treatment × date interaction (P<.05). During lactation, bone P levels were higher (P<.10) in P supplemented cows than in control cows. After lactation, bone P did not differ (P>.10) between groups and was higher (P<.001) than during lactation, which indicates bone P levels can be replenished following lactation without P supplementation.
    • President's Address

      Schuster, Joseph L. (Society for Range Management, 1985-03-01)
    • Recovery of Sagebrush-Grass Vegetation Following Wildfire

      West, N. E.; Hassan, M. A. (Society for Range Management, 1985-03-01)
      Most studies of the impacts of fire in sagebrush-grass vegetation in the Great basin have involved recovery on sites seriously depleted of native perennial bunchgrasses. The usual recommendation is to promptly seed such areas artificially. This is costly, not always successful, and if unnecessary, could produce no more than a natural recovery. The natural recovery of a good condition sagebrush-grass site in central Utah was monitored for 2 years after a mid-summer wildfire. Total plant cover 1 year after the fire was similar to that before the fire and on unburned controls. Annual herbaceous growth 1 year later was almost twice that before the fire. Most of the plant growth the first year was due to cheatgrass (Bromus tectorum). By the second year after fire, however, the perennial bunchgrasses had cover and production levels near those recorded prior to the burn. Two years after the fire, total grazable forage was 2.5 times that before the fire. Total precipitation, however, had been higher than average both years. Sagebrush-grass sites in good condition may be improved for cattle production with a few years of livestock exclusion following wildfire. Prescribed or controlled burns would probably be appropriate on similar high condition rangelands if cattle grazing is the dominant use and conflicts with wildfire are minor.
    • Rough Fescue Response to Season and Intensity of Defoliation

      McLean, A.; Wikeem, S. (Society for Range Management, 1985-03-01)
      Rough fescue (Festuca scabrella Torr.) was subjected to 10 clipping regimes which varied in time or intensity of defoliation. The experiment was repeated at 2 sites for 3 consecutive years. Plant survival and vigor were evaluated the summer following defoliation. Clipping treatments involving weekly defoliation to a 5-cm stubble height from mid May to late June resulted in the greatest injury. Reduced injury occurred when clipping ceased in May or when 10 or 15 cm of herbage was retained. Season long defoliation to 20 cm or clipping only in the fall caused no apparent damage. Cutting in the fall plus spring resulted in greater injury than spring clipping alone on plants clipped from mid May to late June but a fall clipping effect was not observed consistently on plants clipped in May plus fall.
    • Seasonal Nutrient Estimates of Mule Deer Diets in the Texas Panhandle

      Sowell, B. F.; Koerth, B. H.; Bryant, F. C. (Society for Range Management, 1985-03-01)
      Botanical composition and estimated seasonal nutrient quality of mule deer (Odocoileus hemionus) diets from the Canadian River and Clarendon areas of the Texas Panhandle were determined from 1979 to 1980. Deer from the Canadian River area consumed annually 62% browse, 34% forbs, 1% grasses, and 3% unknowns. Deer from the Clarendon area averaged 56% browse, 28% forbs, 11% grasses, and 5% unknowns annually. Deer consumed more grass at Clarendon because they had access to cultivated small grains, primarily winter wheat and rye. Annual deer diets from the Canadian River area contained 8 +/- 1% crude protein (CP), 0.14 +/- .03% phosphorus (P), and 47 +/- 2% in vitro organic matter digestibility (IVOMD). Deer diets from the Clarendon area averaged 10 +/- 3% CP, 0.15 +/- .03% P, and 50 +/- 2% IVOMD annually. Higher nutrient quality of mule deer diets at Clarendon suggests cultivated small grains/legumes have excellent potential to enhance Texas Panhandle deer herds that normally subsist on a fair to poor nutritional plane.
    • Seasonal Trends in the Chemical Composition of Ten Range Plants in South Texas

      Meyer, M. W.; Brown, R. D. (Society for Range Management, 1985-03-01)
      The chemical composition of 10 range plants of dietary importance to cattle and white-tailed deer (Odocoileus virginianus) was determined on the Texas A&I University Range and Wildlife Research Pastures from October 1980-September 1981. Samples were analyzed for crude protein (CP), neutral detergent fiber (NDF), lignin, organic matter (OM), in vitro dry matter digestibility (IVDMD), phosphorus (P), and calcium (Ca) concentration. The grasses were lower (P<.05) in CP and Ca concentration than the non-grasses, while non-grasses had lower (P<.05) NDF content. On the basis of digestibility, fiber content, protein, and mineral concentration, forage quality was highest in the spring. Winter forage samples were of a higher quality than were late summer samples. Low phosphorus concentrations were common throughout the year.
    • Technical Notes: An Effective Fecal Harness for Free-grazing Goats

      Pfister, J. A. (Society for Range Management, 1985-03-01)
      A fecal harness for goats proved useful for total fecal collections under rigorous field conditions in dense brush. An important aspect of this fecal harness is that feeding mobility of goats is not impaired.
    • The Decline of the Angora Goat Industry in Three Texas Counties

      Schrivner, J. H. (Society for Range Management, 1985-03-01)
      One hundred three present and 104 past Angora goat producers in 3 Texas counties were questioned regarding the relative importance of factors contributing to the decline of the goat industry in Texas. While the distribution of past and present producers among herd-size, ownership, and age classes was similar, it differed with regard to kidding. More present producers attempted to reduce livestock losses by shed and shed/trap kidding and use of predator control and husbandry techniques. Present producers also reported fewer kids and adults killed by predators. Predation losses was the production-limitation factor of greatest concern to both present and past goat ranchers. Disease problems and concern over competition from the synthetic fiber industry were ranked second and third, respectively, by present producers whereas mohair prices were ranked second and shortage of shearers, disease problems, and competition from the synthetic fiber industry collectively were ranked third by past producers.
    • Values of Four Communities for Mule Deer on Ranges with Limited Summer Habitat

      Austin, D. D.; Urness, P. J. (Society for Range Management, 1985-03-01)
      Four plant communities were evaluated from May through September for mule deer dietary and nutritional values. The communities were dominated by Utah serviceberry, Gambel oak, big sagebrush, and mixed browse. In early summer deer diets contained many browse and forb species and were high in crude protein, but as summer progressed fewer species were selected and dietary crude protein declined, especially in the big sagebrush and serviceberry communities. Thus late summer was determined the critical period for forage quality. Range conditions were reflected by body size and condition of deer in fall.
    • Western Wheatgrass Responses to Simulated Grazing

      Stroud, D. O.; Hart, R. H.; Samuel, M. J.; Rodgers, J. D. (Society for Range Management, 1985-03-01)
      To evaluate responses of range grasses to herbage removal, removal patterns should simulate those under grazing. We compared responses of western wheatgrass (Agropyron smithii Rydb.) in mixed-grass range to no clipping, conventional clipping, and clipping which simulated continuous grazing. Two years of simulated grazing did not affect herbage production or tiller numbers, but both declined under conventional clipping. Belowground phytomass decreased as herbage removal increased. Total nonstructural carbohydrate concentration in rhizomes decreased when utilization exceeded about 40%, but that of roots and crowns decreased only when utilization exceeded 60-70%.