Animal Nutritional Response to Sward Structure Under Short Duration Grazing Management

A ten-paddock short duration grazing cell was stocked with yearling heifers at a stocking rate of 0.7 ha per animal unit month and a stocking density of 0.14 ha per animal unit. A continuously-season- long-grazed (CSLG) pasture was used as a control. It was stocked at the same stocking rate, but at a stocking density of 1.4 ha per animal unit. Grazing periods in SDG paddocks were two or three days. Dietary quality was assessed by crude protein · content and in vitro digestibility of esophageal fistula estrusa samples. Three variables of ingestive behavior were measured, including ingestion rate, biting rate, and grazing time. Daily forage in take was estimated by multiplying ingestion rate by grazing time. Animals in CSLG gained significantly more weight in 1983, no statistical differences were detected in 1984, and, in 1985, animals gained more in SDG. No differences were detected in diet quality between SDG and CSLG throughout the study. No treatment differences were de tee ted in ingestive behavior variables in 1984, but ingestion rate was significatantly higher and grazing time significantly less in SDG during 1985. Differences in diet quality and ingestive behavior be tween SDG and CSLG at the beginning and end of the grazing season were evaluated for indications of possibly extending the season of nutritious forage. Such differences were few and inconsistent. Daily changes in diet quality and ingestive behavior during the grazing period within SDG paddocks were large. Diet quality declined significantly during the grazing period in all three years. Ingestive behavioral responses changed significantly, including declines in ingestion rate and increases in grazing time. Forage in take declined during the grazing period on a particular paddock. A model was developed that related behavioral responses to sward characteristics. Ingestion rate and grazing time were predicted from available biomass and herbage crude protein content. The model indicated that declines in biomass and herbage crude protein content translate into rapid declines in ingestion rate, and thus, forage in take. Based on the system studied, grazing periods in SDG paddocks should be two days or less to maintain high levels of livestock performance

Reducing Costs of Delivering Feed to Cattle - Supplementation Frequency

Winter supplementation of beef cattle is an important economic and production decision that producers make each year. Supplementation is often necessary to overcome nutrient deficiencies to allow adequate cattle performance. However, supplementation is an expensive input cost, par-ticularly with current high feed prices and deliv¬ery costs. The initial decision is about the correct type and amount of feed to use as the supplement, with the goal to provide the needed nutrients at the least feed cost. After this decision, opportuni¬ties for reducing other costs of supplementation should be considered. One option that can have a major impact on input costs is how often supple-ment is delivered. Reducing the frequency that supplement is delivered can reduce fuel, labor, and machinery costs. The important concern is creating the right balance between frequency of delivery and cattle performance

Cottonwood and Antelope Range Livestock Research Stations Unit Report

Two research stations, the Cottonwood and Antelope Range Livestock Research Stations, are located in western South Dakota that allow research projects focused on needs of range livestock producers in that region. The stations are comprised primarily of native rangeland that is grazed by cattle at both stations, and also by sheep at Antelope. The philosophy of the research efforts has been focused on conducting applied research to solve problems and address rangeland and livestock management opportunities relevant to the livestock producers and land mangers of the region

The Effect of Short and Long Recovery Periods on the Contribution of Oxidative Processes to Energy Expenditure During Multiple Bouts of Supramaximal Exercise

The Effect of Short and Long Recovery Periods on the Contribution of Oxidative Processes to Energy Expenditure During Multiple Bouts of Supramaximal Exercise Olson, E. (undergraduate), Christensen, K., Jajtner, A., Copeland, J., Unthank, M., and Mitchell, J. Exercise Physiology Lab, Texas Christian University, Ft. Worth, TX. The contribution of oxidative energy production to multiple sprint exercises is of interest due to implications for the training needs of people engaging in anaerobic activities. PURPOSE: The purpose of this study was to examine the effect of short and long active recovery durations on oxidative and anaerobic contributions to energy output during maximal intensity cycle ergometry. METHODS: Six male subjects, including well-trained endurance athletes and well-trained strength athletes, completed the study. After a VO2max test on the bicycle ergometer, each subject completed two conditions: a short recovery condition (SRC) and a long recovery condition (LRC). The SRC consisted of 10, 10-sec. supramaximal sprints with 30-sec. recovery periods. The LRC consisted of 10, 10-sec supramaximal sprints with 3-min. recovery periods. The load applied to the ergometer was 1.2 g/kg and the RPM during the sprints varied based on the maximal output. During recovery, no load was applied and subjects maintained a cadence of 80 RPM. Oxygen uptake was measured during the entirety of both conditions and peak power and total work were calculated from two, 5-sec RPM averages generated during the sprints. Blood samples were taken pre-exercise, after sprints 4, 7, and 10, and 3 minutes post-exercise. RESULTS: Peak power and total work were significantly greater (p \u3c 0.05) in the LRC (1091.3 + 88.7 W and 1363.6 + 34.6 kg-m) compared to the SRC (915.3 + 109.2 W and 1161.6 + 33.9 kg-m). In addition, peak power decayed by 21.7% over the 10 sprints in the SRC compared to no decay in the LRC. Oxygen uptake averaged 28.3 + 0.9 ml/kg/min for the entirety of the LRC; whereas, in the SRC there was a large increase in oxygen uptake during the second sprint that remained elevated and averaged 47 + 1.5 ml/kg/min for the remaining 8 sprints. There was no difference in blood lactate concentrations between conditions. CONCLUSION: The heightened aerobic response and the lower work and power outputs seen in the SRC are suggestive of a decrement in both anaerobic glycolysis and phosphocreatine (PCr) activity as successive sprints were completed. After repeated bouts of explosive exercise with short rest periods, oxidative processes play a more important role in energy production, most likely due to fatigue occurring in the anaerobic energy producing systems. These findings point to the need for enhancing the aerobic capacity of athletes engaging in consecutive high intensity bouts of exercise when rest intervals are short

Early Weaning Reduces Rangeland Herbage Disappearance

Early weaning of beef calves reduces nutrient and forage demand in a cow–calf enterprise, potentially contributing to reduction in forage utilization on the pasture from which calves are removed by a nonlactating cow vs. a cow–calf pair. Research was conducted to evaluate weaning beef calves 90 days early (EW) vs. normal weaning (NW) on pasture herbage disappearance in mixed-grass prairie pastures in the northern Great Plains. Spring-calving cows (n = 48) were utilized in each study year (2003, 2004, and 2006) from the date of early weaning (August) until the date of normal weaning (November). Cow–calf pairs were randomly assigned each year to each NW pasture (n = 8 pasture–1); cows whose calves had been weaned early were randomly assigned to each EW pasture (n = 8 pasture–1). No calves grazed EW pastures. Cattle were weighed and body condition scored at the beginning and end of each trial period. Available herbage was determined before and after grazing in each pasture. The effect of weaning treatment on cow average daily gain and body condition score change was highly significant (P \u3c 0.001). Early-weaned cows gained weight and condition; normal-weaned cows lost weight and condition. Herbage disappearance was lower (P = 0.017) in EW than NW pastures, resulting in 18.9 lb cow–1day–1, or 36%, herbage savings. This is equivalent to an additional 1.1 month of grazing saved per animal unit over a 90-day period. The value of the additional animal-unit months includes extending the grazing season, increasing cow numbers, or as “banked” forage for drought management

Sodium-Bearing Waste Treatment, Applied Technology Plan

Settlement Agreement between the Department of Energy and the State of Idaho mandates treatment of sodium-bearing waste at the Idaho Nuclear Technology and Engineering Center within the Idaho National Engineering and Environmental Laboratory. One of the requirements of the Settlement Agreement is to complete treatment of sodium-bearing waste by December 31, 2012. Applied technology activities are required to provide the data necessary to complete conceptual design of four identified alternative processes and to select the preferred alternative. To provide a technically defensible path forward for the selection of a treatment process and for the collection of needed data, an applied technology plan is required. This document presents that plan, identifying key elements of the decision process and the steps necessary to obtain the required data in support of both the decision and the conceptual design. The Sodium-Bearing Waste Treatment Applied Technology Plan has been prepared to provide a description/roadmap of the treatment alternative selection process. The plan details the results of risk analyzes and the resulting prioritized uncertainties. It presents a high-level flow diagram governing the technology decision process, as well as detailed roadmaps for each technology. The roadmaps describe the technical steps necessary in obtaining data to quantify and reduce the technical uncertainties associated with each alternative treatment process. This plan also describes the final products that will be delivered to the Department of Energy Idaho Operations Office in support of the office's selection of the final treatment technology

Do cladistic and morphometric data capture common patterns of morphological disparity?

The distinctly non-random diversity of organismal form manifests itself in discrete clusters of taxa that share a common body plan. As a result, analyses of disparity require a scalable comparative framework. The difficulties of applying geometric morphometrics to disparity analyses of groups with vastly divergent body plans are overcome partly by the use of cladistic characters. Character-based disparity analyses have become increasingly popular, but it is not clear how they are affected by character coding strategies or revisions of primary homology statements. Indeed, whether cladistic and morphometric data capture similar patterns of morphological variation remains a moot point. To address this issue, we employ both cladistic and geometric morphometric data in an exploratory study of disparity focussing on caecilian amphibians. Our results show no impact on relative intertaxon distances when different coding strategies for cladistic characters were used or when revised concepts of homology were considered. In all instances, we found no statistically significant difference between pairwise Euclidean and Procrustes distances, although the strength of the correlation among distance matrices varied. This suggests that cladistic and geometric morphometric data appear to summarize morphological variation in comparable ways. Our results support the use of cladistic data for characterizing organismal disparity

A MULTIDISCIPLINARY APPROACH TO INFORMATION SYSTEMS RESEARCH

Information Systems Working Papers Serie