8 research outputs found
Impact of different handling styles (good vs. adverse) on growth performance, behavior, and cortisol concentrations in beef cattle
Our objective was to determine effects of aggressive handling on growth performance, behavior, and cortisol concentrations in beef calves. Crossbred calves (313 ± 4.7 kg; n = 54; 24 steers, 30 heifers) from a single herd were stratified by gender, body weight, and initial chute score, then allocated randomly to one of six pens. Each pen was randomly assigned to one of two handling treatments (good or adverse) applied on days 7, 35, 63, and 91. The objective of good treatment was to handle the calves quietly and gently to minimize stress. The objective of adverse treatment was to move the calves quickly and expose them to stimuli. Body weight, exit velocity, and chute scores (based on 5 point subjective scale) were recorded and salivary samples for cortisol were collected (4 calves/ pen) on days 0, 7, 35, 63, and 91. Pen scores (5 point subjective scale) were recorded on days 12, 42, and 87. Data were analyzed statistically using a mixed model. Chute scores tended to be higher (more agitated) in the adverse treatment on day 7, but scores did not differ on subsequent days (treatment × day; P = 0.06). Salivary cortisol concentrations on day 63 were greater in cattle on the adverse treatment (treatment × day, P = 0.001). Body weight, exit velocity, and pen scores were not affected by treatment (P ≥ 0.24). While differences were observed, these cattle appeared to acclimate to short-term adverse handling which did not seem to dramatically affect performance or behavior of beef cattle
Isoflupredone acetate as ancillary therapy for bovine respiratory disease in high-risk stocker calves
Bovine respiratory disease (BRD) is the most prevalent and devastating disease in U.S. feedlot cattle. This study evaluated the use of isoflupredone acetate in the treatment of BRD. Crossbred male beef calves (n = 192; body weight = 221 ± 3.9 kg) were acquired in two blocks from regional auction markets and transported to the University of Arkansas Stocker and Receiving Cattle Unit. Calves were observed daily for signs of respiratory illness. Antibiotic treatment was administered if calves displayed signs of respiratory illness and rectal temperature was ≥40 °C. Calves (n = 72) requiring antibiotic treatment were assigned randomly to either treatment 1 (florfenicol) or treatment 2 (florfenicol plus isoflupredone acetate). Treatment efficacy was determined by rechecking the rectal temperature of treated cattle 48 hours post treatment. Blood was collected (at treatment and recheck) via jugular venipuncture to evaluate complete blood count. Weights were recorded on days 0, 14, 28, 45, and 46. No difference existed for medical cost (P = 0.54) or temperature at recheck (P = 0.43). Upon recheck, neutrophils were higher and lymphocytes were lower in calves that received isoflupredone acetate (P ≤ 0.04). No difference existed in overall white blood cell count at recheck (P = 0.67). Calves that received isoflupredone acetate tended to exhibit greater (P = 0.09) average daily gain (ADG) between days 14 and 28 of the study. Results indicate that using isoflupredone acetate as ancillary therapy in the treatment of BRD did not have a positive effect on overall ADG or medical costs
Effects of grain by-products as supplements for stocker cattle grazing bermudagrass
Two experiments were conducted to compare corn, dried distillers’ grains (DDG), and pelleted soybean hulls (SH) as supplements for cattle grazing bermudagrass. In Exp. 1, 66 crossbred steers (306 ± 3.2 kg) were stratified by weight and allotted randomly to six 2.4-ha bermudagrass pastures for a 107-d study. One of three supplement treatments (corn, DDG, or SH) was assigned randomly to each pasture group and was offered at 0.5% (as fed) of body weight. Calves were weighed at 28-d intervals and supplement was adjusted after each weigh period. In Exp. 2, five ruminally cannulated steers grazed bermudagrass pasture and were individually fed supplements (corn, DDG, or SH) at 0.5% of body weight in a 3 x 3 replicated, incomplete Latin-square design with a 14-d adaptation and a 5-d sampling period. In Exp. 1, supplementation with DDG and corn increased (P \u3c 0.04) the average daily gain compared to supplementation with SH (0.89, 0.87, and 0.74 kg for DDG, corn, and SH, respectively). In Exp. 2, in situ dry-matter-disappearance kinetic measures of bermudagrass were not affected by type of supplementation. The potential extent of digestion for DDG (93%) was lower than for corn (97%, P = 0.01) and SH (96%, P = 0.06). Supplementation with corn or DDG at 0.5% of body weight improved the gain of stocker cattle grazing bermudagrass compared to supplementation with SH, but these differences were not explained by differences in bermudagrass degradation kinetic
Investigating current efficacies of several nematocides for use in cattle according to the fecal egg count reduction test
Utilizing small groups of naturally infected replacement heifers, fecal egg count reduction tests (FECRT) were conducted in the later months of 2007 at the University of Arkansas Savoy Research Station. Each test was 28 d in length, consisting of individual fecal nematode egg counts (EPG) and coprocultures. For the first test, the calves were ranked by beginning EPG, blocked, and randomly assigned treatment within each block. Nine to ten animals were in each treatment group. In this test, neither IVOMEC (® Merial) or IVERMECTIN (® Durvet), both delivered as an injectable at the rate of 0.2 mg of ivermectin kg-1 BW, resulted in egg count reductions of ≥ 90%. Post-treatment coprocultures relative to both products contained a mixture of Cooperia and Haemonchus spp larvae. Also in this first test, Safe-Guard (® Intervet), delivered as a suspension at the rate of 5.0 mg of fenbendazole kg-1 BW, resulted in egg count reductions of 100% (d 7 and 14) and 88-87% (d 21 and 28). Posttreatment coprocultures specific to Safe-Guard yielded only Cooperia spp larvae. In the second test, which was of follow-up treatments given immediately after the first test (animals re-sorted to treatment group), Safe-Guard at the above rate resulted in egg count reductions of 99-100% (d 7 and 14) and 54-18% (d 21 and 28). Also in the second test, Cydectin (® Fort Dodge) treatment at the rate of 0.2 mg of moxidectin kg-1 BW resulted in egg count reductions of 96-92% (d 7 to 28) and SafeGuard treatment at the rate of 10 mg of fenbendazole kg-1 BW resulted in egg count reductions of 100-88% (d 7 to 28). As was the case in the first test, post-treatment coprocultures from animals treated with Safe-Guard yielded only Cooperia spp larvae. Treatment of cattle with Cydectin resulted in coprocultures that primarily yielded Cooperia, but with a trace of Haemonchus spp larvae
Reduction of Martian Sample Return Mission Launch Mass with Solar Sail Propulsion
Solar sails have the potential to provide mass and cost savings for spacecraft traveling within the inner solar system. Companies like L'Garde have demonstrated sail manufacturability and various in-space deployment methods. The purpose of this study was to evaluate a current Mars sample return architecture and to determine how cost and mass would be reduced by incorporating a solar sail propulsion system. The team validated the design proposed by L'Garde, and scaled the design based on a trajectory analysis. Using the solar sail design reduced the required mass, eliminating one of the three launches required in the original architecture
Deep Space Habitat Configurations Based On International Space Station Systems
A Deep Space Habitat (DSH) is the crew habitation module designed for long duration missions. Although humans have lived in space for many years, there has never been a habitat beyond low-Earth-orbit. As part of the Advanced Exploration Systems (AES) Habitation Project, a study was conducted to develop weightless habitat configurations using systems based on International Space Station (ISS) designs. Two mission sizes are described for a 4-crew 60-day mission, and a 4-crew 500-day mission using standard Node, Lab, and Multi-Purpose Logistics Module (MPLM) sized elements, and ISS derived habitation systems. These durations were selected to explore the lower and upper bound for the exploration missions under consideration including a range of excursions within the Earth-Moon vicinity, near earth asteroids, and Mars orbit. Current methods for sizing the mass and volume for habitats are based on mathematical models that assume the construction of a new single volume habitat. In contrast to that approach, this study explored the use of ISS designs based on existing hardware where available and construction of new hardware based on ISS designs where appropriate. Findings included a very robust design that could be reused if the DSH were assembled and based at the ISS and a transportation system were provided for its return after each mission. Mass estimates were found to be higher than mathematical models due primarily to the use of multiple ISS modules instead of one new large module, but the maturity of the designs using flight qualified systems have potential for improved cost, schedule, and risk benefits
The Positioning of the Parish in a Context of Individualization
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Genomic reconstruction of the SARS-CoV-2 epidemic in England
AbstractThe evolution of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus leads to new variants that warrant timely epidemiological characterization. Here we use the dense genomic surveillance data generated by the COVID-19 Genomics UK Consortium to reconstruct the dynamics of 71 different lineages in each of 315 English local authorities between September 2020 and June 2021. This analysis reveals a series of subepidemics that peaked in early autumn 2020, followed by a jump in transmissibility of the B.1.1.7/Alpha lineage. The Alpha variant grew when other lineages declined during the second national lockdown and regionally tiered restrictions between November and December 2020. A third more stringent national lockdown suppressed the Alpha variant and eliminated nearly all other lineages in early 2021. Yet a series of variants (most of which contained the spike E484K mutation) defied these trends and persisted at moderately increasing proportions. However, by accounting for sustained introductions, we found that the transmissibility of these variants is unlikely to have exceeded the transmissibility of the Alpha variant. Finally, B.1.617.2/Delta was repeatedly introduced in England and grew rapidly in early summer 2021, constituting approximately 98% of sampled SARS-CoV-2 genomes on 26 June 2021.</jats:p