Animal mortality

About: Animal mortality is a research topic. Over the lifetime, 526 publications have been published within this topic receiving 14887 citations.

Limited myocardial muscle necrosis model allowing for evaluation of angiogenic treatment modalities.

Abstract: The currently accepted model for creating infarcted cardiac tissue in a rat model involves ligation of the left anterior descending artery (LAD), either proximally or at the bifurcation level. This procedure requires significant technical expertise and, even in skilled hands, commonly results in a 30% to 60% animal mortality. The authors propose a new model for creating a limited area of myocardial muscle necrosis that can be effectively studied. It involves a distal electrocautery occlusion of the LAD terminal branches and coagulation of the surrounding muscle. The model is consistently reproducible and decreases the morbidity of the study animals. It provides a cardiac muscle necrosis model not dependent on survival, while allowing study of the post injured state of the muscle and surrounding scar. This allows researchers to evaluate neovascularization and healing of the scar and peri-necrotic muscle, to assess improving blood flow with treatment by techniques designed to improve and stimulate angiogenesis, and to measure the outcome of stem-cell transplants for potential clinical use.

A model of cerebral circulation disorders created by staged ligation of the common carotid arteries.

Abstract: A model of brain ischemia induced by staged ligation of the left and right common carotid arteries has been developed in experiments on rats. The use to this model led to reduction of animal mortality. On days 2-5 after the second ligature, the animals lost weight, the level of their CNS vulnerability increased, the volume of perceived information reduced, adaptation to environmental conditions and reproduction of conditioned reflexes were disordered. Focal and diffuse destructive changes in the nerve and glia cells were found in the cerebral cortex, hippocampus, and thalamic nuclei. The severity of disorders in the blood supply to the brain depended on the interval between ligation of the carotid arteries. This recommends this model for evaluation of the efficiency of drugs of various pharmacological groups.

Factors influencing the movement, spatial patterns, and wildlife underpass use of coyotes and bobcats along State Route 71 in Southern California

Abstract: Funding Source: California Department of Transportation Total Budget: $130,000 Project Period: February 1998-February 2000 Mammalian carnivores may be sensitive to habitat fragmentation due to roadway construction. As a solution, roadway underpasses have received increasing attention; however, relatively little data exist on how carnivores respond to roadways or use the underpasses. We present results from a study of movement patterns and underpass use of coyotes and bobcats along CA 71, a freeway bisecting the eastern end of the Puente-Chino Hills wildlife corridor in urban Los Angeles. Recent reconstruction of a 5-km segment included installation of wildlife fencing, three large wildlife culverts, and 20 smaller water culverts. From February 1998 to February 2000, we captured and radio-tracked 29 coyotes and 4 bobcats and fitted an additional 24 coyotes with dog collars. Telemetry data were augmented by remotely triggered camera surveys at the culverts. Mean home range sizes for 15 coyotes and 3 bobcats were 13.72±3.92 and 8.89±3.45 km2 while core-use area sizes were 1.71±0.48 and 1.31±0.40 km2, respectively; both area sizes differed between age and social classes. Nine individuals maintained core-use areas that overlapped roadways and several had linear home ranges paralleling the roadways. Buffer zones established alongside roadways were not used proportional to their availability by 10 individuals. Telemetry and remotely triggered cameras documented 320 roadway crossings, which included 150 confirmed uses of underpasses by 16 collared individuals. However, hourly traffic volume influenced frequency of culvert use. In addition, surface crossings, particularly in areas where wildlife fencing was absent, accounted for 67 percent of study animal mortality. Mortality patterns for age classes and traffic direction differed. Overall, our study has provided valuable information for the California Department of Transportation on factors influencing underpass use and the effectiveness of roadway design for target species in fragmented landscapes.

Determining Animal Mortality Compost Maturity and Suitability for Road ProjectApplications for the Virginia Department of Transportation

Abstract: A series of studies on the effectiveness, feasibility, and costs of composting as a means of managing animal mortality removed from roadways has been conducted at the Virginia Center for Transportation Innovation and Research (VCTIR). In these studies, three composting methods were evaluated for use by the Virginia Department of Transportation (VDOT) and found to be effective: static compost windrows, a forced aeration system, and a rotary drum. Successful pilot studies at VDOT maintenance facilities have led to a growing interest in adopting this method of mortality management. As plans for additional composting vessels are underway, final tests are needed in order to develop guidance on composting procedures that generate mature, or finished, compost that is suitable for road project applications. The purpose of this study was to determine the time and treatment conditions necessary for VDOT compost vessels to generate mature compost and to evaluate the suitability of this compost for potential VDOT applications. Four methods were used to assess compost maturity: temperature monitoring, the Solvita compost maturity test, plant germination and growth tests, and qualitative observations. Tests were conducted on compost generated from the rotary drum and forced aeration system and on compost subsequently transferred to curing areas. The suitability of compost for road project applications was determined by testing compost for a suite of biological, physical, and chemical properties and conducting a demonstration project at a VDOT facility. Of the compost maturity tests, temperature decline was the most conservative indicator of finished compost. As determined primarily by temperature monitoring and supported by the other maturity tests, compost generated from the forced aeration system and rotary drum should be transferred to curing areas to cure for approximately 8 to 9 weeks. Mature compost generated from these vessels met the U.S. Environmental Protection Agency’s compost specifications for transportation applications. It is recommended that VCTIR and VDOT incorporate the findings of this study into a guidance document for VDOT animal mortality composting.

Benzene-Induced Hematotoxicity and Myelotoxicity by Short-Term Repeated Oral Administration in Mice

Abstract: Exposure dose of benzene has been postulated to be critical to induce hemopoietic malignancies. By long-term inhalation of benzene, 300 ppm has been shown to be the dose that induces high frequency of leukemia with the least animal mortality in the mouse. With regard to the benzene studies, determination of the oral dose that will be corresponding to the critical inhalation dose could be important to design the experimental protocol based on oral administration. Based on the background data such as the respiratory volume, absorption factor, and so on, we, therefore, calculated a potential oral dose that is expected to be corresponding to 300 ppm of inhalation dose. The determined oral dose was 150 ㎎/㎏ B.W. We then evaluated, using C57BL/6 mice, the toxic effects of benzene on the peripheral blood and the bone marrow (BM) by oral administration of the selected dose once a day for 1 and 2 weeks. Leukocyte, red blood cell number and BM cellularity were respectively decreased to 47.8%, 72.3% and 66.7% of the respective control level by 1-week oral administration of benzene, and to 30.8%, 60.2% and 80.2% by 2-week oral administration. Changes in the leukocyte numbers were mainly due to the marked decrease of lymphocytes. According to the results, the changes of the parameters examined were generally corresponding to the change levels by the 2-week inhalation. In conclusion, the selected dose, 150 ㎎/㎏ B.W., was a reliable dose corresponding to the 300 ppm benzene inhalation, which was verified by in vivo mouse study.