Dan L. Brown - Associate Professor and Staff Scientist
PhD from Cornell University
Graduate fields: Animal Science, Nutrition, Toxicology
Area(s) of interest: nutritional toxicology, sustainable animal agriculture, poisonous plants
Teaching:
Professional Organizations:
Email: dlb20@cornell.edu
Current Research
Dan Brown at home with his dog.
Nutritional Toxicology includes the study of toxic doses of nutrients, naturally occurring toxicants in food and feedstuffs, the detoxification or transfer of toxicants to the human food chain, and toxicants that affect the metabolism of nutrients. This laboratory has active investigations into both the toxic and potential beneficial effects of the following materials:
Farmers in developing nations will increasingly depend on new varieties of plants to sustain and improve their livestock herds. Many of these new forages defend themselves from pests with natural chemicals that need to be properly managed to ensure the health of the livestock utilizing them. Our current focus is on the toxic amino acids, tannins and phenethylamines found in such woody legumes as Acacia angustissima. Graduate student Mary Robertson recently isolated and characterized anaerobic microbes from the rumen of both wild and domestic animals that tolerate and reduce angustissima toxins. Supported by ILRI, the Cornell Department of Animal Science and ACIAR.
This program develops cheap simple tests for toxins and teaches farmers how to use them. Supported by The Conservation, Food and Health Foundation.
The ingestion of maple leaves by horses
results in a severe anemia, kidney damage and death. graduate student Jeanelle
Boyer has identified two compounds that contribute to these effects and
has detected a the presence of a third. We are tracking down the as yet
unknown toxic principle, how these toxins are activated and interactions
with whole body antioxidan status. Supported by the Cornell Department
of Animal Science and the Howard Bain Fund.
This toxic amino acid analog of arginine is found in alfalfa seeds and sprouts, jack beans and a host of other legumes. Canavanine is a naturally occurring insecticide that protects seeds and young foliage. In addition to killing insects and inhibiting their reproduction, canavanine has been shown to be an NO and urea synthesis inhibitor, and to disrupt the activity of a wide variety of proteins in which it has been incorporated rather than arginine. This laboratory has observed that canavanine disrupts reproduction in mice and increases the survival of mice to 477 days of age in populations that ingest high levels of dietary protein. Subsequent investigations indicate that this effect is less pronounced with low protein diets. Explorations of the mechanisms for this apparent life extension effect are ongoing. Previously supported by USDA Hatch funds and the Cornell Department of Animal Science.
In collaboration with the Cornell Department of Natural Resources and under the leadership of Peter Smallidge, we are investigating the feasibility of using meat goats to reduce the undesirable woody species (striped maple and American beech) present in commercial oak and sugar mapleforests. This work is funded by the USDA/SARE program.
Although a variety of mineral deficiencies limit livestock production systems in developing countries, commercial mineral supplements are usually unavailable or too expensive for most producers. We have found that certain kinds of cooking ash are rich sources of calcium, magnesium and other essential nutrients. Investigations are underway to learn how to find and manage this valuable resource to the benefit of Third World livestock and their owners.