Author: Jennifer Marie Duringer Publisher: ISBN: Category : Livestock poisoning plants Languages : en Pages : 390
Book Description
The pyrrolizidine alkaloids (PAs) and ergot alkaloids are known natural toxicants found in livestock forage. These alkaloids contribute to large economic losses in livestock throughout the world. An understanding of the mechanisms of toxicity and development of better diagnostic tools for better management practices was investigated. Variability exists in the toxicity of PAs in ruminants where cattle are more susceptible and sheep are more resistant. The mechanism of PA resistance in sheep has been attributed to hepatic metabolism or rumen microbial degradation of PAs to non-toxic moieties. The hepatic metabolism of the PA senecionine was investigated in cattle and sheep liver microsomes. The level of a toxic pyrrole metabolite 6,7-dihydro-7-hydroxy-1-hydroxymethyl-5H-pyrrolizine pyrrole (DHP) formed in cattle and sheep were similar. However, the level of a non-toxic N-oxide metabolite was greater in sheep than in cattle. Cytochrome P450 and flavin monooxygenases (FMOs) responsible for PA oxidative metabolism were similar in both ruminant species. Therefore, hepatic metabolism of PAs is not solely responsible for resistance observed in sheep versus cattle. Ergot alkaloids present in endophyte-infected plants also cause toxicity in livestock. HPLC is the typical method used to quantify ergot alkaloid content; however, it is costly and time-consuming. An enzyme-linked immunosorbent assay (ELISA) developed with lysergol as the hapten was evaluated to ascertain its feasibility as an analytical tool for the ergot alkaloids found in forage plants. The ELISA detected the presence of lysergic acid but was not a reliable assay for the ergopeptine alkaloids such as ergovaline. The genetic divergence in mice previously selected into ergot alkaloid susceptible and resistant lines was studied after ten generations of relaxed selection. Physiologically no difference was seen between the susceptible and resistant line for average daily weight gain. However, hepatic metabolism of the ergot alkaloid ergotamine showed differences between genders and between animals on diets containing no ergot alkaloids or a high concentration of ergot alkaloids. Four major biotransformation products were identified as hydroxylated ergotamine isomers based on mass spectroscopic analysis.
Author: Richard F. Keeler Publisher: Elsevier ISBN: 1483270181 Category : Technology & Engineering Languages : en Pages : 619
Book Description
Effects of Poisonous Plants on Livestock documents the proceedings of a U.S.-Australian symposium on the effects of poisonous plants on domestic livestock. The symposium was held at Utah State University in Logan, Utah, on 19-24 June 1977. The volume is organized into eight parts. Part I discusses poisonous plant problems in the United States and Australia. Part II contains papers on general topics such as inorganic toxicants and poisonous plants; the hazard of plant toxicities to the human population; and selenium in plants as a cause of livestock poisoning. Part III examines the effects of simple phytotoxins such as selenium and oxalate on livestock. Part IV focuses on the effects of plant hepatotoxins, including pyrrolizidine alkaloids, Artemisia nova, and Tetradymia spp. Part V deals with plant cardio/pulmonary toxins such as Myoporum spp. and Pimelea spp. Part VI tales up plant neurotoxins while Part VII discusses plant teratogens and toxins affecting reproduction. Part VII presents studies on other toxic substances. It includes studies on oak poisoning and pine needle abortion in cattle.
Author: Peter R. Cheeke Publisher: A V I Publishing Company ISBN: Category : Medical Languages : en Pages : 514
Book Description
Natural toxicants and their general biological effects; Techniques and calculations in toxicology; Metabolism of toxicants; Effects of toxicants on livestock production and human health; Alkaloids; Glycosides. Proteins and amino acids; Carbohydrates, lipids, and conjugates; Metal-binding substances and inorganic toxicants; Tannins and polyphenolic compounds; Other plant toxins and poisonous plants; Mycotoxins.
Author: Peter R. Cheeke Publisher: CRC Press ISBN: 9780849369902 Category : Medical Languages : en Pages : 350
Book Description
This comprehensive treatise offers an in-depth discussion of natural toxicants in plants, emphasizing their effects as defenses against herbivory. Coevolution of plants and her-bivores are covered with a detailed treatment of toxicant metabolism and systemic effects in mammalian tissues. Con-sideration of the economic importance of plant toxins, modi-fication by plant breeding, management of toxico-sis, and toxicant problems in various geographic areas are in-cluded. Each volume offers an extensive description of chemistry, biosynthesis, analysis, distribution in plants, metabolism in mam-mals and insects, and practical problems in humans and livestock.
Author: Bryan M. Waldridge Publisher: John Wiley & Sons ISBN: 1119191874 Category : Medical Languages : en Pages : 205
Book Description
Nutritional Management of Equine Diseases and Special Cases offers a concise, easy-to-comprehend text for equine veterinarians with questions about commonly encountered nutritional problems. Assists veterinarians in supporting equine patients with special nutritional needs Focuses on nutritional problems and impact on different body systems Covers ponies, miniature horses, draft horses, donkeys, and mules Offers complete coverage of common diseases and problems helped by nutrition Includes useful chapters on poisonous plants and mycotoxins
Author: International Program on Chemical Safety Publisher: ISBN: Category : Medical Languages : en Pages : 24
Book Description
This is a companion volume to Environmental Health Criteria 80: Pyrrolizidine alkaloids. Published by WHO for the International Programme on Chemical Safety, (a collaborative programme of UNEP, ILO and WHO)
Author: Jennifer Marie Duringer
Author: Richard F. Keeler
Author: P. Gopalakrishnakone
Author: Peter R. Cheeke
Author: Peter R. Cheeke
Author: 
Author: Alan Andrew Seawright
Author: Charles R. Hart
Author: Bryan M. Waldridge
Author: International Program on Chemical Safety