Compara??o da toxicidade de Vicia villosa e Vicia sativa na alimenta??o de bovinos

• Author(s): Veronezi, Luciane Orbem
• Date: 2018
• Origin: Oasisbr
• Subject(s): Experimental poisoning; Cows; Heifers; Vicia villosa; Vicia sativa; Intoxica??o experimental; Vacas; Novilhas; Medicina Veterin?ria
• Document Type: Doctoral thesis
• Language: Portuguese

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Made available in DSpace on 2018-01-24T19:09:14Z (GMT). No. of bitstreams: 1 2016 - Luciane Orbem Veronezi.pdf: 3213369 bytes, checksum: 660b54c56b80e667f1e30d110c395df3 (MD5) Previous issue date: 2016-07-27

CAPES - Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior

In this study the epidemiology, clinical signs, macroscopic and microscopic lesions related to spontaneous and experimental intoxication by Vicia villosa and the evaluation of the possible toxicity of Vicia villosa in cattle were characterized. The systematic granulomatous disease (SGD associated with vetch) was verified in 7 localities distributed in Paran?, Santa Catarina and Rio Grande do Sul States, with main feed that includes oats and/or ryegrass in association and V. villosa and/or ryegrass associated with Vicia sativa, and in lower quantity. All cattle that developed the disease were cows, lactating and Dutch. The SGD associated with vetch was reproduced in six lactating Dutch cows, by supplying green V. villosa in the trough and V. villosa and ryegrass pasture. In the other experimental groups (group 3, V. villosa / V. sativa/cows, grazing; group 4, V. sativa/cows, grazing; group 5, V. villosa/V. sativa/heifers and group 6, V. villosa/heifers, grazing) do not verified clinical and pathological alterations related to the SGD associated with vetch. Six cows developed the SGD, one cow presented a leigh clinical condition (group 2/cow 6/V. villosa, pasture), four cows developed a moderated clinical condition (group 1, cows 1 and 2/V. villosa/trough and group 2, cows 4 and 5/V. villosa, grazing), and just one cow presented a severe clinical condition (group 2, cow 3/V. villosa/pasture. V. villosa was toxic to cattle and produced a chronic granulomatous disease when ingested in amounts greater than 38.2 g/kg/day for 71 days, or in direct grazing for a period of more than 28 days The main clinical signs consisted of alopecia and cutaneous crusts, pruritus, fever, conjunctivitis, diarrhea, reduction of milk production and weight loss. Macroscopically, multiple white-grayish nodules were observed, specifically in the lymph nodes, kidneys and heart, and histology revealed a granulomatous infiltrate composed of macrophages, lymphocytes, giant cells, epithelioid cells, plasma cells and eosinophils. When ingested by young cattle, the V. villosa pasture, for a period of 68 days, do not produce clinical modifications. When ingested by cows with high milk yield, the V. sativa pasture, for a period of 78 days, does not produce chronic granulomatous disease. Ingestion of V. villosa for a long time led to low production rates, such as low milk production, low reproduction rates and predisposition to infection diseases. In the bromatological analysis, the presence of phytate, in low levels, in the samples of Vicia used in experimental works, in different phases of the culture was determined. The biochemical blood and feces results showing lower amounts of serum sinc and loss of Ca and Zn feces in animals poisoned by V. villosa, that developed granulomatous disease in severe and moderate conditions, possibly indicated the presence of a metabolic disorder in the pathogen of the disease.

No presente estudo caracterizou-se a epidemiologia, os sinais cl?nicos, as les?es macrosc?picas e microsc?picas da intoxica??o espont?nea e experimental por Vicia villosa, bem como a avalia??o da poss?vel toxicidade de Vicia sativa em bovinos. A doen?a granulomatosa sist?mica (DGS ervilhaca-associada) foi verificada em 7 propriedades distribu?das nos Estados de Santa Catarina, Paran? e Rio Grande do Sul, onde a alimenta??o principal era aveia e/ou azev?m consorciados com V. villosa e/ou de azev?m consorciado com V. villosa e em menor quantidade V. sativa. Todos os bovinos que desenvolveram a doen?a eram vacas, em lacta??o e da ra?a Holand?s. A DGS ervilhaca-associada foi reproduzida em seis vacas holandesas em lacta??o, atrav?s do fornecimento de V. villosa verde no cocho e em pastagens de V. villosa e azev?m. Nos demais grupos experimentais (grupo 3, V. villosa/V. sativa/vacas, pastejo; grupo 4, V. sativa/vacas, pastejo; grupo 5, V. villosa/V. sativa/novilhas e grupo 6, V. villosa/novilhas, pastejo) n?o verificou-se altera??es cl?nicas e patol?gicas relacionadas a DGS ervilhaca-associada. Das seis vacas que desenvolveram a doen?a granulomatosa sist?mica, uma vaca apresentou quadro cl?nico leve (grupo 2/vaca 6/V.villosa, pastejo), quatro vacas desenvolveram o quadro moderado da doen?a (grupo 1, vacas 1 e 2/V. villosa/cocho e grupo 2, vacas 4 e 5/V.villosa/pastejo) e apenas em uma vaca verificou-se o quadro grave da doen?a (grupo 2, vaca 3/V.villosa/pastejo). V. villosa foi t?xica para bovinos, produzindo doen?a granulomatosa cr?nica quando ingerida em quantidades superiores a 38,2g/kg/dia, por um per?odo de 71 ou, em pastoreio direto por um per?odo superior a 28 dias. As principais manifesta??es cl?nicas consistiam em ?reas de alopecia e crostas na pele, coceira, febre, conjuntivite, diarreia, queda na produ??o de leite e perda de peso. Macroscopicamente verificaram-se m?ltiplos n?dulos branco-acinzentados principalmente em linfonodos, rins e cora??o, e na histologia estes caracterizavam um infiltrado granulomatoso composto por macr?fagos, linf?citos, c?lulas gigantes, c?lulas epitelioides, plasm?citos e eosin?filos. As pastagens de V. villosa quando ingerida por bovinos jovens, por um per?odo 68 dias n?o produziu altera??es cl?nicas. As pastagens de V. sativa quando ingerida por vacas de alta produ??o leiteira por um per?odo de 76 dias n?o produziu doen?a granulomatosa cr?nica. A ingest?o de V. villosa por per?odos prolongados conduziu a baixos ?ndices produtivos como: baixa produ??o leiteira, baixos ?ndices reprodutivos e pode predispor o surgimento de doen?as infeciosas. Na an?lise bromatol?gica determinou-se a presen?a de fitato, em pequenas quantidades, nas amostras de Vicia utilizadas na experimenta??o, em diferentes fases do seu crescimento. Os resultados das an?lises bioqu?micas de amostras de sangue e fezes evidenciaram baixas quantidades s?ricas de zinco e excessivas perdas fecais de Ca e Zn nos animais intoxicados por V. villosa que desenvolveram a doen?a granulomatosa na forma moderada e grave, indicando um poss?vel envolvimento de dist?rbios de ordem metab?lica na patogenia da doen?a.