| Summary: | Dissertação (mestrado)—Universidade de Brasília, Faculdade de Agronomia e Medicina Veterinária, 2007. === Submitted by Luis Felipe Souza (luis_felas@globo.com) on 2008-12-12T17:26:17Z
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Tese_2007_FlaviaMacedo.pdf: 254981 bytes, checksum: f52008703e08f7407856169ede3f36eb (MD5) === O objetivo desse experimento foi avaliar os efeitos de Nim (Azadirachta indica A. Juss) à
infecção natural de helmintos em ovinos mantidos em regime de pastejo. Quarenta ovinos inteiros da raça Santa Inês com peso médio inicial de 11 + 2,7 kg foram mantidos em pasto de Andropogon gayanus durante 20 semanas sob quatro tratamentos: Sem Nim (SN), 3 g de folha seca moída de Nim (A3), 6 g de folha seca moída de Nim (A6), e 9 g de folha seca moída de Nim (A9) ingeridos durante cinco dias consecutivos com intervalos de 25 dias. As fezes foram colhidas semanalmente, o peso e o sangue dos animais foram coletados a cada 15 dias. Após cinco meses, todos os cordeiros foram abatidos e a necropsia foi realizada para contagem dos vermes intestinais. Nenhuma diferença significativa entre tratamentos
foi observada no desempenho dos cordeiros. Os parâmetros sanguíneos acompanharam o
desenvolvimento da verminose, com os tratamentos A6 e A9 terminando o experimento com quadro clínico de anemia dos animais. No número de parasitos total, foi verificado aumento associado com as doses crescentes de Nim, principalmente devido à elevação na população de H contortus em detrimento do número de T. colubriformis para os valores mais altos de Nim (A6 e A9). As doses crescentes das folhas de Nim não promoveram o controle de endoparasitas em ovinos naturalmente infectados, ocorrendo maior desenvolvimento da hemoncose.
_________________________________________________________________________________________ ABSTRACT === The objective of this study was to evaluate the effects of neem (Azadirachta indica) on
natural helminth infection in lambs. Forty, four-month-old entire Santa Ines lambs, with
average live weight of 11 ± 2,7 kg were grazed on an Andropogon gayanus pasture, over a 20 week period. They were divided into four treatments: without drenching (ND), 3g A. indica/animal (A3), 6g A. indica/animal (A6) and 9g A. indica/animal (A9) over five
consecutive days, with an interval of 28 days between drenchings. Faeces were collected weekly and lamb weight and blood collection were carried out fortnightly. Four weeks after the last drenching all lambs were slaughtered, and worm burdens calculated. No significant differences were observed for lamb performance between treatments. Only treatment A3 showed faecal egg counts (FEC) lower than treatment ND from the 12th week, although this was also not significant. Blood parameters highlighted the progress of the worm infections, with sheep on treatments A6 and A9 ending the experiment showing anemia. There was an increase in the total number of worms associated with increasing levels of neem, especially due to the increase in number of H contortus in detriment to the number of T. colubriformis for highest levels of neem (A6 and A9). The increasing doses of neem did not improve the control of endoparasites in sheep naturally infected, increasing the development of hemonchosis.
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