Ocorrência e efeito temporal das espécies do gênero Eimeria Schneider, 1875 em cordeiros confinados
Data
2018-11-13
Autores
Rahal, Natália Machado
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
A infecção patogênica por Eimeria spp., denominada eimeriose ou coccidiose, tem sido indicada como responsável por mortes, queda no desenvolvimento e baixa produtividade em criações animais, ocorrendo principalmente em indivíduos jovens devido à imaturidade do sistema imunológico. Quando são submetidos a um sistema intensivo de produção, como em situação de confinamento, cordeiros podem se tornar ainda mais susceptíveis às infecções por espécies de Eimeria, devido à alta concentração de indivíduos, que potencializa a dispersão do parasito, e ao estresse associado à criação. No estado de São Paulo, já foram identificadas dez espécies de Eimeria em estudos prévios e, dentre elas, E. ovinoidalis foi considerada a mais patogênica para ovinos. Dessa forma, o objetivo deste trabalho foi descrever as espécies do gênero Eimeria Schneider, 1875 que ocorreram em um confinamento de cordeiros, bem como as dinâmicas da eliminação de oocistos no ambiente e correlação com o ganho de peso médio diário (GMD) durante nove semanas. Cento e quatro cordeiros de diversas raças e cruzas, com aproximadamente 60 dias de vida, foram confinados e submetidos a pesagens, avaliações clínicas e coprológicas periódicas. Amostras de fezes que continham mais de 500 oocistos de Eimeria por gramas de fezes (OoPG) foram separadas para esporulação, posteriormente determinando-se as espécies às quais os oocistos pertenciam. Dentre os 677 oocistos avaliados, as seguintes espécies foram identificadas: E. parva Kotlan, Moscy & Vajda, 1929, E. crandallis Honess, 1942, E. ovinoidalis McDougald, 1979, E. weybridgensis Norton, Joyner & Catchpole 1974, E. bakuensis Musaev, 1970 (sinônimo E. ovina Levine & Ivens, 1970), E. marsica Restani, 1971, E. ahsata Honess, 1942, E. granulosa Christensen, 1938, E. pallida Christensen, 1938 e E. faurei Moussu & Marotel, 1902. Eimeria crandallis foi a espécie mais frequente, sendo identificada em 44 das 58 amostras avaliadas, enquanto Eimeria parva, na maioria das semanas, foi a mais abundante nas contagens individuais. Nenhum dos animais apresentou quadro de eimeriose clínica e houve correlação negativa, porém não significativa, entre o GMD e o OoPG para todos os cordeiros (- 0,075), bem como para os dados referentes a animais das cruzas Dorper e Ile de France (– 0,143 e – 0,077, respectivamente). Conclui-se que, para este estudo, a constante exposição a oocistos esporulados, inclusive de espécies patogênicas, e o estresse, gerado pelo manejo diário e sistema de criação, não foram suficientes para causar quadros de eimeriose.
Pathogenic infection caused by Eimeria spp., denominated eimeriosis or coccidiosis, has been pointed out as responsible for deaths, decreased development and low productivity for livestock animals, affecting mainly young individuals due to immature immunological system. When submitted to an intensive breeding system, as a feedlot, lambs can become even more susceptible to Eimeria infections, due to high concentration of animals, which potentializes parasite dispersion, and to stress generated by farming conditions. In São Paulo State, ten Eimeria species were identified in previous studies and, among them, E. ovinoidalis, was considered the most pathogenic for ovine. So, this study aimed to describe species of the Eimeria Schneider, 1875 that occurred in a lamb feedlot, as well as the dynamics of oocyst output in the environment and its correlation with daily weight gain (DWG) during nine weeks. One hundred and four lambs of various breeds and crossbreeds, at approximately 60 days old, were placed in a feedlot and submitted to periodic weighing, clinical and coprological evaluations. Fecal samples that had more than 500 Eimeria spp. oocysts per gram (OPG) were separated for sporulation, and oocysts were identified at species level. Among the 677 evaluated oocysts, the following species were identified: E. parva Kotlan, Moscy & Vajda, 1929, E. crandallis Honess, 1942, E. ovinoidalis McDougald, 1979, E. weybridgensis Norton, Joyner & Catchpole 1974, E. bakuensis Musaev, 1970 (synonym E. ovina Levine & Ivens, 1970), E. marsica Restani, 1971, E. ahsata Honess, 1942, E. granulosa Christensen, 1938, E. pallida Christensen, 1938 and E. faurei Moussu & Marotel, 1902. Eimeria crandallis was the most frequent one, being identified in 44 of the 58 evaluated samples, while Eimeria parva was the more abundant in individual counts in most weeks. None of the animals presented clinical signs of eimeriosis and there was a negative, though non significant, correlation between OPG and DWG for all lambs (- 0.075), as for data reffering to animals of Dorper and Ile de France crossbreed (–0,143 e –0,077, respectively). The constant exposure to sporulated oocysts, including pathogenic Eimeria species, and the stress, caused by daily handling of the animals and the intensive breeding system, were not sufficient to cause eimeriosis.
Pathogenic infection caused by Eimeria spp., denominated eimeriosis or coccidiosis, has been pointed out as responsible for deaths, decreased development and low productivity for livestock animals, affecting mainly young individuals due to immature immunological system. When submitted to an intensive breeding system, as a feedlot, lambs can become even more susceptible to Eimeria infections, due to high concentration of animals, which potentializes parasite dispersion, and to stress generated by farming conditions. In São Paulo State, ten Eimeria species were identified in previous studies and, among them, E. ovinoidalis, was considered the most pathogenic for ovine. So, this study aimed to describe species of the Eimeria Schneider, 1875 that occurred in a lamb feedlot, as well as the dynamics of oocyst output in the environment and its correlation with daily weight gain (DWG) during nine weeks. One hundred and four lambs of various breeds and crossbreeds, at approximately 60 days old, were placed in a feedlot and submitted to periodic weighing, clinical and coprological evaluations. Fecal samples that had more than 500 Eimeria spp. oocysts per gram (OPG) were separated for sporulation, and oocysts were identified at species level. Among the 677 evaluated oocysts, the following species were identified: E. parva Kotlan, Moscy & Vajda, 1929, E. crandallis Honess, 1942, E. ovinoidalis McDougald, 1979, E. weybridgensis Norton, Joyner & Catchpole 1974, E. bakuensis Musaev, 1970 (synonym E. ovina Levine & Ivens, 1970), E. marsica Restani, 1971, E. ahsata Honess, 1942, E. granulosa Christensen, 1938, E. pallida Christensen, 1938 and E. faurei Moussu & Marotel, 1902. Eimeria crandallis was the most frequent one, being identified in 44 of the 58 evaluated samples, while Eimeria parva was the more abundant in individual counts in most weeks. None of the animals presented clinical signs of eimeriosis and there was a negative, though non significant, correlation between OPG and DWG for all lambs (- 0.075), as for data reffering to animals of Dorper and Ile de France crossbreed (–0,143 e –0,077, respectively). The constant exposure to sporulated oocysts, including pathogenic Eimeria species, and the stress, caused by daily handling of the animals and the intensive breeding system, were not sufficient to cause eimeriosis.
Descrição
Palavras-chave
Ganho de peso, Oocistos, Ovinos, Coccidiose, Weight gain, Oocysts, Ovine, Coccidiosis