Seasonal effect of three pasture plants species on the free-living stages of Haemonchus contortus
Carregando...
Data
2008-08-01
Autores
Carneiro, R.D.
Amarante, Alessandro Francisco Talamini do [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Federal de Minas Gerais (UFMG), Escola de Veterinária
Resumo
Avaliaram-se o desenvolvimento e a sobrevivência dos estágios de vida livre de Haemonchus contortus em fezes obtidas de ovinos infectados por esse nematódeo, depositadas nas quatro estações do ano, em pastagens de três espécies de gramíneas (Brachiaria decumbens cv Australiana, Cynodon dactylon cv. Coast-cross e Panicum maximum cv. Aruana), com duas alturas (5cm e 30cm) no momento da deposição das fezes. Amostras de fezes e de capim foram coletadas uma, duas, quatro, oito, 12 e 16 semanas após a deposição das fezes e processadas em laboratório, para recuperação de larvas infectantes. O maior número de larvas infectantes foi recuperado das amostras de capim e de fezes nas pastagens com 30cm de altura. As condições climáticas que mais favoreceram o desenvolvimento e a sobrevivência das larvas nas fezes, bem como a sobrevivência e a manutenção das larvas no capim foram aquelas com temperaturas médias em torno de 17ºC, acompanhadas de baixas precipitações pluviométricas. As temperaturas mais altas e as precipitações elevadas, que ocorrem na chamada estação das águas, foram desfavoráveis para a recuperação de larvas infectantes da pastagem. de forma geral, a pastagem de Aruana foi a que possibilitou as maiores recuperações de larvas.
To evaluate both the development and survival of free-living stages of Haemonchus contortus obtained from feces of infected ovine in the four seasons of the year, eggs of this nematode were deposited on three grass species commonly used as sheep pasture in Brazil (Brachiaria decumbens cv. Australian, Cynodon dactylon cv. Coast-cross, and Panicum maximum cv. Aruana). The grasses were cut 5 or 30cm height before depositing the feces. Samples of grasses and feces were collected in six sub-plots from each plot one, two, four, eight, 12, and 16 weeks after contamination to determine the recovery of infective H. contortus larvae. Most infective larvae were recovered from feces or grass samples deposited on 30cm height herbage. High temperature and precipitation levels during the rainy season reduced the infective larvae recovery period from the environment. The best weather conditions for larvae development and survival, in both feces and grasses, were lower temperatures, around 17ºC, in association with low precipitation levels. In general, more larvae were recovered when fecal samples were deposited on Aruana grass.
To evaluate both the development and survival of free-living stages of Haemonchus contortus obtained from feces of infected ovine in the four seasons of the year, eggs of this nematode were deposited on three grass species commonly used as sheep pasture in Brazil (Brachiaria decumbens cv. Australian, Cynodon dactylon cv. Coast-cross, and Panicum maximum cv. Aruana). The grasses were cut 5 or 30cm height before depositing the feces. Samples of grasses and feces were collected in six sub-plots from each plot one, two, four, eight, 12, and 16 weeks after contamination to determine the recovery of infective H. contortus larvae. Most infective larvae were recovered from feces or grass samples deposited on 30cm height herbage. High temperature and precipitation levels during the rainy season reduced the infective larvae recovery period from the environment. The best weather conditions for larvae development and survival, in both feces and grasses, were lower temperatures, around 17ºC, in association with low precipitation levels. In general, more larvae were recovered when fecal samples were deposited on Aruana grass.
Descrição
Palavras-chave
ovino, Haemoncus contortus, pastagem, sheep, Haemonchus contortus, pasture
Como citar
Arquivo Brasileiro de Medicina Veterinária e Zootecnia. Universidade Federal de Minas Gerais, Escola de Veterinária, v. 60, n. 4, p. 864-872, 2008.