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Registro Completo |
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Biblioteca(s): |
Embrapa Caprinos e Ovinos. |
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Data corrente: |
01/08/1992 |
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Data da última atualização: |
23/07/2025 |
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Autoria: |
SOUTHCOTT, W. H.; MAJOR, G. W.; BARGER, I. A. |
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Título: |
Seasonal pasture contamination and avaibality of nematodes for grazing sheep. |
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Ano de publicação: |
1976 |
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Fonte/Imprenta: |
Australian Journal of Agricultural Research, v. 27, n. 2, p. 277-286, 1976. |
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DOI: |
10.1071/AR9760277 |
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Idioma: |
Inglês |
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Conteúdo: |
Abstract: In December 1970 and in January, February, March, April, May and September 1971 separate plots of sown pasture, each 0.1 ha, were contaminated by grazing sheep infected with gastrointestinal nematodes. In succeeding months each plot was grazed by worm-free tracer lambs for 2 weeks; the lambs were then withdrawn and held for 2 weeks in pens before slaughter for total differential worm counts. Observations on each plot continued for 12 months; the numbers of worms found in the tracer lambs indicated the seasonal occurrence of nematode larvae on pasture. For Haemonchus contortus, larval availability from deposition was rapid in summer and slow in autumn, maximum inhibition at the fourth larval stage occurring in larvae picked up in the winter months. Ostertagia spp. presented a marked contrast, with curtailed development in summer and contamination in autumn producing high levels of infection on pasture in late winter and early spring when inhibition was at maximum levels. Of the other species studied, intestinal Trichostrongylus spp, showed a similar pattern of development to H. contortus in summer, but as with Ostertagia spp. autumn contamination could produce infection peaks in late winter and spring. Inhibition at the fourth larval stage was not a characteristic of intestinal Trichostrongylus spp. For T. axei autumn and winter conditions favoured development, and peak infestations occurred in spring and coincided with maximum inhibition. Nematodirus spp. developed mainly in summer and most inhibition occurred at this time. Spring (September) contamination with Nematodirus spp. did not result in detectable levels of infection. For all other species spring contamination was rapidly translated to pasture and the infection was comparatively short-lived. All species were capable of overwintering on pasture and with the possible exception of T. axei a persistence of infection of at least 12 months was demonstrated. For Ostertagia spp. the importance of late summer and autumn contamination in its epizootiology and control in a summer rainfall region has been confirmed. MenosAbstract: In December 1970 and in January, February, March, April, May and September 1971 separate plots of sown pasture, each 0.1 ha, were contaminated by grazing sheep infected with gastrointestinal nematodes. In succeeding months each plot was grazed by worm-free tracer lambs for 2 weeks; the lambs were then withdrawn and held for 2 weeks in pens before slaughter for total differential worm counts. Observations on each plot continued for 12 months; the numbers of worms found in the tracer lambs indicated the seasonal occurrence of nematode larvae on pasture. For Haemonchus contortus, larval availability from deposition was rapid in summer and slow in autumn, maximum inhibition at the fourth larval stage occurring in larvae picked up in the winter months. Ostertagia spp. presented a marked contrast, with curtailed development in summer and contamination in autumn producing high levels of infection on pasture in late winter and early spring when inhibition was at maximum levels. Of the other species studied, intestinal Trichostrongylus spp, showed a similar pattern of development to H. contortus in summer, but as with Ostertagia spp. autumn contamination could produce infection peaks in late winter and spring. Inhibition at the fourth larval stage was not a characteristic of intestinal Trichostrongylus spp. For T. axei autumn and winter conditions favoured development, and peak infestations occurred in spring and coincided with maximum inhibition. Nematodirus spp. developed... Mostrar Tudo |
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Palavras-Chave: |
Nematodeo. |
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Thesagro: |
Epidemiologia; Haemonchus Contortus; Ovino; Parasitologia. |
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Thesaurus Nal: |
Epidemiology; Gastrointestinal nematodes; Nematodirus; Ostertagia; Parasitology; Sheep diseases; Trichostrongylus. |
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Categoria do assunto: |
H Saúde e Patologia |
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Marc: |
LEADER 02974naa a2200301 a 4500
001 1521952
005 2025-07-23
008 1976 bl uuuu u00u1 u #d
024 7 $a10.1071/AR9760277$2DOI
100 1 $aSOUTHCOTT, W. H.
245 $aSeasonal pasture contamination and avaibality of nematodes for grazing sheep.$h[electronic resource]
260 $c1976
520 $aAbstract: In December 1970 and in January, February, March, April, May and September 1971 separate plots of sown pasture, each 0.1 ha, were contaminated by grazing sheep infected with gastrointestinal nematodes. In succeeding months each plot was grazed by worm-free tracer lambs for 2 weeks; the lambs were then withdrawn and held for 2 weeks in pens before slaughter for total differential worm counts. Observations on each plot continued for 12 months; the numbers of worms found in the tracer lambs indicated the seasonal occurrence of nematode larvae on pasture. For Haemonchus contortus, larval availability from deposition was rapid in summer and slow in autumn, maximum inhibition at the fourth larval stage occurring in larvae picked up in the winter months. Ostertagia spp. presented a marked contrast, with curtailed development in summer and contamination in autumn producing high levels of infection on pasture in late winter and early spring when inhibition was at maximum levels. Of the other species studied, intestinal Trichostrongylus spp, showed a similar pattern of development to H. contortus in summer, but as with Ostertagia spp. autumn contamination could produce infection peaks in late winter and spring. Inhibition at the fourth larval stage was not a characteristic of intestinal Trichostrongylus spp. For T. axei autumn and winter conditions favoured development, and peak infestations occurred in spring and coincided with maximum inhibition. Nematodirus spp. developed mainly in summer and most inhibition occurred at this time. Spring (September) contamination with Nematodirus spp. did not result in detectable levels of infection. For all other species spring contamination was rapidly translated to pasture and the infection was comparatively short-lived. All species were capable of overwintering on pasture and with the possible exception of T. axei a persistence of infection of at least 12 months was demonstrated. For Ostertagia spp. the importance of late summer and autumn contamination in its epizootiology and control in a summer rainfall region has been confirmed.
650 $aEpidemiology
650 $aGastrointestinal nematodes
650 $aNematodirus
650 $aOstertagia
650 $aParasitology
650 $aSheep diseases
650 $aTrichostrongylus
650 $aEpidemiologia
650 $aHaemonchus Contortus
650 $aOvino
650 $aParasitologia
653 $aNematodeo
700 1 $aMAJOR, G. W.
700 1 $aBARGER, I. A.
773 $tAustralian Journal of Agricultural Research$gv. 27, n. 2, p. 277-286, 1976.
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Registro original: |
Embrapa Caprinos e Ovinos (CNPC) |
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