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Registro Completo |
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Biblioteca(s): |
Embrapa Caprinos e Ovinos. |
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Data corrente: |
25/11/1997 |
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Data da última atualização: |
03/10/2016 |
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Autoria: |
MORRIS, C. A.; VLASSOFF, A.; BISSET, S. A.; BAKER, R. L.; WEST, C. J.; HURFORD, A. P. |
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Título: |
Responses of romney sheep to selection for resistance or susceptibility to nematode infection. |
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Ano de publicação: |
1997 |
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Fonte/Imprenta: |
Animal Science, v. 64, n. 2, p. 319-329, 1997. |
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Idioma: |
Inglês |
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Conteúdo: |
Abstract: Divergent breeding lines of Romney sheep, selected as lambs for consistently low or high faecal worm egg count (FEC) following natural multispecific challenge by nematode parasites, have been maintained at Wallaceville Animal Research Centre since 1979. From the start of the trial until 1992, 821 and 736 experimental lambs in lines selected for increased resistance (R) and increased susceptibility (S), respectively, were generated, with the use of 44 different sires. In order to assess genetic responses to selection, FEC and productivity data were analysed using restricted maximum likelihood procedures. By 1988 the two lines had diverged in average loge (FEC+100) by 0·67 log units, and by 1992 divergence had increased to 1·48 log units, representing 2·90 genetic standard deviations of divergence. No significant correlated responses were observed in live weights. However, by 1992 the mean score for breech soiling (dags) in the R line was proportionally 0·41 greater than in the S line (F < 0·001). Yearling fleece weight was proportionally 0·15 greater in S-line than in R-line animals when grazed together under identical levels of challenge (P < 0·001) but the lines did not differ significantly in fleece weight when they were grazed apart. The R line had significantly higher reproductive success than the S line (P < 0·05), as measured by lambs weaned per ewe mated (1·01 v. 0·92, respectively). It is concluded that selective breeding can change the degree of resistance or susceptibility to nematode infection in Romney sheep, and selection for productivity needs to be continued at the same time in any practical breeding programme. MenosAbstract: Divergent breeding lines of Romney sheep, selected as lambs for consistently low or high faecal worm egg count (FEC) following natural multispecific challenge by nematode parasites, have been maintained at Wallaceville Animal Research Centre since 1979. From the start of the trial until 1992, 821 and 736 experimental lambs in lines selected for increased resistance (R) and increased susceptibility (S), respectively, were generated, with the use of 44 different sires. In order to assess genetic responses to selection, FEC and productivity data were analysed using restricted maximum likelihood procedures. By 1988 the two lines had diverged in average loge (FEC+100) by 0·67 log units, and by 1992 divergence had increased to 1·48 log units, representing 2·90 genetic standard deviations of divergence. No significant correlated responses were observed in live weights. However, by 1992 the mean score for breech soiling (dags) in the R line was proportionally 0·41 greater than in the S line (F < 0·001). Yearling fleece weight was proportionally 0·15 greater in S-line than in R-line animals when grazed together under identical levels of challenge (P < 0·001) but the lines did not differ significantly in fleece weight when they were grazed apart. The R line had significantly higher reproductive success than the S line (P < 0·05), as measured by lambs weaned per ewe mated (1·01 v. 0·92, respectively). It is concluded that selective breeding can change the degree of resistance... Mostrar Tudo |
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Palavras-Chave: |
Nematodeo. |
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Thesagro: |
Ovino; Resistência. |
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Categoria do assunto: |
-- |
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Marc: |
LEADER 02267naa a2200217 a 4500
001 1517822
005 2016-10-03
008 1997 bl uuuu u00u1 u #d
100 1 $aMORRIS, C. A.
245 $aResponses of romney sheep to selection for resistance or susceptibility to nematode infection.
260 $c1997
520 $aAbstract: Divergent breeding lines of Romney sheep, selected as lambs for consistently low or high faecal worm egg count (FEC) following natural multispecific challenge by nematode parasites, have been maintained at Wallaceville Animal Research Centre since 1979. From the start of the trial until 1992, 821 and 736 experimental lambs in lines selected for increased resistance (R) and increased susceptibility (S), respectively, were generated, with the use of 44 different sires. In order to assess genetic responses to selection, FEC and productivity data were analysed using restricted maximum likelihood procedures. By 1988 the two lines had diverged in average loge (FEC+100) by 0·67 log units, and by 1992 divergence had increased to 1·48 log units, representing 2·90 genetic standard deviations of divergence. No significant correlated responses were observed in live weights. However, by 1992 the mean score for breech soiling (dags) in the R line was proportionally 0·41 greater than in the S line (F < 0·001). Yearling fleece weight was proportionally 0·15 greater in S-line than in R-line animals when grazed together under identical levels of challenge (P < 0·001) but the lines did not differ significantly in fleece weight when they were grazed apart. The R line had significantly higher reproductive success than the S line (P < 0·05), as measured by lambs weaned per ewe mated (1·01 v. 0·92, respectively). It is concluded that selective breeding can change the degree of resistance or susceptibility to nematode infection in Romney sheep, and selection for productivity needs to be continued at the same time in any practical breeding programme.
650 $aOvino
650 $aResistência
653 $aNematodeo
700 1 $aVLASSOFF, A.
700 1 $aBISSET, S. A.
700 1 $aBAKER, R. L.
700 1 $aWEST, C. J.
700 1 $aHURFORD, A. P.
773 $tAnimal Science$gv. 64, n. 2, p. 319-329, 1997.
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Registro original: |
Embrapa Caprinos e Ovinos (CNPC) |
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Registro Completo
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Biblioteca(s): |
Embrapa Cerrados. |
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Data corrente: |
27/12/2004 |
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Data da última atualização: |
28/10/2009 |
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Autoria: |
KINPARA, D. I. |
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Título: |
A importância estratégica do potássio para o Brasil. |
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Ano de publicação: |
2003 |
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Fonte/Imprenta: |
Planaltina, DF: Embrapa Cerrados, 2003. |
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Páginas: |
27 p. |
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Série: |
(Embrapa Cerrados. Documentos, 100). |
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Idioma: |
Português |
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Conteúdo: |
ABSTRACT: This paper presents the strategic importance of potassium (K) in Brazil, focusing four aspects: the function in the plant; the K content of Brazilian soil; the different K forms; and its demand in the Brazilian agricultural system. The K is not a structural element of plants, but it participates in many biochemical plant processes, like carbohydrates and proteins synthesis, showing its economical importance in terms of production. A major problem in Brazilian soils is the leaching process due to the rain regimes. Since k is a very soluble ion in the soil profile, it must be replaced in regular basics to the culture. There are five sources of K, all them of high solubility. Less soluble K compounds have been studied as a way to minimize the leaching problem. Brazil imported 88,5% of the K consumed in 2002, coming from Canada, Germany, Russia and Israel. The organic agriculture and pasture reclamation are rising as potential markets for new forms of K. |
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Palavras-Chave: |
Brasil; Demand; Econimia; Potássi; Socioeconomia; Socioeconomic. |
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Thesagro: |
Cerrado; Demanda; Economia; Exportação; Fertilizante; Importação; Mercado; Pastagem; Potássio; Solo. |
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Thesaurus NAL: |
Brazil; economics; exports; fertilizers; imports; markets; potassium. |
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Categoria do assunto: |
-- |
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URL: |
https://ainfo.cnptia.embrapa.br/digital/bitstream/CPAC-2009/25159/1/doc_100.pdf
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Marc: |
LEADER 01933nam a2200409 a 4500
001 1568191
005 2009-10-28
008 2003 bl uuuu u0uu1 u #d
100 1 $aKINPARA, D. I.
245 $aA importância estratégica do potássio para o Brasil.
260 $aPlanaltina, DF: Embrapa Cerrados$c2003
300 $a27 p.
490 $a(Embrapa Cerrados. Documentos, 100).
520 $aABSTRACT: This paper presents the strategic importance of potassium (K) in Brazil, focusing four aspects: the function in the plant; the K content of Brazilian soil; the different K forms; and its demand in the Brazilian agricultural system. The K is not a structural element of plants, but it participates in many biochemical plant processes, like carbohydrates and proteins synthesis, showing its economical importance in terms of production. A major problem in Brazilian soils is the leaching process due to the rain regimes. Since k is a very soluble ion in the soil profile, it must be replaced in regular basics to the culture. There are five sources of K, all them of high solubility. Less soluble K compounds have been studied as a way to minimize the leaching problem. Brazil imported 88,5% of the K consumed in 2002, coming from Canada, Germany, Russia and Israel. The organic agriculture and pasture reclamation are rising as potential markets for new forms of K.
650 $aBrazil
650 $aeconomics
650 $aexports
650 $afertilizers
650 $aimports
650 $amarkets
650 $apotassium
650 $aCerrado
650 $aDemanda
650 $aEconomia
650 $aExportação
650 $aFertilizante
650 $aImportação
650 $aMercado
650 $aPastagem
650 $aPotássio
650 $aSolo
653 $aBrasil
653 $aDemand
653 $aEconimia
653 $aPotássi
653 $aSocioeconomia
653 $aSocioeconomic
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