| |
|
|
| Registros recuperados : 360 | |
| Registros recuperados : 360 | |
|
|
|
 | Acesso ao texto completo restrito à biblioteca da Embrapa Gado de Leite. Para informações adicionais entre em contato com cnpgl.biblioteca@embrapa.br. |
Registro Completo
|
Biblioteca(s): |
Embrapa Gado de Leite. |
|
Data corrente: |
19/12/2012 |
|
Data da última atualização: |
09/08/2022 |
|
Tipo da produção científica: |
Artigo em Periódico Indexado |
|
Circulação/Nível: |
B - 5 |
|
Autoria: |
MADALENA, F.; PEIXOTO, M. G. C. D.; GIBSON, J. |
|
Afiliação: |
FERNANDO MADALENA; MARIA GABRIELA CAMPOLINA D PEIXOTO, CNPGL; J. GIBSON, UNIVERSITY OF NEW ENGLAND. |
|
Título: |
Dairy cattle genetics and its applications in Brazil. |
|
Ano de publicação: |
2012 |
|
Fonte/Imprenta: |
Livestock Research for Rural Development, v. 24, n. 6, article 97, 2012. |
|
Idioma: |
Inglês |
|
Conteúdo: |
The Brazilian dairy industry is based mainly on pasture-oriented, dual purpose systems in the tropical part of the Country, utilizing B. taurus x B. indicus hybrid animals, mostly Holstein/Gir, milked with restricted suckling of calves, which was shown to be more economical than artificial rearing in most circumstances. The Brazilian farmers have maintained for decades the dairy herd intermediate between B. taurus and B. indicus. Results of surveys and census data reveal a wide variation in dairy farm size, which is associated with different genotype use; low-input, smaller farms use a higher proportion of the more resilient, low B. taurus grade cows, while larger farms use more of the higher yielding, higher B. taurus grades. A trial comparing contemporaneous females (527) of six Holstein-Friesian (H) x Guzerá crosses (¼ to ?31/32/ H) milked twice a day with the calf stimulus in 67 farms showed important favourable heterosis in milk solids yield, fertility, mortality, herd life, weight, weight/height ratio and tick resistance, leading to an overwhelming importance of heterosis for profitability, particularly in lower input farms. Profit per day of herd life was higher for F1 than for other crossbreeding strategies. In low management farms crisscrossing attained predicted 59% of the F1 profit, ? inter se 30% and ?31/32 H (upgrading to H) -21%, i.e. were uneconomic. In better managed farms a strategy of repeating the H sires for two generations followed by one generation by Zebu sires attained 75% of the F1 profit, the same as the ?31/32 H, while the ? H inter se showed a negative profit of -18%. Hence, new breeds developed from crossbred foundations would suffer from loss of heterosis. Subsequent analyses of data from institutional or private herds supported those conclusions except for cows mechanically milked and artificial calf rearing, in which milk yield increased with higher Holstein gene fractions, although economic analyses have not been conducted in such systems. The published evidence does not support the widely held breeders? belief that a ? inter se Holstein composite is an optimal goal. For systems in which the male calves were not reared, three way Jersey/H/Gir crosses were more profitable than H/Gir and Brown Swiss/H/Gir on account of their higher fertility, lower weight and longer herd life. Progeny testing programmes in the Gir, Guzerá and Girolando breeds are described along with an associated embryo transfer full-sib selection programme in the Guzerá. These programmes have given great commercial impact to those breeds. Holstein genes flow into Brazil from abroad, mostly via imported semen which accounts for 92% of the total semen sold of this breed. Very little genetic progress has been made for milk yield in this breed despite the high genetic correlation between yield in Brazil and in semen exporting countries and fertility and health problems have been reported. Extensive research is conducted in Minas Gerais State on production systems based on F1 B. taurus x B. indicus hybrids. Milk yield per day of calving interval in H x Gir, H x Guzerá and H x Nelore F1 crosses was 7.1, 6.4 and 5.6 kg/d, respectively, and weight at first calving 448, 466 and 461 kg. A strategy of continuous replacement with F1 B. taurus x B. indicus heifers may be very profitable depending on price and availability of such animals and several current commercial developments in the production of F1s, either by artificial insemination or by ovum pick up and in vitro fertilization with sexed semen are reviewed. MenosThe Brazilian dairy industry is based mainly on pasture-oriented, dual purpose systems in the tropical part of the Country, utilizing B. taurus x B. indicus hybrid animals, mostly Holstein/Gir, milked with restricted suckling of calves, which was shown to be more economical than artificial rearing in most circumstances. The Brazilian farmers have maintained for decades the dairy herd intermediate between B. taurus and B. indicus. Results of surveys and census data reveal a wide variation in dairy farm size, which is associated with different genotype use; low-input, smaller farms use a higher proportion of the more resilient, low B. taurus grade cows, while larger farms use more of the higher yielding, higher B. taurus grades. A trial comparing contemporaneous females (527) of six Holstein-Friesian (H) x Guzerá crosses (¼ to ?31/32/ H) milked twice a day with the calf stimulus in 67 farms showed important favourable heterosis in milk solids yield, fertility, mortality, herd life, weight, weight/height ratio and tick resistance, leading to an overwhelming importance of heterosis for profitability, particularly in lower input farms. Profit per day of herd life was higher for F1 than for other crossbreeding strategies. In low management farms crisscrossing attained predicted 59% of the F1 profit, ? inter se 30% and ?31/32 H (upgrading to H) -21%, i.e. were uneconomic. In better managed farms a strategy of repeating the H sires for two generations followed by one generation by Z... Mostrar Tudo |
|
Thesagro: |
Cruzamento Animal; Gado Gir; Gado Guzerá; Produção Leiteira. |
|
Thesaurus NAL: |
Girolando; heterosis. |
|
Categoria do assunto: |
L Ciência Animal e Produtos de Origem Animal |
|
Marc: |
LEADER 04182naa a2200217 a 4500
001 1943149
005 2022-08-09
008 2012 bl uuuu u00u1 u #d
100 1 $aMADALENA, F.
245 $aDairy cattle genetics and its applications in Brazil.$h[electronic resource]
260 $c2012
520 $aThe Brazilian dairy industry is based mainly on pasture-oriented, dual purpose systems in the tropical part of the Country, utilizing B. taurus x B. indicus hybrid animals, mostly Holstein/Gir, milked with restricted suckling of calves, which was shown to be more economical than artificial rearing in most circumstances. The Brazilian farmers have maintained for decades the dairy herd intermediate between B. taurus and B. indicus. Results of surveys and census data reveal a wide variation in dairy farm size, which is associated with different genotype use; low-input, smaller farms use a higher proportion of the more resilient, low B. taurus grade cows, while larger farms use more of the higher yielding, higher B. taurus grades. A trial comparing contemporaneous females (527) of six Holstein-Friesian (H) x Guzerá crosses (¼ to ?31/32/ H) milked twice a day with the calf stimulus in 67 farms showed important favourable heterosis in milk solids yield, fertility, mortality, herd life, weight, weight/height ratio and tick resistance, leading to an overwhelming importance of heterosis for profitability, particularly in lower input farms. Profit per day of herd life was higher for F1 than for other crossbreeding strategies. In low management farms crisscrossing attained predicted 59% of the F1 profit, ? inter se 30% and ?31/32 H (upgrading to H) -21%, i.e. were uneconomic. In better managed farms a strategy of repeating the H sires for two generations followed by one generation by Zebu sires attained 75% of the F1 profit, the same as the ?31/32 H, while the ? H inter se showed a negative profit of -18%. Hence, new breeds developed from crossbred foundations would suffer from loss of heterosis. Subsequent analyses of data from institutional or private herds supported those conclusions except for cows mechanically milked and artificial calf rearing, in which milk yield increased with higher Holstein gene fractions, although economic analyses have not been conducted in such systems. The published evidence does not support the widely held breeders? belief that a ? inter se Holstein composite is an optimal goal. For systems in which the male calves were not reared, three way Jersey/H/Gir crosses were more profitable than H/Gir and Brown Swiss/H/Gir on account of their higher fertility, lower weight and longer herd life. Progeny testing programmes in the Gir, Guzerá and Girolando breeds are described along with an associated embryo transfer full-sib selection programme in the Guzerá. These programmes have given great commercial impact to those breeds. Holstein genes flow into Brazil from abroad, mostly via imported semen which accounts for 92% of the total semen sold of this breed. Very little genetic progress has been made for milk yield in this breed despite the high genetic correlation between yield in Brazil and in semen exporting countries and fertility and health problems have been reported. Extensive research is conducted in Minas Gerais State on production systems based on F1 B. taurus x B. indicus hybrids. Milk yield per day of calving interval in H x Gir, H x Guzerá and H x Nelore F1 crosses was 7.1, 6.4 and 5.6 kg/d, respectively, and weight at first calving 448, 466 and 461 kg. A strategy of continuous replacement with F1 B. taurus x B. indicus heifers may be very profitable depending on price and availability of such animals and several current commercial developments in the production of F1s, either by artificial insemination or by ovum pick up and in vitro fertilization with sexed semen are reviewed.
650 $aGirolando
650 $aheterosis
650 $aCruzamento Animal
650 $aGado Gir
650 $aGado Guzerá
650 $aProdução Leiteira
700 1 $aPEIXOTO, M. G. C. D.
700 1 $aGIBSON, J.
773 $tLivestock Research for Rural Development$gv. 24, n. 6, article 97, 2012.
Download
Esconder MarcMostrar Marc Completo |
|
Registro original: |
Embrapa Gado de Leite (CNPGL) |
|
|
Biblioteca |
ID |
Origem |
Tipo/Formato |
Classificação |
Cutter |
Registro |
Volume |
Status |
Fechar
|
| Nenhum registro encontrado para a expressão de busca informada. |
|
|
