Parâmetros genéticos das características produtivas e reprodutivas de búfalos na Amazônia brasileira

Cassiano, Lisângela Aparecida Pinheiro; Mariante, A. da S.; McManus, Concepta; Marques, J. R. F.; Costa, N. A. da

doi:10.1590/s0100-204x2004000500007

Cited by 21 publications

(14 citation statements)

References 5 publications

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“…This result agrees with Sampaio Neto et al (2001) who reported a mean age at first calving of 1132.69 6 166.99 days for buffaloes from Ceará , Brazil. Cassiano et al (2004) found a mean age at first calving of 1088.03 days, a value similar to those reported in the literature. The practically constant mean ages at first calving observed for each measure of ST suggests the absence of changes in management and selection over the years with the intention to reduce the age at first calving.…”

Section: Resultssupporting

confidence: 89%

“…Sampaio Neto et al (2001) also observed a higher percentage of calvings during the rainy period (79.3%) compared to the dry season (20.7%). However, Cassiano et al (2004) who characterized phenotypically buffaloes of the Carabao, Jafarabadi, Murrah and Mediterranean breeds and Baio type observed a higher concentration of calvings between August and October, a period that precedes the one observed here.…”

Section: Resultssupporting

confidence: 54%

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Analysis of culling probability in dairy buffalo using survival models

Galeazzi

Mercadante²,

Silva³

et al. 2010

Animal

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In order to contribute to the genetic breeding programs of buffaloes, this study aimed to determine the influence of environmental effects on the stayability (ST) of dairy female Murrah buffalo in the herd. Data from 1016 buffaloes were used. ST was defined as the ability of the female to remain in the herd for 1, 2, 3, 4, 5 or 6 years after the first calving. Environmental effects were studied by survival analysis, adjusted to the fixed effects of farm, year and season of birth, class of first-lactation milk yield and age at first calving. The data were analyzed using the LIFEREG procedure of the SAS program that fits parametric models to failure time data (culling or ST 5 0), and estimates parameters by maximum likelihood estimation. Breeding farm, year of birth and first-lactation milk yield significantly influenced ( P , 0.0001) the ST to the specific ages (1 to 6 years after the first calving). Buffaloes that were older at first calving presented higher probabilities of being culled 1 year after the first calving, without any effect on culling at older ages. Buffaloes with a higher milk yield at first calving presented a lower culling probability and remained for a longer period of time in the herd. The effects of breeding farm, year of birth and first-lactation milk yield should be included in models used for the analysis of ST in buffaloes.

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Section: Resultssupporting

confidence: 89%

Section: Resultssupporting

confidence: 54%

Analysis of culling probability in dairy buffalo using survival models

Galeazzi

Mercadante²,

Silva³

et al. 2010

Animal

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“…Com aplicação do programa MTDFREML (metodologia de máxima verossimilhança restrita), Cassiano et al (2004) obtiveram estimativa de 0,62 para a raça Murrah, 0,28 para Jafarabadi e 0,39 para Carabao, enquanto que o valor estimado para a raça Mediterrâneo (0,16) foi próximo àquele de 0,14 encontrado por Mahdy et al (1999), em búfalos egípcios, indicando que a maior parte da variação seria consequência de fatores ambientais. Já Silveira (2012) utilizando o programa MTGSAM, obteve estimativa de 0,30 para a raça Mediterrâneo, que de acordo com o autor, esse valor indica bons ganhos na seleção direta desta característica.…”

Section: Discussionunclassified

“…Variabilidade genética do peso ao nascer e seleção para crescimento em bubalinos do Estado do Pará, Brasil foi igual a 0,16 (Tabela 2), valor superior ao encontrado por Thiruvenkadan et al (2009) na raça Murrah (0,12), mas semelhante ao observado em animais Mediterrâneo por Cassiano et al (2004) e em búfalos egípcios por Mahdy et al (1999). Esse valor indica grande influência de fatores de ambiente sobre a característica, no entanto assinala a existência de variabilidade genética que pode ser trabalhada em programas de seleção e melhoramento da espécie.…”

Section: Discussionunclassified

“…Neste estudo, porém, os valores de moda e mediana foram iguais a 0,14, superiores àqueles obtidos por Cassiano et al (2004) para a raça Carabao (0,11) e Murrah (0,04) e por Thiruvenkadan et al (2009) para Murrah (0,11). Todavia esses valores foram inferiores quando comparados com as raças Jafarabadi (0,17) e Mediterrâneo (0,37) no estudo de Cassiano et al (2004) e com a raça Mediterrâneo (0,31) no estudo de Silveira (2012), raças essas caracterizadas por seu maior tamanho corporal.…”

Section: Discussionunclassified

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Variabilidade genética do peso ao nascer e seleção para crescimento em bubalinos do Estado do Pará, Brasil

Aguiari¹,

Marcondes

Marques

et al. 2014

Acta Amaz.

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RESUMOO peso ao nascer constitui característica produtiva de elevada importância zootécnica, devido à sua relação com a taxa de sobrevivência à desmama e com os pesos nas demais fases de desenvolvimento do animal, quer seja para a produção de carne, leite ou em animais que se destinam à reprodução. O objetivo deste trabalho foi obter estimativas de herdabilidade e tendências fenotípicas e genéticas do peso ao nascer, em bubalinos do Estado do Pará, Brasil. Foram calculadas as estatísticas descritivas e realizado o teste de Normalidade de Shapiro-Wilk por meio do pacote estatístico Statistical Analisys System. As estimativas de herdabilidade foram obtidas por inferência Bayesiana. O peso ao nascer apresentou média de 36,6 kg. O modelo de análise considerou como fixos os efeitos de sexo, ano de nascimento e composição racial do animal e como efeitos aleatórios animal, efeito materno e residual. A distribuição da herdabilidade direta apresentou-se platicúrtica (achatada) e com maior assimetria, tendo uma distribuição bimodal com a primeira moda próxima a 0,10 e a segunda próxima a 0,30; a materna apresentou-se trimodal, com picos bem próximos a 0,15 e outro menos evidente próximo a 0,20. A tendência genética direta do peso ao nascer mostrou-se negativa (-0,03kg ano -1 ) e a tendência genética materna próxima à zero (0,001 kg ano -1 ), ainda que a tendência fenotípica tenha sido positiva (0,156kg ano -1 ). Existe variabilidade genética possível de ser trabalhada em um programa de melhoramento, no entanto, pouco foi feito quanto à seleção para crescimento em búfalos no Estado do Pará. PALAVRAS-CHAVE:Herdabilidade, inferência Bayesiana, tendência. Genetic variability of birth weight and selection for growth of water buffaloes from State of Pará, BrazilABSTRACT Birth weight is a performance parameter of great zootechnical importance for both meat and dairy production, as well as for breeding animals, mainly due to its relation to survival rate at weaning, and the weight of animals throughout their developmental and growth phases. Therefore, the objective of this work was to establish heritability estimates, as well as phenotypic and genetic trends of birth weight of water buffaloes from State of Pará, Brazil. Descriptive statistics were calculated and the Shapiro-Wilk Normality test was performed with a Statistical Analysis System package. Heritability estimates were established by Bayesian inference. BW was 36.6 kg in average. The statistical model considered sex, year of birth and breed composition of the animals as fixed effects, and animal, maternal and residual as random effects. Direct heritability was platykurtic (flattened) and with higher asymmetry, presenting a bimodal distribution with the first mode close to 0.10, and the second mode close to 0.30; the maternal heritability was trimodal, with peaks very close to 0.15, and another, less evident, close to 0.20. The direct genetic trend of birth weight was negative (-0.03kg year -1 ) and maternal genetic trend was close to zero (0.001kg ano -1 ), even though t...

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Present status of the conservation of livestock genetic resources in Brazil

et al. 2009

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Brazil has various species of domestic animals, which developed from breeds brought by the Portuguese settlers soon after the discovery of the country. After being submitted to a long process of natural selection, these breeds present characteristics adapted to specific Brazilian environmental conditions, and are known as "criollo", "local" or naturalized breeds. From the beginning of the 20th century, some exotic breeds, selected in temperate regions, have begun to be imported, and, although more productive, they do not have adaptive traits, such as resistance to disease and parasites found in the naturalized breeds. Even so, they gradually replaced the native breeds, to such an extent that the latter are in danger of extinction. To avoid further loss of this important genetic material, in 1983 the National Research Center for Genetic Resources and Biotechnology (Cenargen) of the Brazilian Agricultural Research Corporation (Embrapa) decided to include conservation of animal genetic resources among its priorities. The conservation activities have been conducted under the Brazilian Genetic Resources Network -Renargen, and is carried out by various research centres of Embrapa, universities and State research institutions, as well as by private farmers, with a single coordinator at national level, Cenargen. The in situ conservation of cattle, horses, buffaloes, donkeys, goats, sheep and pigs is being carried out by Conservation Nuclei, located in the animal's original habitat. Ex situ conservation is centred at the Brazilian Animal Germplasm Bank (AGB), kept at Cenargen. This is responsible for the storage of semen and embryos of various breeds of domestic animals threatened with extinction. Presently the AGB has almost 60,000 doses of semen and more than 250 embryos, as well as over 7000 DNA samples. An important challenge for this program is to increase awareness within the different segments of society in terms of the importance of the conservation of animal genetic resources. The development and evolution of Renargen and its efforts to facilitate the conservation of genetic resources of livestock in Brazil are described in this paper.

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Parâmetros genéticos das características produtivas e reprodutivas de búfalos na Amazônia brasileira

Cited by 21 publications

References 5 publications

Analysis of culling probability in dairy buffalo using survival models

Analysis of culling probability in dairy buffalo using survival models

Variabilidade genética do peso ao nascer e seleção para crescimento em bubalinos do Estado do Pará, Brasil

Present status of the conservation of livestock genetic resources in Brazil

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