Efeitos da raça e da heterozigose sobre características ponderais de bezerros Nelore e mestiços Red Angus x Nelore

Perotto, Daniel; Abrahão, José Jorge dos Santos; Cubas, Antonio Carlos

doi:10.1590/s1516-35981999000300010

Cited by 11 publications

(12 citation statements)

References 7 publications

(6 reference statements)

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“…Many authors (Madalena et al, 1990;Perotto et al, 1999;Facó et al, 2002Facó et al, , 2008 used the multiple regression model (Robison et al, 1981) to obtain estimates of heterosis effects separated from the breed's transmitted effects. This approach is based on the assumption that the expression of heterosis is a linear function of the coefficient of individual heterozygosis (an expression which defines the expected proportion of loci with one gene from one breed and the other gene from another breed).…”

Section: Resultsmentioning

confidence: 99%

Milk production of crossbred Holstein × Zebu cows in the northeastern region of Paraná State

2010

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-The objective of this work was to evaluate milk production of a Holstein × Zebu herd managed on a semiintensive system at Estação Experimental Joaquim Távora, IAPAR, in the northeastern region of Paraná -Brazil. Two hundred and seventeen records on milk production per lactation period (MY), milk production up to 305 days of lactation (MY305) and length of lactation period (LL) of 82 crossbred cows varying in breed composition were analyzed according to a linear statistical model that included the fixed effects of breed composition, season and year at onset of lactation, order of parturition and place of birth, in addition to the experimental error. Cows born in Joaquim Távora had longer lactation periods and produced more milk than cows born in Ibiporã. The effects of year and season at the beginning of the lactation period influenced all three traits. Both milk production per lactation period and milk production up to 305 days of lactation that began from April to June were superior to those that began from October to December, as well as to those starting from January to March. The order of parturition had a strong effect upon both milk production per lactation period and milk production up to 305 days of lactation. Maximum milk production was attained during the sixth lactation period, although no difference was detected for the contrasts between the sixth and other higher order lactation periods. All traits increased as the proportion of Holstein in the breed composition of the animal increased from 0.5 to 0.875 and decreased thereafter. These results support the argument against complete grading up to Holstein in semi-intensive production systems in sub-tropical regions.

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Section: Resultsmentioning

confidence: 99%

Milk production of crossbred Holstein × Zebu cows in the northeastern region of Paraná State

2010

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“…Os valores que atestam a superioridade dos machos sobre as fêmeas já foram relatados previamente (PEROTTO et al, 1999). O efeito aleatório de touro dentro de cada grupo genético foi significativo para PNT (P<0,05), PDS (P<0,01) e GMD_ND (P<0,01), indicativo de marcantes diferenças entre touros dentro de cada raça.…”

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Desempenho até a desmama de bezerros Nelore e cruzas com Nelore

et al. 2001

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Foi analisado o desempenho ponderal pré-desmama de bezerros Nelore (N), Guzerá x N (GN), Red Angus x N (RN) e Marchigiana x N (MN), oriundos de um experimento de cruzamentos realizado na Estação Experimental do IAPAR de Paranavaí, nascidos no período de 1985 a 1998, produzidos por meio de inseminação artificial, em duas estações anuais de nascimento (janeiro a abril e julho a dezembro). Foi utilizado o método dos quadrados mínimos para análise de 721 observações de pesos ao nascimento (PNT) e 686 de pesos à desmama (PDS) e ganho médio diário de peso do nascimento até a desmama (GMD_ND). Para PNT, o efeito de classe de datas julianas com intervalos de dez dias entre classes mostrou-se mais útil para explicar variações de épocas de nascimento do que o mês de nascimento, cuja influência foi muito grande para PDS e GMD_ND. Para as três características avaliadas, houve importante efeito (linear e quadrático) da idade da vaca (dias) mãe do bezerro, bem como dos efeitos fixos de raça do touro ou grupo genético, ano de nascimento do bezerro e sexo do bezerro. A interação grupo genético x sexo do bezerro foi efeito importante para PNT, PDS e GMD_ND. O efeito aleatório de touro dentro de grupo genético foi importante para PNT, PDS e GMD_ND. As médias dos quadrados mínimos e respectivos erros-padrão, sempre na seqüência N, GN, RN e MN, foram: 28,5 ± 0,38 kg, 29,0 ± 0,44 kg, 29,4 ± 0,46 kg e 31,3 ± 0,47 kg, para PNT; 141,3 ± 1,47 kg, 147,6 ± 1,61 kg, 167,5 ± 1,72 kg e 162,0 ± 1,89 kg, para PDS; 0,510 ± 0,007 kg, 0,540 ± 0,008 kg, 0,627 ± 0,008 kg e 0,583 ± 0,009 kg, para GMD_ND.

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“…These estimates show higher magnitudes than those obtained through the RM model, being closer to the R and H estimates and disagreeing with a possible inflation attributed to these models. Perotto et al (1999), working on data from crossbred Red Angus and Nellore in Brazil, found maternal and individual heterosis effects (P < 0.001) equal to 30.5 and 27.2 kg, respectively.…”

Section: Resultsmentioning

confidence: 99%

“…In Brazil, Perotto et al (1999), studying the weight of crossbred young males of Red Angus and Nellore breeds, obtained significant values (P < 0.05) for individual and maternal heterosis.…”

Section: Introductionmentioning

confidence: 99%

Non-additive genetic effects on weights and performance of a Brazilian Bos taurus x Bos indicus beef composite

Mourão¹,

Ferraz²,

Eler³

et al. 2008

Genet. Mol. Res.

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ABSTRACT. The aim of the present study was to evaluate the heterosis effects on weaning weight at 205 days (WW, N = 146,464), yearling weight at 390 days (YW, N = 69,315) and weight gain from weaning to yearling (WG, N = 59,307) in composite beef cattle. The fixed models were: RM, which included contemporary groups, class of age of dam, outcrossing percentages for direct and maternal effects, and additive direct and maternal (AM) breed effects; R, RM model, minus AM breed effects, and H, RM model, minus additive breed effects. The estimates for W205 were in general positive (P < 0.01). The R and H models resulted in similar estimates, but they were very different from the ones estimated by the RM model. For W390, the R and H models resulted in general positive estimates (P < 0.05). For WG, the RM model resulted in 1157 ©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 7 (4): 1156-1163 (2008 Non-additive genetic effects in Bos taurus x Bos indicus general significant heterosis effects (P < 0.05). It can be concluded that the RM model seems to supply estimates of better quality (P < 0.01).

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Efeitos da raça e da heterozigose sobre características ponderais de bezerros Nelore e mestiços Red Angus x Nelore

Cited by 11 publications

References 7 publications

Milk production of crossbred Holstein × Zebu cows in the northeastern region of Paraná State

Milk production of crossbred Holstein × Zebu cows in the northeastern region of Paraná State

Desempenho até a desmama de bezerros Nelore e cruzas com Nelore

Non-additive genetic effects on weights and performance of a Brazilian Bos taurus x Bos indicus beef composite

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