Research Article

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Given the important role of leptin in metabolism, we looked for a possible association of leptin and leptin receptor polymorphisms with carcass and growth traits in Nellore cattle. We examined associations of leptin and leptin receptor SNPs with ultrasound carcass (longissimus dorsi muscle area (ribeye area), backfat thickness and rump fat thickness and growth traits (weaning weight ... more

R.C.G. da Silva; J.B.S. Ferraz; F.V. Meirelles; J.P. Eler; J.C.C. Balieiro; D.C. Cucco; E.C. Mattos; F.M. Rezende; S.L. Silva
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Age at first calving; Beef cattle; Hip height; Scrotal circumference; Weight gain

We investigated genetic associations between mature cow weight (MW) and weaning weight (WW), yearling weight (YW), weight gain from birth to weaning (GBW), weight gain from weaning to yearling (GWY), weaning hip height (WHH), yearling hip height (YHH), scrotal circumference (SC), and age at first calving (AFC). Data from 127,104 Nellore animals born between 1993 and 2006, belonging to ... more

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Beef cattle; Performance tests; Random regression

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Beef cattle; Gibbs sampling; Monte Carlo method; Threshold models

Finishing precocity visual score selection was adopted to estimate the time from birth to reach slaughter age. This study estimated (co)variance components and genetic correlations for the finishing precocity score at weaning (WP) and yearling (YP) stages by using daily weight gain (BWG = from birth to weaning; WYG = from weaning to yearling) and speed of weight gain (BWR = from birth to ... more

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Beef cattle; Categorical trait; Conformation; Production traits

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Beef cattle; Breeding value; Genetic evaluation; Selection index; Sire ranking

For genetic evaluation of beef cattle, univariate or bivariate analyses are often performed as an alternative to decrease the complexity of matrices and mathematical models compared to multivariate analysis, which considers a larger number of joint traits. The use of bivariate methods to calculate genetic predictors may cause bias in the estimation of breeding values and, as a ... more

V.B. Pedrosa; E. Groeneveld; J.P. Eler; J.B.S. Ferraz
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Beef cattle; Censored records; Fertility; Heritability; Reproduction

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M.H. Van Melis; L.G.G. Figueiredo; H.N. Oliveira; J.P. Eler; G.J.M. Rosa; M.L. Santana; F.M. Rezende; J.B.S. Ferraz
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Beef cattle; Bos taurus indicus; Molecular markers; Ultrasonographic traits; Weight

The aim of the study was to detect polymorphisms in the leptin gene and to determine the association of these polymorphisms with growth and carcass traits in Nellore cattle. The single nucleotide polymorphisms (SNPs) -1457 (AJ571671:g.-1457A>G) and A59V (AF536174.1:g. 321C>T), as well as the microsatellite BM1500 (3.9 kb downstream), were genotyped. The measures of body weight and ... more

D.B.S. Silva; B.A. Crispim; L.E. Silva; J.A. Oliveira; F. Siqueira; L.O. Seno; A.B. Grisolia
06/29/2015
Beef cattle; Legendre polynomials; Scrotal circumference; Yearling weight

The objective of this study was to quantify the magnitude of genotype-environment interaction (GxE) effects on age at first calving (AFC), scrotal circumference (SC), and yearling weight (YW) in Nellore cattle using reaction norms. For the study, 89,152 weight records of female and male Nellore animals obtained at yearling age were used. Genetic parameters were estimated with a single- ... more

M.V.A. Lemos; H.L.J. Chiaia; M.P. Berton; F.L.B. Feitosa; C. Aboujaoude; G.C. Venturini; H.N. Oliveira; L.G. Albuquerque; F. Baldi

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