Research Article

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03/11/2008
Beef cattle; Genetic trend; Heritability; Productive efficiency; Selection

With the aim of estimating the coefficient of heritability of average annual productivity of Nellore cows (COWPROD), a data set from 24,855 animals with known pedigree was analyzed. COWPROD is defined as the amount (in kilograms) of weaned calves produced yearly by one cow during her remaining time in herd ignoring a fixed period of 365 days. COWPROD was calculated regarding three standards: a ... more

J.P. Eler; J.B.S. Ferraz; J.C.C. Balieiro; E.C. Mattos
03/23/2010
Beef cattle; Genetic and phenotypic correlations; Heritability; Maternal effect; Swiss cattle; Weight gain

Genetic parameters for traits related to postweaning growth in Braunvieh cattle, reared under tropical and sub-tropical conditions in Brazil, were studied. Weight traits were weight at 365 days of age (W365, N = 4055), at 450 days (W450, N = 3453), and at 550 days (W550, N = 1946), while weight gains were gain from weaning to 365 days of age (WGW365, N = 3060), from weaning to 450 days ( ... more

D.C. Cucco; J.B.S. Ferraz; J.P. Eler; J.C.C. Balieiro; E.C. Mattos; L. Varona
12/19/2012
Bayesian inference; Beef cattle; Fertility; Genetic parameters

We estimated heritability for subsequent rebreeding (SR) of heifers and genetic correlations between this trait and weaning weight (WW), weight gain from weaning to yearling (WG), age at first calving (AFC), and mature cow weight (MW), in order to evaluate whether SR could be included as selection criterion in Nellore cattle. The SR of heifers was defined by attributing a value of 1 ( ... more

A.A. Boligon; F. Baldi; L.G. Albuquerque
03/10/2009
Beef cattle; Genetic and phenotypic correlation; Heritability; Maternal effect; Suizo cattle; Weight gain

The objective of this study was to estimate genetic parameters for pre-weaning traits of Braunvieh cattle raised under tropical conditions in Brazil. The weight and weight gain parameters were birth weight (BW, N = 9955), weight at 120 days of age (W120, N = 5901), weaning weight at 205 days (WW, N = 6970), weight gain from birth to 205 days (GAIN205, N = 6013), weight gain from birth to 120 ... more

D.C. Cucco; J.B.S. Ferraz; L.F.B. Pinto; J.P. Eler; J.C.C. Balieiro; E.C. Mattos
02/02/2010
Bayesian approach; Beef cattle; Bos indicus; Genetic correlation; Growth traits; Reproduction

Survival or longevity is an economically important trait in beef cattle. The main inconvenience for its inclusion in selection criteria is delayed recording of phenotypic data and the high computational demand for including survival in proportional hazard models. Thus, identification of a longevity-correlated trait that could be recorded early in life would be very useful for selection ... more

M.H. Van Melis; H.N. Oliveira; J.P. Eler; J.B.S. Ferraz; J. Casellas; L. Varona
02/21/2014
Beef cattle; Contemporary group; Genetic correlation; Heritability

Data from 69,525 animals were used to compare two types of analyses, one of them having the weaning management group (WEMANG) included as an effect in the contemporary group (F_WEMANG) and the other considering the weaning management group as a random effect, not related to the mathematical model (R_WEMANG) for post-weaning traits. The components of (co)variance were estimated for pre- ... more

V.B. Pedrosa; J.P. Eler; J.B.S. Ferraz; E. Groeneveld
07/05/2011
Fertility; Genetic association; Hatchability; Heritability; White leghorn

Studies estimating genetic parameters for reproductive traits in chickens can be useful for understanding and improvement of their genetic architecture. A total of 1276 observations of fertility (FERT), hatchability of fertile eggs (HFE) and hatchability of total eggs (HTE) were used to estimate the genetic and phenotypic parameters of 467 females from an F2 population generated by ... more

R.P. Savegnago; M.E. Buzanskas; B.N. Nunes; S.B. Ramos; M.C. Ledur; K. Nones; D.P. Munari
01/25/2003
Africanized; Apis mellifera; Effective reproduction; Fertility; Reproduction; Varroa

Varroa destructor reproductive success is considered an important character for determining the resistance of honey bees to this mite parasite. However, most of the published data are not comparable due to the different methods of ascertaining and reporting reproduction. A recently published technique that involves reconstructing mite families in older worker brood gives ... more

M.H. Corrêa-Marques; L.Medina Medina; S.J. Martin; D. De Jong
10/22/2002
Beef cattle; Heritability; Selection; Tropics; Weights

(Co)variance components and genetic parameters were estimated for body weights of an elite Brahman herd under a designed, supervised management and genetic program, including strategic artificial insemination (AI). Restricted maximum likelihood methods were used with a univariate animal model for birth weight (BW) and a bivariate model for weaning weight (205-day weight, 205W) and 18 ... more

D. Plasse; O. Verde; J. Arango; L. Camaripano; H. Fossi; R. Romero; C.Rodriguez M.; J.L. Rumbos
11/02/2008
Beef cattle; Breeding efficiency; Longevity; Selection

The objective of the present study was to estimate (co)variance components for length of productive life (LPL) and some alternative reproductive traits of 6-year-old Nellore cattle. The data set contained 57,410 records for age at first calving from Nellore females and was edited to remove animal records with uncertain paternity and cows with just one piece of calving information. Only animals ... more

J.C.C. Balieiro; J.P. Eler; J.B.S. Ferraz; E.C. Mattos; C.C. Balieiro

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