The classical twin design (CTD) circumvents parameter indeterminacy by assuming (1) negligible higher-order epistasis; and (2) either nonadditive genetic or common environmental effects are nonexistent, creating two potential sources of bias (Eaves et al., 1978; Grayson, 1989). Because the extended twin-family design (ETFD) uses many more unique covariance observations to estimate parameters, c...

Genetic parameters for a random regression model of growth in Gelbvieh beef cattle were constructed using existing estimates. Information for variances along ages was provided by parameters used for routine Gelbvieh multiple-trait evaluation, and information on correlations among different ages was provided by random regression model estimates from literature studies involving Nellore cattle. B...

the objective followed in this study was to compare six software packages (dfreml, wombat, asreml, matvec, dmu and thrgibbsf90) as based on some such features as being user friendly, easing computational facilities as well as accuracy and precision of the estimated genetic vs. environmental parameters. for conduction of the study, simulated and field data (birth weights and weaning weight of ba...

correlation between breeding value of crude milk (cm) and energy-corrected milk (ecm) was studied based on a total of 774,013 test day records belongs to 88,456 first-parity holsteins dairy cattle calving during 1997-2009 in 165 herds (from six provinces). genetic analysis of the traits was carried out by a fixed regression test day model. in the model, effects of herd, calving year, production...

This study aimed to clarify genetic and environmental contributions to Carabelli trait variation on permanent first molar teeth in a large sample of South Australian twins. Estimates of polychoric correlations were obtained between pairs of monozygous (MZ) and dizygous (DZ) twins for Carabelli data and various gene-environment models fitted by a weighted least-squares approach. The favored mode...

The mode of agronomic traits inheritance was investigated in safflower (Carthamus tinctorius L.) in drought stress as a new report. Five generation including P1, P2, F1, F2 and F3 that derived from the cross of IL.111 (drought sensitive) ×Mex.22-191 (drought tolerance) were used in a randomized complete block design with two replic...

Genetic parameters from a second generation (F 2) disconnected diallel progeny test of the New Zealand radiata pine improvement progamme are presented. Heritability estimates of growth and yield traits of 0.2 are similar to progeny test results of the previous generation (F 1). Coefficients of variation for additive genetic and phenotypic variances are also similar between generations. Quality ...

the purpose of this study was to investigate the relationship of maternal breeding values of the weight of day-old chick chicks in a commercial broiler line with egg traits including yolk fatty acids. maternal breeding values of 63 hens of known pedigree were estimated through an animal model, containing direct additive genetic effect, maternal additive genetic effect, maternal common environme...