Variance components were estimated for maturing age, first litter size, and animal size in Finnish minks. The fitted animal models had direct genetic and maternal genetic effects, litter effects, and maternal environmental effects. Multivariate analysis was performed to determine covariances between the traits. Maternal effects represented a significant source of phenotypic variance in the matu...

introduction kurdish sheep breed is one of the most important native breeds of iran. they are fat-tailed, large-sized, well adapted to the mountainous regions in northern khorasan province and mainly raising for meat production under pastoral production system (28). feed efficiency is a major component in the profitability of the small ruminant enterprise, because quality of range and pasture i...

Pregnancy rate, calf survival rate to weaning and calf age at weaning of several types of crossbred cows (2/3 or more Brahman) were compared to those of straightbred Brahman and Angus cows over a 1 2 9 period at Subtropical Agricultural Research Station near Brooksville, FL. The purpose of this study was to determine the relative importance of additive vs nonadditive genetic effects on reproduc...

Restricted maximum likelihood (REML) was used to determine the choice of statistical model, additive genetic maternal and common litter effects and consequences of ignoring these effects on estimates of variance–covariance components under random and phenotypic selection in swine using computer simulation. Two closed herds of different size and two traits, (i) pre-weaning average daily gain and...

The genetic analysis of composite data is very complicated, mainly because it is necessary to adjust data to the effects of heterosis and breed complementarity, and because there is usually considerable confounding of these data with several other effects, such as contemporary group effects, breed composition of the animal and maternal breed composition, among others. Data on birth weight (n = ...

in this study the data of 2332 lambs from 815 dams and 61 sires, collected during 1993-2004 in kermani sheep breeding station were used to estimate phenotypic, genetic and environmental trends for birth weight (bw), weaning weight (ww), 6 months weight (6mw), 9 months weight (9mw) and yearling weight (yw). heritability estimates were determined for each trait using derivative free reml procedur...

Body weight (BW) records (n=11,659) of 4961 Kurdi sheep from 215 sires and 2085 dams were used to estimate the additive genetic, direct and maternal permanent environmental effects on growth from 1 to 300 days of age. The data were collected from 1993 to 2015 at a breeding station in North Khorasan province; Iran. Genetic parameters for growth traits were estimated using random regression test-...

The aim of this study was to model the variances and covariances of body weight in Zandi sheep from 60 to 365 days of age using random regression models (RRM). Legendre polynomials of different orders were used to model the direct and maternal covariances. Mean trends were also modeled through a quadratic regression on orthogonal polynomials of age. Homogeneity and heterogeneity of the residual...

The main objective of this study was to estimate the genetic parameters for multi-trait evaluation of birth weight (BW), gestation length (GL) and calving difficulty (CD) in first-parity Iranian Holstein dairy cattle. The data included 29,950 calving records collected during 1995 to 2014 by the Animal Breeding and Improvement Center of Iran. A threshold-linear sire-maternal grandsire model was ...

While theoretical models of the evolution of parental care are based on the assumption of underlying genetic variance, surprisingly few quantitative genetic studies of this life-history trait exist. Estimation of the degree of genetic variance in parental care is important because it can be a significant source of maternal effects, which, if genetically based, represent indirect genetic effects...