نتایج جستجو برای: maternal additive genetic effect
تعداد نتایج: 2326057 فیلتر نتایج به سال:
Maternal inputs to offspring early in development are initially high but the process of development suggests that ontogenetic shifts in the importance of maternal genetic variation relative to other sources should occur. We investigated additive genetic variance and covariance for direct (animal), sire, and maternal effects on embryonic length (EL), yolk sac volume (YSV), and alevin (after yolk...
Estimates of (co)variance components and genetic parameters were obtained for birth, 205-d, and 365-d weight for Nelore cattle in Brazil, using single and multiple-trait animal models. Data were from the Brazilian Zebu Breeders Association (ABCZ). Records of 27,549 calves sired by 587 bulls and raised on pasture in 57 herds were analyzed by restricted maximum likelihood fitting an animal model ...
Epidemiological studies suggest that allergy risk is preferentially transmitted through mothers. This can be due to genomic imprinting, where the phenotype effect of an allele depends on its parental origin, or due to maternal effects reflecting the maternal genome's influence on the child during prenatal development. Loss-of-function mutations in the filaggrin gene (FLG) cause skin barrier def...
The objective of this study was to estimate genetic parameters and to investigate the type of gene action in controlling androgenesis in wheat. Two wheat cultivars of Grebe and Houtman were reciprocally crossed with two synthetic genotypes of Do1 and Pol and then a complete set of the parents, F1, reciprocal F1 (RF1), F2 and back-cross generations (BC1 and BC2) of each cross were used for anthe...
Direct additive and maternal genetic effects on birth and weaning weight of Chios lambs were investigated. The data originated from the Agricultural Research Station of Chalkidiki and comprised 7318 lambs, raised over the period from 1977 to 1992. Variance components were estimated using restricted maximum likelihood, fitting six different animal models, by 2 including or excluding maternal eff...
Genetic and environmental (co)variances for birth weight, adjusted 200-d weight, and postweaning gain were estimated in nine parental and three composite populations of beef cattle. The parental breeds were Angus (A), Braunvieh (B), Charolais (C), Gelbvieh (G), Hereford (H), Limousin (L), Pinzgauer (P), Red Poll (R), and Simmental (S). The composites were MARC I (1/4 B, 1/4 C, 1/4 L, 1/8 H, 1/8...
The objective of the present study was to estimate genetic parameters and trends for average daily gains and Kleiber ratios in Moghani sheep. The included traits were average daily gain from birth to 3 months of age (ADG1), average daily gain from birth to 6 months of age (ADG2), average daily gain from 3 months to 6 months of age (ADG3), average daily gain from 3 months to 9 months of age (ADG...
Effects of nine generations of 450r per generation of ancestral spermatogonial X irradiation of inbred rats on genetic parameters of body weight at 3, 6, and 10 weeks of age and of weight gains between these periods were studied. Covariances among relatives were estimated by mixed model and regression techniques in randomly selected lines with (R) and without (C) radiation history. Analyses of ...
Additive genetic variances and covariances of quantitative characters are necessary to predict the evolutionary response of the mean phenotype vector in a population to natural or artificial selection. Standard formulas for estimating these parameters, from the resemblance between relatives in one or two characters at a time, are biased by natural selection on the parents and by maternal effect...
Optimum weighting ratios of maternal:direct EBV for litter size using an animal model were examined to achieve maximum genetic improvement (direct plus maternal response). Stochastic simulation of a 120-sow herd over a 10-yr period of selection was used (20 replicates). Directional selection was based on a merit function of maternal and direct EBV for first-parity litter size. Optimum weighting...
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