scholarly journals Genetic parameters for some growth traits of Nigerian local chickens

2017 ◽  
Vol 33 (1) ◽  
pp. 65-71 ◽  
Author(s):  
Ifeanyichukwu Udeh
Keyword(s):  
Unbiased Estimator ◽  
Variance Components ◽  
Genetic Parameters ◽  
Mixed Model ◽  
Wing Length ◽  
Growth Traits ◽  
Genetic Correlations ◽  
Mass Selection ◽  
Minimum Norm ◽  
Local Chickens

Genetic parameters were estimated for bodyweight (BWT), shank length (SHL), and wing length (WL) of Nigerian local chicken (NLC) from 4 to 20 weeks of age by fitting dyadic mixed model (dmm) equations which yield estimates of variance components equivalent to minimum norm quadratic unbiased estimator (MINQUE). Data obtained from 600 chicks, progenies of 300 hens and 30 cocks were used for the analysis. The heritability estimates range from 0.08 to 0.80 for BWT, 0.03 to 0.69 for SHL and 0.22 to 0.47 for WL. The genetic correlations among BWT, SHL and WL at different ages were high and positive and range from 0.18 to 0.96 with the exemption of SHL and WL at 16 weeks (- 0.06). The phenotypic correlations were positive and range from 0.10 to 0.91. The results imply that NLC could be improved on any of the studied traits through mass selection and that improvement in one trait will result to correlated improvement in the others.

scholarly journals EFFECT OF FIXED FACTORS AND ESTIMATION OF GENETIC PARAMETERS OF GROWTH TRAITS FOR MOUNTAIN KIDS

2019 ◽  
Vol 50 (6) ◽  
Author(s):  
Hermiz & Baper
Keyword(s):  
Variance Components ◽  
Fixed Effects ◽  
Genetic Parameters ◽  
Maximum Likelihood Method ◽  
Growth Traits ◽  
Genetic Correlations ◽  
Likelihood Method ◽  
Phenotypic Correlations ◽  
Body Weights ◽  
Genetic And Phenotypic Correlations

Body weights at birth (469), weaning (394) and at six month of age (358) for kids utilized in this study were raised at private project in Duhok governorate, Iraq during two kidding season (2016-2017) and (2017-2018). GLM within SAS programme was used to analyze the data which include the fixed effects (age of doe, year and season of kidding, sex of kid and type of birth, regression on doe weight at kidding, and the regression of later weights of kids on earlier weights) influencing the studied traits. Restricted Maximum Likelihood Method was used to estimate repeatability, heritability, genetic and phenotypic correlations after adjusting the records for fixed effects. Variance components of random effects were tested for positive definite. Overall mean of weights at birth (BWT), weaning (WWT) and 6 month of age (WT6M) were 2.92, 15.32 and 24.45 kg, respectively. Differences among groups of age of doe in all studied traits were not significant, while year of kidding and sex of kid affect all traits significantly (p<0.01). Season of kidding affect BWT and WWT significantly (P<0.01). Single born kids were heavier (P<0.01) than twins in BWT only. Regression of BWT on doe weight at kidding (0.033 kg/kg) was significant (P<0.01), while the regressions of WWT and WT6M were not significant. The regression coefficients of WWT on BWT (1.906 kg/kg) and of WT6M on WWT (0.835 kg/kg) were highly significant (P<0.01). Repeatability estimates for BWT, WWT and WT6M were 0.47, 0.45 and 0.35, respectively; on the same order the estimates of heritability were 0.41, 0.61 and 0.79. Genetic correlations between BWT with each of WWT (0.45) and WT6M (0.55), and between WWT and WT6M (0.68) were highly significant. All phenotypic correlations between each pair of body weights were higher than genetic correlations and ranged between 0.48 and 0.73.

scholarly journals 211 Changes in genetic parameters of fitness and growth traits under genomic selection in pigs

2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 41-41
Author(s):  
Jorge Hidalgo ◽  
Shogo Tsuruta ◽  
Daniela Lourenco ◽  
Yijian Huang ◽  
Kent Gray ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Genomic Selection ◽  
Variance Components ◽  
Genetic Parameters ◽  
Growth Traits ◽  
Average Daily Gain ◽  
Genetic Correlations ◽  
Data Set ◽  
Daily Gain ◽  
Over Time

Abstract Genomic selection increases intensity of selection and decreases generation interval. However, intensive selection reduces genetic variation and can strengthen undesirable genetic correlations. The purpose of this study was to investigate changes in genetic parameters of litter size (LS), number born alive (NBA), number born dead (NBD) and average daily gain (ADG) and weight at off-test (WT) in pigs over time. The data set contained 20,086 (LS), 21,230 (NBA), 21,230 (NBD), 144,717 (ADG) and 144,718 (WT) phenotypic records. Pedigree file included 369,776 animals born between 2001 and 2018, of which 39,038 were genotyped. Two trait models were evaluated (LS-ADG, LS-WT, NBA-ADG, NBA-WT, NBD-ADG and NBD-WT) using 3-year sliding subsets starting from 2010. Variance components and genetic parameters were estimated using GIBBS2F90 program. Computations were performed with (BLUP) or without (ssGBLUP) genotypes. For BLUP (ssGBLUP), the changes in heritability from 2010–2012 to 2015–2018 were 0.08 to 0.09 (0.08 to 0.06) for LS, 0.33 to 0.24 (0.37 to 0.16) for ADG, 0.11 to 0.07 (0.10 to 0.07) for NBD, and 0.32 to 0.24 (0.38 to 0.17) for WT. Differences were also observed for genetic correlations as they were -0.23 to -0.73 (-0.31 to -0.58) for LS-ADG, -0.24 to -0.74 (-0.31 to -0.50) for LS-WT, -0.33 to -0.65 (-0.41 to -0.53) for NBA-ADG, -0.35 to -0.66 (-0.42 to -0.45) for NBA-WT, 0.12 to 0.04 (0.12 to 0.16) for NBD-ADG, and 0.11 to 0.05 (0.11 to 0.22) for NBD-WT. Genomic selection in pigs reduced heritabilities and emphasized the antagonistic relationship that are under strong selection. Heritabilities estimated from ssGBLUP declined more than those by BLUP while changes in the genetic correlations were smaller and more gradual by ssGBLUP. Differences between ssGBLUP and BLUP could be caused by genomic pre-selection unaccounted for by BLUP.

scholarly journals Estimation of heritability for immunoglobulin concentrations in colostrum and serum in Holstein cows and their calves

2021 ◽  
Vol 66 (No. 5) ◽  
pp. 149-155
Author(s):  
Serdar Duru ◽  
Elif Abdullahoğlu ◽  
Abdurrahman Özlüer ◽  
İsmail Filya
Keyword(s):  
Immunoglobulin G ◽  
Variance Components ◽  
Genetic Improvement ◽  
Genetic Parameters ◽  
Mixed Model ◽  
Genetic Correlations ◽  
Passive Transfer ◽  
Holstein Cows ◽  
Bivariate Analysis ◽  
Serum Total Protein

In the present study, colostrum quality in Holstein cows and their genetic parameters for passive transfer traits in calves were estimated. In order to get an estimation, colostrum Brix (ColBrix), colostrum immunoglobulin G (ColIgG) of Holstein cows, and serum total protein (STP) and serum immunoglobulin G (SIgG) levels of the calves of selected cows raised in a private livestock company in Turkey were assessed. Variance components and genetic parameters were estimated by MTDFREML using a mixed model. The heritability for ColBrix, ColIgG, STP and SIgG was estimated to be 0.19 ± 0.07, 0.19 ± 0.07, 0.36 ± 0.10 and 0.34 ± 0.10, respectively. According to the results of bivariate analysis, genetic correlations between the traits varied between –0.98 and +0.98. There was a sufficient genetic variance for SIgG in the calves in the population and thus a significant genetic improvement may be achieved by selection in order to increase the passive transfer. It will be worthwhile to continue the efforts for genetic improvement studies which have the potential to reduce calf deaths in the future.

scholarly journals Estimates of (co)variance components and genetic parameters of growth traits in Marwari sheep

2014 ◽  
Vol 44 (1) ◽  
pp. 27-35 ◽  
Author(s):  
H. Singh ◽  
U. Pannu ◽  
H.K. Narula ◽  
A. Chopra ◽  
V. Naharwara ◽  
...  
Keyword(s):  
Variance Components ◽  
Genetic Parameters ◽  
Growth Traits

scholarly journals GENETIC PARAMETERS FOR GROWTH TRAITS OF SANTA INES SHEEP USING GIBBS SAMPLING

2015 ◽  
Vol 28 (4) ◽  
pp. 211-216 ◽  
Author(s):  
LEANDRO TEIXEIRA BARBOSA ◽  
GLEICIANNY DE BRITO SANTOS ◽  
EVANDRO NEVES MUNIZ ◽  
HYMERSON COSTA AZEVEDO ◽  
JAILSON LARA FAGUNDES
Keyword(s):  
Gibbs Sampling ◽  
Genetic Parameters ◽  
Mixed Model ◽  
Growth Traits ◽  
Meat Production ◽  
Gibbs Sampling Algorithm ◽  
Santa Inês ◽  
Variance Parameters ◽  
Additive Genetic Effects ◽  
Maternal Heritability

ABSTRACT: This study sought to estimate (co)variance and genetic parameters for birth weight (BWT) and weaning weight (WWT) in Santa Ines sheep. A total of 2,111 records were obtained from EMBRAPA/CPATC experimental herds, dating from the years 1998 to 2008. (Co)variance parameters were obtained through a two-trait analysis with the Gibbs sampling algorithm using the MTGSAM program. The mixed model included the environmental effects of sex, contemporary group and type of birth, in addition to residual, direct and maternal additive effects. Mean estimates of direct heritability for BWT and WWT were 0.25 and 0.09, respectively. Mean estimates of maternal heritability were 0.34 for BWT and 0.24 for WWT. The genetic correlation between BWT and WWT was 0.14. The results suggest that breeding Santa Ines sheep for meat production must take into consideration direct and maternal additive genetic effects.

scholarly journals Evaluación fenotípica y genética para características de crecimiento en la raza criolla colombiana Costeño con Cuernos

2007 ◽  
Vol 7 (2) ◽  
pp. 12 ◽  
Author(s):  
Rodrigo Alfredo Martínez ◽  
Juan Esteban Pérez ◽  
Teófilo Herazo
Keyword(s):  
Birth Weight ◽  
Variance Components ◽  
Fixed Effects ◽  
Genetic Parameters ◽  
Growth Traits ◽  
Phenotypic Correlation ◽  
Phenotypic Variance ◽  
Direct Effects ◽  
Weaning Weight ◽  
Number Of Births

<p>Se establecieron componentes de varianza, así como parámetros fenotípicos y genéticos, respecto de las variables ‘peso al nacimiento’, ‘peso al destete’ (ajustado a los 270 días) y ‘peso a los 480 días’ en un hato del ganado criollo colombiano Costeño con Cuernos. Se analizaron 2.281 registros de pesos al nacer, 1.722 de pesos al destete  y 1.086 de pesos ajustados a los 480 días utilizando la metodología de máxima verosimilitud restringida (DFREML). También se ajustó un modelo animal que incluyó efectos genéticos directos, maternos y de ambiente permanente, asumiendo como efectos fijos el año de nacimiento, el sexo del ternero y el número de partos de la madre; finalmente, se estimaron los parámetros genéticos ‘heredabilidad’, ‘repetibilildad’ y se establecieron correlaciones genéticas y fenotípicas. Se reportan bajas estimaciones de heredabilidad de los efectos directos, que varían entre 0,17 ± 0,001 y 0,21 ± 0,074 para los pesos al nacer y al destete, respectivamente; así mismo, fue baja la heredabilidad de los efectos genéticos maternos con relación al peso al nacimiento, aunque estos estimados aumentaron respecto de los pesos al nacer y al destete. Las correlaciones entre efectos directos y maternos fueron negativas, pero el mayor valor se encontró para el peso al nacimiento (-0,89). La contribución del ambiente permanente como proporción de la varianza fenotípica total fue baja y disminuyó a medida que aumentó la edad del animal.</p><p> </p><p><strong>Genetic and phenotypic evaluation to characterize growth traits of the native Colombian breed Costeño con Cuernos</strong></p><p>For a herd of native Colombian breed of cattle -Costeño con Cuernos (CCC)- estimates of variance components for phenotypic and genetic parameters were obtained for birth weight, weight at weaning (adjusted to 270 days) and weight at 480 days. Using the restricted maximum likelihood (REMI) methodology, 2281 birth weight records (PN), 1722 weaning weight records and 1086 weight records adjusted to 480 days were analyze by fitting a model which included direct and maternal genetics effects as well as permanent environmental effects, assuming that fixed effects were year of birth weight, calf gender and the mother number of births. The genetic parameters for heritability, repeatability, genetic and phenotypic correlation were estimated and genotypic and phenotypic correlation was established. Heritability estimates for direct effects are low and range from 0.17 ± 0.001 and 0.21 ± 0.074 for birth and weaning weight respectively; while estimates for maternal genetics effects were also low for PN, they were higher for weaning weight and weight at 480 days. There was a negative correlation between direct and maternal effects, and the higher value was for PN (-0.89). The contribution of the variable permanent environment measured as the contribution of the phenotypic variance was low and diminished as animal age increased.</p>

scholarly journals Estimation of variance components of milk, fat, and protein yields of Tunisian Holstein dairy cattle using Bayesian and REML methods

2016 ◽  
Vol 59 (2) ◽  
pp. 243-248 ◽  
Author(s):  
Hafedh Ben Zaabza ◽  
Abderrahmen Ben Gara ◽  
Hedi Hammami ◽  
Mohamed Amine Ferchichi ◽  
Boulbaba Rekik
Keyword(s):  
Dairy Cattle ◽  
Bayesian Methods ◽  
Milk Fat ◽  
Variance Components ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Bayesian Procedure ◽  
Milk Traits ◽  
Residual Variances ◽  
Estimation Of Variance

Abstract. A multi-trait repeatability animal model under restricted maximum likelihood (REML) and Bayesian methods was used to estimate genetic parameters of milk, fat, and protein yields in Tunisian Holstein cows. The estimates of heritability for milk, fat, and protein yields from the REML procedure were 0.21 ± 0.05, 0.159 ± 0.04, and 0.158 ± 0.04, respectively. The corresponding results from the Bayesian procedure were 0.273 ± 0.02, 0.198 ± 0.01, and 0.187 ± 0.01. Heritability estimates tended to be larger via the Bayesian than those obtained by the REML method. Genetic and permanent environmental variances estimated by REML were smaller than those obtained by the Bayesian analysis. Inversely, REML estimates of the residual variances were larger than Bayesian estimates. Genetic and permanent correlation estimates were on the other hand comparable by both REML and Bayesian methods with permanent environmental being larger than genetic correlations. Results from this study confirm previous reports on genetic parameters for milk traits in Tunisian Holsteins and suggest that a multi-trait approach can be an alternative for implementing a routine genetic evaluation of the Tunisian dairy cattle population.

scholarly journals Estimates of (co)variance components and genetic parameters for body weights and growth efficiency traits in the New Zealand white rabbit

2017 ◽  
Vol 25 (4) ◽  
pp. 329 ◽  
Author(s):  
M. Sakthivel ◽  
D. Balasubramanyam ◽  
P. Kumarasamy ◽  
H. Gopi ◽  
A. Raja ◽  
...  
Keyword(s):  
Body Weight ◽  
New Zealand ◽  
Variance Components ◽  
Environmental Effect ◽  
Genetic Parameters ◽  
Growth Traits ◽  
Genetic Effect ◽  
Growth Efficiency ◽  
Body Weights ◽  
Heritability Estimates

The genetic parameters of growth traits in the New Zealand White rabbits kept at Sheep Breeding and Research Station, Sandynallah, The Nilgiris, India were estimated by partitioning the variance and covariance components. The (co)variance components of body weights at weaning (W42), post-weaning (W70) and marketing (W135) age and growth efficiency traits viz., average daily gain (ADG), relative growth rate (RGR) and Kleiber ratio (KR) estimated on a daily basis at different age intervals (42 to 70 d; 70 to 135 d and 42 to 135 d) from weaning to marketing were estimated by restricted maximum likelihood, fitting 6 animal models with various combinations of direct and maternal effects. Data were collected over a period of 15 yr (1998 to 2012). A log-likelihood ratio test was used to select the most appropriate univariate model for each trait, which was subsequently used in bivariate analysis. Heritability estimates for W42, W70 and W135 were 0.42±0.07, 0.40±0.08 and 0.27±0.07, respectively. Heritability estimates of growth efficiency traits were moderate to high (0.18 to 0.42). Of the total phenotypic variation, maternal genetic effect contributed 14 to 32% for early body weight traits (W42 and W70) and ADG1. The contribution of maternal permanent environmental effect varied from 6 to 18% for W42 and for all the growth efficiency traits except for KR2. Maternal permanent environmental effect on most of the growth efficiency traits was a carryover effect of maternal care during weaning. Direct maternal genetic correlations, for the traits in which maternal genetic effect was significant, were moderate to high in magnitude and negative in direction. Maternal effect declined as the age of the animal increased. The estimates of total heritability and maternal across year repeatability for growth traits were moderate and an optimum rate of genetic progress seems possible in the herd by mass selection. The genetic and phenotypic correlations among body weights and between growth efficiency traits were also estimated. Moderate to high heritability and higher genetic correlation in body weight traits promise good scope for genetic improvement provided measures are taken to keep the inbreeding at the lowest level.

scholarly journals (Co)variance components and genetic parameters for growth rate and Kleiber ratio in fat-tailed Mehraban sheep

2013 ◽  
Vol 56 (1) ◽  
pp. 564-572 ◽  
Author(s):  
F. Ghafouri-Kesbi
Keyword(s):  
Growth Rate ◽  
Variance Components ◽  
Genetic Parameters ◽  
Average Daily Gain ◽  
Genetic Correlations ◽  
Phenotypic Variance ◽  
Genetic Progress ◽  
Kleiber Ratio ◽  
Derivative Free ◽  
Maternal Heritability

Abstract. The aim of the present study was to estimate (co)variance components and genetic parameters for average daily gain from birth to weaning (ADGa), weaning to 6 months (ADGb), weaning to 9 months (ADGc), 6 months to 9 months (ADGd) and corresponding Kleiber ratios (KRa, KRb, KRc and KRd) in Mehraban sheep. A derivative-free algorithm combined with a series of six univariate linear animal models was used to estimate phenotypic variance and its direct, maternal and residual components. In addition, bivariate analyses were done to estimate (co)variance components between traits. Estimates of direct heritability (h2) were 0.10, 0.11, 0.16, 0.09, 0.13, 0.13, 0.15 and 0.08 for ADGa, ADGb, ADGc, ADGd, KRa, KRb, KRc and KRd, respectively and indicate that in Mehraban sheep genes contribute very little to the variance of the growth rate and Kleiber ratio. Estimates of maternal heritability (m2) were 0.10, 0.08 and 0.05 for ADGa, KRa and KRb, respectively. Direct additive genetic correlations ranged from −0.32 (KRa-KRd) to 0.99 (ADGb-KRb) and phenotypic correlations ranged from −0.53 (ADGa- ADGd) to 0.99 (ADGa-KRa). Estimates of direct heritability and genetic correlations show that genetic improvement in efficiency of feed utilization through selection programmes is possible, though it would generate a relatively slow genetic progress.

Genetic parameters for daily live-weight gain, live fleshiness and bone thinness in station-tested Piemontese young bulls

2001 ◽  
Vol 72 (3) ◽  
pp. 449-456 ◽  
Author(s):  
A. Albera ◽  
R. Mantovani ◽  
G. Bittante ◽  
A. F. Groen ◽  
P. Carnier
Keyword(s):  
Weight Gain ◽  
Genetic Parameters ◽  
Growth Traits ◽  
Genetic Correlations ◽  
Live Weight ◽  
Adaptation Period ◽  
Production Traits ◽  
Multiple Trait ◽  
Live Weight Gain ◽  
Total Gain

AbstractEstimates of genetic parameters for beef production traits were obtained for Piemontese cattle. Data were from 988 young bulls station-tested from 1989 till 1998. Bulls entered the station at 6 to 8 weeks of age and, after an adaptation period of 3 months, were tested for growth, live fleshiness and bone thinness. Length of test was 196 days. Growth traits considered were gain at farm, gain during the adaptation period, gain on test and total gain at the station. Six different fleshiness traits and bone thinness were scored on live animals at the end of the test using a linear system. Live evaluations of fleshiness were adjusted for the weight at scoring in order to provide an assessment of conformation independent of body size. Genetic parameters were estimated using animal models. Heritability of live-weight gain ranged from 0·20 in the adaptation period to 0·60 for total gain at the station. Genetic correlations between gains at station in different periods were high (from 0·63 to 0·97). Residual correlation between gain during the adaptation period and gain during test was negative, probably due to the occurrence of compensatory growth of the animals.Live fleshiness traits and bone thinness were of moderate to high heritability (from 0·34 to 0·55) and highly correlated indicating that heavy muscled bulls also have thin bones. Accuracy of breeding values and therefore response to selection were improved by multiple trait analysis of the live fleshiness traits and bone thinness. Overall weight gain at the station had a moderate negative genetic correlation with all live fleshiness traits and bone thinness (from –0·11 to –0·39).

Sign in / Sign up

Export Citation Format

Share Document