Estimates of genetic parameters and genetic trends for pre-weaning growth traits in Sardi sheep

2017 ◽  
Vol 146 ◽  
pp. 61-68 ◽  
Author(s):  
I. Boujenane ◽  
I.T. Diallo
Keyword(s):  
Genetic Parameters ◽  
Growth Traits ◽  
Genetic Trends

scholarly journals Analysis of genetic parameters and genetic trends for early growth traits in Iranian Afshari sheep

2018 ◽  
Vol 34 (3) ◽  
pp. 289-301
Author(s):  
Meysam Latifi ◽  
Ali Mohammadi
Keyword(s):  
Genetic Improvement ◽  
Fixed Effects ◽  
Genetic Parameters ◽  
Growth Traits ◽  
Early Growth ◽  
Information Criteria ◽  
Daily Weight Gain ◽  
Data Set ◽  
Female Birth ◽  
Genetic Trends

The purpose of the present study was estimation of genetic parameters and genetic trends of early growth traits using Bayesian approach by Gibbs3f90 software in Iranian Afshari sheep. The data set [birth weight (BW), weaning weight (WW) and pre-weaning daily weight gain (PWDG)] were collected during the period 1999 to 2010 from Agriculture Jahad of Zanjan province, Iran. The fitted fixed effects were herd-year-season as interactions, sex (male, female), birth type (single, multiple) and age of dam. Based on Derivative Information Criteria (DIC), for studied traits the most appropriate model was determined. Therefore, based on the most appropriate fitted model, the direct additive heritabilities estimate for BW, WW and PWDG were 0.32?0.02, 0.05?0.01 and 0.24?0.02, respectively. The estimates of maternal heritabilities were 0.17?0.04, 0.07?0.02 and 0.12?0.05 and total heritabilities 0.11?0.05, 0.08?0.02 and 0.08?0.03 for BW, WW and PWDG, respectively. Direct genetic trends were positive for all traits but only significant for BW 0.75?0.31 g/year (P <0.05). Also, maternal genetic trends were for all traits negative and was significant for BW -0.63?0.27 g/year (P <0.05). The moderate estimates of heritabilities for early growth traits indicate that in Afshari sheep faster genetic improvement through selection is possible for these traits. Furthermore, the results genetic trends in this current study indicated that genetic improvement through selection is suitable only for BW in Afshari sheep.

scholarly journals Genetic parameters and genetic trends for growth traits of the Red Maasai sheep and its crosses to Dorper sheep under extensive production system in Kenya

2022 ◽  
Vol 206 ◽  
pp. 106588
Author(s):  
Edwin Oyieng ◽  
Raphael Mrode ◽  
Julie M.K. Ojango ◽  
Chinyere C. Ekine-Dzivenu ◽  
James Audho ◽  
...  
Keyword(s):  
Production System ◽  
Genetic Parameters ◽  
Growth Traits ◽  
Dorper Sheep ◽  
Genetic Trends

scholarly journals Genetic evaluation of body weight traits in Iranian native Ghezel sheep

Genetika ◽  
2018 ◽  
Vol 50 (1) ◽  
pp. 275-284 ◽  
Author(s):  
H. Baneh ◽  
J. Ahmadpanah
Keyword(s):  
Body Weight ◽  
Genetic Parameters ◽  
Growth Traits ◽  
Univariate Analysis ◽  
Genetic Effect ◽  
Additive Genetic Effect ◽  
Pedigree Information ◽  
Breeding Values ◽  
Maternal Heritability ◽  
Genetic Trends

The aim of the current study was to estimate genetic parameters and trends for body weight traits at different ages in Ghezel lambs. Traits included were birth weight (BW), 3-month weight (3MW), 6-month weight (6MW), 9-month weight (9MW), and yearling weight (YW). Data and pedigree information used in the present study were collected at the Breeding Station of Ghezel sheep during 1986-2009. (Co) variance components were estimated using REML procedure and breeding values of animals were predicted with Best Linear Unbiased Prediction (BLUP) methodology under univariate analysis. Three different animal models were fitted. The models consisted of the direct additive genetic effect but differed in combinations of maternal additive genetic and maternal permanent environmental effects. Genetic trends for each trait were obtained by regressing the means of predicted breeding values on year of birth. The estimates of direct heritability were 0.285, 0.371, 0.388, 0.450 and 0.179, respectively. Also, the maternal heritability was estimated 0.113, 0.031, 0.021 and 0.030 for BW, WW, 6MW and 9MW, respectively. Direct genetic trends were positive and significant for BW, WW, 6MW (p<0.01), 9MW and YW (p<0.05) and were obtained 2.34, 46.20, 55.11, 33.40 and 24.01 (g/year), respectively. Also, maternal trends for BW, WW, 6MW and YW were positive and highly significant (p<0.01) and were 3.37, 17.05, 12.56 and 16.30 (g/year), respectively. The results indicated that considering maternal effects in the statistical model make accurate estimates of genetic parameters. Also, improvement of growth traits in Ghezel sheep seems to be likely in selection programs.

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 Adaptability, stability, productivity and genetic parameters in slash pine second-generation families in early age

2016 ◽  
Vol 65 (1) ◽  
pp. 71-82 ◽  
Author(s):  
M.K. Pagliarini ◽  
W.S. Kieras ◽  
J.P. Moreira ◽  
V.A. Sousa ◽  
J.Y. Shimizu ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Genetic Parameters ◽  
Second Generation ◽  
Growth Traits ◽  
Environmental Influence ◽  
Block Design ◽  
Slash Pine ◽  
Phenotypic Traits ◽  
Early Age ◽  
Wood Volume

AbstractThe study was conducted to estimate the stability, adaptability, productivity and genetic parameters in Slash pine second-generation half-sib families, considering phenotypic traits in early age. Forty-four families from a first generation seed orchard in Colombo-PR, Brazil, were used in this study. Two progenies tests were established in a randomized complete block design. The first test was implemented in March 2009 in Ribeirão Branco, São Paulo state, containing 40 blocks, one tree per plot, 44 treatments (progenies) and 6 controls. Another test was implemented in Ponta Grossa, Paraná state, using the same experimental design and number of plants per plot, and with 24 treatments, 32 blocks. The growth traits evaluated were total height, diameter at breast height (dbh) and wood volume, within five years. The form traits evaluated were stem form, branch thickness, branch angle, number of branches, fork and fox tail five years after planting. Deviance analysis and estimates of stability, adaptability, productivity and genetic parameters were performed using the methods of best linear unbiased predictor (BLUP) and residual maximum likelihood (REML). There was significant variation among progenies for growth and form traits. Considerable genetic variation was detected mainly for wood volume. High coefficients of genetic variation and heritability showed low environmental influence on phenotypic variation, which is important for the prediction of genetic gain by selection. Crosses between different progenies individuals groups will be prioritized for obtaining heterotics genotypes and increase the probability of obtaining high specific combining ability.

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