&lt;b&gt;Estimates of genetic and phenotypic parameters for reproductive traits in Iranian native Kordi sheep

Saghi, Davoud Ali; Shahdadi, Ali Reza

doi:10.4025/actascianimsci.v39i3.35378

Cited by 9 publications

(2 citation statements)

References 19 publications

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“…However, reproductive traits are aggregate traits and a small improvement in these traits would mean sizeable gain in terms of overall change in the other traits and is usually realized with simultaneous change in all components. Direct heritability of LS was higher than Ethiopian Horro sheep and other exotic sheep breeds [25,26].…”

Section: Heritability Estimationmentioning

confidence: 68%

Estimation of co-variance components, genetic parameters, and genetic trends of reproductive traits in community-based breeding program of Bonga sheep in Ethiopia

Areb

Getachew²,

Kirmani³

et al. 2021

Anim Biosci

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Objective: The objectives of the study were to evaluate reproductive performance and selection response through genetic trend of community-based breeding programs (CBBPs) of Bonga sheep.Methods: Reproduction traits data were collected between 2012 and 2018 from Bonga sheep CBBPs. Phenotypic performance was analyzed using the general linear model procedures of Statistical Analysis System. Genetic parameters were estimated by univariate animal model for age at first lambing (AFL) and repeatability models for lambing interval (LI), litter size (LS), and annual reproductive rate (ARR) traits using restricted maximum likelihood method of WOMBAT. For correlations bivariate animal model was used. Best model was chosen based on likelihood ratio test. The genetic trends were estimated by the weighted regression of the average breeding value of the animals on the year of birth/ lambing.Results: The overall least squares mean±standard error of AFL, LI, LS, and ARR were 375± 12.5, 284±9.9, 1.45±0.010, and 2.31±0.050, respectively. Direct heritability estimates for AFL, LI, LS, and ARR were 0.07±0.190, 0.06±0.120, 0.18±0.070, and 0.25±0.203, respectively. The low heritability for both AFL and LI showed that these traits respond little to selection programs but rather highly depend on animal management options. The annual genetic gains were –0.0281 days, –0.016 days, –0.0002 lambs and 0.0003 lambs for AFL, LI, LS, and ARR, respectively.Conclusion: Implications of the result to future improvement programs were improving management of animals, conservation of prolific flocks and out scaling the CBBP to get better results.

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Section: Heritability Estimationmentioning

confidence: 68%

Estimation of co-variance components, genetic parameters, and genetic trends of reproductive traits in community-based breeding program of Bonga sheep in Ethiopia

Areb

Getachew²,

Kirmani³

et al. 2021

Anim Biosci

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“…Kurdi sheep is an important native dual-purpose (meat and milk) sheep breed in Iran, numbering about 3.5 million heads and mainly distributed in North Khorasan province, North-eastern of the country (Saghi, Shahdadi, Borzalabad, & Mohammadi 2018). The breed is kept mainly for meat production by nomadic pastoralists under low quality pastures (Saghi & Shahdadi, 2017), is fat-tailed, light-brown to yellowish in color, relatively large-sized and suitable for fattening purposes.…”

Section: Introductionmentioning

confidence: 99%

Inferring phenotypic causal structures among body weight traits via structural equation modeling in Kurdi sheep

Mohammadi

Saghi

Shahdadi

et al. 2020

Acta Sci. Anim. Sci.

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Data collected on 2550 Kurdi lambs originated from 1505 dams and 149 sires during 1991 to 2015 in Hossein Abad Kurdi Sheep Breeding Station, located in Shirvan city, North Khorasan province, North-eastern area of Iran, were used for inferring causal relationship among the body weights at birth (BW), at weaning (WW), at six-month age (6MW), at nine-month age (9MW) and yearling age (YW). The inductive causation (IC) algorithm was employed to search for causal structure among these traits. This algorithm was applied to the posterior distribution of the residual (co)variance matrix of a standard multivariate model (SMM). The causal structure detected by the IC algorithm coupling with biological prior knowledge provides a temporal recursive causal network among the studied traits. The studied traits were analyzed under three multivariate models including SMM, fully recursive multivariate model (FRM) and IC-based multivariate model (ICM) via a Bayesian approach by 100,000 iterations, thinning interval of 10 and the first 10,000 iterations as burn-in. The three considered multivariate models (SMM, FRM and ICM) were compared using deviance information criterion (DIC) and predictive ability measures including mean square of error (MSE) and Pearson's correlation coefficient between the observed and predicted values (r(y, )) of records. In general, structural equation based models (FRM and ICM) performed better than SMM in terms of lower DIC and MSE and also higher r(y, ). Among the tested models ICM had the lowest (36678.551) and SMM had the highest (36744.107)DIC values. In each case of the traits studied, the lowest MSE and the highest r(y, ) were obtained under ICM. The causal effects of BW on WW, WW on 6MW, 6MW on 9MW and 9MW on YW were statistically significant values of 1.478, 0.737, 0.776 and 0.929 kg, respectively (99% highest posterior density intervals did not include zero).

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Goat and Sheep Farming

Rout

Behera

2021

Sustainability in Ruminant Livestock

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<b>Estimates of genetic and phenotypic parameters for reproductive traits in Iranian native Kordi sheep

Cited by 9 publications

References 19 publications

Estimation of co-variance components, genetic parameters, and genetic trends of reproductive traits in community-based breeding program of Bonga sheep in Ethiopia

Estimation of co-variance components, genetic parameters, and genetic trends of reproductive traits in community-based breeding program of Bonga sheep in Ethiopia

Inferring phenotypic causal structures among body weight traits via structural equation modeling in Kurdi sheep

Goat and Sheep Farming

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