Genetic parameters for gaussian and categorical traits in organic and low input dairy cattle herds based on random regression methodology

2012 ◽  
Vol 147 (1-3) ◽  
pp. 159-169 ◽  
Author(s):  
T. Yin ◽  
B. Bapst ◽  
U.U.v. Borstel ◽  
H. Simianer ◽  
S. König
2016 ◽  
Vol 50 (1) ◽  
pp. 64-70 ◽  
Author(s):  
Gebregziabher Gebreyohannes ◽  
Skorn Koonawootrittriron ◽  
Mauricio A. Elzo ◽  
Thanathip Suwanasopee

PLoS ONE ◽  
2018 ◽  
Vol 13 (2) ◽  
pp. e0192864 ◽  
Author(s):  
Luise A. Seeker ◽  
Joanna J. Ilska ◽  
Androniki Psifidi ◽  
Rachael V. Wilbourn ◽  
Sarah L. Underwood ◽  
...  

2020 ◽  
Vol 241 ◽  
pp. 104178
Author(s):  
Nabil Soumri ◽  
Maria Jesus Carabaño ◽  
Oscar González-Recio ◽  
Sonia Bedhiaf-Romdhani

2014 ◽  
Vol 14 (1) ◽  
pp. 55-68 ◽  
Author(s):  
Ali Mohammadi ◽  
Sadegh Alijani ◽  
Hossein Daghighkia

Abstract The aim of this research was to compare different polynomial functions including Legendre polynomials (LP), Wilmink (WRR) and Ali-Schaeffer (ARR) functions, in random regression model (RRM) for estimation of genetic parameters for milk production traits of Iranian Holstein dairy cattle. For this purpose the performance records obtained from test-day (TD) regarding milk yield, fat and protein contents of the cows calving for the first time were used. The numbers of records for the above mentioned traits were 701212, 657004, and 560775, respectively. These records were collected from the years 2006 to 2010 by the National Breeding Center of Iran. The genetic parameters were estimated using Restricted Maximum Likelihood (REML) method by applying RRM. Residual variances were considered homogeneous over the lactation period. To compare the model, different criteria (-2Logl, AIC, BIC and RV) were used for considered traits. Based on the results obtained, for all traits, RRM with LP function (2,5) were chosen as the best model. Considering residual variance (RV), LP (2,2) was proved to be a model which has the lowest performance, while using -2Logl, AIC, BIC criteria, RRM with ARR function was the worst model. According to the results, it is recommended to use LP with low orders for the additive genetic effects and with more orders for the permanent environment effects in the RRM for Iranian Holstein cattle. Permanent environment variance was higher in early lactation than during lactation and additive genetic variance in the early lactation was lower than at the end of lactation. Heritability range of milk yield, fat and protein contents was estimated to be from 0.08 to 0.23, 0.05 to 0.20 and 0.08 to 0.14, respectively. Phenotypic variance of the considered traits during lactation was not constant and it was higher at the beginning and the end of lactation. The additive genetic correlation between adjacent test days was higher than between distant test days.


2017 ◽  
Vol 52 (11) ◽  
pp. 1109-1117 ◽  
Author(s):  
Virgínia Mara Pereira Ribeiro ◽  
Fernanda Albuquerque Merlo ◽  
Gabriela Canabrava Gouveia ◽  
Larissa Kretli Winkelstroter ◽  
Luíza Rodrigues Alves Abreu ◽  
...  

Abstract: The objective of this work was to determine whether the random regression model using linear splines (RRMLS) is suitable to estimate the genetic parameters for productive and reproductive traits of a multiple-breed dairy cattle population, as well as to investigate the effect of the genetic group of the progeny on the genetic merit of the sire. The multiple-trait model (MTM) and the RRMLS with one knot fitted for every genetic group were used to obtain the genetic parameters. Records of 1/2 Holstein + 1/2 Gyr (1/2HG), 5/8 Holstein + 3/8 Gyr (5/8HG), and 3/4 Holstein + 1/4 Gyr (3/4HG) crossbreed dams were considered. The RRMLS showed better fitting. The additive and residual variances estimated by the MTM and the RRMLS were similar. Heritability varied from 0.20 to 0.33 for age at first calving, from 0.09 to 0.22 for first lactation length, and from 0.15 to 0.35 for first lactation 305-day milk yield, according to the genetic composition of the dams. The RRMLS is suitable to estimate the genetic parameters for productive and reproductive traits of multiple-breed dairy cattle populations. The genetic merit of the sires is affected by the genetic group of the progeny by which they are evaluated.


2016 ◽  
Vol 29 (12) ◽  
pp. 1682-1687 ◽  
Author(s):  
Masoumeh Naserkheil ◽  
Seyed Reza Miraie-Ashtiani ◽  
Ardeshir Nejati-Javaremi ◽  
Jihyun Son ◽  
Deukhwan Lee

2020 ◽  
Vol 33 (9) ◽  
pp. 1387-1399
Author(s):  
Sayan Buaban ◽  
Somsook Puangdee ◽  
Monchai Duangjinda ◽  
Wuttigrai Boonkum

Objective: The objective of this study was to estimate the genetic parameters and trends for milk, fat, and protein yields in the first three lactations of Thai dairy cattle using a 3-trait,- 3-lactation random regression test-day model.Methods: Data included 168,996, 63,388, and 27,145 test-day records from the first, second, and third lactations, respectively. Records were from 19,068 cows calving from 1993 to 2013 in 124 herds. (Co) variance components were estimated by Bayesian methods. Gibbs sampling was used to obtain posterior distributions. The model included herd-year-month of testing, breed group-season of calving-month in tested milk group, linear and quadratic age at calving as fixed effects, and random regression coefficients for additive genetic and permanent environmental effects, which were defined as modified constant, linear, quadratic, cubic and quartic Legendre coefficients.Results: Average daily heritabilities ranged from 0.36 to 0.48 for milk, 0.33 to 0.44 for fat and 0.37 to 0.48 for protein yields; they were higher in the third lactation for all traits. Heritabilities of test-day milk and protein yields for selected days in milk were higher in the middle than at the beginning or end of lactation, whereas those for test-day fat yields were high at the beginning and end of lactation. Genetics correlations (305-d yield) among production yields within lactations (0.44 to 0.69) were higher than those across lactations (0.36 to 0.68). The largest genetic correlation was observed between the first and second lactation. The genetic trends of 305-d milk, fat and protein yields were 230 to 250, 25 to 29, and 30 to 35 kg per year, respectively.Conclusion: A random regression model seems to be a flexible and reliable procedure for the genetic evaluation of production yields. It can be used to perform breeding value estimation for national genetic evaluation in the Thai dairy cattle population.


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