Title : ( Quantile regression mixed model at different milk production levels of Iranian Holsteins )
Authors: Hossein Naeemipour , Mohammad Mahdi Shariati , Saeed Zerehdaran , Mehdi Jabbari Nooghabi , P. Lovendahl ,
Full TextAbstract
The objective of this study was to estimate the effects of environmental factors such as herd, year and season of calving, Holstein gene percentage, age at first calving as fixed effects, and random animal effects on milk yield using quantile regression (QR) mixed model. An animal model was used to compare and discuss the results. Data comprised of 64,530 primiparous cows from 754 herds calved between 1996 and 2010. Mixed QR model was carried out using LQMM package of R software. The results showed that the effects of age at first calving and Holstein gene percentage across different quantiles were not similar. The spearman correlation between predicted breeding values from QR analyses at different quantiles with ones from animal model were high (0.88). It shows the ranking of animals based on EBV from different models is almost identical, while, the fixed effects differ across quantiles. The genetic trends estimated with QR at different quantiles were different, such that the genetic progress was highest among high producing cows (0.75th quantile).
Keywords
, Quantile regression, Mixed model, Milk yield, Holstein, Animal model
@inproceedings{paperid:1066927,
author = {Naeemipour, Hossein and Shariati, Mohammad Mahdi and Zerehdaran, Saeed and Jabbari Nooghabi, Mehdi and P. Lovendahl},
title = {Quantile regression mixed model at different milk production levels of Iranian Holsteins},
booktitle = {European Association for Animal Production (EAAP) Annual Meeting 2017, Tallin, Estonia},
year = {2017},
location = {تالین},
keywords = {Quantile regression; Mixed model; Milk yield; Holstein; Animal model},
}
%0 Conference Proceedings
%T Quantile regression mixed model at different milk production levels of Iranian Holsteins
%A Naeemipour, Hossein
%A Shariati, Mohammad Mahdi
%A Zerehdaran, Saeed
%A Jabbari Nooghabi, Mehdi
%A P. Lovendahl
%J European Association for Animal Production (EAAP) Annual Meeting 2017, Tallin, Estonia
%D 2017
