alexa Abstract | Use of the random regression model for the genetic parameters estimation of milk yield in a Holstein cows herd

European Journal of Experimental Biology
Open Access

OMICS International organises 3000+ Global Conferenceseries Events every year across USA, Europe & Asia with support from 1000 more scientific Societies and Publishes 700+ Open Access Journals which contains over 50000 eminent personalities, reputed scientists as editorial board members.

Open Access Journals gaining more Readers and Citations

700 Journals and 15,000,000 Readers Each Journal is getting 25,000+ Readers

This Readership is 10 times more when compared to other Subscription Journals (Source: Google Analytics)

Research Article Open Access


To estimate genetic parameters for daily milk yield, test day records of first lactation Holstein cows were used. The data included 9782 test day records of 1140 Mahdasht herd cows recorded from 2001 to 2009. Analysis of test day records was performed using the REML procedure in DFREML software. Legendre polynomials on days in milk of order 5 were used to fit the population mean as fixed regression and of order 3 for both additive genetic and permanent environmental effect as random regression. Residual variances for the model considered to be constant for all days in milk and estimated as 305. The minimum value for heritability estimate (0.039) occurred in early lactation but had increase increased toward the lactation and in the ninth month of lactation reached the maximum value (0.280). Phenotypic variance of daily milk yield was higher in early and late lactation. The maximum (18.750) and minimum (2.360) values of genetic variance were in month 10 and early lactation respectively. The maximum values for genetic and phenotypic correlations were between records of adjacent days in milk and as the distance between the days increased the correlations decreased. Using test day records, increased accuracy for genetic parameters will be achieved.

To read the full article Peer-reviewed Article PDF image

Author(s): Shahabodin Gharahveysi Mehrdad Irani Ruhollah Abdullahpour and Zabihollah Kalashi

Peer Reviewed Journals
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2017-18
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

© 2008-2017 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version