Reza Seyed-Sharifi  , Jamal Seif-Davati  , Bahram Fathi-Achachlouei  , 
    Correlation of Breeding Value, Milk Production and Lactation Persistency Traits During Complete and Incomplete Lactation Using Random Regression Model,
    Journal of Animal and Veterinary Advances,
    Volume 7,Issue 11,
    2008,
    Pages 1405-1409,
    ISSN 1680-5593,
    javaa.2008.1405.1409,
    (https://makhillpublications.co/view-article.php?doi=javaa.2008.1405.1409)
    Abstract: In this investigation, 29800 data related to test day of milk production from 2716 Holstein first calving and daughter from 167 sire cows were analyzed based of random regression model (RR/CF) and REML (Restricted Maximum Likelihood). Method incomplete lactating 5-90 and 5-120 days in correlations to complete lactating were 0.67 and 0.72, respectively. With lactation progress, the correlation was increased. The correlation during incomplete lactation period 5-240 days was 0.91. The correlation value for lactating persistency trait for incomplete lactating period 5-150 days were 0.68. By milk production increasement during incomplete production period of 5-240 days this value reached to 0.91. Also, this correlation for 2 month interval (3 month recording) for milk production and lactating persistency was 0.88 and 0.59, respectively. This correlation for milk production and lactating persistency in 1 month interval (2 month recording) was reached to higher than 0.90.
    Keywords: Milk production and persistency;random regression model;test day records