Authors : Reza Seyed-Sharifi , Jamal Seif-Davati and Bahram Fathi-Achachlouei
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.
Reza Seyed-Sharifi , Jamal Seif-Davati and Bahram Fathi-Achachlouei , 2008. 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, 7: 1405-1409.