Keywords : Genetic persistency
journal of kerbala university,
Volume 6, Issue 2, Pages 29-33
This study was carried out at the Faihaa Station (20 km north of Babel), and over period 2007 and 2008, using 310 records product by 119 cow analysis statistically. The aim of this investigate the estimation of genetic persistency on milk production from the difference between genetic estimation to produce 280 days from genetic estimation to produce first 60 days of milk season in Holstein Friesian cows after studying the effect of fixed factors and estimation heritability to produce 60 and 280 milk day.
The overall mean of milk production of the first 60 and 280 days of milk season was 625.16 and 2300.34 kg respectively. Highly significant effect of parity and season of parturition in milk production of 60and 280 days, Heritability of this traits 0.25 and 0.22 respectively. There wide variation in genetic values estimation of bulls of 60 and 280 days milk production. The maximum estimation of genetic persistency was 30.27 while the minimum was – 10.04 , depending of above mentioned estimations will increase gain and later the economically in the herd.