Genetic analysis of functional longevity in Holstein cattle
Streszczenie
Records of 1039 Holstein cattle were analyzed. Cows were culled during years from 1998 to 2004 at the Nasr Dairy Cattle
Station, United Company for Animal Resources Ltd., Al-Soueira. General
linear model within the SAS program was used to study the effect of some fixed factors (season and year
of birth , stage of lactation and level of first milk yield ) on longevity.
Results obtained that season of birth have a significant effect ( P < 0.05 ) on longevity, whereas
the residual factors had a high significant effect ( P < 0.01 ). The heritability of
founctional and true longevity using MIVIQUE method were 0.03 , 0.008 respectively and the
corresponding heritability were 0.04 and 0.03 by using TYPE 1 method.
Best linear unbiased pridiction ( BLUP ) for 24 sire using Harvey program were ranged from
17.15 to – 11.71 months respectively
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