STABILITY OF ESTIMATED BREEDING VALUES FOR AVERAGE DAILY GAIN IN PANNON WHITE RABBITS

Stability of estimated breeding values for average daily gain (ADG) between the age of 5 and 10 weeks was analyzed for 50,869 Pannon White rabbits, reared in 7,911 litters and born between 1999 and 2007. The data set was divided into successive 5-year long periods (1999-2003, 2000-2004, 2001-2005, 2002-2006 and 2003-2007), then after selecting the appropriate part of the pedigree for these sub-datasets genetic parameters and breeding values were estimated for ADG using REML and BLUP methods. Estimated heritabilities for the successive 5-year long periods were moderate and stable (0.24±0.01, 0.28±0.02, 0.25±0.02, 0.25±0.02 and 0.26±0.02). Magnitudes of random litter effects were low and stable (0.17±0.01, 0.16±0.01, 0.16±0.01, 0.16±0.01 and 0.15±0.01). After breeding value estimation the most recent sub-dataset (2003-2007) was merged pair wise with each sub-dataset (2002-2006, 2001-2005, 2000-2004 and 1999-2003) using inner join. Thus, in the merged datasets only those records of most recent sub-dataset (2003-2007) were included that matched the other datasets records (i.e. records of rabbits born in 2003-2006, 2003-2005, 2003-2004 and 2003, respectively). In these merged datasets, each rabbit had two breeding values for ADG based on two different 5-year long dataset. The breeding values based on the most recent dataset were regressed on the breeding values based on other 5-year long datasets. With the successive years the coefficients of determination decreased (0.976, 0.963, 0.929 and 0.848). However, the coefficients of determination were moderately high, even when the proportion of the common rabbits in the merged datasets was low. Using a rolling base dataset, therefore, did not result the instability of breeding values estimated for ADG