When genomic selection was first being introduced, whether this would result in more or less inbreeding for the animals was a topic of debate. As we can now scientifically demonstrate, it has not resulted in more inbreeding for VikingHolstein. So, the answer to the headline is “NO”.
Genetic progress is now at 4.3 NTM units per year – the aim is 4.0 NTM units per year. There is no doubt that the VikingGenetics breeding programme is very efficient, but how is inbreeding doing?
From basic breeding theory, we know that a very one-sided use of the best bulls and cows leads to high genetic progress, but also much inbreeding. Genetic variation will be reduced and with this, the chance of maintaining genetic progress in the long run. Plus, we can face an increased risk of genetic defects. Finding the right balance between these two parameters – genetic progress and inbreeding – is essential.
The main factor for high genetic progress is the generation interval. In Figure 1 we can see the development between 2009 that was before genomic selection and today. It is measured on all purchased VikingHolstein bulls during this period. The figures show in particular bulls and not females in 2009 that bulls were 2,500 days old when they had sons born and now they are almost 800 days old.
The parental average falls from 1,910 days to 819 days – less than half. This means that the parents were 18 months old at time of insemination. For bulls in particular, we can shorten the interval even further