Managing Inbreeding in the Genomic Age
Angie Ahlgrim, Global Development Administrator, CRI
Bennet Cassell put it best when he said, "The goal is to increase the frequency of genes that improve profitability and minimize those that don't." Genex has taken this perspective when producing and procuring the sires of the next generation. By providing a genetically diverse lineup and tools that make cow-side decision making easy, Genex is focused on improved profitability.
Which Measure of Inbreeding Should I Use on the Farm?
Former inbreeding values based on pedigrees were limited to mostly 1960 records documentation, and the animal's individual known pedigree history. In the genomic age, we can more precisely estimate the number of genes in common among animals, and it's not surprising to find that the founder animals of 1960 were at least a little related to one another.
Two values of inbreeding are calculated for animals that have been genomic tested. First is the animal's own genomic inbreeding percent (GIB%), a reflection of the common genes inherited from its parents. The more useful value in making mating decisions and in bull selection is the genomic future inbreeding percent (GFI%), indicating how likely the resulting offspring of a bull is to inherit common genes due to general use as a service sire.
But wait... the phrase "don't throw the baby out with the bath water" comes to mind. PTAs for all animals are already adjusted to account for any current and future losses due to inbreeding depression. Identifying bulls that meet your breeding goals is and always should be the first criteria. Use of GFI as a secondary selection serves as a risk management tool. Steps taken to maintain genetic diversity provide insurance for the future - to preserve genes that are favorable for traits we don't yet measure and to minimize the impact of future undesirable traits or genes as they are discovered.
Cow-side Management Tools
In addition to providing genetically diverse sires, Genex has a variety of tools to help make breeding decisions easy. Mating your herd through MAP™ or G-MAP™ is the first step to managing inbreeding. This program takes into account past pedigrees when suggesting mating options for the next generation. To learn more about using MAP in your herd, turn to page 15.
Just released with the August sire summary is the Genex Inbreeding Guide. This one-page flyer, available for both Holstein and Jersey breeds, lists the lineup in alphabetical order and then indicates which popular sires or families are present in each sire's pedigree. You can access this flyer online at: http://genex.crinet.com/inbreeding or ask your Genex representative for a copy.