The advantage of the German genomic breeding value estimation system
In many Holstein countries the usage of genomic sires is increasing. The German genomic breeding value estimation has set an impressive standard when compared internationally. German genomic-enhanced breeding values are officially available and well accepted since August 2010. Over time our world-leading reference population as part of the Eurogenomic consortium has steadily increased representing all Holstein bloodlines, European and North American. It has been shown that German Holstein genomics validate very well in the INTERBULL validation tests for national evaluation systems and also in practice. Several studies by the German proof centre VIT could impressively demonstrate that the deviations are within the expected range, that German Holstein genomics are realistic predictions and that the gEBV of young bulls are fully comparable to daughter proofs. German genomic breeding values are realistic predictions and gEBV data of young bulls is fully comparable to daughter proofs. Different to other countries these studies have been always made fully available to the public, so breeders could see that the results have been realistic for all traits. Nevertheless, considering the lower reliability of gEBV’s it is still recommended to spread the remaining risk by selecting a larger group of genomic sires in order to optimize the benefit from the industry-leading German genomic technology.
More details behind the genomic selection
Many breeders have experienced this before – the supposed best cow doesn’t always have the best offspring. Responsible for that is the difference between what we can see or measure with our own eyes (phenotype) and the “inner values” (genotype = breeding value) of a cow that get passed on to the offspring. A cow’s performance is not only dependent on her genetic predisposition. Genetics makes up approximately 30% of performance while environmental factors like feeding and care contribute approximately 70%.
Because of this, is almost impossible to determine the breeding value of the cow based only on her performance. Generally, it is only possible to determine breeding values with high certainty (up to 99%) with bulls that have a high number of daughters. Therefore, much information on a certain animal, or more specifically the offspring, is needed before it is possible to estimate breeding values with higher certainty. This is a relatively time consuming process.
The German genomic breeding value estimation system can determine which traits an animal will pass on to their offspring. Based on the differences in genetic information (SNP –Single-nucleotide polymorphism) the traits an animal will pass on can be predicted. Consequently, even in very young animals it can be identified whether they have good traits and performance themselves, but also if they will pass on those traits to the subsequent generation. This means that based on their genomic information we can already predict in young calves whether they will pass on fertility (gRZR), longevity and vitality (gRZN) and good udder health (gRZN) to their offspring.
The value of individual genetic information (SNP) for hereditability was previously determined by sampling bulls with well-known breeding values with high certainty. Using those SNP-results, estimation formulas for all traits with guaranteed breeding values were derived. These formulas enable the calculation of the genomic breeding value of an animal based on the SNP-results. This method is able to produce genomic breeding values not only for performance but also for functional traits like conformation.
The accuracy of genomic breeding values for traits like performance, cell count, longevity, maternal calving ease and fertility can be derived off the certainty of the breeding value. The following graph shows that breeding values for performance and cell count can be predicted with a high level of certainty.
SNP-genotyping at MASTERRIND
Blood samples are drawn from animals that are of particular interest for the breeder and are SNP-typed. These blood samples are then sent to a lab, which prepares and forwards them to a more specific “genotyping lab”.
The results from the genotyping lab are then sent to the “VIT” in Verden (Germany), where the genomic breeding values are determined. These results are very helpful for the selection of animals to use for breeding and stock replacement.
MASTERRIND supports its members with “SNP-genotyping” of their herds and offers a specialized consulting program, based on the information of the genomic analysis.
Furthermore, MASTERRIND supports the project „Kuhvision“, which SNP-types whole herds up until the first lactation. In addition, information and data about general health and foot health are being collected.