Table 1.
Comparison of methods by pedigree and genomic tools for the estimation of genetic merit in dairy cattle
| Trait | Prediction by Pedigree Tools |
Prediction by Genomic Tools |
|---|---|---|
| Reliability | High, depending on the size of the progeny studied (between 46.00 and 72.00%) [144] | Very high (between 73.30 and 93.50%) [145] |
| Time to obtain predictive data (Progeny Testing) | High (A long waiting period must be expected to have sufficient production data in children and grandchildren that in animals of long generations like cattle can take years) [96] | Very low. A sample of ear cartilage tissue (DNA) is sufficient and the waiting time for the laboratory results is relatively short. Animals can be genotyped as early as being newborns [96] |
| Time involved | High, because it requires taking and analyzing production data from generations on a large number of daughters and granddaughters [11] | Low [11] |
| Cost | Low-medium [11] |
High (but constantly decreasing as technology advances) [11] |
| Modeling with unknown parent groups to model differences in genetic merit with 0.3 and 0.1 heritability accuracy | Estimation of minor and more biased predictions. Suggests poor estimates of genetic trends despite having little bias for validations in young genotyped animals [146] | Estimates accurate and unbiased predictions for young animals and, at the same time, adequately considers genetic trends [146] |
| Estimation of genetic variance and genetic merit variance predicted through the use of genome ratio or pedigree matrices | Reliability: young bulls; without pedigree: 0.00; known sire: 0.22; with full pedigree: 0.35 [147] |
Reliability: young bulls; without pedigree: 0.48; known sire: 0.58; with full pedigree: 0.68 [147] |
Pedigree and genomically obtained prediction data can be used in combination. This is highly desirable to obtain higher accuracy in the estimation of genetic merit. As daughter information gradually becomes available, it may be included in the bull’s genetic evaluation, and the reliability of the bull’s data will tend to increase. [11,96,144,145,146,147].