Browsing by Author "Siltala, Enni"

The breeding of dairy cattle has changed due to genomic evaluation. Breeding values can be evaluated for young animals who don’t yet have phenotypic data or offspring. However, achieving a high reliability for genomic breeding values requires a large reference population. In the case of rarer breeds, such as Finncattle, acquiring a large reference population can be difficult. In a small population genomic evaluation can thus lead to results with poor reliabilities. The aim of this study was to find out if adding genomic data to the breeding evaluation of Western Finncattle would increase the reliability of the breeding values. The phenotype used in this study was the energy corrected 305-day milk yield of the first lactation and the observations were fixed to the environment factors. Phenotypic data had observations for 26 258 Finncattle cows. Genomic data had the imputed genotypes of 728 Western Finncattle. Estimated breeding values (EBV) were obtained using a single trait BLUP-animal model and genomic estimated breeding values (GEBV) were obtained using a single trait genomic ssGBLUP animal model. The results were standardised, and a validation was carried out. The milk yield of Western Finncattle was better than the yield of the other Finncattle breeds and the yield had also steadily increased. Likewise, the genetic trend of Western Finncattle had been increasing. The breeding values of bulls were lower than those of the cows and the genetic trend of bulls was uneven due to the small number of bulls in the study. In addition, the correlation between EBV and GEBV was lower in bulls than in cows. The correlations were higher in older animals than in younger ones. Cows with an observation had a higher correlation than those without an observation. Similarly, the non-genotyped animals had higher correlations than the genotyped individuals. For genotyped bulls, the correlation increased with the number of offspring. The addition of genomic data to the evaluation increased the reliability of the values in the validation. Despite the small population of Western Finncattle, the reliability of breeding values can be increased by adding genomic data to the evaluation. This reliability can be further increased by increasing the size of the reference population. The limited number of bulls in the population of Western Finncattle resulted in unreliable results in this study and acquiring enough genomic data from bulls can prove to be difficult. Therefore, it could be reasonable to focus on cows in the genomic evaluation of Western Finncattle