Totum descendit geneticae artis these words were coined down by the Romans nearly 2000 years ago, what do they mean? It all comes down to genetics! Even though their society was in a period that lacked many scientific advancements they still understood the importance of preservation of genetic in livestock. Today we’ll be diving into the topic of Estimated breeding values and Selection indices, looking at what they are, how they can help you as a livestock farmer and how their use can revolutionize your enterprise
What are EBV’s and SI’s
Estimated breeding value (EBV) and selection indices are important tools in animal breeding that help to improve the genetic potential of livestock populations (Aker 1988). These tools are used to predict the genetic merit of animals for specific traits and aid in the selection of superior individuals for breeding purposes. In this article, we will explore the concept of estimated breeding value and how it is calculated, as well as the role of selection indices in animal breeding.
Estimated Breeding Value (EBV)
Estimated breeding value (EBV) is a prediction of an animal’s genetic merit for a particular trait. It is an estimate of the genetic contribution an individual will pass on to its offspring for that specific trait. EBVs are calculated using statistical models that take into account various sources of information, such as pedigree data, performance records, and genomic information (Aker 1988).
The calculation of EBVs involves comparing an animal’s performance or genetic markers to the average performance or markers of a reference population. The difference between an individual’s performance and the average performance of the reference population is known as the breeding value. This breeding value is then adjusted for factors such as heritability, genetic correlations between traits, and environmental effects to obtain the EBV.
EBVs are expressed in units that are specific to each trait, such as kilograms for weight or liters for milk production. A positive EBV indicates that an animal is expected to have above-average genetic merit for a particular trait, while a negative EBV suggests below-average genetic merit.
Selection Indices
Selection indices are composite measures that combine multiple traits into a single value to facilitate selection decisions (Cameron 1997). They are designed to account for the economic importance of different traits and their genetic relationships. By using selection indices, breeders can simultaneously improve multiple traits without sacrificing progress in any one trait.
The construction of selection indices involves assigning weights to different traits based on their economic importance and heritability (Cameron 1997). Traits with higher economic importance or higher heritability receive greater weights in the index.
Selection indices provide a more comprehensive approach to breeding by considering the overall genetic merit of animals rather than focusing on individual traits. They allow breeders to make more informed decisions by balancing the trade-offs between different traits and selecting animals that have the greatest overall genetic potential.
Why are EBVs and Selection Indices important to me as a livestock farmer?
Increased Genetic Gain: By accurately predicting an animal’s genetic merit, breeders can select superior individuals for breeding, leading to faster genetic progress within a population.
Efficient Resource Allocation: EBVs and selection indices help breeders allocate their limited resources, such as time, space, and financial investments, more effectively by focusing on animals with higher genetic potential.
Balanced Trait Improvement: Selection indices enable breeders to improve multiple traits simultaneously, ensuring a balanced approach to genetic improvement and avoiding unintended consequences on other traits.
Armed with proper EBV’s and SI’s alongside DLS support you can be sure to reach the peak of genetic quality in your livestock and ensure that you make a sound profit from your endeavors!