Why does the EBI value of my animals keep changing?
Ans: This is probably one of the most common questions about the EBI system. Here at ICBF we have a large computer, called a database, which receives information about animals on a daily basis.
Data such as calving surveys, milk recording, weights and birth and death dates are sent to us from farmers, milk recorders, Linear Scorers, Marts & Factories etc.
We then take all of this information out of the database 3 times a year and run it through the genetic evaluation system (you can find the publication schedule here). The new information that has gone into the ICBF database since the previous run is then reflected in a change to the EBI of animals connected to that data. It could be that a full sibling of your animal has found to be very hard calving in another herd – this will then affect your animal’s rating for calving difficulty. So it is crucial to remember that the EBI of your animals are not just affected by the progeny that he sires on your farm.
It is crucial to remember that the EBI of your cows are not just affected by the cow’s performance on your farm.
Why are relatives so important in the evaluation of an animal?
Ans: When ICBF evaluates bulls with large numbers of daughters, information on daughter performance compared to herdmates is the most powerful source for estimating the bull’s genetic merit. Provided that the genetic evaluation system has appropriately accounted for the genetic merit of the dams of the bull’s daughters, and that the bull’s daughters have not been given special treatment to enhance their performance.
For a cow, it’s important to take into account the performance of her close relatives compared to their herdmates, because these cows have genes in common with her.
How does the Animal Evaluation system cater for the fact that not all farmers have the same objectives?
Ans: The Animal Evaluation system identifies bulls that have high merit for profit – which is a common objective for farmers – while collecting data on other traits that farmers can use to meet their other objectives.
High EBI bulls have a wide range of size, breed, milk, type and other traits to suit all farmer preferences – Note that you can select bulls using traits in the ‘Sire Advice’ application. For example ‘I want a high EBI sire that is in the top 10% for EBI but I want to use a bull that is also in the top 5% for milk index as I feel this area of my herd needs some improvement’ – In this case the ‘Sire Advice’ application will return only the bulls in the database that meet this criteria. The application then ranks them in order of their EBI figure and displays the bulls. The user can then tick which bulls he wants to use on cows and heifers.
Will we lose the progress we’ve already made if we select animals for multiple traits (e.g. fertility & production), instead of sticking to selecting animals for yield?
Ans: No, We have been very successful at selecting for yield over the last 50 years. We try to maintain that excellent rate of progress while getting better at addressing other important traits – those traits that are generally referred to as functional traits, like fertility, resistance to mastitis, longevity, etc.