Calculation of indices

Genetic evaluations of beef cattle are calculated five times per year. The indices are based on live weights. In Finland the indices calculated for beef cattle are birth weight, weaning weight, yearling weight and mothering ability index. The indices are calculated for the five most common beef breeds in Finland: Hereford, Charolais, Aberdeen Angus, Limousin and Simmental.

Birth weight should be measured within the first 24 hours after birth. The index for birth weight is published in two options: the relative index and the kilogram index. Weaning weight (measured between 150–250 days of age) has its own index, but it is also used to calculate the index of mothering ability for the cows. Weaning weight is also published as a relative index and a kilogram index. The index for mothering ability is published only as a relative index. Yearling weight (measured between 325–405 days of age) is used to calculate the yearling weight index, which is published both as a relative index and a kilogram index.

Total merit index:

• for bulls = -0,5 x birth weight index + 0,3 x weaning weight index + 1,0 x yearling weight index
• for cows = -0,3 x birth weight index + 0,3 x mothering ability index + 1,0 x yearling weight index

An animal born in Finland will have a published index when it belongs to the beef cattle recording scheme and there is a record of the weight needed to calculate the index. An exception is the index for mothering ability, because the cow has to have at least one offspring with a recorded weaning weight before the cow can get an index for mothering ability.

If a bull does not have a record of a weight, the index will be published when it has five offspring with records from the weight in question. A cow without a record from a weight needs two offspring with recorded weights before it can have an index of the weight. Imported animals will get their indices only through results of their offspring; an imported bull needs ten offspring and a cow needs two offspring with recorded weights. Animals born through embryo transfer will also get their indices only through their offspring except for the yearling weight.