Index Guide

Production traits

• Milk yield index
• Protein yield index
• Fat yield index
• Protein-% index
• Fat-% index

Index is a prediction of an animal's breeding value (EBV), which is twice the ability to transmit the trait to his/her progeny. The indices for production traits are based on individual milk recording test-day results from all lactations. Persistency is calculated using sire model and it describes the kind of lactation curve bull’s daughters have.

Live weight index

Bull's live weight index is based on their daughters' live weight data collected by milk recording technicians. Index is an indication of bull's genetic level of mature weight. Indices are calculated using animal model BLUP.

Fertility and calving performance

Both female and male fertility are included in dairy cattle breeding program. Index calculated on the basis of bull's own non-return percentage shows bull’s fertilization ability. The better the non-return-% index is, the better are the pregnancy results from the first inseminations which means that cows conceived on their first service. Non-return rate is evaluated using sire-maternal grandsire-model

Bulls' daughter fertility index describes female fertility. It is a combined index which includes bull's daughters' days open information with a weight of 2/3 and fertility treatments index with a weight of 1/3. The days open index is calculated on the basis of the time period from calving to conception using animal model BLUP. When a bull's days open index is high the daughters have good fertility. Fertility treatment index calculations are based on information of fertility treatments and culling due to fertility disorders. Data is collected during a period of 150 days from calving. The higher the index is the less fertility disorders the daughters have.

The calf mortality index describes the mortality of bull's daughters' calves. So the bull is the maternal grandsire for the calves. Index being over 100 means that according to milk recording information the bulls' daughters have less calves born dead or calves which have died within 24 hours from birth than cows on average. For example if the calf mortality index for an Ayrshire bull is 110 it means that approximately 3 % of his daughters' calves are expected to die at calving. On the other hand if the calf mortality index is 60 for a Holstein-Friesian bull it means that nearly 8 % of bulls daughters' calves die at calving.

A calf mortality index for the bulls when the bull is the sire for calves is also calculated. When this index is higher than 100 it means that the bull has less dead calves than on average.

Indices for calving difficulties are calculated for bulls as a sire and maternal grandsire of the calf. When the index is over 100 as a sire, calves of the bull are born easier than average. When the index as a grandsire is over 100, calvings of bull's daughters are easier than average. Evaluations for calving mortality and calving difficulties are done using sire-maternal grandsire-model BLUP.

Management traits

Milkability index shows the milking speed of bulls daughters. The higher index is the faster the daughters give their milk. By selection we avoid the extreme animals of both slow and fast and hence the goal is a normal milking cow which means that bull's index is appr. 100.

Temperament index is based on collected information of bull's daughters' temperament. High index shows that a bull transmits a good temperament.

Leakage index shows if bull's progeny have problems with leakage. If the index is less than 100 the daughters have a tendency to leak. About 8 % of the cows have more or less problems with leakage. The milkability, leakage and temperament records are based on interview information collected by A.I. technicians. Genetic evaluation is done by sire model BLUP. Longevity describes how long bull’s daughters stay in milking in herds.

Health evaluation

Udder health index is a combined index which includes somatic cell count information from animal model with a weight of 2/3 and udder disease index from sire model with a weight of 1/3. In calculation of somatic cell index the information is received from the analyzes of somatic cell content in milk of milk recording samples. Index less than 100 shows that a bull transmits a high somatic cell content. The comparison basis is the average cell count of recorded cows by breed. Udder disease index is based on information received from health recording within 150 days from calving. The information includes records of mastitis treatments and cullings due to udder diseases.

Other treatments index includes all the treatments, besides fertility disorders and mastitis, that bull's daughters have had within 150 days from calving.

The treatment indices of bulls' daughters are based on data collected in health recording. In progeny testing for health traits are included only those herds which participate both in milk recording and health recording and data only of treatments made by veterinarians. Health evaluations are done using sire model BLUP but somatic cell score is done using test day model.

Conformation traits

The indices for conformation traits are calculated with BLUP animal model. Due to animal model the breeding values are published also to the conformation scored cows. The advisers of FABA evaluate the animals for conformation traits using linear scoring. The goal of this evaluation is to improve animals' longevity. The importance of good conformation becomes more emphasized the higher the milk yield gets and the harder the production stress is. For example the number of cullings due to udder attachment or leg conformation can be reduced by the means of breeding program.

In linear type evaluation the traits are scored on a scale of 1 to 9 according to the recommendations of World Holstein-Friesian Federation and World Ayrshire Federation. The total amount of conformation traits is 21. If a cow has more than one type evaluation then all her evaluations are included in analysis. The conformation indices for the bulls are published if the bull has 20 daughters in evaluation for conformation.

The udder conformation index has the weight of 0,5 in total merit index. In the udder conformation index there are udder depth, fore udder attachment, rear udder attachment (hight), suspensory ligament, and udder balance. If the index value is over 100 the bull transmits a good udder conformation. Body index includes three traits: chest width, body depth and stature.