4.11 Value of indicator traits (2024)
- Tessa Jacobs
- Kor Oldenbroek
In the past in animal breeding a lot of emphasis was paid on indicator traits. They were of great value for important breeding goal traits that are difficult to measure or are expressed later in life or at the end of life. If in horses a good relationship (correlation) exists between the score for the quality of the legs and longevity, the score for the leg quality can be used as a predictor of longevity. In that situation leg quality may be used as a selection criterion in horses to improve the breeding goal trait longevity. In pigs a halothane test was developed in which young pigs were anaesthetized with halothane. This gas gave different reactions in pigs that were a good predictor of their stress susceptibility. Stress around slaughter has a deteriorating effect on pork quality. The outcome of the halothane test is used as an indicator trait to be selected for to decrease stress susceptibility and consequently improve pork quality.
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Nowadays, stress susceptibility is an example of a breeding goal trait where a DNA test has replaced the complicated test or the recording of an indicator. DNA tests and genomic selection also changed the value of information of relatives in the estimation of breeding values. The application of halothane test and later on the DNA test resulted in the existence nowadays of selection lines in pigs that are free of this type of stress susceptibility. The DNA test is used now and then to verify this.