Genetic parameters for mid-infrared spectroscopy–predicted fertility

Summary: MFERT is the probability of conception to first insemination using mid-infrared spectroscopy of a milk sample collected during lactation as part of routine milk recording, age at calving, days in milk, and milk production. Because MFERT can be estimated during routine milk recording, it can become available on a much larger number of records than the traditional fertility phenotypes. To test the potential of MFERT for genetic selection, we estimated genetic parameters for MFERT. While MFERT had a higher heritability than traditional fertility phenotypes, genetic correlations between MFERT and traditional fertility phenotypes were low to moderate. The strongest genetic correlation was found with calving to first service, with a genetic correlation of -0.61. Therefore, MFERT will only be able to increase the accuracy of a fertility index if there are many more records for MFERT than for traditional fertility phenotypes.