Genetic parameters of somatic cell scores for Holstein cows were estimated using an animal model and REML for two data sets. Set 1, with 13,017 records from 5278 cows, was used to obtain variance components, heritability, and repeatability for two lactation measures: the simple average and the weighted average of test day data. Set 2, with 14,418 records from 4806 cows, was used to obtain genet...

Effects of twinning on lactation and days open in Holsteins were studied from calving records compiled by member surveys of Eastern Artificial Insemination Cooperative. Records of cows with 305-day mature-equivalent records from the Northeast Dairy Records Processing Laboratory were grouped according to whether the twin calving was associated with dystocia. Records of each cow that had a twin c...

The identification of dairy cows with greater or lower potential to develop mastits has been pursued for many years among different segments of the milk industry, including governmental organizations. Genomic studies have suggested that Single Nucleotide Polymorphisms (SNPs) within the pattern recognition receptors (PRR) could lead to different responses to pathogens, and consequently result in...