Genome changes due to artificial selection in U.S. Holstein cattle

BMC Genomics

Table 2 Correlation between SNP effects of milk yield and daughter pregnancy rate (SNP effects were from the April 2017 CDCB/USDA genomic evaluation)

	Whole-genome^a	234 selection signatures^a	109 signatures without known fertility genes^a	125 signatures with known fertility genes^a
Number of SNPs	60,671	3893	1555	2338
Correlation	−0.27	−0.27	−0.21	−0.30

^a The 1,463,676–2,138,926 region of Chr14 containing DGAT1 is not included in the calculation of correlation between milk yield and daughter pregnancy rate, because the extremely negative milk effect of DGAT1 drastically reduced the correlations. With this region, the correlation between milk yield and daughter pregnancy rate reduced to − 0.17 from − 0.27 for the 234 regions with selection signature, to − 0.09 from − 0.21 for the 109 regions without known fertility genes, to − 0.17 from − 0.30 for the 125 regions with known fertility genes, and to − 0.26 from − 0.27 for the whole-genome correlation. All correlations were statistically significant with p < 0.0001

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