Animal Science Department


Date of this Version

July 1975


Published in Journal of Dairy Science. Copyright © 1975 American Dairy Science Association. Used by permission.


Henderson's mixed model procedure was used to determine sire comparisons for Holstein sires from the United States, Canada, or local bred in 48 Mexican herds. For sires with five or more daughters, 74% of the sires in artificial insemination from the United States had plus values compared to 34% from Canada, 44% from the local stud, and 40% for local bred sires. Genetic correlations with Mexican sire comparisons were Northeast Artificial Insemination Sire Comparison with >20 daughters in Mexico .86, with 10 to 20 daughters .71, United States Department of Agriculture (USDA) proof >10 daughters .81, and Canada Northeast Artificial Insemination Sire Comparison with >10 daughters .61. Correlations with United States proofs indicate effects of sire by location were small. Cow origins were imports from Canada or the United States (imports), sired by imported semen or sires (.5 imports), and locally bred (locals). Differences between imports and .5 imports were small, but cows of United States origin exceeded Canadian by 300 to 500 kg in milk yield. Progeny of imported sires (.5 imports) were lower in milk yield than progeny from sires in artificial insemination. Locally produced cattle were poorer than imports or .5 imports by sires in the United States or Canada.