Abstract
Frequencies of alleles at the DRB3.2 locus of the bovine major histocompatibility complex for two genetic lines of Holsteins were compared, and allelic effects on yield and udder health traits were examined. The DRB3.2 genotypes of 186 cows and heifers were determined using DNA that had been extracted from blood samples. The cattle were from a designed selection experiment for milk yield. After edits, 173 cows and heifers with known alleles remained (54 from a control line and 119 from a selection line for milk yield). A total of 19 alternative DRB3.2 alleles appeared across the two lines, and frequencies ranged from 0.3 to 21.4%. Allelic frequencies differed significantly between the selection and control lines. Alleles 3, 8, 9, 10, 26, and 28 were more frequent in the control line, but alleles 16, 24, and 27 were more frequent in the selection line. An animal model was used to estimate gene substitution effects of alternative alleles on milk yield, fat yield, and protein yield, SCS, chronically elevated SCS, acutely elevated SCS, and mastitis incidence. First, second, and third lactations were analyzed separately. Allele 7 was associated with a significant increase in protein yield during first and second lactations and a significant increase in chronically elevated SCS and acutely elevated SCS during second lactation. Because of conflicting results with other studies and a limited numbers of cows, additional research is needed before specific alleles are confirmed to be associated with measures of yield and udder health.
Original language | English (US) |
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Pages (from-to) | 3411-3419 |
Number of pages | 9 |
Journal | Journal of Dairy Science |
Volume | 80 |
Issue number | 12 |
DOIs | |
State | Published - Dec 1997 |
Bibliographical note
Funding Information:Received October 15, 1996. Accepted July 29, 1997. 1Contribution Number 22,566 of the Minnesota Agricultural Experiment Station based on research supported by the station. 2Present address: ABS Global, PO Box 459, DeForest, WI 53532. 3Reprint requests. 4Southern Experiment Station, Waseca, MN 56093.
Keywords
- Bovine lymphocyte antigen
- Genetics
- Milk yield
- Somatic cells