Abstract #276
Section: Breeding and Genetics (orals)
Session: Breeding and Genetics Symposium: Fertility: filling the gaps
Format: Oral
Day/Time: Tuesday 11:00 AM–11:30 AM
Location: Ballroom A
Presentation is being recorded
Session: Breeding and Genetics Symposium: Fertility: filling the gaps
Format: Oral
Day/Time: Tuesday 11:00 AM–11:30 AM
Location: Ballroom A
Presentation is being recorded
# 276
Identification of loci associated with pregnancy in Holstein heifers and primiparous cows.
H. L. Neibergs*1, J. N. Kiser1, E. Clancy1, E. M. Keuter1, J. Dalton2, J. G. N. Moraes3, C. M. Seabury4, T. E. Spencer3, 1Department of Animal Sciences, Washington State University, Pullman, WA, 2Department of Animal and Veterinary Science, University of Idaho, Moscow, ID, 3Division of Animal Sciences, University of Missouri, Columbia, MO, 4Department of Veterinary Pathobiology, Texas A&M University, College Station, TX.
Key Words: genome-wide association study (GWAS), dairy heifer, loci
Speaker Bio
Identification of loci associated with pregnancy in Holstein heifers and primiparous cows.
H. L. Neibergs*1, J. N. Kiser1, E. Clancy1, E. M. Keuter1, J. Dalton2, J. G. N. Moraes3, C. M. Seabury4, T. E. Spencer3, 1Department of Animal Sciences, Washington State University, Pullman, WA, 2Department of Animal and Veterinary Science, University of Idaho, Moscow, ID, 3Division of Animal Sciences, University of Missouri, Columbia, MO, 4Department of Veterinary Pathobiology, Texas A&M University, College Station, TX.
Pregnancy per artificial insemination at observed estrus is estimated to be 55–70% for dairy heifers and 35% in lactating dairy cows. Pregnancy rates for females that require more than one breeding are further reduced. The objective of this study was to investigate if loci associated with pregnancy at first service were shared with loci associated with pregnancy at ≥4 services in Holstein heifers and cows. Nine hundred 2 heifers and 1032 primiparous cows were bred by artificial insemination during observed estrus for up to 5 consecutive estrus cycles for heifers and up to 13 cycles for cows. Pregnancy was determined via palpation on d 35 for heifers and cows not returning to estrus. Heifers and cows were genotyped using the Illumina BovineHD BeadChip (777,962 SNPs) and a genome-wide association study (GWAS) was conducted with a significance threshold of P < 5 × 10–8 to identify individual associations and P < 1 × 10–5 to identify shared associations. The GWAS identified 65 SNPs associated with pregnancy to first service in heifers and 138 SNPs associated with pregnancy to first service in cows. Eleven SNPs associated with pregnancy to first service were shared among heifers and cows. One hundred 64 SNPs were associated with the number of times bred (1, 4 or 5 times) required for pregnancy at d 35 in heifers, 79 SNPs were associated with times bred (1, 4–13 times) in cows and 7 SNPs were shared among Holstein heifers and cows. Two loci were associated with all phenotypes in heifers and cows. These results indicate that although most loci associated with pregnancy per artificial insemination in heifers and primiparous cows are unique, there are shared loci that are important in achieving pregnancy in both groups that could be used for genomic selection. This project was supported by Agriculture and Food Research Initiative Competitive Grant no. 2013-68004-20365 and 2018-67015-27577 from the USDA National Institute of Food and Agriculture.
Key Words: genome-wide association study (GWAS), dairy heifer, loci
Speaker Bio
Holly Neibergs attended Washington State University, where she received BS and MS degrees in animal science and reproductive physiology, respectively. She received her PhD from Texas A&M University in genetics. Neibergs did a post-doctoral fellowship at the National Animal Disease Center in Ames, Iowa, where she studied milk fever prior to an appointment at the College of Medicine at the University of Louisville, and at Norton Healthcare. In Louisville, she investigated the role of genetics in inflammatory bowel disease and directed the Norton Hereditary Cancer Institute. In 2006, Neibergs returned to Washington State University to study the role of genetics in bovine paratuberculosis, bovine respiratory disease, and bovine viral diarrhea. She is also involved in research addressing the genetic variance associated with feed efficiency in cattle.
