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Genome-wide association studies of female reproduction in tropically adapted beef cattle

journal contribution
posted on 05.11.2018, 00:00 by RJ Hawken, YD Zhang, MRS Fortes, E Collis, WC Barris, Nicholas Corbet, PJ Williams, G Fordyce, RG Holroyd, JRW Walkley
The genetics of reproduction is poorly understood because the heritabilities of traits currently recorded are low. To elucidate the genetics underlying reproduction in beef cattle, we performed a genomewide association study using the bovine SNP50 chip in 2 tropically adapted beef cattle breeds, Brahman and Tropical Composite. Here we present the results for 3 female reproduction traits: 1) age at puberty, defined as age in days at first observed corpus luteum (CL) after frequent ovarian ultrasound scans (AGECL); 2) the postpartum anestrous interval, measured as the number of days from calving to first ovulation postpartum (first rebreeding interval, PPAI); and 3) the occurrence of the first postpartum ovulation before weaning in the first rebreeding period (PW), defined from PPAI. In addition, correlated traits such as BW, height, serum IGF1 concentration, condition score, and fatness were also examined. In the Brahman and Tropical Composite cattle, 169 [false positive rate (FPR) = 0.262] and 84 (FPR = 0.581) SNP, respectively, were significant (P < 0.001) for AGECL. In Brahman, 41% of these significant markers mapped to a single chromosomal region on BTA14. In Tropical Composites, 16% of these significant markers were located on BTA5. For PPAI, 66 (FPR = 0.67) and 113 (FPR = 0.432) SNP were significant (P < 0.001) in Brahman and Tropical Composite, respectively, whereas for PW, 68 (FPR = 0.64) and 113 (FPR = 0.432) SNP were signifycant (P < 0.01). In Tropical Composites, the largest concentration of PPAI markers were located on BTA5 [19% (PPAI) and 23% (PW)], and BTA16 [17% (PPAI) and 18% (PW)]. In Brahman cattle, the largest concentration of markers for postpartum anestrus was located on BTA3 (14% for PPAI and PW) and BTA14 (17% PPAI). Very few of the significant markers for female reproduction traits for the Brahman and Tropical Composite breeds were located in the same chromosomal regions. However, fatness and BW traits as well as serum IGF1 concentration were found to be associated with similar genome regions within and between breeds. Clusters of SNP associated with multiple traits were located on BTA14 in Brahman and BTA5 in Tropical Composites. © American Society of Animal Science.

Funding

Category 4 - CRC Research Income

History

Volume

90

Issue

5

Start Page

1398

End Page

1410

Number of Pages

13

eISSN

1525-3163

ISSN

0021-8812

Publisher

American Society of Animal Science

Peer Reviewed

Yes

Open Access

No

External Author Affiliations

Cooperative Research Centre (CRC) for Beef Genetic Technologies; (CSIRO) Livestock Industries; University of New England; University of Queensland; Department of Employment, Economic Development and Innovation

Era Eligible

Yes

Journal

Journal of Animal Science

Exports