Location: Livestock Bio-SystemsTitle: Research on gilt first estrus and pubertal development at USMARC
Submitted to: Plant and Animal Genome Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 11/7/2014
Publication Date: 1/14/2015
Citation: Nonneman, D., Lents, C.A., Schneider, J.F., Vallet, J.L., Rohrer, G.A. 2015. Research on gilt first estrus and pubertal development at USMARC [abstract]. Plant and Animal Genome XXIII Conference Proceedings. Abstract #W827.
Technical Abstract: Gilts comprise a significant portion of breeding females and gilts that reach puberty earlier tend to stay in the herd longer and be more productive. A significant proportion (10-30%) of gilts that enter the herd never farrow a litter and reproductive insufficiency accounts for a third of gilt removals; anestrous and failure to conceive are the most common reasons for culling gilts. About half of the gilts that fail to display estrous behavior have not cycled by six months of age whereas the other half have cycled but are behaviorally anestrus. Genetic markers associated with estrus and age at puberty will allow selection for age at puberty and traits correlated with sow lifetime productivity. Seven hundred fifty-nine gilts detected for estrus between 140 and 240 days of age were genotyped using the Illumina PorcineSNP60 BeadChip. SNP were tested using the Bayes C option of GENSEL, assigned to five-SNP windows and analyzed using the Predict option of GENSEL. Twenty-seven QTL were found to be statistically significant (P < 0.01) and explained 29.4% of the genetic variance. Two QTL, one on SSC12 at 15 Mb and the other on SSC7 at 75 Mb, explained 16.87% of the total QTL variance. Candidate genes in these regions include the growth hormone gene (GH1) on SSC12 and PRKD1 on SSC7. Eight QTL correspond to regions previously reported for age at puberty and five regions contained genes associated with age at menarche in humans. Case-control association studies using littermates for delayed puberty and behavioral anestrus are also being completed.