Main content

GENETIC ANALYSIS OF GROUPS OF MID-INFRARED PREDICTED FATTY ACIDS IN MILK

Show simple item record

dc.contributor.advisor Miglior, Filippo
dc.contributor.advisor Schenkel, Flavio S.
dc.contributor.author Narayana, Saranya
dc.date.accessioned 2016-08-19T13:24:07Z
dc.date.available 2016-08-19T13:24:07Z
dc.date.copyright 2016-08
dc.date.created 2016-08-08
dc.date.issued 2016-08-19
dc.identifier.uri http://hdl.handle.net/10214/9865
dc.description.abstract This thesis investigated the phenotypic and genetic variation of five groups of mid-infrared (MIR) predicted fatty acids; short-chain (4 to 10 carbons), medium-chain (12 to 16 carbons), long-chain (17 to 22 carbons), saturated, and unsaturated fatty acids. The predicted fatty acid values (g/dL of milk) were log transformed in order to improve normality. The data set included 49,127 test-day records from 10,029 first lactation Holstein cows in 810 herds. The total number of animals in the pedigree was 76,074. The random regression animal test-day model included: days in milk, herd-test date, and season-age of calving (polynomial regression) as fixed effects, and herd-year of calving, animal and permanent environment effects as random polynomial regressions, and random residual effect. Third and fourth degree of Legendre polynomial were estimated for fixed regression of season-age of calving effect and for the three random regressions, respectively. The average daily heritability estimates were 0.24, 0.32, 0.23, 0.33, and 0.21 for short-chain, medium-chain, long-chain, saturated, and unsaturated fatty acids, respectively. Estimated average daily genetic correlations were positive among all fatty acid groups and ranged from moderate to high (0.63-0.96). This study demonstrates the existence of genetic variation in milk fatty acid profile predicted by MIR spectra. Therefore, milk fatty acid composition can be improved through genetic selection. Keywords: milk fatty acid, mid-infrared, random regression model, heritability en_US
dc.description.sponsorship I would like to acknowledge; Participating dairy producers CanWest DHI (Guelph, ON) and Valacta (Sainte-Anne-de-Bellevue, QC) Supported by Contribution from the Dairy Research Cluster Initiative (Dairy Farmers of Canada, Agriculture and Agri‐Food Canada, the Canadian Dairy Network and the Canadian Dairy Commission) Ontario Genomics NSERC of Canada DairyGen Council of Canadian Dairy Networ en_US
dc.language.iso en en_US
dc.rights Attribution-NoDerivs 2.5 Canada *
dc.rights.uri http://creativecommons.org/licenses/by-nd/2.5/ca/ *
dc.subject milk fatty acid en_US
dc.subject mid-infrared en_US
dc.subject random regression model en_US
dc.subject heritability en_US
dc.subject Cardio vascular diseases en_US
dc.subject CLA en_US
dc.subject Long-chain fatty acid en_US
dc.subject Saturated fatty acid en_US
dc.subject Short-chain fatty acid en_US
dc.subject Medium-chain fatty acid en_US
dc.subject Unsaturated fatty acid en_US
dc.subject Negative energy balance en_US
dc.title GENETIC ANALYSIS OF GROUPS OF MID-INFRARED PREDICTED FATTY ACIDS IN MILK en_US
dc.type Thesis en_US
dc.degree.programme Animal and Poultry Science en_US
dc.degree.name Master of Science en_US
dc.degree.department Department of Animal Biosciences en_US
dc.rights.license All items in the Atrium are protected by copyright with all rights reserved unless otherwise indicated.


Files in this item

Files Size Format View Description
Narayana_Saranya_201608_MSc.pdf 1017.Kb PDF View/Open Thesis- Main article

This item appears in the following Collection(s)

Show simple item record

Attribution-NoDerivs 2.5 Canada Except where otherwise noted, this item's license is described as Attribution-NoDerivs 2.5 Canada