Cytoplasmic and mitochondrial genetic effects on economic traits in dairy cattle

dc.contributor.advisor A. E. Freeman
dc.contributor.author Schutz, Michael
dc.contributor.department Animal Science
dc.date 2018-08-17T10:59:47.000
dc.date.accessioned 2020-07-02T06:14:36Z
dc.date.available 2020-07-02T06:14:36Z
dc.date.copyright Tue Jan 01 00:00:00 UTC 1991
dc.date.issued 1991
dc.description.abstract <p>Maternal lineage effects on milk production traits, considered indicative of cytoplasmic inheritance, were evaluated with animal models. Cattle were from a selection experiment begun in 1968. Maternal pedigrees were traced to the first female member in the Holstein-Friesian Herd Book, and foundation females were assigned to maternal lineage groups. All models accounted for year-season of calving, parity, and selection lines. Maternal lineage effects were included in a repeated records model with cow effects and preadjustment for sire and maternal grandsire transmitting abilities. Maternal lineage accounted for 5.2, 4.1, and 10.5 percent of phenotypic variation in milk yield, fat yield, and fat percentage, respectively. Maternal lineage was evaluated as a fixed effect in an animal model including random animal and permanent environmental effects. Ranges of maternal lineage estimates were 2934 kg milk, 154 kg fat, and.907 percent fat. Maternal lineage significantly affected fat percentage. Maternal genetic (nuclear) effects and their covariance with additive animal effects did not significantly account for additional variation nor did they influence maternal lineage estimates. Maternal lineage also affected calculated net energy of milk;Mitochondrial DNA (mtDNA) displacement-loop (D-loop) sequence polymorphism information from 36 maternal lineages was evaluated. Of 17 base pair substitutions evaluated, several were significantly associated with milk, fat, and solids-not-fat production. Another marked a large impact on fat percentage and net energy concentration. Positive and negative effects on all production traits were observed. One base pair substitution was related to a large favorable decrease in days open, number of breedings, and reproductive costs;Maternal lineage groups defined by several methods of classification using mtDNA sequence characteristics were evaluated with animal models. Groups defined as those maternal lineages with or without base pair substitution at nucleotide 169 accounted for increased milk fat and estimated milk energy production. Clustering the 36 maternal lineages using 17 mtDNA D-loop sequence differences produced groups with significant effect on fat percentage and energy concentration.</p>
dc.format.mimetype application/pdf
dc.identifier archive/lib.dr.iastate.edu/rtd/9619/
dc.identifier.articleid 10618
dc.identifier.contextkey 6360750
dc.identifier.doi https://doi.org/10.31274/rtd-180813-9266
dc.identifier.s3bucket isulib-bepress-aws-west
dc.identifier.submissionpath rtd/9619
dc.identifier.uri https://dr.lib.iastate.edu/handle/20.500.12876/82737
dc.language.iso en
dc.source.bitstream archive/lib.dr.iastate.edu/rtd/9619/r_9207254.pdf|||Sat Jan 15 02:35:42 UTC 2022
dc.subject.disciplines Agriculture
dc.subject.disciplines Animal Sciences
dc.subject.disciplines Genetics
dc.subject.keywords Animal science
dc.subject.keywords Animal breeding
dc.title Cytoplasmic and mitochondrial genetic effects on economic traits in dairy cattle
dc.type article
dc.type.genre dissertation
dspace.entity.type Publication
relation.isOrgUnitOfPublication 85ecce08-311a-441b-9c4d-ee2a3569506f
thesis.degree.level dissertation
thesis.degree.name Doctor of Philosophy
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