{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/119011"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/119011","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Molecular phenotypes associated with heifer fertility","abstract":"Before the early 2000s, many producers were heavily selecting for production traits without accounting for the negative relationship between many production traits and fertility. The large decrease in fertility that occurred as a result of these selection practices put a heavy burden on producers. Replacement heifer development is the third largest cost incurred by producers, behind feed and labor. Consequently, the failure of a heifer to conceive in her first breeding season translates directly into financial loss for the producer and lasting consequences on the animal's longevity and performance in subsequent breeding seasons. To make improvements in a trait, or traits, of interest, producers often selectively breed two animals with desirable characteristics. However, the complex nature of fertility traits limits the effectiveness of this method. As a result, researchers have been attempting to identify biological molecules whose abundance differs between cattle of differing fertility potential, termed molecular markers, that could be used to identify superior cattle earlier and more accurately. While a good amount of research has been conducted in mature cows and in a laboratory setting, very few studies have attempted to identify molecular markers of fertility in heifers. Therefore, the objective of this work was to identify different biological molecules (genomic variants, genes, proteins, and metabolites) whose abundance differed between heifers with varying fertility potential. Investigation into DNA variations led to the identification of three variants that were associated with fertility, 16 variants that were associated with health, and 29 variants that were associated with both health and fertility. Given that some variants can impact a trait by changing gene expression, we attempted to identify variations in RNA that were having this effect on heifer fertility. Although some variants were found to influence gene expression, we were unable to correlate these changes with fertility differences. However, in a different study, we were able to identify two genes (APMAP and DNAI7), as well as one protein (alpha-ketoglutarate-dependent-dioxygenase FTO), that differed significantly between fertile and sub-fertile heifers. Importantly, the results of this study allowed us to create a biological profile that was capable of accurately distinguishing 21/22 heifers based on their fertility potential. Finally, investigation of the metabolite profile revealed one metabolite (2-dehydro-D-gluconate) that was differentially abundant between fertile and sub-fertile heifers. Overall, this work sheds light on the complex nature of heifer fertility and provides several potential molecular that could be used to distinguish between heifers of varying reproductive potential.","abstract_html":"Before the early 2000s, many producers were heavily selecting for production traits without accounting for the negative relationship between many production traits and fertility. The large decrease in fertility that occurred as a result of these selection practices put a heavy burden on producers. Replacement heifer development is the third largest cost incurred by producers, behind feed and labor. Consequently, the failure of a heifer to conceive in her first breeding season translates directly into financial loss for the producer and lasting consequences on the animal's longevity and performance in subsequent breeding seasons. To make improvements in a trait, or traits, of interest, producers often selectively breed two animals with desirable characteristics. However, the complex nature of fertility traits limits the effectiveness of this method. As a result, researchers have been attempting to identify biological molecules whose abundance differs between cattle of differing fertility potential, termed molecular markers, that could be used to identify superior cattle earlier and more accurately. While a good amount of research has been conducted in mature cows and in a laboratory setting, very few studies have attempted to identify molecular markers of fertility in heifers. Therefore, the objective of this work was to identify different biological molecules (genomic variants, genes, proteins, and metabolites) whose abundance differed between heifers with varying fertility potential. Investigation into DNA variations led to the identification of three variants that were associated with fertility, 16 variants that were associated with health, and 29 variants that were associated with both health and fertility. Given that some variants can impact a trait by changing gene expression, we attempted to identify variations in RNA that were having this effect on heifer fertility. Although some variants were found to influence gene expression, we were unable to correlate these changes with fertility differences. However, in a different study, we were able to identify two genes (APMAP and DNAI7), as well as one protein (alpha-ketoglutarate-dependent-dioxygenase FTO), that differed significantly between fertile and sub-fertile heifers. Importantly, the results of this study allowed us to create a biological profile that was capable of accurately distinguishing 21/22 heifers based on their fertility potential. Finally, investigation of the metabolite profile revealed one metabolite (2-dehydro-D-gluconate) that was differentially abundant between fertile and sub-fertile heifers. Overall, this work sheds light on the complex nature of heifer fertility and provides several potential molecular that could be used to distinguish between heifers of varying reproductive potential.","abstract_has_math":false,"creators":["Marrella, Mackenzie Ann"],"institution":"Virginia Tech","degree_name":"Doctor of Philosophy","degree_level":"doctoral","degree_discipline":"Animal and Poultry Sciences","degree_department":"Animal and Poultry Sciences","school":null,"contributors":[],"advisors":[],"committee_chairs":["Biase, Fernando H."],"committee_members":["Mercadante, Vitor Rodriques Gomes","Moorey, Sarah","Morota, Gota"],"year":2024,"date_issued":"2024-05-16","date_published":"2024-05-16","updated_at":"2026-07-22T22:20:07Z","subjects":["molecular marker","heifer fertility","genomic variants"],"languages":["en"],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["vt_gsexam:40290"],"render_values":[{"text":"vt_gsexam:40290","href":null,"code":true}]}]},"links":{"outbound_url":"https://hdl.handle.net/10919/119011","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Biase, Fernando H."]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Mercadante, Vitor Rodriques Gomes","Moorey, Sarah","Morota, Gota"]},{"key":"dc:contributor.department","label":"Department","values":["Animal and Poultry Sciences"]},{"key":"dc:creator","label":"Author","values":["Marrella, Mackenzie Ann"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2024-05-17T08:01:16Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2024-05-17T08:01:16Z"]},{"key":"dc:date.issued","label":"Date","values":["2024-05-16"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Dissertation"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Animal and Poultry Sciences"]},{"key":"thesis:degree_level","label":"Degree Level","values":["doctoral"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Doctor of Philosophy"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute and State University"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["molecular marker","heifer fertility","genomic variants"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["vt_gsexam:40290"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://hdl.handle.net/10919/119011"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstractgeneral","label":"General Abstract","values":["Before the early 2000s, many producers were heavily selecting for production traits without accounting for the negative relationship between many production traits and fertility. The large decrease in fertility that occurred as a result of these selection practices put a heavy burden on producers. Replacement heifer development is the third largest cost incurred by producers, behind feed and labor. Consequently, the failure of a heifer to conceive in her first breeding season translates directly into financial loss for the producer and lasting consequences on the animal's longevity and performance in subsequent breeding seasons. To make improvements in a trait, or traits, of interest, producers often selectively breed two animals with desirable characteristics. However, the complex nature of fertility traits limits the effectiveness of this method. As a result, researchers have been attempting to identify biological molecules whose abundance differs between cattle of differing fertility potential, termed molecular markers, that could be used to identify superior cattle earlier and more accurately. While a good amount of research has been conducted in mature cows and in a laboratory setting, very few studies have attempted to identify molecular markers of fertility in heifers. Therefore, the objective of this work was to identify different biological molecules (genomic variants, genes, proteins, and metabolites) whose abundance differed between heifers with varying fertility potential. Investigation into DNA variations led to the identification of three variants that were associated with fertility, 16 variants that were associated with health, and 29 variants that were associated with both health and fertility. Given that some variants can impact a trait by changing gene expression, we attempted to identify variations in RNA that were having this effect on heifer fertility. Although some variants were found to influence gene expression, we were unable to correlate these changes with fertility differences. However, in a different study, we were able to identify two genes (APMAP and DNAI7), as well as one protein (alpha-ketoglutarate-dependent-dioxygenase FTO), that differed significantly between fertile and sub-fertile heifers. Importantly, the results of this study allowed us to create a biological profile that was capable of accurately distinguishing 21/22 heifers based on their fertility potential. Finally, investigation of the metabolite profile revealed one metabolite (2-dehydro-D-gluconate) that was differentially abundant between fertile and sub-fertile heifers. Overall, this work sheds light on the complex nature of heifer fertility and provides several potential molecular that could be used to distinguish between heifers of varying reproductive potential."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Doctor of Philosophy"]},{"key":"dc:format.medium","label":"Dc Format Medium","values":["ETD"]},{"key":"dc:title","label":"Title","values":["Molecular phenotypes associated with heifer fertility"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Biase, Fernando H."],"dc:contributor.committeemember":["Mercadante, Vitor Rodriques Gomes","Moorey, Sarah","Morota, Gota"],"dc:contributor.department":["Animal and Poultry Sciences"],"dc:creator":["Marrella, Mackenzie Ann"],"dc:date.accessioned":["2024-05-17T08:01:16Z"],"dc:date.available":["2024-05-17T08:01:16Z"],"dc:date.issued":["2024-05-16"],"dc:description.abstractgeneral":["Before the early 2000s, many producers were heavily selecting for production traits without accounting for the negative relationship between many production traits and fertility. The large decrease in fertility that occurred as a result of these selection practices put a heavy burden on producers. Replacement heifer development is the third largest cost incurred by producers, behind feed and labor. Consequently, the failure of a heifer to conceive in her first breeding season translates directly into financial loss for the producer and lasting consequences on the animal's longevity and performance in subsequent breeding seasons. To make improvements in a trait, or traits, of interest, producers often selectively breed two animals with desirable characteristics. However, the complex nature of fertility traits limits the effectiveness of this method. As a result, researchers have been attempting to identify biological molecules whose abundance differs between cattle of differing fertility potential, termed molecular markers, that could be used to identify superior cattle earlier and more accurately. While a good amount of research has been conducted in mature cows and in a laboratory setting, very few studies have attempted to identify molecular markers of fertility in heifers. Therefore, the objective of this work was to identify different biological molecules (genomic variants, genes, proteins, and metabolites) whose abundance differed between heifers with varying fertility potential. Investigation into DNA variations led to the identification of three variants that were associated with fertility, 16 variants that were associated with health, and 29 variants that were associated with both health and fertility. Given that some variants can impact a trait by changing gene expression, we attempted to identify variations in RNA that were having this effect on heifer fertility. Although some variants were found to influence gene expression, we were unable to correlate these changes with fertility differences. However, in a different study, we were able to identify two genes (APMAP and DNAI7), as well as one protein (alpha-ketoglutarate-dependent-dioxygenase FTO), that differed significantly between fertile and sub-fertile heifers. Importantly, the results of this study allowed us to create a biological profile that was capable of accurately distinguishing 21/22 heifers based on their fertility potential. Finally, investigation of the metabolite profile revealed one metabolite (2-dehydro-D-gluconate) that was differentially abundant between fertile and sub-fertile heifers. Overall, this work sheds light on the complex nature of heifer fertility and provides several potential molecular that could be used to distinguish between heifers of varying reproductive potential."],"dc:description.degree":["Doctor of Philosophy"],"dc:format.medium":["ETD"],"dc:identifier.other":["vt_gsexam:40290"],"dc:identifier.uri":["https://hdl.handle.net/10919/119011"],"dc:language.iso":["en"],"dc:publisher":["Virginia Tech"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:subject":["molecular marker","heifer fertility","genomic variants"],"dc:title":["Molecular phenotypes associated with heifer fertility"],"dc:type":["Dissertation"],"thesis:degree_discipline":["Animal and Poultry Sciences"],"thesis:degree_level":["doctoral"],"thesis:degree_name":["Doctor of Philosophy"],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:20:07Z"}