{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/77700"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/77700","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"The Relationship between Residual Feed Intake, Dry Matter Intake, and Reproductive Performance in Holstein Dairy Cows","abstract":"Feed represents a large portion of input costs for dairy operations. Decreasing the feed consumed, measured here as dry matter intake (DMI), would therefore be advantageous to producers. However, this decrease could result in cows that do not supply the necessary energy to maintain high production, growth, and reproduction. Measures of feed efficiency try to capture important energy expenditures to ensure that cows consume less while maintaining production. Feed efficiency in this study is measured in residual feed intake (RFI), which is calculated as the difference between DMI and expected DMI based on production and growth measures. However, the RFI model does not capture the energy stores required for reproduction; therefore, selection for RFI may lead to reduced reproductive performance. In this thesis, I explored the phenotypic and genetic relationships between RFI, DMI, and reproductive performance as measured by number of services (NS), days open (DO), and days to first calving (DFC). First, ANOVA tests and phenotypic correlations determined the phenotypic relationship between the traits. Then, heritability and genetic correlations were used to estimate the genetic parameters. Phenotypically, results indicated mixed relationships between traits. Heritability estimates were low for reproductive traits and moderate for DMI and RFI. There was no unfavorable genetic relationship between DMI or RFI with any of the reproductive traits. Therefore, neither selection for DMI nor RFI will unfavorably impact reproduction.","abstract_html":"Feed represents a large portion of input costs for dairy operations. Decreasing the feed consumed, measured here as dry matter intake (DMI), would therefore be advantageous to producers. However, this decrease could result in cows that do not supply the necessary energy to maintain high production, growth, and reproduction. Measures of feed efficiency try to capture important energy expenditures to ensure that cows consume less while maintaining production. Feed efficiency in this study is measured in residual feed intake (RFI), which is calculated as the difference between DMI and expected DMI based on production and growth measures. However, the RFI model does not capture the energy stores required for reproduction; therefore, selection for RFI may lead to reduced reproductive performance. In this thesis, I explored the phenotypic and genetic relationships between RFI, DMI, and reproductive performance as measured by number of services (NS), days open (DO), and days to first calving (DFC). First, ANOVA tests and phenotypic correlations determined the phenotypic relationship between the traits. Then, heritability and genetic correlations were used to estimate the genetic parameters. Phenotypically, results indicated mixed relationships between traits. Heritability estimates were low for reproductive traits and moderate for DMI and RFI. There was no unfavorable genetic relationship between DMI or RFI with any of the reproductive traits. Therefore, neither selection for DMI nor RFI will unfavorably impact reproduction.","abstract_has_math":false,"creators":["Cayford, Eleonor Marilyn"],"institution":"Virginia Tech","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Dairy Science","degree_department":"Dairy Science","school":null,"contributors":[],"advisors":[],"committee_chairs":["Cockrum, Rebecca R."],"committee_members":["Hanigan, Mark D.","Rhoads, Michelle"],"year":2017,"date_issued":"2017-05-22","date_published":"2017-05-22","updated_at":"2026-07-22T22:20:21Z","subjects":["Residual feed intake","dairy","Reproduction"],"languages":[],"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:11336"],"render_values":[{"text":"vt_gsexam:11336","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/77700","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Cockrum, Rebecca R."]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Hanigan, Mark D.","Rhoads, Michelle"]},{"key":"dc:contributor.department","label":"Department","values":["Dairy Science"]},{"key":"dc:creator","label":"Author","values":["Cayford, Eleonor Marilyn"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2017-05-23T08:00:28Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2017-05-23T08:00:28Z"]},{"key":"dc:date.issued","label":"Date","values":["2017-05-22"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Dairy Science"]},{"key":"thesis:degree_level","label":"Degree Level","values":["masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science"]},{"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":["Residual feed intake","dairy","Reproduction"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"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:11336"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/77700"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Feed represents a large portion of input costs for dairy operations. Decreasing the feed consumed, measured here as dry matter intake (DMI), would therefore be advantageous to producers. However, this decrease could result in cows that do not supply the necessary energy to maintain high production, growth, and reproduction. Measures of feed efficiency try to capture important energy expenditures to ensure that cows consume less while maintaining production. Feed efficiency in this study is measured in residual feed intake (RFI), which is calculated as the difference between DMI and expected DMI based on production and growth measures. However, the RFI model does not capture the energy stores required for reproduction; therefore, selection for RFI may lead to reduced reproductive performance. In this thesis, I explored the phenotypic and genetic relationships between RFI, DMI, and reproductive performance as measured by number of services (NS), days open (DO), and days to first calving (DFC). First, ANOVA tests and phenotypic correlations determined the phenotypic relationship between the traits. Then, heritability and genetic correlations were used to estimate the genetic parameters. Phenotypically, results indicated mixed relationships between traits. Heritability estimates were low for reproductive traits and moderate for DMI and RFI. There was no unfavorable genetic relationship between DMI or RFI with any of the reproductive traits. Therefore, neither selection for DMI nor RFI will unfavorably impact reproduction."]},{"key":"dc:description.abstractgeneral","label":"General Abstract","values":["Dairy cows consume significant resources in the form of feed. Decreasing the feed consumed, measured here as dry matter intake (DMI), would therefore be advantageous to producers and consumers. However, this decrease could result in cows that do not supply the necessary energy to maintain high production, growth, and reproduction. Measures of feed efficiency try to capture important energy expenditures to ensure that cows consume less while maintaining production. Feed efficiency in this study is measured in residual feed intake (RFI), which is calculated as the difference between DMI and expected DMI based on production and growth measures. However, the RFI model does not capture the energy stores required for reproduction; therefore, selection for RFI may lead to reduced reproductive performance. In this thesis, I explored the phenotypic and genetic relationships between RFI, DMI, and reproductive performance as measured by number of services, days open, and days to first calving. First, ANOVA tests and phenotypic correlations determined the phenotypic relationship between the traits. Then, heritability and genetic correlations were used to estimate the genetic relationship between traits. Heritability estimates were low for reproductive traits and moderate for DMI and RFI. There was no unfavorable genetic relationship between DMI or RFI with any of the reproductive traits. Therefore, neither selection for DMI nor RFI will unfavorably impact reproduction."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Master of Science"]},{"key":"dc:format.medium","label":"Dc Format Medium","values":["ETD"]},{"key":"dc:title","label":"Title","values":["The Relationship between Residual Feed Intake, Dry Matter Intake, and Reproductive Performance in Holstein Dairy Cows"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Cockrum, Rebecca R."],"dc:contributor.committeemember":["Hanigan, Mark D.","Rhoads, Michelle"],"dc:contributor.department":["Dairy Science"],"dc:creator":["Cayford, Eleonor Marilyn"],"dc:date.accessioned":["2017-05-23T08:00:28Z"],"dc:date.available":["2017-05-23T08:00:28Z"],"dc:date.issued":["2017-05-22"],"dc:description.abstract":["Feed represents a large portion of input costs for dairy operations. Decreasing the feed consumed, measured here as dry matter intake (DMI), would therefore be advantageous to producers. However, this decrease could result in cows that do not supply the necessary energy to maintain high production, growth, and reproduction. Measures of feed efficiency try to capture important energy expenditures to ensure that cows consume less while maintaining production. Feed efficiency in this study is measured in residual feed intake (RFI), which is calculated as the difference between DMI and expected DMI based on production and growth measures. However, the RFI model does not capture the energy stores required for reproduction; therefore, selection for RFI may lead to reduced reproductive performance. In this thesis, I explored the phenotypic and genetic relationships between RFI, DMI, and reproductive performance as measured by number of services (NS), days open (DO), and days to first calving (DFC). First, ANOVA tests and phenotypic correlations determined the phenotypic relationship between the traits. Then, heritability and genetic correlations were used to estimate the genetic parameters. Phenotypically, results indicated mixed relationships between traits. Heritability estimates were low for reproductive traits and moderate for DMI and RFI. There was no unfavorable genetic relationship between DMI or RFI with any of the reproductive traits. Therefore, neither selection for DMI nor RFI will unfavorably impact reproduction."],"dc:description.abstractgeneral":["Dairy cows consume significant resources in the form of feed. Decreasing the feed consumed, measured here as dry matter intake (DMI), would therefore be advantageous to producers and consumers. However, this decrease could result in cows that do not supply the necessary energy to maintain high production, growth, and reproduction. Measures of feed efficiency try to capture important energy expenditures to ensure that cows consume less while maintaining production. Feed efficiency in this study is measured in residual feed intake (RFI), which is calculated as the difference between DMI and expected DMI based on production and growth measures. However, the RFI model does not capture the energy stores required for reproduction; therefore, selection for RFI may lead to reduced reproductive performance. In this thesis, I explored the phenotypic and genetic relationships between RFI, DMI, and reproductive performance as measured by number of services, days open, and days to first calving. First, ANOVA tests and phenotypic correlations determined the phenotypic relationship between the traits. Then, heritability and genetic correlations were used to estimate the genetic relationship between traits. Heritability estimates were low for reproductive traits and moderate for DMI and RFI. There was no unfavorable genetic relationship between DMI or RFI with any of the reproductive traits. Therefore, neither selection for DMI nor RFI will unfavorably impact reproduction."],"dc:description.degree":["Master of Science"],"dc:format.medium":["ETD"],"dc:identifier.other":["vt_gsexam:11336"],"dc:identifier.uri":["http://hdl.handle.net/10919/77700"],"dc:publisher":["Virginia Tech"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:subject":["Residual feed intake","dairy","Reproduction"],"dc:title":["The Relationship between Residual Feed Intake, Dry Matter Intake, and Reproductive Performance in Holstein Dairy Cows"],"dc:type":["Thesis"],"thesis:degree_discipline":["Dairy Science"],"thesis:degree_level":["masters"],"thesis:degree_name":["Master of Science"],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:20:21Z"}