{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/54321"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/54321","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Gastrointestinal acidity, protein and starch digestibility and amino acid absorption in ruminants fed a high-concentrate diet with limestone, magnesium oxide or defluorinated phosphate","abstract":"Twelve wether lambs (32kg) with abomasal and ileal cannula were fed a 90% concentrate basal diet (800 g/d), basal + 1.5% magnesium oxide (MgO)(812 g/d), basal + 1.5% limestone (812 g/d) or basal + 3.0% limestone (824 g/d) to study the effect of·these minerals on intestinal pH, rumen fermentation, N balance, dry matter and crude protein digestibility (DMD, CPD), and small intestinal disappearance of amino acids (AAD). Limestone (3%) increased (P < .03) rumen pH. Magnesium oxide increased (P < .10) ileal and fecal pH. Limestone significantly increased N absorption and pre-abomasal DMD, but decreased (P < .03) AAD. N retention was not improved by the treatments. An 82-d feeding trial was conducted with 72 wether lambs (avg initial wt: 28 kg) to study the effect of 1 or 3% fine (70% < 53 µ) or coarse (85% > 425 µ) limestone on rumen environment, weight gain and feed efficiency of lambs fed an all-concentrate diet. Rumen pH and VFA molar proportions were not affected by the treatments. Limestone (3.0%) decreased (P < .10) total rumen VFA concentrations and increased (P < .10) fecal pH. Weight gain was not different (P > .10) among the treatments. Coarse limestone increased (P < .10) feed efficiency. Five Angus heifers (285 kg) with duodenal and ileal cannulae were fed a 90% concentrate control diet (7.5 kg/d) or the same diet containing 1.60% defluorinated phosphate-regular (5.5%, 19.0% and 33.0% on 1400, 1180 and 850 µ sieves, respectively, DRP-R), 1.60% defluorinated phosphate-coarse (85% evenly among large sieves, DRP-C), 1.28% limestone or .5% MgO to study the effect of limestone or MgO on intestinal pH, DMD, starch digestibility (SD), CPD and AAD in beef cattle fed a high-concentrate diet. Ileal pH was increased by MgO. Fecal pH was increased (P < .05) as follows: MgO > DRP > limestone and control. Minerals increased (P < .05) duodenal liquid flow. Limestone and DRP-C increased (P < .05) acid flow to the duodenum. Total tract DMD, SD and CPD were similar among treatments. Limestone and DRP-R increased (P < .10) AAD. DRP-C tended to increase AAD, but differences were not statistically significant.","abstract_html":"Twelve wether lambs (32kg) with abomasal and ileal cannula were fed a 90% concentrate basal diet (800 g/d), basal + 1.5% magnesium oxide (MgO)(812 g/d), basal + 1.5% limestone (812 g/d) or basal + 3.0% limestone (824 g/d) to study the effect of·these minerals on intestinal pH, rumen fermentation, N balance, dry matter and crude protein digestibility (DMD, CPD), and small intestinal disappearance of amino acids (AAD). Limestone (3%) increased (P &lt; .03) rumen pH. Magnesium oxide increased (P &lt; .10) ileal and fecal pH. Limestone significantly increased N absorption and pre-abomasal DMD, but decreased (P &lt; .03) AAD. N retention was not improved by the treatments. An 82-d feeding trial was conducted with 72 wether lambs (avg initial wt: 28 kg) to study the effect of 1 or 3% fine (70% &lt; 53 µ) or coarse (85% &gt; 425 µ) limestone on rumen environment, weight gain and feed efficiency of lambs fed an all-concentrate diet. Rumen pH and VFA molar proportions were not affected by the treatments. Limestone (3.0%) decreased (P &lt; .10) total rumen VFA concentrations and increased (P &lt; .10) fecal pH. Weight gain was not different (P &gt; .10) among the treatments. Coarse limestone increased (P &lt; .10) feed efficiency. Five Angus heifers (285 kg) with duodenal and ileal cannulae were fed a 90% concentrate control diet (7.5 kg/d) or the same diet containing 1.60% defluorinated phosphate-regular (5.5%, 19.0% and 33.0% on 1400, 1180 and 850 µ sieves, respectively, DRP-R), 1.60% defluorinated phosphate-coarse (85% evenly among large sieves, DRP-C), 1.28% limestone or .5% MgO to study the effect of limestone or MgO on intestinal pH, DMD, starch digestibility (SD), CPD and AAD in beef cattle fed a high-concentrate diet. Ileal pH was increased by MgO. Fecal pH was increased (P &lt; .05) as follows: MgO &gt; DRP &gt; limestone and control. Minerals increased (P &lt; .05) duodenal liquid flow. Limestone and DRP-C increased (P &lt; .05) acid flow to the duodenum. Total tract DMD, SD and CPD were similar among treatments. Limestone and DRP-R increased (P &lt; .10) AAD. DRP-C tended to increase AAD, but differences were not statistically significant.","abstract_has_math":false,"creators":["Christiansen, Michael Lee"],"institution":"Virginia Polytechnic Institute and State University","degree_name":"Ph. D.","degree_level":"doctoral","degree_discipline":"Animal Science","degree_department":"Animal Science","school":null,"contributors":[],"advisors":[],"committee_chairs":["Webb, Jr., Kenneth"],"committee_members":["Thye, Forrest W.","McCarthy, Farabee D.","Fontenot, Joseph P.","Herbein, Joseph H. Jr."],"year":1988,"date_issued":"1988","date_published":"1988","updated_at":"2026-07-22T22:19:38Z","subjects":[],"languages":["en_US"],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/10919/54321","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Webb, Jr., Kenneth"]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Thye, Forrest W.","McCarthy, Farabee D.","Fontenot, Joseph P.","Herbein, Joseph H. 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Limestone (3%) increased (P < .03) rumen pH. Magnesium oxide increased (P < .10) ileal and fecal pH. Limestone significantly increased N absorption and pre-abomasal DMD, but decreased (P < .03) AAD. N retention was not improved by the treatments. An 82-d feeding trial was conducted with 72 wether lambs (avg initial wt: 28 kg) to study the effect of 1 or 3% fine (70% < 53 µ) or coarse (85% > 425 µ) limestone on rumen environment, weight gain and feed efficiency of lambs fed an all-concentrate diet. Rumen pH and VFA molar proportions were not affected by the treatments. Limestone (3.0%) decreased (P < .10) total rumen VFA concentrations and increased (P < .10) fecal pH. Weight gain was not different (P > .10) among the treatments. Coarse limestone increased (P < .10) feed efficiency. Five Angus heifers (285 kg) with duodenal and ileal cannulae were fed a 90% concentrate control diet (7.5 kg/d) or the same diet containing 1.60% defluorinated phosphate-regular (5.5%, 19.0% and 33.0% on 1400, 1180 and 850 µ sieves, respectively, DRP-R), 1.60% defluorinated phosphate-coarse (85% evenly among large sieves, DRP-C), 1.28% limestone or .5% MgO to study the effect of limestone or MgO on intestinal pH, DMD, starch digestibility (SD), CPD and AAD in beef cattle fed a high-concentrate diet. Ileal pH was increased by MgO. Fecal pH was increased (P < .05) as follows: MgO > DRP > limestone and control. Minerals increased (P < .05) duodenal liquid flow. Limestone and DRP-C increased (P < .05) acid flow to the duodenum. Total tract DMD, SD and CPD were similar among treatments. Limestone and DRP-R increased (P < .10) AAD. DRP-C tended to increase AAD, but differences were not statistically significant."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Ph. D."]},{"key":"dc:format.mimetype","label":"Dc Format Mimetype","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Gastrointestinal acidity, protein and starch digestibility and amino acid absorption in ruminants fed a high-concentrate diet with limestone, magnesium oxide or defluorinated phosphate"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Webb, Jr., Kenneth"],"dc:contributor.committeemember":["Thye, Forrest W.","McCarthy, Farabee D.","Fontenot, Joseph P.","Herbein, Joseph H. Jr."],"dc:contributor.department":["Animal Science"],"dc:creator":["Christiansen, Michael Lee"],"dc:date.accessioned":["2015-07-09T20:43:42Z"],"dc:date.available":["2015-07-09T20:43:42Z"],"dc:date.issued":["1988"],"dc:description.abstract":["Twelve wether lambs (32kg) with abomasal and ileal cannula were fed a 90% concentrate basal diet (800 g/d), basal + 1.5% magnesium oxide (MgO)(812 g/d), basal + 1.5% limestone (812 g/d) or basal + 3.0% limestone (824 g/d) to study the effect of·these minerals on intestinal pH, rumen fermentation, N balance, dry matter and crude protein digestibility (DMD, CPD), and small intestinal disappearance of amino acids (AAD). Limestone (3%) increased (P < .03) rumen pH. Magnesium oxide increased (P < .10) ileal and fecal pH. Limestone significantly increased N absorption and pre-abomasal DMD, but decreased (P < .03) AAD. N retention was not improved by the treatments. An 82-d feeding trial was conducted with 72 wether lambs (avg initial wt: 28 kg) to study the effect of 1 or 3% fine (70% < 53 µ) or coarse (85% > 425 µ) limestone on rumen environment, weight gain and feed efficiency of lambs fed an all-concentrate diet. Rumen pH and VFA molar proportions were not affected by the treatments. Limestone (3.0%) decreased (P < .10) total rumen VFA concentrations and increased (P < .10) fecal pH. Weight gain was not different (P > .10) among the treatments. Coarse limestone increased (P < .10) feed efficiency. Five Angus heifers (285 kg) with duodenal and ileal cannulae were fed a 90% concentrate control diet (7.5 kg/d) or the same diet containing 1.60% defluorinated phosphate-regular (5.5%, 19.0% and 33.0% on 1400, 1180 and 850 µ sieves, respectively, DRP-R), 1.60% defluorinated phosphate-coarse (85% evenly among large sieves, DRP-C), 1.28% limestone or .5% MgO to study the effect of limestone or MgO on intestinal pH, DMD, starch digestibility (SD), CPD and AAD in beef cattle fed a high-concentrate diet. Ileal pH was increased by MgO. Fecal pH was increased (P < .05) as follows: MgO > DRP > limestone and control. Minerals increased (P < .05) duodenal liquid flow. Limestone and DRP-C increased (P < .05) acid flow to the duodenum. Total tract DMD, SD and CPD were similar among treatments. Limestone and DRP-R increased (P < .10) AAD. DRP-C tended to increase AAD, but differences were not statistically significant."],"dc:description.degree":["Ph. D."],"dc:format.mimetype":["application/pdf"],"dc:identifier.uri":["http://hdl.handle.net/10919/54321"],"dc:language.iso":["en_US"],"dc:publisher":["Virginia Polytechnic Institute and State University"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:title":["Gastrointestinal acidity, protein and starch digestibility and amino acid absorption in ruminants fed a high-concentrate diet with limestone, magnesium oxide or defluorinated phosphate"],"dc:type":["Dissertation"],"dc:type.dcmitype":["Text"],"thesis:degree_discipline":["Animal Science"],"thesis:degree_level":["doctoral"],"thesis:degree_name":["Ph. D."],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:19:38Z"}