Two rumen fistulated Holstein cows, weighing approximately 550 kg, were used in a switchback design experiment to evaluate the effects of consuming large amounts (38% of total ration dry matter) of dried whey on rumen microbial protein synthesis. Cows were fed total mixed rations consisting of (dry matter basis) 45% corn silage, 10% alfalfa hay, and 45% concentrate mix. The concentrate mix was primarily corn and soybean meal (control) or 85% dried whole whey. Dry matter intakes averaged 16.4 and 15.3 kg/day for control and whey diets. Concentrations of bacteria and protozoa in rumen contents were estimated using diaminopimelic acid and aminoethylphosphonic acid, respectively, as markers. Diaminopimelic acid-N as percent of bacterial-N was similar for both diets (.61 and .63% for control and whey diets). Likewise, aminoethylphosphonic acid-N as percent of protozoal-N was similar for both diets (.17 and .19% for control and whey diets). For the control diet, total rumen-N was estimated to be 45% bacterial-N and 27% protozoal-N. Bacterial-N and protozoal-N, respectively, accounted for 52 and 22% of the total rumen-N in the cows fed the whey diet. Rumen fluid volume (33.8 and 39.2 liters for control and dried whey diets) and dilution rates (10.2 and 12.8%/h), as estimated with polyethylene glycol, were higher when fed dried whey. Rumen ammonia (5.0 and 3.4 mg/dl) was lower when fed dried whey. Butyrate (16.5 and 24.4 moles/100 moles total volatile fatty acids) was higher while propionate was lower (32.4 and 23.2 moles/100 moles total volatile fatty acids) when fed dried whey; concentrations of other volatile fatty acids were similar with both diets. Bacterial synthesis appeared to be increased when cows were fed a diet containing large amounts of dried whey.
","abstract_html":"<p>Two rumen fistulated Holstein cows, weighing approximately 550 kg, were used in a switchback design experiment to evaluate the effects of consuming large amounts (38% of total ration dry matter) of dried whey on rumen microbial protein synthesis. Cows were fed total mixed rations consisting of (dry matter basis) 45% corn silage, 10% alfalfa hay, and 45% concentrate mix. The concentrate mix was primarily corn and soybean meal (control) or 85% dried whole whey. Dry matter intakes averaged 16.4 and 15.3 kg/day for control and whey diets. Concentrations of bacteria and protozoa in rumen contents were estimated using diaminopimelic acid and aminoethylphosphonic acid, respectively, as markers. Diaminopimelic acid-N as percent of bacterial-N was similar for both diets (.61 and .63% for control and whey diets). Likewise, aminoethylphosphonic acid-N as percent of protozoal-N was similar for both diets (.17 and .19% for control and whey diets). For the control diet, total rumen-N was estimated to be 45% bacterial-N and 27% protozoal-N. Bacterial-N and protozoal-N, respectively, accounted for 52 and 22% of the total rumen-N in the cows fed the whey diet. Rumen fluid volume (33.8 and 39.2 liters for control and dried whey diets) and dilution rates (10.2 and 12.8%/h), as estimated with polyethylene glycol, were higher when fed dried whey. Rumen ammonia (5.0 and 3.4 mg/dl) was lower when fed dried whey. Butyrate (16.5 and 24.4 moles/100 moles total volatile fatty acids) was higher while propionate was lower (32.4 and 23.2 moles/100 moles total volatile fatty acids) when fed dried whey; concentrations of other volatile fatty acids were similar with both diets. Bacterial synthesis appeared to be increased when cows were fed a diet containing large amounts of dried whey.</p>","abstract_has_math":false,"creators":["Windschitl, Paul M"],"institution":null,"degree_name":"Master of Science (MS)","degree_level":"Thesis - Open Access","degree_discipline":"Dairy Science","degree_department":null,"school":null,"contributors":["David J. Schingoethe"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":1983,"date_issued":"1983-01-01T08:00:00Z","date_published":"1983-01-01T08:00:00Z","updated_at":"2026-07-24T04:29:00Z","subjects":["Dairy Science"],"languages":["en"],"rights":["In Copyright - Non-Commercial Use Permitted
http://rightsstatements.org/vocab/InC-NC/1.0/
In Copyright - Non-Commercial Use Permitted
http://rightsstatements.org/vocab/InC-NC/1.0/
Two rumen fistulated Holstein cows, weighing approximately 550 kg, were used in a switchback design experiment to evaluate the effects of consuming large amounts (38% of total ration dry matter) of dried whey on rumen microbial protein synthesis. Cows were fed total mixed rations consisting of (dry matter basis) 45% corn silage, 10% alfalfa hay, and 45% concentrate mix. The concentrate mix was primarily corn and soybean meal (control) or 85% dried whole whey. Dry matter intakes averaged 16.4 and 15.3 kg/day for control and whey diets. Concentrations of bacteria and protozoa in rumen contents were estimated using diaminopimelic acid and aminoethylphosphonic acid, respectively, as markers. Diaminopimelic acid-N as percent of bacterial-N was similar for both diets (.61 and .63% for control and whey diets). Likewise, aminoethylphosphonic acid-N as percent of protozoal-N was similar for both diets (.17 and .19% for control and whey diets). For the control diet, total rumen-N was estimated to be 45% bacterial-N and 27% protozoal-N. Bacterial-N and protozoal-N, respectively, accounted for 52 and 22% of the total rumen-N in the cows fed the whey diet. Rumen fluid volume (33.8 and 39.2 liters for control and dried whey diets) and dilution rates (10.2 and 12.8%/h), as estimated with polyethylene glycol, were higher when fed dried whey. Rumen ammonia (5.0 and 3.4 mg/dl) was lower when fed dried whey. Butyrate (16.5 and 24.4 moles/100 moles total volatile fatty acids) was higher while propionate was lower (32.4 and 23.2 moles/100 moles total volatile fatty acids) when fed dried whey; concentrations of other volatile fatty acids were similar with both diets. Bacterial synthesis appeared to be increased when cows were fed a diet containing large amounts of dried whey.
"]},{"key":"dc:title","label":"Title","values":["Rumen Microbial Protein Synthesis in Cows Fed Dried Whey"]}]}],"canonical_facts":{"dc:contributor":["David J. Schingoethe"],"dc:creator":["Windschitl, Paul M"],"dc:date.available":["2017-07-21T07:00:00Z"],"dc:description.abstract":["Two rumen fistulated Holstein cows, weighing approximately 550 kg, were used in a switchback design experiment to evaluate the effects of consuming large amounts (38% of total ration dry matter) of dried whey on rumen microbial protein synthesis. Cows were fed total mixed rations consisting of (dry matter basis) 45% corn silage, 10% alfalfa hay, and 45% concentrate mix. The concentrate mix was primarily corn and soybean meal (control) or 85% dried whole whey. Dry matter intakes averaged 16.4 and 15.3 kg/day for control and whey diets. Concentrations of bacteria and protozoa in rumen contents were estimated using diaminopimelic acid and aminoethylphosphonic acid, respectively, as markers. Diaminopimelic acid-N as percent of bacterial-N was similar for both diets (.61 and .63% for control and whey diets). Likewise, aminoethylphosphonic acid-N as percent of protozoal-N was similar for both diets (.17 and .19% for control and whey diets). For the control diet, total rumen-N was estimated to be 45% bacterial-N and 27% protozoal-N. Bacterial-N and protozoal-N, respectively, accounted for 52 and 22% of the total rumen-N in the cows fed the whey diet. Rumen fluid volume (33.8 and 39.2 liters for control and dried whey diets) and dilution rates (10.2 and 12.8%/h), as estimated with polyethylene glycol, were higher when fed dried whey. Rumen ammonia (5.0 and 3.4 mg/dl) was lower when fed dried whey. Butyrate (16.5 and 24.4 moles/100 moles total volatile fatty acids) was higher while propionate was lower (32.4 and 23.2 moles/100 moles total volatile fatty acids) when fed dried whey; concentrations of other volatile fatty acids were similar with both diets. Bacterial synthesis appeared to be increased when cows were fed a diet containing large amounts of dried whey.
"],"dc:identifier":["https://openprairie.sdstate.edu/etd/1314"],"dc:language":["en"],"dc:rights":["In Copyright - Non-Commercial Use Permitted
http://rightsstatements.org/vocab/InC-NC/1.0/