Master of Science (MS)


Dairy Science (Animal, Dairy, and Poultry Sciences)

Document Type



Six non-lactating Holstein cows with ruminal and duodenal cannulas were used in a replicated 3x3 Latin square design experiment to investigate the effects of supplemental protein source on ruminal and total tract nutrient digestibility. Supplemental protein was provided from soybean meal (SBM), expeller processed soybean meal (EXP), or menhaden fish meal (FM). Basal diets consisted of (DM basis) 33% corn silage, 20% bermudagrass hay, 27% ground corn, and 2% minerals and vitamins. Supplemental protein was provided as (DM % of total diet) 18% soybean meal (SOY), 17% soybean meal and 1% fish meal (FM), or 12% soybean meal and 6% expeller processed soybean meal (EXP). Period length was 14 d. Flow of digesta was estimated using Cr2O3 as an external marker. Due to factors unrelated to the trial, one cow died during the first period of the study and was not replaced. Dry matter intake averaged 9.5 kg/d and was not affected by treatment. Apparent ruminal dry matter digestibility was not affected by source of supplemental protein. Source of supplemental protein did not affect apparent total tract dry matter digestibility. Feeding low ruminal degradable protein to non-lactating cows resulted in no appreciable impact on feed intake or apparent diet digestibility.



Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Gale Bateman

Included in

Dairy Science Commons