This project will provide research-based data evaluating the capacity of soybean hulls to replace increasing portions of corn silage in feedlot rations. Specifically, we will evaluate how replacement of corn silage with soybean hulls impacts ruminal fermentation and pH. Further we will evaluate the characteristics of the fiber contained in soybean hulls in an effort to better understand the implications of fiber digestibility and the subsequent potential for ruminal acidosis. Data will also be collected enabling us to determine how changes in ruminal pH and fiber flow impact protein production within the rumen. The combination of this data will enable us to determine future research objectives and to begin to define recommendations for beef producers.

1) To evaluate changes in ruminal fermentation and pH with increasing concentrations of soybean hull inclusion.
2) To evaluate changes in ruminal and duodenal fiber kinetics of high grain rations containing soybean hulls.

1) Research data on changes in rumen fermentation and pH.
2) Research data on fiber digestibility.
3) Publication and presentation of results at scientific meetings.
4) Presentation of research to local constituents at field days and other events.

Updated December 1, 2020:
To data this project is still ongoing and we currently do not have any data to share at this time. Major animal activities were initiated this past summer and have been completed but laboratory analysis is still ongoing thus we do not have any data to present at this time. In the coming months we anticipate completing lab analysis and subsequent data analysis to allow for publication of research results in both producer-friendly and peer-reviewed formats in the spring and summer of 2021.

Updated June 29, 2021:

View uploaded report

Evaluation of soybean hulls as roughage sources in feedlot rations

Bryan Neville, Animal Scientist, Carrington REC


Goals/Objectives:
The overall objective of this research was to evaluate the fiber value provided by soybean hulls in feedlot diets.
Specific objectives included:
1) To evaluate performance of changes in ruminal fermentation and pH with increasing concentrations of soybean hull inclusion.
2) To evaluate changes in ruminal and duodenal fiber kinetics of high grain rations containing soybean hulls.

Results:
Intake was negatively impacted by increasing soyhull inclusion and decreased by 2.1 kg/d when corn silage was completely replaced with soyhulls. Intake and total tract digestibility of NDF were not affected by rate of soyhull inclusion or added straw. Further, duodenal flow of NDF was not affected by rate of soyhull inclusion but tended to decrease with added straw in the diet. In the current research replacing corn silage with soyhulls did not affect ruminal pH; however, adding wheat straw to the diet increased ruminal pH compared to the same diets without straw. The fact replacing greater amounts of corn silage with soyhulls did not impact ruminal pH is interesting. Based on lower expected effective fiber content of soyhulls we had anticipated that ruminal pH would have decreased with increasing soyhull replacement of corn silage. The response in ruminal fluid pH to the addition of 3% wheat straw to the diet was more traditional, and likely represents increases in rumination and addition of buffers from salvia to the rumen.

Presentations/Deliverables:
1) This data will be presented at the Western Section American Society of Animal Science Meetings in 2021.
2) A manuscript detailing the results of this project is being drafted and will be submitted to a peer-reviewed journal.

Production Outcomes:
In conclusion, decreases in intake observed in this study would likely decrease feedlot cattle performance and underscores the need for additional research prior to recommending utilizing soyhulls as a roughage source for feedlot cattle. Data evaluating soyhulls as a roughage source in high-concentrate diets are lacking and more research on the impacts of soyhull inclusion on performance of feedlot cattle would be needed to fully understand the impacts of utilizing this feed resource.

Feed resources continue to be one of the main expenses in beef operations. Further, nutrition management that results in decreasing the risks associated with ruminal acidosis is critical to optimizing feed efficiency and profitability for livestock producers. Research demonstrating the ability of soybean hulls to serve as a potential feed source in feedlot rations stands to increase the potential use of soybean hulls.

This data will help ascertain the relative value of the fiber contained within soybean hulls when used as a roughage source in feedlot diets. Also, data collected in this project would shed light on the impacts of roughage replacement with soybean hulls on microbial protein production and impacts if decreases in ruminal pH reduce microbial protein production and shift the proportions of degradable and undegradable protein in the rumen.

In two of the past three growing seasons many parts of North Dakota have been impacted by drought, resulting in decreased availability of forage, or expensive forage supplies. One of the barriers to feedlot expansion is acreage for the production of roughage. The cost for hauling hay and silages quickly makes these feeds some of the most expensive feeds offered in feedlot rations. By understanding the potential for feedlots to utilize an easily transportable feed like pelleted soybean hulls, expansion of the market for soybean hulls is possible. This research could increase the use of, and demand for, soybean hulls in the region.