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ARS Home » Midwest Area » Madison, Wisconsin » U.S. Dairy Forage Research Center » Dairy Forage Research » Research » Publications at this Location » Publication #388058
Research Project: Forage Characteristics and Utilization that Improve Efficiency of Growth, Performance, Nutrient Use, and Environmental Impacts of Dairy Production

Location: Dairy Forage Research

Title: Intensive mechanical processing of forage crops to improve fibre digestion

Author
item PINTENS, DAVID - University Of Wisconsin
item SHINNERS, KEVIN - University Of Wisconsin
item FRIEDE, JOSHUA - University Of Wisconsin
item Kalscheur, Kenneth
item DIGMAN, MATTHEW - University Of Wisconsin
item COMBS, DAVID - University Of Wisconsin

Submitted to: Grass and Forage Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/14/2021
Publication Date: 1/25/2022
Citation: Pintens, D.A., Shinners, K.J., Friede, J.C., Kalscheur, K., Digman, M.F., Combs, D.K. 2022. Intensive mechanical processing of forage crops to improve fibre digestion. Grass and Forage Science. 77(1):55-65. https://doi.org/10.1111/gfs.12559.
DOI: https://doi.org/10.1111/gfs.12559

Interpretive Summary: The objective of this research was to determine how intensive forage processing affects forage physical properties and ruminal fiber digestion. This research demonstrated that intensive mechanical processing affected the physical form of both wilted alfalfa and whole plant corn. It is hypothesized that processing increased cell rupture and the amount of fiber exposed to digestion by microorganisms in the rumen. This process increased the rapidly soluble fraction and the rate of dry matter and fiber degradation of wilted alfalfa. As a result, intensive mechanical processing has the potential to improve ruminant animal utilization of forage crops through improved fiber digestion. Processing through impact, rather than through shredding, resulted in greater physical disruption. This research will be of interest to dairy producers, researchers, and ruminant nutritionists interested in improving the value of forages in ruminant diets. Improving the value of forages for ruminants will increase the value of forages both nutritionally and economically resulting in more sustainable ruminant production systems.

Technical Abstract: Two intensive forage processing mechanisms, utilizing either shredding or impact processing, were used to investigate physical disruption of wilted alfalfa and whole-plant corn as a potential means to improve fiber digestion. Physical disruption was quantified by a processing level index (PLI) defined as the ratio of treatment leachate conductivity relative to that of a processed treatment. The goal was to achieve a PLI of at least 60% based on previous research. Impact processing created more physical disruption than shredding and the former method was able to achieve the desired PLI goal. Although impact processing significantly reduced particle size of both wilted alfalfa and whole-plant corn, more than 40% of alfalfa particles were longer than 6.3 mm when the PLI of greater than 60% was achieved. The mean particle-size of the kernel fraction of processed whole-plant corn was less than 1 mm after processing with the impact processor. Impact processing of wilted alfalfa significantly increased the rapidly soluble fraction and increased the rate of degradation of DM and potentially digestible fiber during an in situ digestion experiment. Intensive mechanical processing has the potential to improve ruminant animal utilization of forage crops through improved fiber digestion.