Management of cereal-grain forages for yield, quality, and fiber digestibility

Authors: Coblentz, Wayne; AKINS, MATTHEW - University Of Wisconsin

Submitted to: Journal of Dairy Science
Publication Type: Abstract Only
Publication Acceptance Date: 1/15/2019
Publication Date: 3/2/2019
Citation: Coblentz, W.K., Akins, M.S. 2019. Management of cereal-grain forages for yield, quality, and fiber digestibility. Journal of Dairy Science. March 11-13. Omaha, NE.

Interpretive Summary:

Technical Abstract: Cereal-grains have a long history of providing quality forage for dairy and beef operations. Our objective is to review the existing literature, and describe the principle factors controlling the yield and quality of cereal-grain forages. Generally, cereal-grain forage production can occur via management scenarios that include: i) winter-annuals planted during fall, and then grazed or harvested the following spring; ii) cereals not requiring vernalization planted during early spring, and harvested during late-spring or summer; and iii) cereals not requiring vernalization planted during late-summer and harvested before winter. Winter-annuals planted during fall also are used extensively for fall grazing, particularly for backgrounding stocker cattle. The requirement for vernalization before plants elongate and produce viable seed plays a large role in synchronizing management strategies with producer goals. For example, maximization of fall growth can be attained by choosing a species or cultivar that does not require vernalization and will elongate, but this choice will likely eliminate winter survival and subsequent spring forage production. Ambient temperature during plant maturation affects lignin formation positively; therefore, forages grown during cooler fall temperatures will typically exhibit greater NDF digestibility than those maturing during summer. Most nutritional characteristics are influenced heavily by two competing processes that include the normal negative maturation effects that reduce the quality of most forages. However, this process is juxtaposed against the physiological process of grain fill, which can dilute concentrations of forage fiber components, increase energy density, and improve DM digestibility at advanced plant-growth stages. Digestibility of NDF declines with plant maturity, and generally is not affected by grain fill. A boot-stage harvest for silage often exhibits the most favorable nutritional characteristics for lactating dairy cows; however, producers making this management choice will need to accept a substantial yield penalty compared to a commonly recommended harvest at soft-dough stage, which will likely maximize yield.