|Harrison, J - WASHINGTON STATE UNIV|
|Nennich, T - WASHINGTON STATE UNIV|
Submitted to: American Forage and Grassland Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: June 12, 2004
Publication Date: June 16, 2004
Citation: Rotz, C.A., Harrison, J.H., Nennich, T.D. 2004. Whole farm impact of increasing corn silage cutting height. American Forage and Grassland Conference Proceedings. 13. CDROM. Interpretive Summary: Corn silage is a common forage produced and fed on dairy farms. Small improvements in the nutrient content of this forage can benefit high producing dairy cows by improving their efficiency in using feed nutrients and by increasing milk production. Recent research shows that improvements in corn silage nutrient concentrations can be obtained by raising the cutting device about 12 inches during harvest to leave a portion of the less nutritious stalk in the field. Although this improves the nutritional value of the feed, leaving this long stubble reduces the harvested yield by 5 to 10%. The net benefit of this process is not well understood, and thus it is difficult to recommend whether producers should or should not use this technique. To better understand the effects of increasing the cutting height from the broad view of a producer, a typical dairy farm was simulated over many years of weather to determine the effects of implementing this strategy on farm performance and profitability. The benefits obtained through improved nutritional content were more than offset by the lost yield, causing a small decrease in farm profit. Our recommendation for routine harvest of corn silage is to use a traditional 6-inch cutting height to maximize production of forage having slightly lower nutritional value.
Technical Abstract: Some producers are raising the cutting height in corn silage harvest to obtain higher quality forage for dairy feed. Experimental studies show that increasing the cutting height about 12 inches reduces harvested yield about 7% with a 3% DM decrease in neutral detergent fiber concentration, a 4% increase in energy content, and small increases in crude protein concentration and fiber and DM digestibilities. Depending upon the feeding strategy used, the higher quality forage may increase milk production by 3%. Farm simulation was used to integrate these effects and determine their value to the producer. Long-term implications of increasing cutting height were determined for a representative farm in the Mid Atlantic region. The loss in feed production was found to offset the potential benefit from improved feed quality causing a loss in annual net return or farm profit of $6 to $15/cow. Kernel processing provided a more economical method for improving the feed value of corn silage, increasing net return by almost $50/cow. Our general recommendation is to use a low cutting height to maximize forage production.