Corn Silage Energy and Protein above Average this Year
Dairy Pipeline: January 2000
Charles C. Stallings
Extension Dairy Scientist, Nutrition
The energy and protein in corn silage are running above average this year. Despite our lack of rain during the previous growing season, results from the Virginia Tech Forage Testing Lab indicate energy and protein in corn silage are greater than in the previous year. Net energy of lactation was .02 Mcal/lb. greater (.68 vs. .66 Mcal/lb.) and protein was .8 percentage points greater (8.0 vs. 7.2%). In addition dry matter content was 2.6 percentage points less (35.4 vs. 38%) and acid detergent fiber was 3.9 percentage points less (24.1 vs. 28%). This supports an observation that cows are milking relatively well off of this years corn silage. That is not the situation in all cases, however. The wetter silage this year could have resulted in some situations where corn was ensiled too wet. Wet silage might not be as palatable with more feed refusals being the result. Also if corn silage is limited it is tempting to stretch with by-product feeds that might not supply the roughage factor needed to ensure adequate rumination. One thumb rule is to ensure that 65 to 75% of the ration fiber (ADF or NDF) comes from forages. In summary, this years corn silage is wetter but higher in energy and protein then last year. Also fiber level is less. Make sure cows are consuming enough forage fiber and the rumens are healthy.