Gas Emissions from Dairy Cows Fed Typical Diets of Midwest, South, and West Regions of the United States
- Zifei Liu *a,
- Wendy Powersb,
- Bradley Oldickc,
- Jill Davidsond and
- Deanne Meyere
- a Michigan State Univ., 2265I Anthony Hall, East Lansing, MI 48824
b Michigan State Univ., 2209 Anthony Hall, East Lansing, MI 48824
c Southern States Cooperative, Inc., 6606 W. Broad St., P.O. Box 26234, Richmond, VA 23260
d Oregon State Univ., 112 Withycombe, Corvallis, OR 97331
e Univ. of California, 2209 Meyer Hall, One Shields Ave., Davis, CA 95616. J. Davidson, current address: 100 Danforth Dr., Gray Summit, MO 63039. Assigned to Associate Editor Sean McGinn
Gas emissions were determined for dairy cows fed three diets formulated to represent feed ingredients typical of the Midwest, South, or West regions of the United States. Dairy cows were housed and monitored in 12 environmentally controlled rooms (4 cows diet−1). Two experiments were performed, representing two lactation stages (initial days in milk were 115 ± 39 d in Stage 1 and 216 ± 48 d in Stage 2). The results demonstrated that the combination of different dietary ingredients resulted in different gas emissions while maintaining similar dry matter intake (DMI) and milk yield (MY). Diet effect on ammonia (NH3) emissions was more prominent in Stage 1. During Stage 1, cows fed the Midwest diet had the highest daily NH3 emission, corresponding to the highest crude protein (CP) concentration among the three regions. The differences in NH3 emissions (39.0%) were much larger than the percent difference in CP concentrations between diets (6.8%). Differences in N intake, N excretion, or milk urea N alone may not serve as a strong indicator of the potential to reduce NH3 emissions. Lower emissions of methane (CH4) per unit DMI or per unit MY were observed for cows offered the South diet during Stage 1 as compared with that from cows offered the Midwest or West diets. No diet effect was observed for hydrogen sulfide (H2S) emission per unit S intake, nor for nitrous oxide (N2O) emission. The measured NH3 and CH4 emissions were comparable, but the N2O emissions were much higher than those reported for tie-stall dairy barns in the literature.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
Copyright © 2012. . Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.