In dairy farming systems, growing winter crops for forage is frequently limited to annual grasses grown in monoculture. The objectives of this study were to determine how cropping grasses alone or in mixtures with legumes affects the yield, nutritional composition, and in vitro digestibility of fresh and ensiled winter crops and the yield, nutritional composition, and in vitro digestibility of the subsequent summer crops. Experimental plots were planted with 15 different winter crops at 3 locations in Virginia. At each site, 4 plots of each treatment were planted in a randomized complete block design. The 15 treatments included 5 winter annual grasses [barley (BA), ryegrass (RG), rye (RY), triticale (TR), and wheat (WT)] in monoculture [i.e., no legumes (NO)] or with 1 of 2 winter annual legumes [crimson clover (CC) and hairy vetch (HV)]. After harvesting the winter crops, corn and forage sorghum were planted within the same plots perpendicular to the winter crop plantings. The nutritional composition and the in vitro digestibility of winter and summer crops were determined for fresh and ensiled samples. Growing grasses in mixtures with CC increased forage dry matter (DM) yield (2.84 Mg/ha), but the yield of mixtures with HV (2.47 Mg/ha) was similar to that of grasses grown in monoculture (2.40 Mg/ha). Growing grasses in mixtures with legumes increased the crude protein concentration of the fresh forage from 13.0% to 15.5% for CC and to 17.3% for HV. For neutral detergent fiber (NDF) concentrations, the interaction between grasses and legumes was significant for both fresh and ensiled forages. Growing BA, RY, and TR in mixtures with legumes decreased NDF concentrations, whereas growing RG and WT with legumes did not affect the NDF concentrations of either the fresh or the ensiled forages. Growing grasses in mixtures with legumes decreased the concentration of sugars of fresh forages relative to grasses grown in monoculture. Primarily, this decrease can be attributed to low concentrations of sugars of mixtures with HV (10.5%). Growing grasses in mixtures with legumes reduced the fiber digestibility of both winter crops (75.7% to 72.8% NDF). Growing grasses in mixtures with legumes did not affect estimated DM yield, nutritional composition, or digestibility of the succeeding summer crops. In conclusion, growing grasses in mixtures with legumes as winter forage crops can increase forage estimated DM yields and its nutritional quality in dairy farming sytems.
|Number of pages||11|
|Journal||Journal of Dairy Science|
|State||Published - Mar 2018|
Bibliographical noteFunding Information:
We thank Steve Gulick and Elizabeth Rucker (Department of Crop and Soil Environmental Sciences) for their assistance in preparing the experimental plots. We also thank Yang Yang (Department of Dairy Science) for assistance with harvesting plots. Finally, we thank King's Agriseeds (Ronks, PA) for donating the seeds for winter crops (i.e., ryegrass, rye, triticale, crimson clover, and hairy vetch), Advanta Seeds (Irving, TX) for donating the seeds for forage sorghum, and Lallemand Inc. (Milwaukee, WI) for donating the silage inoculant. This project was funded mainly by the USDA Natural Resources Conservation Virginia Conservation Innovation Grant program and partially by USDA National Institute of Food and Agriculture Hatch Project VA-160025 and USDA National Institute of Food and Agriculture Multistate Project VA-136291 (NC-2042, Management Systems to Improve the Economic and Environmental Sustainability of Dairy Enterprises).
© 2018 American Dairy Science Association
- cover crop
- small grain
ASJC Scopus subject areas
- Food Science
- Animal Science and Zoology