New Research Highlights Alternative Forage Options
Forage is king. As the largest feed component on dairies, it often composes up to 60 percent of the lactating cow diet. When forage is in short supply, it limits options for feeding cows and can reduce the number of cows that a dairy can profitably milk.
Available land base, drought, lack of ground water, climate change and rain or frost at the wrong time all limit how much quality forage can be produced. Historically corn silage and alfalfa have been the predominant forages fed to dairy cows.
Researchers across the country have been studying alternative forage crops. They are looking for forages that support today’s high-producing cows and deliver added benefits as well. Those added benefits include forages that need less water, that can be grown in a double-crop system to maximize forage production per acre and that can help remove additional phosphorus from the soil.
Several new research studies have substituted limited amounts of alternative forages for corn silage and alfalfa in lactating-cow diets. Milk production results have been similar, making these forages viable options to expand your forage supply. Take a look at the research summaries below to see which forages might best fit into your farm’s cropping system.
Researchers at Kansas State University used teff hay as the sole forage in lactating cow diets. Teff hay is a warm-season annual grass native to Ethiopia that is very drought tolerant. Corn silage, alfalfa hay and prairie grass hay were the forages used in the control diet. Two diets with teff hay were evaluated. All three diets were formulated for similar dry matter (DM), crude protein (CP) and starch concentrations. The teff A diet was formulated to match the neutral detergent fiber (NDF) from forage in the control diet (18.23 ±0.15% of DM). The teff B diet had an NDF of 16.63% from forage. DMI, milk production (89.7 lbs/day), milk fat content, lactose content, energy-corrected milk (ECM), body weight (BW) and body condition score (BCS) were unchanged by treatment. However, both teff hay diets increased milk protein concentration from 3.07% to 3.16%. Results indicate that teff hay has the potential to replace alfalfa and corn silage in lactating cow diets without losing productivity. The study abstract was presented at the 2017 ADSA meeting (M171). Journal of Dairy Science 100, Supplement 2, M171, p. 68.
Researchers at the U.S. Dairy Forage Research Center in Wisconsin evaluated whether BMR sudangrass silage could successfully replace conventional corn silage or BMR corn silage in the diet of mid- to late-lactation cows. Diets were formulated to contain 40% corn silage, 20% alfalfa silage and 40% concentrate on a DM basis. BMR sudangrass silage was used to replace 10% of the corn silage in each diet—conventional corn silage or BMR corn silage. Results showed that DMI, milk production, protein, lactose, total solids percentage, ECM and feed efficiency were not affected by the inclusion of BMR sudangrass silage in the diet. Milk fat percentage, however, increased 0.15% for cows fed a diet with 10% BMR sudangrass silage. Researchers concluded that BMR sudangrass silage, which requires less water to grow and is highly digestible, could be used to replace 10% of conventional or BMR corn silage in the diet of lactating cows. The study abstract was presented at the 2017 ADSA meeting (M300). Journal of Dairy Science 100, Supplement 2, M300, p. 114-115.
Penn State researchers evaluated if wheat silage or triticale silage could replace some corn silage in lactating cow diets without affecting production. Cows were fed a control diet containing 44% corn silage on a DM basis or a diet with 10% wheat silage or 10% triticale silage substituted for corn silage. DMI was unchanged, but milk yield declined slightly for wheat silage and triticale silage diets compared to the control diet, 91.3 lbs/day, 90.8 lbs/day and 94.1 lbs/day respectively. Researchers concluded that wheat and triticale cover crops planted after corn silage harvest and harvested at boot stage can support milk production above 90 lbs/day when included at 10% of the diet. For farms that need more forage, double-cropping wheat or triticale after corn silage harvest can help meet that need. Proper harvest timing of alternative forages is critical to produce highly digestible forages to support cow performance. The study was reported in the August 2017 Journal of Dairy Science 100:6151.
Penn State researchers also evaluated BMR 6 dwarf forage sorghum silage and fall-grown oat silage as ways to increase forage options while maintaining cow productivity on farm. Cows were fed a control diet containing 44% corn silage on a DM basis or a diet with 10% BMR sorghum silage or 10% oat silage substituted for corn silage. Results showed that sorghum silage decreased DMI, milk yield and milk protein content, but increased milk fat content and maintained ECM similar to control. Results for the oat silage diet showed DMI, milk yield and milk components were unchanged compared to control. Researchers concluded that both forages could support milk yield above 83.8 lbs/day when included at 10% of the diet DM and provide options to increase the amount of forage grown on farm. Proper harvest timing of alternative forages is critical to produce highly digestible forages to support cow performance. This study was reported in the July 2017 Journal of Dairy Science 100:5250.
Triticale and Crimson Clover Silage
Kansas State University researchers also evaluated a mix of beardless triticale and crimson clover as a winter cover crop to see if it could support milk production and remove phosphorus from the soil. One field of triticale/clover had lagoon water applied; the other field had solid manure applied during the growing season. Cows received a diet with triticale/clover silage (TCS) at 15% of DM or a control diet where TCS was replaced by alfalfa and grass hay. The TCS diet also included additional bypass soybean meal in order to balance the metabolizable protein supplied across both diets. Cows fed the TCS diet ate less, 48.4 lbs/day vs. 55.9 lbs/day DMI for control cows. However, both groups produced nearly the same amount of milk, 80.86 lbs/day for TCS cows and 80.75 lbs/day for control cows. ECM and fat corrected milk were similar across diets. But because of the change in DMI, feed efficiency (ECM/DMI) was greater for cows fed the TCS diet, 1.71 vs. 1.48 for control cows. The winter cover crop of triticale and clover produced more than 3 tons of DM/acre, with a CP content of 21.1%, and removed 38 lbs/a of potassium and 320 lbs/a of phosphorus. This research will be reported at the Kansas Dairy Days in January.