Submitted to: American Dairy Science Association Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 3/9/2017
Publication Date: 6/25/2017
Citation: Kalscheur, K., Brink, G.E. 2017. Replacing conventional or brown-mid rib corn silage with brown-mid rib sudangrass silage in the diets of lactating dairy cows [abstract]. American Dairy Science Association Abstracts. 100(Suppl 2):114-115.
Technical Abstract: Forages that use less water, but are high in digestibility, are sought as alternatives to traditional forages such as corn silage. Brown mid-rib (BMR) sudangrass is a possible alternative that can provide high-quality forage as a replacement for corn silage. The objective of this study was to evaluate whether BMR sudangrass silage (SS) can replace 2 types of corn silage with differing fiber digestibilities [conventional (CONV) or BMR corn silage (CS)] in the diets of lactating dairy cows. Forty-eight Holstein cows in mid- to late-lactation were assigned to 1 of 4 treatments in a randomized complete block design. Cows were fed a common covariate diet for 2 weeks followed by 8 weeks of experimental diets. Diets were formulated to contain 40% CS, 20% alfalfa silage, and 40% concentrate on a dry matter (DM) basis. Sudangrass silage was included in experimental diets at either 0 or 10% of the diet DM replacing either 10% CONV or BMR CS. All other ingredients (high-moisture corn, canola meal, roasted soybeans, soyhulls, and minerals and vitamins) were included equally for all diets. Cow was the experimental unit. Dry matter intake (DMI) averaged 25.2 kg/d and was not affected by the type of CS used nor by the inclusion of SS in the diets (P>0.05). Similarly, milk production averaged 40.0 kg/d and was not affected by type of CS nor SS inclusion. Milk fat percentage increased 0.15% for cows fed the addition of 10% SS compared to cows fed 0% SS. Milk protein, lactose, and total solids percentage were not affected by dietary treatments. Milk protein yield was greater (0.054 kg/d; P=0.03) for cows fed 0% SS compared to cows fed 10% SS. Because the dietary CP% was slightly greater for diets containing 10% SS compared to 0% SS (17.2 vs 16.2%), milk urea nitrogen responded similarly (11.1 vs. 9.6 mg/dL; P=0.001). Because of similar intake and performance, energy-corrected milk (ECM) and feed efficiency (defined as ECM/DMI) was not affected by changes in forage. Overall, the inclusion of 10% SS as a replacement for either CONV or BMR CS did not negatively affect lactation performance. BMR SS can be a successful replacement for CS where CS is limited.