|BRUNS, HEIDI - South Dakota State University|
|HIPPEN, ARNOLD - South Dakota State University|
|SCHINGOETHE, DAVID - South Dakota State University|
Submitted to: Journal of Dairy Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/17/2015
Publication Date: 9/14/2015
Publication URL: http://handle.nal.usda.gov/10113/63160
Citation: Bruns, H.R., Hippen, A.R., Kalscheur, K., Schingoethe, D.J. 2015. Inclusion of various amounts of steam-flaked soybeans in lactating dairy cattle diets. Journal of Dairy Science. 98(10):7218-7225. doi: 10.3168/jds.2015-9381.
Interpretive Summary: High producing dairy cattle require greater amounts of ruminally undegraded protein (protein that is not digested in the rumen but instead passes to the small intestine where it is digested and absorbed by the cow). Solvent-extracted soybean meal, a common protein supplement in dairy cow diets, does not provide enough ruminally undegraded protein. Previous research has demonstrated that heat treatment processing, such as extruding and roasting, of soybean products has the potential to increase ruminally undegraded protein. While heat-treated, full-fat soybean products have been evaluated for their feeding value and effects on production, data regarding steam-flaked soybeans in dairy cow diets is not available. This study evaluated the effects of feeding steam-flaked soybeans in dairy cow diets at 0, 5, 10, and 15% of the diet on milk production and milk composition. This research showed that steam-flaked soybeans can replace a mixture of soybean meal and commercial fat supplements without negatively affecting milk production, milk fat, and milk protein composition. This information gives dairy producers and nutritionists another option for formulating dairy cow diets that have adequate ruminally undegraded protein.
Technical Abstract: While most soybean feedstuffs have been extensively investigated for use in ruminant diets, there is a lack of information regarding steam-flaked soybeans. This research evaluated various inclusion rates of steam-flaked soybeans (SFSB) in lactating dairy cattle diets. Twelve multiparous Holstein cows (103 ± 39 days in milk) were used in a 4 x 4 latin-square experiment with 28-d periods, 14-d for diet transitioning followed by a 14-d sampling period. Treatments were inclusion of SFSB at 0, 5, 10 and 15% of dietary DM, replacing a mixture of soybean meal, soyhulls, calcium salts of fatty acids, and choice white grease. Animals were fed typical lactating dairy cow diets formulated to be isonitrogenous and isoenergetic containing 60% of DM as forage and 40% of DM as concentrate. Dry matter intake (28.8 kg/d), milk production (42.2 kg/d), milk fat percentage (3.52%), and feed efficiency (1.43 kg milk / kg DMI) were similar across all treatments. Milk protein (2.98%) and lactose (4.87%) were also unaffected by the amount of SFSB in the diet. Milk urea nitrogen concentration and yield decreased linearly as the amount of SFSB in the diet increased. Body weight changes tended to increase linearly, and body condition score changes decreased linearly as the amount of SFSB in the diet increased. This research demonstrated that steam-flaked soybeans can be substituted for soybean meal and commercial fat sources while maintaining milk and milk component production and decreasing milk urea nitrogen production.