1a.Objectives (from AD-416):
Develop feeding strategies to grow yearling cattle to slaughter readiness in the fall on high quality forage diets (hay or silage) with limited amounts of supplemental concentrate (flaxseed), and determine the effects on resulting of omega-3 fatty acids in the beef.
1b.Approach (from AD-416):
The USDA-ARS, Northern Great Plains Research Laboratory (NGPRL) will cooperate with North Dakota State University (NDSU) through its Hettinger Research and Extension Center (HREC) to conduct collaborative livestock feeding trials comparing different levels of flaxseed supplementation. Cattle growth rate and feed efficiency will be determined along with the levels of omega-3 fatty acids in the beef.
A winter feeding trial was conducted with 27 yearling Angus and Angus crossbred steers that were randomly divided into nine groups with each group of three steers in a separate feedlot pen. Three groups of steers were fed only round bales of medium to high quality sudangrass or oat hay and gained an average of only 0.61 pounds per day between January 24th and April 24th. Another three groups of steers were fed the same forage plus about two pounds of a mixture of rolled dry peas and ground flaxseed and had an average gain of 1.15 pounds per day during the same period, and a third set of three groups of steers were fed the same forage plus about two pounds of a mixture of rolled peas and soybean meal and had an average weight gain of 1.46 pounds per day between January 24th and April 24th. Both types of supplements were formulated to provide similar amounts of protein and digestible energy, so an explanation for why the steers supplemented with peas and soybean meal gained more weight per day than the steers supplemented with peas and flaxseed was not readily apparent.