Effects of Hay, Baleage, and Soybean Hulls Waste Used as Supplemental Feeds on the Nutritional Profile of Grass-Finished Beef

Abstract

Grass-finished beef (GFB) has demonstrated wide nutritional variations with some GFB having a considerably higher n-6:n-3 ratio compared to grain-finished beef. To better understand these variations, the current study investigated the effects of commonly used supplemental feeds on the nutritional profile of GFB. This two-year study involved 117 steers randomly allocated to one of four diets: (1) grass+hay (G-HAY), (2) grass+baleage (G-BLG), (3) grass+soybean hulls (G-SH), and (4) baleage+soybean hulls in feedlot (BLG-SH). Feed samples were analyzed for their nutritional value, and beef samples underwent analysis for fatty acids (FAs), vitamin E, minerals, lipid oxidation, and shear force. FAs were measured by GC-MS, vitamin E was analyzed chromatographically, minerals were analyzed by ICP-MS, and lipid oxidation was measured via a thiobarbituric acid reactive substances (TBARS) assay. G-SH beef had the highest n-6:n-3 ratio (p < 0.001), while BLG-SH beef contained less vitamin E (p < 0.001) and higher TBARS values (p < 0.001) compared to the other groups. G-HAY beef contained more long-chain n-3 polyunsaturated FAs compared to the other groups (p < 0.001). In conclusion, G-HAY beef had the most beneficial nutritional profile, while soybean hulls increased the n-6:n-3 ratio of beef.

Measuring the Phytochemical Richness of Meat: Effects of Grass/Grain Finishing Systems and Grapeseed Extract Supplementation on the Fatty Acid and Phytochemical Content of Beef

“…The protocol was described previously [6,28,32,45]. Unless otherwise specified, chemicals for FA analysis were obtained from Sigma-Aldrich (St. Louis, MO, USA).…”

“…One µL of beef samples was injected twice (20:1 split) (GC temperatures: 175 • C and 150 • C). For detailed temperature settings, please see Krusinski et al [32]. A third injection in splitless mode followed for beef samples.…”

“…The protocols for vitamin E and mineral analysis of beef were previously reported [32,46]. For vitamin E, the protocol was adapted from Rettenmaier and Schüep [49].…”

“…The mineral analysis protocol was adapted from Wahlen et al [50] and was previously described [6,32]. Briefly, the Agilent 7900 Inductivity Coupled Plasma-Mass Spectrometer (ICP-MS) (Agilent Technologies, Inc., Santa Clara, CA, USA) was used, and a six-point calibration curve and bovine liver and mussel standards (National Institute of Standards and Technology, Gaithersburg, MD, USA) were used as controls.…”

“…There has been interest in using plant byproducts and waste from the food industry to enhance the nutritional profile of meat [30][31][32][33]. In wine-producing regions, like Michigan, great quantities of waste and byproducts are generated causing economic and ecological issues [31].…”