Effects of Silage Diets and Electrical Stimulation on the Palatability, Cooking and pH Characteristics of Beef Loin Steaks

Abstract

Palatability, shear force, cooking and pH properties of beef were evaluated in two trials that compared the effects of feeding either corn concentrate, corn silage, alfalfa silage or orchardgrass silage diets for 112 d before slaughter. Each trial used 48 Angus steers with 12 steers assigned to each diet. The left sides of carcasses in Trial 2 received electrical stimulation. Steaks derived from steers fed the corn concentrate diet were rated highest in tenderness and beef flavor intensity, whereas steaks from steers fed the orchardgrass silage diet had the lowest tenderness and beef flavor intensity and highest shear force values. Differences in sensory properties were minimal between beef from steers fed corn concentrate and those fed corn silage. Electrical stimulation produced tenderness values in silage-fed steers equivalent to those found for steers fed corn concentrate that received no stimulation. Muscle pH decline was more rapid for electrically stimulated sides vs unstimulated sides. Muscle from steers fed orchardgrass silage had the slowest rate of pH decline during chilling. Increased fat gain and decreased protein gain during the feeding period were associated with improved tenderness; however, this relationship was eliminated when the effects of diet were removed. Steaks from silage-fed steers required longer cooking times per 100 g than steaks from steers fed corn concentrate. Feeding an orchardgrass silage diet to slaughter steers likely will produce unacceptable palatability. However, electrical stimulation of carcasses from silage-fed steers appears capable of producing similar tenderness to that obtained without electrical stimulation in steers fed corn concentrate.