Beef production, physicochemical quality, oxidative shelf-life, fatty acid profile and sensory effects of replacing sorghum for maize in finisher diets

Abstract

Climate change and high demand for maize have prompted the search for climate-smart, energy feedstuffs such as sorghum for use in beef finisher diets. Relative to maize, sorghum has comparable metabolizable energy content and contains more polyunsaturated fatty acids and bioactive phenolic compounds that may enhance beef health value, oxidative shelf-life, and sensory quality. The study investigated the impact of graded sorghum levels replacing maize in beef finisher diets on nutrient utilization, production, physicochemical quality, fatty acid composition, oxidative shelf-life, and sensory quality attributes of beef. Thirty-five, seven-months-old (230 ± 28 kg average initial weight) Angus steers were individually housed in pens and randomly allocated to five pellet diets formulated by replacing white maize in the basal diet (control) with 100, 200, 300, and 400 g/kg DM of sorghum. Diet did not affect (P > 0.05) nutrient intake, digestibility and utilization, growth performance, carcass characteristics, longissimus thoracis (LT) meat physicochemical quality, fatty acid contents and colour coordinates. Metmyoglobin and colour coordinates increased (P ≤ 0.05) with retail display except redness which declined (P ≤ 0.05). Lipid oxidation of LT meat aged for day 1 tended to increase (P ≤ 0.10) with increased dietary substitution of sorghum for maize in beef finishing diets. In addition, antioxidant activity, metallic aroma and liver-like flavour linearly increased (P ≤ 0.05) with sorghum inclusion in the diet. In conclusion, sorghum can fully replace maize in beef finisher diets with neutral effects on beef production, physicochemical quality, health value and colour stability, and somewhat desirable impact on antioxidant activity and myoglobin stability and undesirable effects on aroma and flavour of LT meat.