Feeding microalgae at a high level to finishing heifers increases the long‐chain n‐3 fatty acid composition of beef with only small effects on the sensory quality

The aim of the study was to determine the effect of feeding a low and high level of microalgae (MA, high in C22:6n-3) on the fatty acid (FA) composition and sensory attributes of beef. Thirty Charolais cross Limousin/Friesian heifers were fed one of the three diets (n = 10 per treatment): Control (no MA), low MA (LMA; inclusion rate of 15 g kg−1) or high MA (HMA; inclusion rate of 30 g kg−1) for 95 days before slaughter. Heifers fed HMA had a higher (P < 0.05) content of C20:5n-3: eicosapentaenoic acid (EPA) and C22:6n-3: docosahexaenoic acid (DHA) in the longissimus thoracis muscle than those receiving the Control (mean values for EPA of 0.5, 0.92, 1.20 and DHA of 0.31, 0.89 and 1.05 % of total FA for Control, LMA and HMA, respectively), and a lower n-3 to n-6 ratio (2.9, 1.9 and 1.6 in Control, LMA and HMA, respectively; P < 0.001). Steaks from animals fed either of the MA diets had a marginally higher (P < 0.05) ‘seaweedy flavour’ that was positively correlated with muscle C22:6n-3 concentration. Steaks from animals fed HMA were rated as being higher (P < 0.05) in tenderness and had a lower (P < 0.05) shear force than those from Control fed animals. It is concluded that feeding microalgae at high levels can beneficially improve the health attributes of beef with only a few effects on sensory quality.