Increasing the inclusion of swedes in dairy cows’ diets increased saturated and omega-3 fatty acids without affecting sensory characteristics of cheese

Context Swedes (Brassica napus spp. napobrassica) are fodder crops used during winter in grazing dairy systems. However, their high concentration of sugar and secondary compounds such as glucosinolates and S-methyl-L-cysteine sulphoxide may alter the fatty acid profile and sensory characteristics of cow milk by-products. Aims The objective of this study was to determine the effect of three different inclusion levels of swedes in the diet of dairy cows on the fatty acid profile and sensory characteristics of cheese. Methods Multiparous Holstein Friesian cows were selected (n = 12) according to days in milk (96 ± 19 days), live weight (576 ± 42 kg), and milk yield (25.6 ± 2.6 L/day). Cows were offered three different inclusion levels of swedes in their diets: 0% (CON), 30% (S-30), and 45% (S-45) dry matter, in a replicated 3 × 3 Latin square design. Key results In blood plasma, S-30 cows had a greater proportion of eicosatrienoic acid (C20:3n-3; P < 0.03) and tended to increase stearic acid (C18:0; P = 0.08). In cheese, inclusion of swedes increased (P < 0.05) omega-3 fatty acid content, and saturated and polyunsaturated fatty acids tended to increase (P = 0.06), while monounsaturated fatty acids tended to be lower. Finally, none of the 18 attributes evaluated during sensory analysis were affected (P > 0.05) by swede inclusion. Conclusion Swedes did not produce major changes in the fatty acid profile and sensory properties of cheese, even with 45% inclusion. Implications Swedes can be fed up to 45% without affecting cheese properties.