Linseed, microalgae or fish oil dietary supplementation affects performance and quality characteristics of light lambs

The aim of this work was to improve the fatty acid profile of meat from light lamb, frequently reared in Spain and in other Mediterranean countries. A total of 44 light lambs fed different n-3 polyunsaturated fatty acids sources were studied: control (C) (palm oil), extruded linseed (L), extruded linseed mixed with microalgae (LM) and fish oil (FO). The productive performance from 14.7 to 26.2 kg of live weights and meat quality characteristics during refrigerated storage were assessed. Lambs fed FO showed lower feed intake (p <0.001), average daily gain (p <0.001) and higher feed conversion ratio (p <0.001) than lambs from the other treatments. Fish oil meat had the lowest (p <0.01) protein proportion and the highest (p <0.001) C20:5n-3, C22:5n-3 and C22:6n-3 proportions, while L or LM produced the highest (p <0.001) C18:3n-3 deposition. Fish oil meat had higher (p <0.05) L* and lower (p <0.001) a* than meats from the other treatments. After 7 days of storage, FO meat showed the highest TBARS (p <0.001), while C meat showed similar value to 0 days of storage. Additionally, FO underwent higher microbial growth after 7 days of storage as compared to the other treatments. Dietary supplementation with L and LM leads to C18:3n-3 meat enrichment and to a microbial load and colour characteristics similar to those of C, without adverse effect on lamb performance. However the use of FO improves the fatty acid profile of meat, but negatively affects lamb performance and meat quality