Fatty acid profile in two berseem clover (Trifolium alexandrinum L.) cultivars: Preliminary study of the effect of part of plant and phenological stage

Abstract
Grazing animals have diets rich in poly-unsaturated fatty acids (PUFA), in particular α-linolenic acid (C18:3n-3), so pasture is the richest and most environmentally sustainable source of unsaturated fatty acids for animal products. The concentration of PUFA in forages varies with species, cultivar, phenological stage, silage making technique, regrowth interval, nitrogen fertilization level and other management factors. An experiment was carried out, by a randomized block design with three replicates, to study in two widespread berseem clover cultivars (Trifolium alexandrinum L. Sacromonte and Marmilla) the influence of part of plant and phenological stage on fatty acid profile. In this study Sacromonte showed a higher proportion of leaves (94 vs 85% on DM basis; P<0.05) and lower proportion of stems (6 vs 15% on a DM basis; P<0.05) if compared with Marmilla during the vegetative stage. Leaves were characterized by higher levels of MUFA (0.50 vs 0.23 mg/g DM) and PUFA (10.33 vs 3.84 mg/g DM) if compared to stems (P<0.01) in both cultivars. Total unsaturated fatty acids represent 10.83 and 4.04 mg/g DM in leaves and stems respectively (P<0.01). No influence of phenological stage in different parts of plant was detected in terms of total unsaturated fatty acid and polyunsaturated fatty acids. These results firstly point out in berseem clover the change of FA profile in different parts of plant during vegetative and reproductive stage, but need to be confirmed in a long-term study.