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

Grazing animals have diets rich in polyunsaturated 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 the influence of part of plant and phenological stage on the fatty acid profile of two widespread berseem clover cultivars ( Trifolium alexandrinum L. 'Sacromonte' and 'Marmilla'). In the present study, 'Sacromonte' showed a higher proportion of leaves (94 vs 85% on a dry matter yield [ 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 monounsaturated fatty acids (0.50 vs 0.23 mg g⁻¹ DM) and PUFA (10.33 vs 3.84 mg g⁻¹ DM) if compared to stems ( P < 0.01) in both cultivars. Total unsaturated fatty acids represent 10.83 and 4.04 mg g⁻¹ 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 PUFA. These results are the first to point out the change of fatty acids profile in different parts of berseem clover plant during the vegetative and reproductive stages, but need to be confirmed in a long-term study. [ABSTRACT FROM AUTHOR]