Chemical composition, nutritive value, fatty acid and amino acid contents of Galega officinalis L. during its growth stage and in regrowth.

摘要

The aim of this study was to determine the chemical composition, nutritive value, fatty acid profile and amino acid concentrations of Galega officinalis L. during its first growth cycle and in regrowth. Herbage samples were collected three times at progressive morphological stages from the vegetative to the budding stage, and during regrowth. The dry matter (DM), organic matter (OM), neutral detergent fibre (NDFom), acid detergent fibre (ADFom), lignin (sa) and gross energy (GE) increased during maturation, while the crude protein (CP), ether extract (EE), ash and OM digestibility (OMD) decreased with increasing stage. During the whole growth cycle, and in regrowth, the NEL was unchanged. Analyses of fatty acids did not reveal differences among plant stages, but did instead between the first cut and regrowth cut. The fatty acid profiles in the plant during growth was characterised by three dominant fatty acids, being alpha -linolenic acid (C18:3n-3), palmitic acid (C16:0), and linoleic acid (C18:2n-6). The alpha -linolenic acid content was instead lower than in the whole plant during growth. The n-6-3 polyunsaturated fatty acid ratio of the plant was steady at 0.13 during the growth cycle and in regrowth, while it was 0.78 in the seed. The individual amino acid contents of G. officinalis declined with increasing stage of maturity, as the CP declined, but with the exception of the serine content, there was no change in the relative proportions of the individual amino acids due to stage of maturity. Data shows that the nutritive value of G. officinalis forage did not diminish during its growth cycle and that it can improve the self sufficiency of dairy farms. Autumn regrowth was judged to be a good quality forage with a high nutritive value and a higher level of alpha -linolenic acid than during the first growth cycle..