The influence of plant polyphenols on lipolysis and biohydrogenation in dried forages at different phenological stages: in vitro study.
BACKGROUND
It is known that forage legumes show a higher transfer efficiency of polyunsaturated fatty acids (PUFA) to ruminant dairy products in comparison with grasses. Legumes are usually characterised by moderate levels of plant secondary metabolites, which can have an effect on lipolysis and biohydrogenation in the rumen. An in vitro study was carried out to compare two species with different plant phenol compositions, Vicia sativa (VS, common vetch, cv. Jose) and Trifolium incarnatum (TI, crimson clover, cv. Viterbo) cut at the vegetative (Veg) and reproductive (Rep) stages, on lipolysis and PUFA biohydrogenation in the rumen.


RESULTS
The study showed that forage species and phenological stage affected the levels of bound phenols (BP) and tannic polyphenols (TP). VS was characterised by a higher level of TP than TI at both Veg and Rep stages, whereas BP levels were low in both forages. BP and TP had a negative effect on lipolysis and biohydrogenation, but TP showed a greater negative correlation than BP for both forages.


CONCLUSIONS
These results showed that lipolysis and biohydrogenation of PUFA could be affected by plant phenols, particularly TP.
Cabiddu
Andrea
A
Dipartimento per la Ricerca nelle Produzioni Animali, AGRIS Sardegna, I-07040 Olmedo, Italy. acabiddu@agrisricerca.it
Salis
Lorenzo
L
Tweed
John K S
JK
Molle
Giovanni
G
Decandia
Mauro
M
Lee
Michael R F
MR
D000821:Animal Feed / Q000032:analysis* / Q000145:classification; D000818:Animals; D002417:Cattle; D004040:Dietary Carbohydrates / Q000032:analysis; D004042:Dietary Fats, Unsaturated / Q000032:analysis / Q000378:metabolism; D004043:Dietary Fiber / Q000032:analysis; D004044:Dietary Proteins / Q000032:analysis; D005419:Flavonoids / Q000032:analysis*; D005612:Freeze Drying; D005766:Gastrointestinal Contents; D006865:Hydrogenation; D008066:Lipolysis; D010636:Phenols / Q000032:analysis* / Q000378:metabolism; D035261:Plant Components, Aerial / Q000737:chemistry / Q000254:growth & development / Q000378:metabolism; D059808:Polyphenols; D012098:Reproduction; D012417:Rumen / Q000378:metabolism; D013045:Species Specificity; D013634:Tannins / Q000032:analysis / Q000378:metabolism; D029921:Trifolium / Q000737:chemistry / Q000254:growth & development; D033022:Vicia sativa / Q000737:chemistry / Q000254:growth & development
D004040:Dietary Carbohydrates; D004042:Dietary Fats, Unsaturated; D004043:Dietary Fiber; D004044:Dietary Proteins; D005419:Flavonoids; D010636:Phenols; D059808:Polyphenols; D013634:Tannins