By-products from viticulture and the wine industry: potential as sources of nutrients for ruminants

BACKGROUND: This work aimed to study the chemical composition, in vitro digestibility, ruminal degradability and intestinal digestibility of nutrients of vine shoot (VS), grape marcs (GMG and GMM), white (WL), red (RL) and sherry (SL) wine lees and grape marc plus lees (GML). The effect of polyethylene glycol (PEG) on nutrient availability was also studied. RESULTS: By-products had variable crude protein (CP) and cell walls (from 44.8 to 203 and from 122 to 741 g kg(-1) dry matter (DM) for CP and neutral detergent fibre (NDF) respectively). DM and CP in vitro digestibility ranged from 0.30 to 0.91 and from 0.51 to 0.84 respectively. The effective ruminal degradability of DM and CP was low (from 0.27 to 0.36 and from 0.34 to 0.53, respectively). The intestinal digestibility of the ruminally undegraded fraction was 0.25 and 0.29 for VS and GMG, respectively. The effect of PEG was different in VS and GMG. CONCLUSION: This is the first information available on ruminal and intestinal availability of nutrients from a diversity of vine and winery by-products. The use of a combination of the different by-products studied may represent a valuable source of energy and protein for ruminants. Further research on the effect of diets including these by-products on animal performance and the quality of products is necessary. (c) 2007 Society of Chemical Industry.