A note on digestibility and energy value for sheep of different grape pomace

Abstract

It was the objective to compare the digestibility and energy value of fresh grape pomace originating from either white or red wine species. The white grape pomace had higher sugar, but lower fiber concentrations than the red wine pomace. Pomace was mixed with a basal diet and digestibilities were determined with adult wether sheep for the basal diet and the diets containing grape pomace. Faeces were quantitatively collected for 6 days following 14 days of adjustment to the diets. Inclusion of grape pomace in the diet significantly reduced digestibilities and the ME content of the diet, these effects being more pronounced for red grape pomace than for white grape pomace. Digestibilities calculated by difference for the white (and red) grape pomace were 56% (32%) for organic matter, 8% (30%) for crude protein, 19% (6%) for crude fiber, 21% (15%) for neutral detergent fiber, and 7% (0%) for acid detergent fiber. The ME concentration was 8.3 and 5.8 MJ/kg dry matter for white and red grape pomace, respectively. It was concluded that grape pomace can substantially vary in the feeding value for ruminants, depending on the technical details of the wine production process.