Composition of vine-branches with leaves of Vitis vinifera L. fresh and ensiled using different additives (previous results)

Abstract

Owing to the great extension of vineyards cultivated in Spain, the traditional use of leaves and vine-branches by grazing sheep in some areas and the lack of recent data about composition and nutritive value, a series of trials have been carried out in order to determine the feeding value of this material. In this study previous results on composition and in vitro and in vivo digestibilities are presented. The chemical composition of vine-branches with leaves from first pruning harvested at Moral de Calatrava, Ciudad Real (“Valdepeñas” white vine) were as follows: dry matter, 70%; crude protein, 6.7%; ether extract, 6.2%; crude fiber, 28.1%; ash, 6.7%; nitrogen free extractives, 52.3%; neutral detergent fiber, 52.7%; acid detergent fiber, 33.3%; hemicelluloses, 19.8%; permanganate lignin, 14.0%; permanganate cellulose, 19.3%; acid detergent lignin, 10.2%; Ca, 1.15%; and P, 0.33%. No noticeable content of Silica was detected. Tannins (as tannic acid equivalents), 2.7%. In vitro digestibility, 42.7%. A field silo “in situ” with 20 Kg of fresh material and laboratory microsilos of 2 l were made. Of the latter, four had no additives, four contained added formic acid (5 l t −1 fresh material) and four contained added formaldehyde-sulphuric acid (1.8 and 3.5 Kg t −1 fresh material, respectively). The chemical composition for microsilos without additives, with formic acid, with formaldehyde-sulphuric and for the field silo was, respectively: dry matter, 65.8, 62.4, 64.4 and 68.4%; crude protein, 5.8, 6.3, 6.8 and 6.3%; ether extract, 5.6, 5.4, 5.4 and 5.2%; crude fiber, 31.6, 29.4, 32.3 and 28.3%; ash, 6.8, 6.4, 6.9 and 5.9%; nitrogen free extractives, 50.1, 52.4, 48.5 and 54.3%; neutral detergent fiber, 59.9, 55.1, 62.4 and 56.9%; acid detergent fiber, 39.3, 36.6, 42.7 and 35.4%; hemicelluloses, 20.5, 18.5, 19.6 and 21.4%; permanganate lignin, 18.9, 17.2, 20.4 and 15.6%; permanganate cellulose, 20.4, 19.1, 22.5 and 19.1%; acid detergent lignin, 11.4, 10.5, 14.4 and 9.9%; Ca, 0.95, 1.31, 1.15 and 0.74%; P, 0.41, 0.36, 0.31 and 0.54%; tannins (as tannic acid equivalents, 2.4, 2.6, 1.4 and 2.5 and in vitro digestibility, 34.3, 39.2, 33.7 and 39.1. In vivo digestibility for the field silo was 32.9%. There was no butyric acid and lactic, malic and acetic acids were 66, 22.6 and 11.4% of total acids, respectively. Ammonia nitrogen-total nitrogen ratio was very low; less than 3.2%, the pH value (about 4) was high. From these values it appears that chemical composition and in vitro digestibility of vine-branches with leaves are similar both in fresh and ensiled samples with and without additives. All those values and in vivo digestibility are similar and sometimes higher than those reported for other fibrous feeds commonly used by ruminants.