SEASONAL AND ALTITUDINAL VARIATIONS IN NUTRITIONAL QUALITY OF KERMES OAK (QUERCUS COCCIFERA L.) IN NORTHWEST GREECE AND EXTENSIVE GOAT FARMING

Ch. Roukos

Abstract: The growth and nutritional quality of kermes oak (Quercus coccifera L.) are affected by climatic environment and stage of maturity. The study aimed to determine changes in the nutritional quality of kermes oak components (i.e., twigs and leaves) in shrublands across a mountainside, where climatic conditions change with altitude above sea level, in northwest Greece. The study involved monthly collection of forage samples during March–October from 15 experimental plots located in three altitudinal zones (lower, middle, and upper) over two consecutive years. Samples were manually separated into the two shrub components and analyzed for crude protein (CP), neutral detergent fiber (aNDFom), acid detergent fiber (ADFom), lignin(sa), in vitro dry matter (DM) digestibility (IVDMD), in vitro neutral detergent fiber digestibility (IVNDFD), digestible energy (DE) and minerals (i.e., Ca, P). Altitudinal zone, in terms of existing climatic conditions, strongly affected the nutritive value of leaves and twigs. Indeed, altitude above sea level was positively correlated with mean monthly precipitation and negatively correlated with mean monthly air temperature, which, in turn, strongly influenced CP, IVDMD, IVNDFD, fiber contents, DE, and mineral contents. The Ca:P ratio exceeded the animal functional disorder threshold, which posed a hazard.

Keywords: chemical composition; digestibility; Greece; kermes oak

Date published: 2017-08-28