NUTRITIONAL-VALUE OF COMMON OAK (QUERCUS-CALLIPRINOS) BROWSE AS FODDER FOR GOATS - EXPERIMENTAL RESULTS IN ECOLOGICAL PERSPECTIVE

Feed intake, in vivo digestibility, and nitrogen balance of common oak (Quercus calliprinos) browse and vetch hay were determined in two tri als using native Mamber black goats. Vetch hav served as a control tre atment for evaluating the methodological accuracy of the experimental system. Individual average intake was 63 and 94 g/day/kg (W0.75), orga nic matter digestibility 46% and 61%, and the nitrogen balance (N rete ntion as g/day/goat ) was -0.6 and 4.9 for oak and vetch hay, respecti vely. Accordingly, Q. calliprinos, used as the sole feed for goats cou ld supply the energy but not the protein requirements for maintenance. Intake, digestibility and nitrogen balance of the common oak were sim ilar to values in studies of other oak species in the Mediterranean re gion, but deviated from data in studies in the USA. Possible reasons f or this difference, such as different content of secondary compounds s uch as tannins, goat breed and duration of adaptive interactions betwe en goats and plants, are discussed.