Foraging selectivity of three goat breeds in a Mediterranean shrubland

Foraging behaviors of the Damascus, Mamber and Boer goat breeds were compared on shrublands of the South Carmel mountain ridge of Israel. Dietary choice was determined for a group of yearling animals of each breed (n = 11 or 12), housed and grazed separately to prevent social facilitation, during a total of 4 (Mamber) or 5 (Damascus and Boer) sessions of four days each in fall 2004 and spring 2005. The proportions in the diet (including concentrate feed) of three main dietary components - Pistacia lentiscus L. (20% tannins), Phillyrea latifolia L. (3% tannins) and herbaceous vegetation - were determined by application of near-infrared reflectance spectroscopy to faecal samples (n = 147). On average, P. lentiscus constituted 14.9% of the DM ingested by Damascus goats, but only 5.6 and 5.0% of that ingested by Mamber and Boer goats, respectively. In the fall season, Damascus goats ingested diets richer in tannins than did Mamber or Boer goats (P < 0.001). In the spring, the contribution of herbaceous vegetation to DM intake was higher in Mamber goats (38.5%) than in the other breeds (27.7%). Boer goats selected the most nutritious diets in terms of crude protein (CP) content and in vitro dry matter digestibility (IVDMD). Despite their differences in foraging selectivity, the local Damascus and Mamber goats selected similar diets in terms of CP and IVDMD. Our data suggests that, of the three breeds examined, the Damascus should provide the best control of P. lentiscus encroachment and the least competition with cattle for green grass in the spring. These findings may help to develop ecologically sound ways of controlling the spread of the tannin-rich shrub P. lentiscus L., which threatens rangeland biodiversity and amenity values in the Mediterranean climatic region of Israel.