Foraging selectivity of three goat breeds in a Mediterranean shrubland

Foraging behaviours of the Damascus, Mamber and Boer goat breeds were compared on the South Carmel mountain ridge in Israel. Dietary choice was determined for a group of 10 or 11 yearling animals of each breed, housed and grazed separately to prevent social facilitation, during a total of 4 (Mamber) or 5 (Damascus and Boer) 4-day periods in the fall of 2004 and spring of 2005. The proportions of the three main dietary components – P. lentiscus L. (20% tannins), Phillyrea latifolia L. (3% tannins) and herbaceous species (as a single category) in the diet (which also included concentrate) were determined by application of near-infrared reflectance spectroscopy to faecal samples ("faecal NIRS") (n = 129). On average, P. lentiscus accounted for 13.0% of the dry matter ingested by Damascus goats, but only 5.0% and 4.9%, respectively, of that ingested by Mambers and Boers (Damascus > Mambers = Boers, P < 0.0001). Damascus goats ingested diets richer in tannins (5.4% vs. 4.2%, respectively, P < 0.0001). The contribution of herbaceous species to ingested DM in the spring was higher in Mambers than in the other breeds (33% vs. 27%, respectively). Boer goats selected the most nutritious diets in terms of crude protein (CP) content and in-vitro dry matter digestibility (IVDMD). In spite of their differences in foraging selectivity, the local Damascus and Mamber goats had similar dietary percentages of CP and similar IVDMD. Our data suggest that the Damascus is a preferred candidate to control P. lentiscus encroachment and is the least likely to compete with cattle for green grass in the spring. These findings may contribute to the attempt to find ecologically sound ways of controlling the spread of the tannin-rich shrub Pistacia lentiscus L., which threatens rangeland biodiversity and amenity values in the Mediterranean climatic region of Israel.