Use of deciduous woody species as a diet supplement for goats grazing Mediterranean shrublands during the dry season

Abstract

Nutritional stress during the dry summer period is considered as a primary factor limiting goat production in the Mediterranean region. This study was conducted to determine if the browse of deciduous woody fodder plants is useful as a supplement for goats grazing kermes oak shrublands during July and September. Browses used were of Amorpha fruticosa L., Carpinus orientalis Mill., Colutea arborescens L., Fraxinus ornus L., Ostrya carpinifolia Scop. and Robinia pseudoacacia L.. Treatments included: (1)–(6) kermes oak ( Quercus coccifera L.) shrubland plus fresh branches (2 kg/animal/day) of one of the above fodder plants as browse supplement, (7) kermes oak shrubland plus 0.25 (July) or 0.5 (September) kg alfalfa pellets/animal/day and (8) grazing in kermes oak shrubland as a control. Fodder plants produced high amounts of grazable material during summer whose quality ranged from medium ( Carpinus, Fraxinus, Ostrya) to high ( Amorpha, Colutea and Robinia). Goats ingested higher ( p ≤ 0.05) browse of Fraxinus (268 g DM) and Ostrya (285 g DM) than the remaining browses (22–177 g DM) and alfalfa pellets (170 g DM) during July, but of Robinia and alfalfa (469 and 434 g DM, respectively) in September. During September, intake of all supplement feeds increased compared to July except for Ostrya, which remained constant. Goats supplemented by alfalfa pellets and browse supplements gained weight in both these periods in contrast to the animals grazing only kermes oak shrubland, except for Amorpha and Colutea in July. It is concluded that during summer, when the forage quality of kermes oak shrubland declines, browse supplement with certain deciduous woody fodder plants allows weight gains similar to those of alfalfa pellets; thereby, improving grazing animal performance.