Argan (Argania spinosa)

In spite of their importance in local economies, nutritional information about argan foliage and argan by-products is almost non-existent. At the time of writing (February 2015), these products have not been tested in in vivo trials.

Leaves and fruits

In Morocco, argan leaves and fruits are regarded as a valuable feed for ruminants (Göhl, 1982). In the argan forest area, sheep, and more particularly goats, rely on argan trees for their daily diet. The argan tree forest was reported to hold between 26 and 30% of Morocco's goat population in 2005 (Jaouen, 2005). Argan forage has been reported to account for 48-95% of goat diets (El-Aich et al., 2007; Zugmeyer, 2006). Local Moroccan goats use Argan tree woodlands with a large flexibility and adaptation capacity to meet their dietary needs, and often climb or reach up the trees to graze (they are particularly fond of aerial grazing) (El-Aich et al., 2007). The meat of kids browsing on argan trees was reported to be tasty and of high nutritional quality (Bas et al., 2005). It was suggested that goats were the only ruminants able to produce meat on a diet of argan (El-Aich et al., 2007). In the absence of formal nutritional evaluation, this indicates that argan leaves and fruits have a reasonable feeding value for meat production in small ruminants. The OM of argan leaves was reported to be fermentable in the rumen (Merouane et al., 2014).

During the dry period, the only feed available for goats is from the argan trees, resulting in a reduced intake and a poor condition of the animals. The rate of overgrazing was estimated to be as high as 88%, which also stunts development of the argan trees. After several years of drought in the argan tree forest, sheep rearing has been developed at the expense of goats because sheep eat less argan forage (reported to be only 17% of their diet) and are consequently less detrimental to the forest (Zugmeyer, 2006).

Fruit pulp

Argan fruit pulp (alig) has been traditionally fed to livestock in Morocco. The dried fruit pulp is relished by ruminants and camelids. An early study (based only on the chemical composition) estimated that its nutritive value was 70-100% that of barley (Sandret, 1956). Argan pulp was reported to meet about 50% of the nutritional requirements of goats (Boscher, 1992). The OM of the fruit pulp was reported to be readily fermentable (Merouane et al., 2014). Argan fruit pulp is sensitive to the Mediterranean fly Ceratitis capitata which can dramatically reduce its nutritive value (Orwa et al., 2009). Some attempts have been made in the 2000s to improve the argan value chain, by extracting some valuable components from the pulp while making protein and sugars still available for livestock feeding (Pioch et al., 2011).

Oil meal

Argan oil meal is rich in oil and is thus a source of energy for livestock (Charrouf, 1999). Cattle readily consume argan oil cake in spite of the presence of saponins that may have antinutritional effects. Up to 2 kg/d can be fed to beef cattle without harm (Göhl, 1982). A silage made of culled opuntia mixed with argan oil meal and fed to sheep resulted in lower growth performance than a commercial concentrate but it reduced feed cost (Bendaou, 2013).