A typical plant of the Karoo ecosystem, Salsola glabrescens is widely browsed by small ruminants. It has a good nutritional value but it cannot be fed alone and must be mixed with poor quality forages.
Palatability
Fresh Salsola glabrescens is known be palatable and readily eaten by sheep and goats, but only when fresh (du Toit et al., 1995; Le Roux et al., 1994; Davies et al., 1986; Hobson et al., 1975; Henrici, 1952; Henrici, 1945). It was not eaten by sheep and goats when the leaves were dried, so it is no use to conserve it in dry form (Henrici, 1952; Henrici, 1945). Fresh Salsola glabrescens was specially selected by rams during drought in Karoo (Davies et al., 1986), which is due to the fact that this very drought-tolerant species is often the only remaining green foliage during those periods (Le Roux et al., 1994; Hobson et al., 1975). Thoughout the year, sheep and goats grazed Salsola glabrescens in proportion to its availability in winter, spring and autumn and in a lower proportion in autumn (du Toit et al., 1995). Salsola glabrescens was less grazed when it occured in homogenous stands (Le Roux et al., 1994).
Digestibility and nutritive value
Salsola glabrescens foliage fed fresh to sheep during winter and early spring had an OM digestibility of 71%, which can be considered high in comparison to other Karoo shrubs (Henrici, 1945). When leaves of Salsola glabrescens are fed dried, the digestibility of fibre and protein became very low (Henrici, 1945, Henrici, 1952).
Salsola glabrescens should not be offered as the only pasture due to the risk of diarrhea (Botha, 1939 cited by Henrici, 1952). It must be treated as a concentrate and poor quality grass should be given to balance the diet (Henrici, 1945, Henrici, 1952). In Henrici's digestibility trials, sheep were fed two parts of fresh Themeda triandra for one part of Salsola glabrescens on a fresh basis (Henrici, 1945).
Sheep are fond of Salsola glabrescens, probably because of its high chloride (potassium and sodium) content, and they do not require need salt in their licks or supplemental feeding. However, the salty character of the shrub may be a constraint. If it is fed alone, sheep will not favour it too much as it is too salty. If it is fed in association with others shrubs it can be heavily grazed but the high level of calcium and magnesium and the unbalanced Ca/P ratio in Salsola decreases phosphorus availability and can be detrimental to sheep.
The high level of magnesium sulphate in Salsola glabrescens has laxative effect on sheep, and sheep sheep fed on small or large quantitities of Salsola glabrescens can only maintain their bodyweight but not fatten. However, these laxative properties have been reported to keep worms down (Buttner, 2012).
Meat quality
Sheep fed in the Karoo were known for the high fat content of their meat, and Salsola glabrescens was known to have positive effect on body weight gain. Henrici attributed this to the relatively higher fat content of Karoo shrubs, which was also, in the case of Salsola glabrescens, highly digestible (Henrici, 1952). More recent observations have shown that Salsola glabrescens could contribute, with other Karoo Salsola species, to the specific sensory profile of Karoo lambs, likely because of the high content in secondary metabolites, such as mono- and sesquiterpenes (Erasmus et al., 2016). Descriptors related to this plant in sensory panels were : dusty, dandy, soapy, woody, damp/musty Cayenne pepper, sheep wool, tobacco, Ceylon tea (Erasmus et al., 2016).
