No information found (2016).
In a cafeteria test, Atriplex nummularia was the most preferred shrub among 6 shrub species offered fresh to sheep (Ben Salem et al., 2000).
Voluntary DM intake of sheep fed only Atriplex nummularia is very variable, ranging from 40 to 115 g/kg BW0.75 (Ben Salem et al., 2010), with a typical value around 70-90 g/kg BW0.75. Voluntary intake of Atriplex nummularia is generally greater than that of cereal straw (Abu-Zanat et al., 2006). In Australia, it was found that the digestible DM intake of Atriplex nummularia was sufficient for maintenance in sheep, provided that fresh water was available (Wilson, 1966). It may be a good supplement to high-fibre, low N diets such as straw (Chriyaa et al., 1997). High sodium concentration may be a major determinant of halophytes palatability, and leads to very high water intake to counter the high concentrations of Na and K (Atiq-Ur-Rehman et al., 1994). The amount of water drunk is frequently between 6 and 10 L/kg DM of Atriplex nummularia consumed (Ben Salem et al., 2010). To counteract this high content of sodium and large drinking water requirement, it is recommended not to exceed 30% of old man saltbush in sheep diets (Aganga et al., 2003; Ben Salem et al., 2010), particularly during periods of water shortages. In ewes fed on a barley straw-concentrate diet (50:50), replacing 100% of the barley straw by dried and chopped old man saltbush increased voluntary DM intake from 63 to 70 g/kg BW0.75 (+11%), but with no effect on BW gain nor on milk production (Abu-Zanat et al., 2006). A similar intake level of 70-73 g/kg BW0.75 was observed in Barbarine wethers fed a diet comprising 80% of Atriplex nummularia. Intakes as high as 105 g/kg BW0.75 have also been observed on sheep fed on straw, Atriplex nummularia representing only 26% of the diet (Chriyaa et al., 1997). Supplementing old man saltbush-based diets with grain always enhanced sheep performance (Franklin-McEvoy et al., 2007; Ben Salem et al., 2010).
The average in vitro DM digestibility reported was close to 60-65%, within a range of 48 to 72% (Benjamin et al., 1995; Chriyaa et al., 1997; Norman et al., 2004; Ben Salem et al., 2010; Revell et al., 2013). In vitro OM digestibility was consistently lower than DM digestibility due to the very high ash content (Benjamin et al., 1995). In vivo OM digestibility of leaves of Atriplex nummularia fed alone to sheep had an average OM digestibility close to 70% (61-78%), but lower values have been reported (50%) (Ben Salem et al., 2010). In sheep fed on straw, providing 26% of the diet as Atriplex nummularia increased OM digestibility from 40 to 46%. Metabolizable energy concentration ranged between 6.3 and 11.4 MJ/kg DM (Khalil et al., 1986; Ben Salem et al., 2010).
Including Atriplex nummularia in sheep diets increased in vitro and in vivo production of enteric methane, which was not related to the high salt content (Mayberry et al., 2009). This may explain the low efficiency of rumen fermentation, low feed conversion efficiency and low animal performance on sheep receiving high amounts of Atriplex nummularia.
In Australia, average daily weight gain of sheep (116 g/head/d) and clear wool production per hectare (17 kg/ha) were similar between rotational grazing and set-stocking management over a 250 days period. Sheep selected old man saltbush in their diet at a rate of 13 to 54% of DM intake according to the season (Norman et al., 2010b). On rangeland, sheep exhibited preferences for some specific plants of Atriplex nummularia, but with no clear relationship with any chemical constituent. Most preferred plants had slightly greater protein (15.4 vs. 12.7% DM) and nitrate (249 vs. 98 mg/kg DM) contents than the least preferred plants (Norman et al., 2004). In South Africa, indoors cafeteria tests also showed sheep preference for high-N and low-fibre plants, with no relationship with rumen degradability parameters (van Niekerk et al., 2009).
Numerous studies have shown the inability of saltbush systems for finishing lambs because they are unable to gain weight when fed on saltbush alone. Sheep grazed on saltbush had a high muscle fluid content, because of the high water intake due to the elevated consumption of salt (Pearce et al., 2010). Feeding Atriplex nummularia did not appear to affect the organoleptic characteristics and apparent meat quality of finishing lambs, compared to lucerne-fed lambs (Hopkins et al., 1999). However, it may lower the proportion of fat, and increase the proportion of lean and vitamin E in carcasses (Pearce et al., 2010). These authors reported that some suppliers may claim for a niche market for saltbush meat because it is considered to be of superior quality.
In a cafeteria test, goats exhibited no clear preference for Atriplex nummularia compared to 5 other shrubs of less digestibility (Ben Salem et al., 2000). In young kids, replacing alfalfa hay by more than 20% Atriplex nummularia hay in the diet reduced intake and weight gain (Meneses et al., 2012).
The total protozoal count (x103) per millilitre was reported to be significantly higher for camels fed rations that contained Atriplex nummularia than for those fed rations containing Acacia saligna and treated rice straw (Kewan, 2003).