ABSTRACT
The accepted daily requirement for sodium for sheep is between 0.09% to 0.18% of DM intake (NRC 1985) and the maximum tolerable level of dietary salt has been set at 9.0% (Meyer and Weir 1954; Meyer et al. 1955; NRC 1985) but, as discussed later in this chapter (and elsewhere in this book), sheep can consume diets with a higher salt content. Sheep that eat either plants of high salt content, such as Atriplex spp. (saltbush), or experimental diets aimed to mimic the salt level in a diet based on halophytic plants, can have a daily intake of salt ranging between 5 to 25% NaCl (Meyer and Weir 1954; Wilson 1966b; Wilson and Hindley 1968; Hemsley et al. 1975; Masters et al. 2005a; Blache et al. 2007; Digby et al. 2008; Chadwick et al. 2009a, 2009b, 2009c), which is greater than the daily requirement and often in excess of the proposed maximum tolerable level (9%). A high intake of salt (sodium chloride) impacts on the reproductive cycle because of its effects on feed intake and water intake, and on the hormonal control of both energy balance and salt and water balance.
