What is saliva consists of?
Saliva contains enzymes for the breakdown of fat (lipase) and starch (amylase) which is used to buffer the pH levels within the reticulum and rumen. The amount of saliva that is produced by the animal will depend greatly on the amount of time spent chewing as this aids the stimulation of saliva production.
If saliva is needed for the breaking down of feedstuff within the rumen then, potentially if more saliva were produced there would be more bacteria within the gut to make the breaking down process more efficient, and Na can be a way of producing more saliva.
Dietary effects of sodium
Minson, states that it can be generally accepted that the animal’s appetite is depressed by a deficiency of Na (voluntary intake of forage) and feeding an Na supplement will effectively improve the growth rate of cattle and sheep as well as the milk production of cattle eating some forages.
The rate of daily gain (kg/day)
The table above shows that the requirement for weaning cattle appears to be low, there is a 59% improvement in animal growth when a Na supplement is being fed to animals grazing on forage which contains 1.0g Na/kg DM.