Influence of food deprivation on SCFA and electrolyte transport across sheep reticulorumen.

Net absorption rates for SCFA, sodium, chloride, magnesium, and water were measured in the temporarily isolated and washed reticulorumen of sheep. The animals were either fed hay ad lib. plus concentrates once daily or were deprived of food for two days. Food deprivation led to decreased net absorption of all the substances tested. Comparing the solutes, the relative decreases varied between 43% (butyrate) and 56% (acetate). The decrease in solute absorption was accompanied by diminished water absorption. It is concluded that the reduction in absorption may be beneficial for the animal in that energy consumption is diminished and the reservoir function of the forestomach will be maintained longer. However, the reduced absorptive capacity may lead to a deficiency of magnesium, which is thought to be absorbed mainly by the forestomachs.