Oral rehydration solution with glycerol to dairy calves: Effects on fluid balance, metabolism, and intestinal microbiota

Response to glycerol and glucose as an additive for oral rehydration solution (ORS) was investigated in two trials comprising of total 24 young calves. The aim was to prevent dehydration and energy deficiency and to increase the population of beneficial bacteria in the intestinal microbiota. Calves responded with a modest elevation of glucose and insulin in plasma when fed ORS with glycerol/glucose. The glycerol/glucose mixture concentration in plasma increased markedly following an oral glycerol load. There was no increase in 1,3-propanediol, and the VFA pattern was unchanged in calves receiving ORS containing glycerol/glucose mixture, indicating that glycerol was rapidly absorbed into blood. Numbers of enterobacteria and lactobacilli were not affected by treatment, and glycerol-utilizing Lactobacillus reuteri was detected in calf feces irrespective of treatment and sampling time. In conclusion, glycerol can be used as a component of ORS for young calves without negative impact on calf performance and health.