Objective—To determine the effects of 3 commercially available, orally administered electrolyte
solutions (OAEs) on abomasal luminal pH and emptying rate in dairy calves, compared
with the effect of orally administered milk replacer.
Design—Randomized crossover study.
Animals—6 male dairy calves (age, 12 to 31 days).
Procedures—Calves were surgically instrumented with an abomasal cannula and were administered
4 treatments in randomized order: all-milk protein milk replacer, high-glucose
high-bicarbonate OAE, high-glucose high-bicarbonate OAE containing glycine, and low-glucose
OAE containing acetate and propionate. Abomasal luminal pH was measured with a
miniature glass pH electrode prior to treatment administration and every second afterward
for 24 hours.
Results—Feeding of orally administered milk replacer resulted in a rapid increase in mean
abomasal luminal pH from 1.3 to 5.8, followed by a gradual decrease to preprandial values
by 8 hours afterward (mean 24-hour pH, 3.2). High-glucose high-bicarbonate OAEs caused a
large and sustained increase from 1.3 to 7.5 (mean 24-hour pH, 4.1 for the solution without
glycine and 3.5 for the solution with glycine). In contrast, feeding of the acetate-containing
OAE was followed by only a mild and transient increase (mean 24-hour pH, 2.1); luminal pH
returned to preprandial values by 3 hours after ingestion.
Conclusions and Clinical Relevance—Ingestion of a bicarbonate-containing OAE resulted
in sustained abomasal alkalinization in dairy calves. Because persistently high abomasal
luminal pH may facilitate growth of enteropathogenic bacteria, administration of OAEs containing
a high bicarbonate concentration (> 70mM) is not recommended for calves with
diarrhea. (J Am Vet Med Assoc 2012;241:1075–1082)