Cryptosporidium parvum produces a prolonged watery
diarrhea unresponsive to conventional antimicrobials. Because of reported efficacy of antibody-based
immunotherapy, we studied the effect of inexpensive, commercially available oral bovine serum concentrate (BSC) in experimental
cryptosporidiosis. Twenty-four calves were treated with 57 g/d BSC (n = 12) or
soy protein (n = 12) added to their standard
whey protein-based milk replacer (227 g/2 L twice daily). Of the 24, 9 were also treated with
L-glutamine (GLN), 8 g/L (50 mM) in the milk (5 calves in the BSC group and 4 in the soy group). Animals were inoculated with 10(8) cryptosporidium oocysts per os on d 8 of life and received
oral rehydration on d 12-14. Eight uninfected controls were treated with BSC or
soy protein. Fecal and urine volume and urinary Cr-
EDTA excretion were measured. Animals were killed on d 18 of life.
Cryptosporidiosis induced severe watery
diarrhea lasting >9 d and produced a 25% increase in intestinal permeability, a 33% decrease in villous surface area, and a 40% reduction in mucosal
lactase specific activity.
Glutamine treatment had no effect on the
diarrhea or any of the intestinal tests; and therefore pooled data were used to compare the 12 calves treated with BSC with the 12 treated with soy. In animals receiving BSC, peak diarrheal volume and intestinal permeability were reduced 33%, fewer oocysts were shed, intestinal crypts were significantly deeper, and villous surface area returned to normal by 9 d after
infection (all p <or= 0.05). BSC should be studied as a treatment for human
cryptosporidiosis.