Abstract
Gamma-globulin fraction was obtained from the blood serum of a steer and colostrum wheys of cows vaccinated against bovine rotavirus (BRV) and bovine coronavirus (BCV), and emulsified with vegetative oil and other ingredients to reconstitute artificial colostrum (AC). The efficacy of AC was studied for protection of colostrum-deprived calves against experimental exposure to BRV and BCV at 22 or 25 hr of age. Calves Nos. 1 and 2 were orally challenged with the cell cultures of BRV and BCV, and Nos. 3, 4 and 5 with BCV; all the inocula were in combination with Escherichia coli K99(+) Ent(+). Calves Nos. 1 and 3, fed no AC, developed severe diarrhea. On the contrary, No. 2, fed AC several times before and after the challenge, and No. 5, once fed AC within 30 min after the challenge, developed no diarrhea. No. 4, once fed AC 4 hr after the challenge, showed only transient diearrhea. The severity and prevention of diarrhea related generally with immunoglobulin levels and antiviral antibody titers, derived from the administered AC, in the serum of the animals at about 100 hr of age. The results obtained indicated that AC has protective effects in calves against the exposure with BRV and/or BCV.
