Effect of an egg yolk immunoglobulin（IgY）product on oocyst shedding and blood and fecal IgY concentrations in cryptosporidium-infected calves

Abstract

　Cryptosporidiosis causes watery diarrhea in calves younger than one month of age. There is no treatment for cryptosporidiosis, but an egg yolk immunoglobulin（IgY）product, which contains the anti-cryptosporidium IgY, has been developed to prevent the calf diarrhea. In this study, the effect of this product on cryptosporidiosis was examined. Twelve calves were divided into three groups: an untreated control group; a colostrum group（received 60 g of IgY mixed in the colostrum）and a 2-week treatment group（received 60 g of IgY in the colostrum and then 10 g/day of IgY mixed in milk for two weeks）. During the 21-day study period, all calves were naturally infected with Cryptosporidium parvum and developed watery diarrhea. The mean number of oocysts per gram of feces was significantly lower in the 2-week treatment group than in the colostrum and control groups（p<0.05）. The total IgY and anti-cryptosporidium IgY concentrations in the serum and feces increased in both the colostrum and 2-week treatment groups, and the total fecal IgY concentration was significantly higher in the 2-week treatment group than in the colostrum group from day 5 to day 14（p<0.05）. The fecal anti-cryptosporidium IgY concentration was significantly higher in the 2-week treatment group on day 5 and 7 than in the colostrum group（p<0.05）. Thus, oral administration of IgY for two weeks reduced oocyst shedding in cryptosporidium-infected calves, indicating that anticryptosporidium IgY may be useful for the prevention of cryptosporidiosis.