Abstract
Neonatal cryptosporidiosis is a major cause of diarrhea, impaired growth, and economic losses in dairy calves. This study compared the effects of halofuginone and paromomycin on diarrhea occurrence, oocyst shedding, and growth performance in preweaned Holstein calves naturally exposed to Cryptosporidium parvum. Seventy newborn calves were randomly allocated to receive halofuginone (n = 30; 100 µg/kg body weight) or paromomycin (n = 40; 50 mg/kg body weight) orally for seven consecutive days from 5 to 11 days of age. Diarrhea incidence, duration, hydration requirements, body weight development, and fecal oocyst excretion were monitored longitudinally. Calves treated with halofuginone had significantly higher odds of diarrhea compared with paromomycin-treated calves (OR = 4.93; 95% CI: 2.98-8.17; P C. parvum.