Prevalence and infestation dynamics of intestinal protozoa infections (cryptosporidiosis, giardiasis and eimeriosis) among calves in dairy farms of Kazakhstan

Cryptosporidium spp. infections were highly concentrated in the youngest calves, with prevalence 49.2% detected in the 1-30-day group. The risk of infection dropped dramatically with older age (<i>p</i> < 0.001). Prevalence Eimeria spp. in the 1-month group was 2.0% and significantly increased with age. Calves aged 31-90 days had 27.3 times higher odds of infection (95% CI: 17.07-45.35, <i>p</i> < 0.001), with elevated odds persisting in older groups (<i>p</i> < 0.001). 5.2% of the youngest calves were infected with Giardia spp., and the species was more evenly distributed across age groups, with no statistically significant variation. No significant seasonal variation in infection rates was found. These findings suggest that at the conditions of intensive dairy farming in central and northern Kazakhstan the age-targeted parasite control strategies may be more effective than seasonal approaches for managing parasitic infections' control in calves.