RESUMEN
Cryptosporidium infections are one of the most prevalent causes of diarrhea in calves and considered to be one of the major sources of economic loss in livestock production. A global trend is currently underway, in identifying natural and sustainable alternatives to support animal husbandry and production. Isoquinoline alkaloids are known for their anti-inflammatory, antimicrobial, and antioxidant properties in the promotion of gut health. Thus, an experiment was designed to evaluate the effects of natural, herbal-based feed isoquinoline alkaloids to support calves experimentally inoculated with Cryptosporidium parvum. Twenty-six calves were randomly divided into control (CN) (n = 13) and treatment (SG) (n = 13) groups. The SG group received 5 g of feed additive in every milk feeding from 1 to 21 days of age. The CN group received milk without any additives. All calves were orally inoculated on the third day of life with 1 × 106Cryptosporidium parvum oocysts. The animals were evaluated daily, from 3 to 30 days of age, for the occurrence, duration, and intensity of diarrhea. Calves with a base deficit of ≥ 9 mEq/L were hydrated to aid recovery. The SG calves showed a higher average weight gain between 14 and 21 days of age, without mortality and with reduced intensity and duration of diarrhea. In contrast, calves in the CN group showed more serious acid-base disorders, required more hydration support, and had a mortality rate of 15.4 %. These results showed that calves supplemented with isoquinoline alkaloids had decreased intensity and duration of symptoms, reduced requirement for supportive therapy, and prevented mortality among animals.