Nutrition impacts the outcome of calves infected with Cryptosporidium parvum. In a Cornell University experiment, calves fed a 28 percent protein, 20 percent fat milk replacer in amounts supplying 4.35 Mcal of metabolizable energy/day for one week and 5.6 Mcal ME/day for two weeks fared much better when experimentally infected with C. parvum than calves fed a 20/20 milk replacer supplying 2.44 Mcal ME/day.
The better-fed calves gained 433 grams per kilogram (of milk replacer ingested) per day, while the conventionally fed calves lost an average of 48 grams per day over the three-week period. And, the conventionally fed calves had a significant increase in packed cell volume, which meant they became more dehydrated over time. Meanwhile, the better-fed calves did not become dehydrated.
The 2.44 Mcal of metabolizable energy supplied to the conventionally fed calves barely met their maintenance requirements. The 4.35 Mcal ME/day and 5.6 Mcal ME/day supplied to the high plane-of-nutrition calves not only met their maintenance requirements, it also allowed them to grow faster and apparently do a better job of withstanding the disease challenge. Perhaps this is why some calves infected with cryptospodium infections handle it better than others, according to Theresa Ollivett, large animal internal medicine resident at Cornell University, who presented the research at the recent American Association of Bovine Practitioners annual meeting.
Read an abstract of Ollivett's paper.