Lactoferrin reduces mortality in preweaned calves with diarrhea.

Calf diarrhea is the most common reason for mortality and antimicrobial therapy in preweaned calves on dairy farms in the United States. Conventional and organic livestock producers require alternative therapies for calf diarrhea to reduce the necessity of conventional antimicrobials. Alternatives administered for mild cases or early in the disease course may be useful to mitigate disease progression and reduce the likelihood of septicemia and negative sequelae. Lactoferrin is a bioactive protein naturally found in colostrum that has been shown to prevent septicemia in high-risk infants. Among organic producers, garlic extract is widely used for the treatment of disease and perceived to be efficacious. The objectives of the study were to determine the effectiveness of lactoferrin and garlic extract to reduce mortality and culling, improve weight gain, and reduce the duration of disease in preweaned calves with the first diagnosis of diarrhea. In total, 628 calves with diarrhea from a single commercial dairy were enrolled in a blinded, randomized field trial. Calves diagnosed with diarrhea (fecal score ≥3), were randomized to 3 consecutive days of oral garlic extract, lactoferrin, or water (control). Calves were clinically evaluated for up to 10 d. Body weight was measured at enrollment and 10 d later. For calves receiving garlic extract, the risk of death or culling was not significantly different than calves in the control group; however, calves that received lactoferrin had approximately half the risk of death or culling in the 120 d following diagnosis. Additionally, the relative risk of death or culling in the 60 d following diagnosis was significantly lower for the subset of calves with severe diarrhea at enrollment. Neither garlic nor lactoferrin had a significant effect on disease duration or average weight gain during the 10-d period. Lactoferrin significantly reduced mortality and culling when administered to preweaned calves with the first diagnosis of diarrhea; however, additional studies conducted across multiple farms are necessary to corroborate the observed reduction in mortality and culling. If the results are confirmed, lactoferrin may become an important tool to improve treatment outcomes and reduce the necessity of antimicrobials.