Short communication: Investigation of antibiotic alternatives to improve health and growth of veal calves.

The inherent disease susceptibility of veal calves results in frequent antimicrobial use. Improvements in antimicrobial stewardship necessitate alternative therapies to improve calf health and growth, while reducing the need for antimicrobials important to human health. This study investigated the effect of 2 alternative therapies, lactoferrin (an iron-binding protein found in colostrum) and cinnamaldehyde (an essential oil of the cinnamon plant) on growth, disease incidence, and mortality risk in special-fed veal calves. On the day of arrival to the growing facility (3 to 7 d of age), calves (n = 80 per treatment) were randomized to 1 of 3 treatments: (1) control (no supplement), (2) lactoferrin (1 g/d in milk replacer for 7 d), or (3) cinnamaldehyde (1 g/d in milk replacer for 21 d). Body weight was measured on the day of arrival (d 0), 21, and 42 d postarrival. Health assessments were performed twice weekly through 21 d, and mortality records were obtained through 6 wk postarrival. A repeated-measures ANOVA was used to compare growth between treatment groups, and a Poisson regression model (PROC GENMOD, SAS v. 9.4, SAS Institute Inc., Cary, NC) was used to test differences between groups in the incidence of diarrhea (fecal score ≥2 with and without depression and temperature) and disease through 3 wk postarrival. Body weight and average daily gain were similar between treatments. Neither lactoferrin nor cinnamaldehyde had an effect on diarrhea incidence. However, the risk of navel inflammation was significantly lower for calves that received cinnamaldehyde compared with calves in the control group. Mortality through 6 wk postarrival was low, with 4, 1, and 0 deaths from the control, lactoferrin, and cinnamaldehyde treatment groups, respectively. Additional research is needed to investigate various doses of these alternative therapies on calf health and growth, in addition to different routes of administration.