Dr Ramesh Selvaraj and colleagues from Ohio State University found that supplementation of turkey feed with increased levels of a form of vitamin D, 25-OH cholecalciferol, improved body weight gain and decreased the faecal shedding of coccidial oocysts following coccidia challenge.

Coccidial infections produce severe symptoms and mortality in turkeys and cause substantial economic loss for the turkey industry despite available treatments.

The research showed:

• Turkey poults supplemented with 110 ug/Kg of feed of 25-OH cholecalciferol [25(OH)D] improved body weight gain and decreased coccidial oocyst shedding.
• Turkey poults supplemented with 55 ug/kg or higher doses of 25(OH)D had decreased faecal oocyst shedding compared to the group fed 27.5 ug/kg 25(OH)D and challenged with coccidia.
• Turkey poults fed 110 ug/kg 25(OH)D had increased body weight gain over a 12-day period following coccidial infection compared to the group fed 27.5 ug/kg 25(OH)D and challenged with coccidia.

The scientists concluded that it might be beneficial to supplement turkey poults with high doses of 25(OH)D during a coccidial infection.

This novel approach to controlling coccidiosis may prove useful for production programs which rely less on the use of anticoccidial compounds that have antimicrobial activity in food animals.