Severity of Tenosynovitis in Reovirus-Infected Chickens Fed Various Dietary Levels of Choline, Folic Acid, Manganese, Biotin, or Niacin

Five experiments were conducted to determine the incidence and severity of tenosynovitis in tendons distal to the tarsal joint in 4-, 6-, and 8-week-old reovirus WVU 2937-infected chickens fed diets containing 20%, 100%, or 200% of the 1977 National Research Council nutrient requirements (NCR-77) of manganese, biotin, niacin, choline, or folic acid. Male chickens, but not female chickens, fed 20% or 100% or the NRC-77 level of folic acid had consistently higher lesion scores of tenosynovitis than male chickens fed the 200% NRC-77 level of folic acid. Increasing dietary manganese levels from 20% to 200% NRC-77 reduced the severity of tendon swelling in 6- and 8-week-old male chickens and appeared to increase the severity of tendon swelling in 8-week-old female chickens. Male chickens fed 20% of the NRC-77 required level of biotin had numerically more severe tenosynovitis at 6 weeks of age and significantly more severe tenosynovitis at 8 weeks of age than male chickens fed 100% and 200% of the NRC-77 level of biotin. Increasing dietary choline levels from 20% to 200% of the NCR-77 required level increased the severity of tenosynovitis numerically at 6 weeks of age and significantly at 8 weeks of age. When data were pooled across diet, male chickens had significantly more severe tenosynovitis than female chickens at 4, 6, and 8 weeks of age in the choline experiment and at 4 and 6 weeks of age in the folic acid experiment. Differences in the severity of tenosynovitis of individual treatment means (sex X diet X infection interaction means) occurred at only the 20% or 100% NRC-77 level of choline or folic acid. Male chickens also had more severe tenosynovitis than female chickens when fed 20% of the NRC-77 required level of manganese for 6 or 8 weeks.