Faecal and urinary losses of nitrogen in cobalt-deficient small East African goats.

Abstract

Cobalt deficiency was induced in 3 rumen-fistulated small East African goats by feeding them on Chloris gayana hay (containing Co 0.02 mg/kg DM) and a small amount of concentrate supplement (150 g each daily, containing Co 0.05 mg/kg) for 23 weeks. An oral cobalt chloride drench was administered to a control group 3 times weekly, providing Co 0.3 g/goat weekly. During week 22, faecal and urinary losses of nitrogen were higher (P<0.01) in Co-deficient goats than in Co-supplemented goats. Concentration of free ammonia in rumen was higher (P<0.01) in Co-supplemented goats. It is suggested that a reduction in rumen fermentation of dietary N, and increased faecal and urinary N losses probably contribute to slow growth and loss of body condition in Co-deficient ruminants.