Toxicity of Leucaena Leucocephala

Steers fed solely on Leucaena leucocephala developed hypothyroidism, with serum thyroxine (T4) levels dropping significantly within six weeks, leading to reduced feed intake, poor weight gain, hair loss, excessive salivation, and oesophageal lesions. Light steers (119 kg) were more severely affected than heavy steers (220 kg), with two light steers dying. Over eight weeks, these steers gained only 0.18 kg/day compared to 0.73 kg/day for those fed cowpea hay. Mineral supplementation improved intake, weight gain, and reduced hair loss and lesions but did not normalize T4 levels. Iodine supplementation had no significant effect. Switching to cowpea hay restored appetite and T4 levels within two weeks, though light steers continued to gain weight poorly.