INTRARUMINAL TREATMENT OF TRACE-ELEMENT DEFICIENCY

In four experiments with suckler cows and growing cattle at grass two sustained release multi-trace element boluses providing, inter alia, 0 .8 mg selenium per day significantly increased initially low blood glu tathione concentrations over periods in excess of 100 days. Two experi ments resulted in significant increases in blood haemoglobin concentra tions. The blood copper concentrations at the start of the summer graz ing season were at the lower end of the normal scale and giving two bo luses (providing 140 mg Cu/day) maintained these levels. On one farm t here was a significant reduction in blood copper concentration for the untreated cattle after 102 days grazing.