Beef cattle losses after grazing Lupinus argenteus (silvery lupine)

Ten yearling steers weighing 270-360 kg died acutely after eating early see d pod stage Lupinus argenteus (silvery lupine) containing high levels of pi peridine alkaloids, including ammodendrine and N-methylammodendrine. Reduce d availability of quality feed from range moderately depleted of quality gr asses appeared a major factor in causing the cattle to graze lupine. Proxim ate analysis of whole plant, seed pods and seed showed high levels of crude protein ranging from 16.4 to 48 % for whole plant and seed. Alkaloid ana s is of the whole plant and individual plant parts such as seed and seed pods (30-40 % seed shatter) showed total alkaloid levels ranging from 0.70 to 2 .5 % (0.70-2.5 mg/100 mg plant) dry weight. Ammodendrine levels ranged from 0.24% in seed pods with > 70% seed loss to 1.35 % in early growth plant wi th no seed. N-methylammodendrine levels ranged from 0.38 % in seed pods wit h > 70 % seed shatter to 1.04 % in pure seed. Other minor alkaloids totaled 0.08 % in seed pods with > 70 % seed shatter to 0.60 % in early growth pla nt before seed pod formation. These cattle ate an estimated 1.8 g/kg dry we ight (486 g to 648 g) of lupine in 24 h. This appears the first report of a cute death in cattle associated with piperidine alkaloid-containing Lupinus argenteus.