OBSERVATIONS OF LUPINUS-SULPHUREUS-INDUCED CROOKED CALF DISEASE

Lupine-induced ''crooked calf disease'' occurred in a fall calving her d of cows in Northeastern Oregon, Sixty-seven calves from a herd of 13 1 cows (51%) were born with congenital skeletal malformations primaril y of the front limbs, neck, or spine and a few had cleft palates, Beca use of the nature of the malformations, lupine was suspected, and inve stigation of the ranch and pastures where cows grazed revealed 2 speci es of lupine (Lupinus sulphureus; Douglas ex, Lindl, and Lupinus leuco phyllus; Douglas ex, Hooker) and poison-hemlock (Conium maculatum). Po ison-hemlock was not grazed and therefore eliminated as the teratogeni c plant. Extensive grazing of the Lupinus sulphureus especially the se ed pods was evident, Chemical analysis of the 2 lupine species demonst rated that L. sulphureus was likely the cause of the birth defects bec ause it contained high level of the quinolizidine alkaloid anagyrine, a known teratogen, Lupinus sulphureus is a yellow-flowered lupine and contained 1.84% anagyrine in the seed, whereas Lupinus leucophyllus, a purple-flowered lupine, contained other quinolizidine alkaloids but n o anagyrine, The seed pods of L. sulphureus were high in total alkaloi ds (42 mg/g of dry seed), of which 45% was anagyrine. After a review o f breeding records, grazing patterns and growth stage of plants, it wa s determined cattle probably ingested L. sulphureus in the seed pod st age during critical fetal developmental periods of gestation, Epidemio logic studies suggested the critical gestational period included day 2 1 to day 100; 70% of the malformed calves were born to cows that were exposed to the plant during gestation days 60 to 80, The risk of defor mities was markedly increased in fetuses exposed during this interval, A few malformations occurred in cows exposed to the lupine as early a s gestation day 21 and as late as day 100, We conclude that L. sulphur eus was the teratogenic species, and producers should prevent cows fro m grazing L. sulphureus during gestation days 40 to 100 and consider h erbicide control of this lupine species.