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Title: Crooked Calf Syndrome: Managing Lupines on Rangelands of the Channel Scablands of East-Central Washington State

item Panter, Kip
item Cook, Daniel
item Lee, Stephen
item Ralphs, Michael

Submitted to: Rangelands
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/7/2009
Publication Date: 2/1/2009
Citation: Panter, K.E., Motteram, E., Cook, D., Lee, S.T., Ralphs, M.H., Platt, T.E., Gay, C.C. 2009. Cooked Calf Syndrome: Managing Lupines on Rangelands of the Channel Scablands of East-Central Washington State. Rangelands 31(1):10-15.

Interpretive Summary: Since the heavy losses of the 1996-1997 calving season the incidence of crooked calves in the scablands of Washington state has returned to pre-1996 levels. However, some ranches have continued to experience up to 5% incidence and two ranches near Spokane reported unusually high numbers of crooked calves in the spring of 2008. Lupine populations and density appear to have steadily declined since 1997 because of drought. However, the isolated populations of lupine where crooked calves continue to occur may be the result of micro climate events such that sufficient precipitation in some localized areas has allowed populations to persist. Seed reserves are believed to be such that given the right environmental conditions and high precipitation, the cyclic population explosion of lupine could occur again, with catastrophic results to cow calf operations. Increased research efforts the last eight years have improved our understanding of conditions that lead to losses. Better understanding of the causes will improve management recommendations and reduce losses overall and help prevent or reduce catastrophic losses in the future.

Technical Abstract: “Crooked calf syndrome”, the contracture-type skeletal defects and cleft palate caused by velvet lupine (Lupinus leucophyllus) on the channel Scablands of east-central Washington State are the same as those defects induced by Conium maculatum (poison-hemlock) and Nicotiana spp. (wild tobacco) in ruminants and swine. Limb flexure (arthrogryposis), twisted spine (scoliosis), deformed neck (torticollis), depressed thoracic spine (kyphosis), hump back (lordosis), asymmetry of the head or skeletal system, and cleft palate are all part of this syndrome of multiple congenital contractures (MCC). These plants cause depressed fetal movement and depending on 1) the stage of pregnancy, 2) the amount of the plant ingested, and 3) the length of time and consistency of lupine eaten, result in one or more of these defects. Ranchers that utilize the Channel scablands for grazing have come to accept a 1-5% incidence of crooked calves in their herds as the cost of grazing in the region. Since 1980, outbreaks in excess of 5% have occurred eight different calving seasons. In the 1996-1997 calving season the losses were catastrophic on many ranches. Research in the region by the Field Investigation Unit of Washington State University and the USDA Poisonous Plant Research Laboratory (PPRL) have provided results to better understand lupine ecology, population cycles, and when and why cattle graze lupine.