Cattle preference for forage kochia, crested wheatgrass, and velvet lupine

Alkaloids in velvet lupine (Lupinus leucophyllus Douglas ex Lindl.) cause a crooked calf syndrome if the dam consumes the plant between d 40 and 100 of gestation. In spring calving operations, this coincides with late summer when annual grasses are mature and senescent in the Scabland region of eastern Washington. Velvet lupine is the only green-growing forb during this period on the annual grasslands and is readily consumed. Planting an alternative forage that is more palatable than velvet lupine may reduce the risk of crooked calves. Preference trials were conducted to compare the palatability of 2 varieties of forage kochia, 'Immigrant' (Kochia prostrata ssp. virescens) and the experimental line Otvsel (K. prostrata ssp. grisea), with crested wheatgrass (Agropyron desertorum [Fisch. ex Link] Schult.) and velvet lupine. Preferences were ranked by sequential Latin squares. The first trial consisted of four 4 × 4 Latin squares: 4 forages, 4 heifers, 4 d, and 4 feed locations. The most preferred forage was then removed and preference for the remaining forages was evaluated in a 3 × 3 Latin square. The 2 trials were repeated using 4 new heifers. Crested wheatgrass was preferred in the first trial, but the Immigrant forage kochia replaced it as most preferred feed in the second set of trials. There was no difference in preference between Otvsel and velvet lupine. Results indicate that Immigrant forage kochia and crested wheatgrass should be selected to evaluate their establishment and palatability in subsequent seeding and field-scale palatability trials in the Scabland region of eastern Washington.