Ranch-management factors associated with antibody seropositivity for Neospora caninum in consignments of beef calves in Texas, USA

A study was conducted with a 1998 retained-ownership population of Texas (U SA) beef calves to determine the ranch-management practices associated with calf seroprevalence to Neospora caninum. Management practices of 76 Texas ranches that consigned 760 calves to a retained-ownership feedlot program w ere reviewed from a mailed questionnaire. Ninety-nine of 760 (13%; 95% CI, 9.4%, 17.7%) calves were positive to N. caninum and 59% of the ranches cons igned at least one positive calf. In the logistic multiple-regression model which controlled for overdispersion, increased odds of calf-level seroposi tivity was associated with seasonal calving patterns, with stocking > 1 cow /calf unit/2.2 ha, using a round-bale feeder, allowing wildlife access to t he weaning supplement, and self-rea-red replacement heifers. However, decre ased odds of seropositivity was associated with using a cattle-working dog and with using a self-contained cattle feeder. There was substantial overdi spersion. due to ranch. (C) 2001 Elsevier Science B.V. All rights reserved.