Z. Li*, K. E. Nestor1*, Y. M. Saif***, W. L. Bacon*, and J. W. Anderson*
*The Ohio State University Department of Animal Sciences
***The Ohio State University Ohio Agricultural Research and Development Center
Food Animal Health Research Program
Mitogenic responses were examined for purified peripheral blood mononuclear cells (PBMC) and whole blood from individuals in a line (F) of turkeys selected for increased 16-week body weight and its corresponding randombred control (RBC2). The PBMC were isolated by centrifugation over Histopaque-1077 density gradient and tested for mitogenic responses to concanavalin A (ConA; 25 mg/mL) and phytohemagglutinin M (PHA-M; 100 mg/mL). For the whole blood assay, 6-week-old poults from both lines were injected with inactivated Pasteurella multocida. Heparinized blood samples were collected prior to injection (0 days), and at 2, 4, 7, and 14 days postinjection. The diluted whole blood was then tested for the mitogenic responses to Con A (25 mg/mL) and PHA-M (25 mg/mL). The cultures were then pulsed with 3H-thymidine, and incorporation was measured using a liquid scintillation counter.
There was a line difference in the mitogenic responses to ConA for PBMC and whole blood assays, but no line difference was observed in the response to PHA-M for both assays. For the purified PBMC assay, the F line had a lower response than its randombred control line (P ² 0.05) to Con A expressed as either cpm or a stimulation index (SI; ratio of cpm for stimulated cells to the cpm for unstimulated cells). For the whole blood assay, the F line had generally lower SI values in the responses to Con A than the RBC2 line with differences being significant at 0 and 2 days postinjection (P ² 0.01) and at 14 days postinjection (P ² 0.05). Genetic selection for increased body weight may have affected the lymphoblastogenic potential of Line F that could affect disease resistance.
1 For more information, contact at: The Ohio State University, Ohio Agricultural Research and Development Center, 125 Gerlaugh Hall, 1680 Madison Avenue, Wooster, OH 44691, 330-263-3757, Fax 330-263-3949, e-mail: nestor.1@osu.edu