• 1 January 1983
    • journal article
    • research article
    • Vol. 44  (11) , 2145-2148
Abstract
Hereford steers were stressed on a large-animal treadmill operating at speeds of 1.8 to 2.2 m/s. Blood samples were collected from indwelling jugular catheters before, during and after exercise. Peripheral blood lymphocytes from stressed calves at 5 and 30 min after exercise had less (P < 0.01) mitogen-induced blastogenic responses when compared to pre- or 60-min postexercise values. Serum from stressed calves incorporated into lymphocyte cultures from nonstressed steers resulted in less (P < 0.01) lymphocyte blastogenic responses. Infectious bovine rhinotracheitis viral growth in bovine kidney cell cultures was enhanced 4-fold when cultured with serum from stressed calves. These data indicate that acute physical exertion may cause physiologic alterations in calves that modulate cellular immunity and viral replication.