Serum levels of selected trace elements, vitamins, and antibodies to i
nfectious bovine rhinotracheitis (IBR), bovine virus diarrhea (BVD), p
arainfluenza3 (PI3), and bovine respiratory syncytial virus (BRSV) wer
e determined in 100 Mexico-origin cattle upon their arrival in Del Rio
, Texas. A majority of the cattle tested were found to be deficient in
copper, zinc, and vitamins A and E; 92% had serum copper levels below
the normal range, 54% were zinc deficient, 62% were Vitamin A deficie
nt, and 75% were Vitamin E deficient. These multiple deficiencies may
result in compromised immune responsiveness and increased predispositi
on to disease. In addition, serologic results suggested susceptibility
to multiple viral pathogens; 84% of cattle were seronegative for IBR,
64% were seronegative for BVD, and 24% were seronegative for BRSV. Th
ese results should be helpful in designing preventive health programs
for Mexico-origin steers.