1De Vries A. Economic value of pregnancy in dairy cattle. J Dairy Sci 2006;89:3876-3885.
2Wikse SE, Rogers GM, Ramachadran S. Prevalence and risk factors of Leptospira infection in beef cow/calf operations in the United States: Leptospira borgpetersenii serovar hardjo. Bovine Practitioner 2007;41(1):15-23.
3Guitian J, Thurmond MC, Hietala SK. Infertility and abortion among first-lactation dairy cows seropositive or seronegative for Leptospira interrogans serovar hardjo. J Am Vet Med Assoc 1999;215:515-518.
4Ridpath J. The contribution of infections with bovine viral diarrhea viruses to bovine respiratory disease. Vet Clin Food Anim 2010;26(2):335-348.
5Ellis WA, Thiermann AB. Isolation of leptospires from the genital tract of Iowa cows. Am J Vet Res 1986;47(8):1694-1696.
6Ellis WA. Leptospirosis as a cause of reproductive failure. Vet Clin North Am Food Amin Pract 1994;10(3):463-478.
7Jones C, Chowdhury S. Bovine herpesvirus type 1 (BHV-1) is an important cofactor in the bovine respiratory disease complex. Vet Clin Food Anim 2010;26(2):303-321.
8Woolums AR, Siger L, Johnson S, Gallo G, Conlon J. Rapid onset of protection following vaccination of calves with multivalent vaccines containing modified-live or modified-live and killed BHV-1 is associated with virus-specific interferon gamma protection. Vaccine 2003;21(11-12):1158-1164.
9Ficken MD, Ellsworth MA, Tucker CM. Evaluation of the Efficacy of a Modified-Live Combination Vaccine against Abortion Caused by Virulent Bovine Herpesvirus Type 1 in a One-Year Duration-of-Immunity Study. Vet Ther 2006;7(3):275-282.
10Rodning SP, Marley MS, Zhang Y. Comparison of three commercial vaccines for preventing persistent infection with bovine viral diarrhea virus. Theriogenology 2010;73(8):1154-1163.
11Cortese VS. Clinical and Immunologic Responses of Cattle to Vaccinal and Natural Bovine Virus Diarrhea Virus (BVDV), Western College of Veterinary Medicine, University of Saskatchewan. 1998. Available at: http://library.usask.ca/theses/available/etd-10212004-001245/unrestricted/NQ37879.pdf. Accessed August 7, 2012.