1. 1. Abutarbush, S. M., Pollock, C. M., Wildman, B. K., Perrett, T., Schunicht, O. C., Fenton, R. K., Hannon, S. J., Vogstad, A. R., Jim, G. K. and Booker, C. W. 2012. Evaluation of the diagnostic and prognostic utility of ultrasonography at first diagnosis of presumptive bovine respiratory disease. Can. J. Vet. Res. 76: 23–32.
2. 2. Allen, J. W., Viel, L., Bateman, K. G., Rosendal, S., Shewen, P. E. and Physick-Sheard, P. 1991. The microbial flora of the respiratory tract in feedlot calves: associations between nasopharyngeal and bronchoalveolar lavage cultures. Can. J. Vet. Res. 55: 341–346.
3. 3. Angen, O., Ahrens, P. and Tegtmeier, C. 1998. Development of a PCR test for identification of Haemophilus somnus in pure and mixed cultures. Vet. Microbiol. 63: 39–48.
4. 4. Angen, O., Thomsen, J., Larsen, L. E., Larsen, J., Kokotovic, B., Heegaard, P. M. and Enemark, J. M. 2009. Respiratory disease in calves: microbiological investigations on trans-tracheally aspirated bronchoalveolar fluid and acute phase protein response. Vet. Microbiol. 137: 165–171.
5. 5. Armengol, R. and Fraile, L. 2016. Colostrum and milk pasteurization improve health status and decrease mortality in neonatal calves receiving appropriate colostrum ingestion. J. Dairy Sci. 99: 4718–4725.