Figure 3.

Calves receiving SCFP supplementation tend to develop less bovine respiratory syncytial virus-PM induced lung pathology and less neutrophil infiltration into the airways. On day 10 post-viral infection, the calves were humanely euthanized and necropsied. The extent of gross pneumonic consolidation was evaluated based upon the percentage of lung affected (0 = free of lesions; 1 = 1% to 5% affected; 2 = 6% to 15% affected; 3 = 16% to 30% affected; 4 = 31% to 50% affected; 5 = >50% affected). Representative gross lung lesions from three individual calves in the control group (top) or SCFP-treated group (1 g/d SmartCare, 5 g/d NutriTek; bottom) (A). Aggregate gross pathology results from all calves (B). Plus symbol indicates the score of the control calf that was euthanized on day 9. BAL samples were collected from all calves (SCFP-treated, n = 13; and controls, n = 12) on day 10 post-viral infection (C). Cytospin preparations were made and differentially stained with Modified Wrights Stain. Relative numbers of neutrophils, macrophages, lymphocytes, eosinophils, and other cell types were determined by microscopy. The relative numbers of macrophages (*P = 0.07) and neutrophils (**P = 0.04) present in the lung airways differed between SCFP and control calves. Data are presented as means ± SEM. The lung location and percentage of lung lobes positive for PM bacterial recovery in each treatment group (D).