Submitted to: Veterinary Immunology and Immunopathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 9, 2011
Publication Date: August 1, 2011
Citation: Hulbert, L., Carroll, J.A., Randel, R., Brown, M., Burdick, N.C., Ballou, M. 2011. Innate immune responses of temperamental and calm cattle after transportation. Veterinary Immunology and Immunopathology. 143:66-74. Interpretive Summary: This research represents a collaborative effort by scientists from Texas Tech University, the Livestock Issues Research Unit, Texas AgriLife Research, and West Texas A&M University to determine the effect of transportation on measures of innate immune function in calm and temperamental Brahman cattle. Stress associated with transportation contributes to the incidence of disease, including bovine respiratory disease complex. Therefore, identifying cattle that may be more susceptible to stressors and subsequently have altered immune responses may help to reduce the impact of sickness after transport. Additionally, cattle classified as temperamental have been demonstrated to show less signs of sickness than calm cattle, although they produced similar innate immune responses to an immune challenge. Therefore, we utilized calm and temperamental cattle to measure innate immune function after exposure to handling, transportation, and exposure to a novel environment. Data from this study suggest that temperamental bulls have more neutrophils present in the periphery, but neutrophil function is less than that of calm bulls following transportation. Specifically, temperamental bulls had an elevated neutrophil to lymphocyte ratio 24 h after initiation of the study. Calm bulls also exhibited an increase in neutrophil cell adhesion marker expression and neutrophil function (phagocytic and oxidative burst activity) compared to temperamental bulls. Temperamental bulls had greater monocyte function at 0, 24, and 48 h compared to calm bulls. Additionally, transportation increased neutrophil function 96 h post-transportation, an effect that was more pronounced in calm bulls. These data suggest that neutrophils from calm bulls may be more likely to resist microbial invasion 96 h after transportation than neutrophils from temperamental bulls. Therefore, when exposed to stressors, temperamental cattle may require special management practices to reduce and prevent stress before and after transportation. This data will be of interest to scientists working in the fields of stress physiology and immunology as well as cattle producers and can be used to modify protocols for working with temperamental cattle as well as protocols for transporting cattle.
Technical Abstract: The objective was to investigate measures of cellular innate immune responses among calm and temperamental Brahman bulls in response to handling and transportation. Sixteen Brahman bulls (344 ± 37 days of age; 271.6 ± 45.5 kg BW) classified as either calm (n = 8) or temperamental (n = 8) were loaded into a trailer, transported for 4 h to a novel facility, rested 16 h, and then were returned to their original facility after a 4-h transport. Blood samples were collected immediately prior to (time 0) and at 24, 48, and 96 h after initial loading for analysis of innate immune and blood parameters. Leukocyte counts did not differ (P > 0.05) due to temperament before or after transportation, but neutrophil:mononuclear cell ratios were elevated among temperamental bulls compared to calm bulls at 24 h. At 24 h, expression of neutrophil Beta-integrin and lymphocyte L-selectin were decreased compared to 0 h (P < 0.01). At 48 h, calm bulls had elevated neutrophil Beta-integrin expression, as well as phagocytic and oxidative burst activity when compared to temperamental bulls (P < 0.05). Temperamental bulls had greater monocyte phagocytic and oxidative burst activity at 0, 24, and 48 h compared to calm bulls (P < 0.10). At 48 h, supernatant collected from whole blood stimulated with lipopolysaccharide (LPS) had greater tumor necrosis factor-alpha (TNF-alpha) concentrations than the other time points (P < 0.05), but no temperament effect was observed (P > 0.05). However, at 96 h, supernatant TNF-alpha concentrations were lower (P < 0.05) among all cattle compared to 0 h. Additionally, transportation increased neutrophil phagocytosis, oxidative burst and cell adhesion molecule expression 96 h post-transportation and the effect was more pronounced among calm bulls. These data suggest that neutrophils from calm bulls may be more likely to resist microbial invasion 96 h after transportation than neutrophils from temperamental bulls.