Innate immune responses of temperamental and calm cattle after transportation

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 d of age; 271.6 ± 45.5 kg BW) classified as either calm ( n = 8) or temperamental ( n = 8) were loaded onto a trailer, transported for 4 h to a novel facility, rested 16 h overnight, 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 analyses 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 greater in temperamental bulls compared to calm bulls at 24 h. At 24 h, expression of peripheral neutrophil β 2-integrin decreased among all bulls compared with 0 h ( P < 0.01). Temperamental bulls had greater glucose and cortisol than calm bulls ( P < 0.01) at 48 h; whereas calm bulls had elevated neutrophil l-selectin expression, and phagocytic and oxidative burst activity compared with temperamental bulls ( P < 0.10) at 48 h. The supernatant collected from endotoxin-stimulated whole blood cultures had greater TNF-α concentrations at 48 h than at the other time points ( P < 0.05), but no temperament effect was observed ( P > 0.05). In contrast, 96 h after initial loading the supernatant TNF-α concentrations were lower ( P < 0.05) among all cattle. Lastly, 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 are more likely to resist microbial invasion at 96 h after transportation than neutrophils from temperamental bulls.