Augmented chemiluminescence response of bronchoalveolar lavage cells in calves receiving repeated daily sprayings of ammonia mist into the nasal cavities

Influence of truck-transportation on the function of bronchoalveolar lavage fluid cells in cattle

The study sought to evaluate whether truck-transportation had an impact on the respiratory immune system of cattle. Six castrated 6-10-month-old Holstein calves were shipped approximately 100 km by road for 4 h. Plasma and bronchoalveolar lavage (BAL) fluid samples, collected immediately before transportation, at 4 h (soon after transportation), and on days 3 and 7 after transportation, were examined. A marked elevation of plasma cortisol concentration was observed at 4 h, but this level was unchanged in controls. The chemiluminescence (CL) response of phagocytes in BAL fluid cells, composed mainly of alveolar macrophage, decreased significantly after transportation (P<0.05). Transportation increased the CD3+ T cell population significantly (P<0.05), and a significant increase (P<0.05) in the ratio of CD4+ to CD8+ cells in BAL fluid was evident. We conclude that short-term road transportation alters pulmonary cells and their function, which may engender bovine respiratory disorders.

Effects of in vitro atmospheric ammonia exposure on recovery rate and luminol-dependent chemiluminescence of bovine neutrophils and bronchoalveolar macrophages

The effects of atmospheric ammonia, a major pollutant in animal confinement facilities, on bovine neutrophils and bronchoalveolar macrophages were evaluated in vitro. Ammonia exposure at concentrations 50, 100 and 200 ppm for one hour impaired recovery rates of neutrophils dose-dependently but enhanced their chemiluminescence activity per cell at lower concentrations (50 and 100 ppm). Macrophages were resistant to the exposure. Their recovery rates and chemiluminescence remained unaffected even at 200 ppm exposure. The present results suggest that ammonia exposure is unfavorable for bovine neutrophils in vitro, and probably in vivo also, in light of causing cell damage and triggering wider inflammatory responses.