Abstract
BACKGROUND: Prevention of diseases in the early rearing of calves is important, particularly because disease occurrence most often requires antimicrobial administration but reduction of their use in animals is a priority. Pegbovigrastim is known for its use as an immunoregulator in cows and heifers, but the effect of its administration on calves has not been fully investigated. OBJECTIVES: Investigate whether administration of pegbovigrastim effectively stimulates nonspecific immunity in healthy calves. ANIMALS: Eleven clinically healthy 5-week-old calves. METHODS: Prospective observational study. Calves were randomly allocated to an experimental or control groups to receive pegbovigrastim or the same volume of phosphate-buffered saline twice over a 7-day period. To evaluate nonspecific immunity, the numbers of total leukocytes and cells in the appropriate cell fractions were determined. Cytometric analyses were carried out to identify cells expressing CD11b and to evaluate the phagocytic and oxidative burst activities of granulocytes and monocytes. Myeloperoxidase (MPO) and selected cytokines were assayed using ELISA. RESULTS: Pegbovigrastim significantly increased the number of total leukocytes and of cells in all of the examined subsets (P < .05). The phagocytic activity of leukocytes expressed as mean fluorescence intensity was significantly potentiated after pegbovigrastim administration (P < .05). The cytokine response was modulated by pegbovigrastim administration toward anti-inflammatory activity. CONCLUSIONS AND CLINICAL IMPORTANCE: Pegbovigrastim effectively stimulated nonspecific immunity in clinically healthy calves, which in the long term could make the prevention of diseases during early rearing possible by strengthening the immune defense mechanisms of the host.