Randomized controlled trial of pegbovigrastim as an adjunct therapy for naturally occurring severe clinical mastitis cases in dairy cows

Abstract

Pegbovigrastim (PEG) is the polyethylene glycolated form of the bovine granulocyte colony-stimulating factor, a growth factor targeting hematopoietic progenitor cells, stimulating production and differentiation of neutrophils, and was developed to improve immunity of dairy cows during the transition period. In Canada, PEG is labeled for the reduction of the incidence of clinical mastitis in the first 30 days of lactation in periparturient dairy cows and replacement heifers. However, it remains unclear if it could be useful as an adjunct therapy in severe clinical mastitis cases; it is possible that an increased recruitment of neutrophils could mitigate the mortality and improve the bacteriological cure and subsequent milk production of affected cows. The main objective of this pilot study was to quantify the effect of PEG as an adjunct therapy on survival, intramammary bacteriological cure, and subsequent milk production for naturally occurring severe mastitis cases. The hypotheses were that the PEG would improve survival in the 7 d after treatment, bacteriological cure 14 d post-treatment, and milk production in the 30 d following treatment.