{Reference Type}: Journal Article {Title}: Effect of recombinant bovine granulocyte colony-stimulating factor treatment during the peripartum period on postpartum diseases, reproductive performance, and milk production in Holstein cattle. {Author}: Yáñez U;Álvarez J;Lorenzo G;Caínzos J;Dubuc J;Becerra JJ;Herradón PG;Peña AI;Quintela LA; {Journal}: Res Vet Sci {Volume}: 177 {Issue}: 0 {Year}: 2024 Sep 31 {Factor}: 2.554 {DOI}: 10.1016/j.rvsc.2024.105368 {Abstract}: To boost the immune function around parturition, recombinant bovine granulocyte colony-stimulating factor (rbG-CSF) has been used to increase the number of neutrophils. Therefore, the aim of this study was to quantify the effect of rbG-CSF administration on the incidence of postpartum pathologies, reproductive performance, and milk production during the first three months of lactation. A total of 199 Holstein cows from one herd were included and were randomly allocated into two groups: Control (n = 103) and rbG-CSF (n = 96). Cows in the rbG-CSF group received 2 doses of a rbG-CSF injectable formulation, one 7 days before the expected date of calving and the other within 24 h after calving. For 6 weeks following calving, animals were examined weekly to assess the presence of postpartum pathologies. Milk production, protein and fat content, and somatic cell count were determined monthly by the regional dairy herd improvement association. Data about the reproductive performance were collected from on-farm software. To analyse the effect of treatment on the incidence of postpartum pathologies, Pearson's χ2 test and multivariable logistic regressions were performed. The effect on reproductive performance was analysed using Cox proportional hazard regression analysis for days open, binary logistic regression for first service conception rate and Oneway ANOVA test for the number of artificial inseminations. The effects of treatment on milk yield and milk composition were checked using GLM repeated measures analysis. No statistically significant differences were observed between treatment groups for any of the parameters evaluated. Only parity had a significant effect on days open and milk production (p < 0.05). In conclusion, in the present study no evidence was found that rbG-CSF could have an effect on the reproductive and productive parameters evaluated.