Pegbovigrastim use in periparturient embryo-recipient cows: Effects on health and reproduction.

The objective of this randomized clinical study was to evaluate the effects of periparturient administration of pegbovigrastim (recombinant bovine granulocyte colony stimulating factor; PEG) on postpartum health and reproductive outcomes in dairy cows carrying transferred embryos. A total of 60 multiparous Jersey cows (second parity n = 21, >second parity n = 39) that were in vitro-fertilized embryo recipients were enrolled. Animals were selected from a commercial herd and assigned to 1 of 2 treatments: (1) PEG (n = 31), which received a subcutaneous injection of 15 mg of PEG 7 d before expected calving and a second dose within 1 h of parturition; or (2) CON, untreated control (n = 29). Parturition was induced pharmacologically in all cows at 280 d of pregnancy with 500 μg of cloprostenol and 25 mg of dexamethasone intramuscularly. Cow health was monitored daily during the periparturient period and included assessment for retained fetal membranes within 24 h after calving and metritis until 20 d in milk. Descriptive statistics were calculated, to determine the incidence of postpartum diseases, causes of culling, and early-lactation reproductive outcomes, including number of inseminations, days to first heat, days to first service, and interval from calving to conception. The Wilcoxon rank sum test was used to assess treatment effects on early-lactation reproductive performance outcomes. The overall incidence of metritis in this cohort of cows was 17.14%. Animals treated with PEG tended to have more cases of metritis (25%) compared with CON (8.8%). Mastitis incidence in PEG was 19.35% compared with CON at 27.59%. These data suggest that in this dairy, with embryo-recipient cows induced to calve at 280 d of pregnancy, the administration of 2 doses of PEG tended to increase postpartum metritis but had no effect on mastitis incidence, culling rate, or early-lactation reproductive outcomes.