title: Efficacy of polyethylene glycol-conjugated bovine granulocyte colony-stimulating factor for reducing the incidence of naturally occurring clinical mastitis in periparturient dairy cows and heifers.
abstract: OBJECTIVE
  To evaluate effects of various doses of polyethylene glycol (PEG)-conjugated bovine granulocyte colony-stimulating factor (bG-CSF) on the incidence of naturally occurring clinical mastitis in periparturient dairy cattle.
  
  
  METHODS
  211 periparturient Holstein cows and heifers.
  
  
  METHODS
  Approximately 7 days before the anticipated date of parturition (day of parturition = day 0), healthy cattle received SC injections of sterile saline (0.9% NaCl) solution (control treatment) or PEG-bG-CSF at 5, 10, or 20 μg/kg. Cattle were commingled and housed in a pen with dirt flooring, which was kept wet to maximize the incidence of naturally occurring clinical mastitis. Within 24 hours after parturition, each animal again received the assigned treatment. Mammary glands and milk were visually scored for abnormalities twice daily for 28 days after parturition. Milk samples were aseptically collected from mammary glands with an abnormal appearance or abnormal milk and submitted for microbial culture. Daily milk production was recorded, and milk composition was assessed on days 3, 5, 7, and 10.
  
  
  RESULTS
  Cattle treated with PEG-bG-CSF at 10 and 20 μg/kg had significantly fewer cases of clinical mastitis (9/54 and 5/53, respectively), compared with control cattle (18/53). Administration of PEG -bG-CSF did not significantly affect daily milk production or milk composition.
  
  
  CONCLUSIONS
  Results suggested that PEG-bG-CSF was effective for reducing the incidence of naturally occurring clinical mastitis in periparturient dairy cattle. Further investigations of the use of PEG-bG-CSF as a potential preventative intervention should be conducted.
authors.affiliation: Biosciences Research & Development, Elanco Animal Health, 2500 Innovation Way, Greenfield, IN 46140.
authors.forename: Renee L
authors.initials: RL
authors.lastname: Hassfurther
authors.forename: Terry N
authors.initials: TN
authors.lastname: TerHune
authors.forename: Peter C
authors.initials: PC
authors.lastname: Canning
mesh_terms: D000822:Animal Husbandry; D000818:Animals; D002417:Cattle; D005260:Female; D016179:Granulocyte Colony-Stimulating Factor / Q000008:administration & dosage*; D015994:Incidence; D007279:Injections, Subcutaneous; D008414:Mastitis, Bovine / Q000517:prevention & control*; D008892:Milk / Q000382:microbiology; D036801:Parturition; D011092:Polyethylene Glycols / Q000008:administration & dosage*; D011247:Pregnancy
chemical_list: D016179:Granulocyte Colony-Stimulating Factor; D011092:Polyethylene Glycols