title: Effects of treatment of periparturient dairy cows with recombinant bovine somatotropin on health and productive and reproductive parameters.
abstract: The objectives of the current experiment were to evaluate the effects of treating periparturient dairy cows with recombinant bovine somatotropin (rbST) on incidence of postpartum diseases and performance. Holstein (HO) and Jersey (JS) cows from 2 herds were enrolled in the experiment at 253 ± 3 d of gestation and assigned to the control (n = 432) and rbST125 (n = 437) treatments. Cows in the rbST125 treatment received 125 mg of rbST, weekly, from -21 to 21 d relative to calving. Blood sampled weekly, from -21 to 21 d relative to calving, from a subsample of cows was used to determine the concentrations of growth hormone (GH, HO = 106) and insulin-like growth factor 1 (IGF-1, HO = 147 and JS = 49). Cows were scored for body condition (BCS) at enrollment and at 1 ± 3, 30 ± 3, and 60 ± 3 d in milk (DIM). Cows were milked thrice daily and energy-corrected milk (ECM) yield was recorded for the first 30 DIM. Treatment of cows with rbST resulted in greater concentrations of GH during the prepartum (log10back-transformed concentrations of GH: HO-control = 7.83 and HO-rbST125 = 10.36 ng/mL) and postpartum (log10back-transformed concentrations of GH: HO-control = 10.45 and HO-rbST125 = 18.47 ng/mL) periods. Similarly, IGF-1 concentrations were higher during the prepartum (HO-control = 115.1 ± 4.9, HO-rbST125 = 137.7 ± 4.7, JS-control = 120.2 ± 8.3, JS-rbST125 = 167.1 ± 8.1 ng/mL) and postpartum (HO-control = 61.3 ± 4.0, HO-rbST125 = 75.2 ± 3.8, JS-control = 35.5 ± 6.9, JS-rbST125 = 54.6 ± 6.9 ng/mL) periods for rbST-treated cows. During the prepartum period, BCS was not affected by treatment, but during the postpartum period, BCS was reduced for rbST-treated cows (HO-control = 3.00 ± 0.03, HO-rbST125 = 2.90 ± 0.03, JS-control = 2.64 ± 0.02, JS-rbST125 = 2.61 ± 0.02). Cows from the rbST125 treatment tended to have lower incidence of retained fetal membranes (HO-control = 14.3, HO-rbST125 = 6.1, JS-control = 1.5, JS-rbST125 = 1.2%) and had reduced incidence of metritis (HO-control = 26.2, HO-rbST125 = 16.6, JS-control = 19.9, JS-rbST125 = 13.3%) compared with control cows. Ketosis incidence tended to be higher for rbST125 cows (HO-control = 9.4, HO-rbST125 = 11.3, JS-control = 8.5, JS-rbST125 = 13.4%) compared with control cows. The interaction between treatment and herd tended to affect yield of ECM during the first 30 DIM because HO cows treated with rbST during the periparturient period had greater yield than control HO cows (HO-control = 35.5 ± 1.0 vs. HO-rbST125 = 39.4 ± 1.0 kg/d), but treatment with rbST did not affect yield of ECM of JS cows (JS-control = 26.7 ± 0.6 vs. JS-rbST125 = 27.8 ± 0.6 kg/d). Treatment of periparturient dairy cows with 125 mg of rbST decreased the incidence of uterine disorders in HO and JS cows and increased yield of ECM during the first 30 DIM among HO cows, despite slightly increasing the incidence of ketosis.
authors.affiliation: Department of Animal Science, University of Minnesota, Saint Paul 55108.
authors.forename: P R B
authors.initials: PRB
authors.lastname: Silva
authors.affiliation: Department of Veterinary Population Medicine, University of Minnesota, Saint Paul 55108.
authors.forename: H F
authors.initials: HF
authors.lastname: Soares
authors.affiliation: Department of Veterinary Population Medicine, University of Minnesota, Saint Paul 55108.
authors.forename: W D
authors.initials: WD
authors.lastname: Braz
authors.affiliation: Department of Veterinary Population Medicine, University of Minnesota, Saint Paul 55108.
authors.forename: G D
authors.initials: GD
authors.lastname: Bombardelli
authors.affiliation: Department of Animal Science, South Dakota State University, Brookings 57007.
authors.forename: J A
authors.initials: JA
authors.lastname: Clapper
authors.affiliation: Division of Animal Science, University of Missouri, Columbia 65211.
authors.forename: D H
authors.initials: DH
authors.lastname: Keisler
authors.affiliation: Department of Animal Science, University of Minnesota, Saint Paul 55108; Department of Veterinary Population Medicine, University of Minnesota, Saint Paul 55108; Department of Large Animal Clinical Sciences, University of Florida, Gainesville 32608; Department of Animal Sciences, University of Florida, Gainesville 32608. Electronic address: rcchebel@ufl.edu.
authors.forename: R C
authors.initials: RC
authors.lastname: Chebel
mesh_terms: D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005260:Female; D013006:Growth Hormone / Q000097:blood / Q000494:pharmacology*; D007774:Lactation / Q000187:drug effects*; D008892:Milk / Q000378:metabolism; D049590:Postpartum Period; D012098:Reproduction
chemical_list: D005230:Fatty Acids, Nonesterified; D013006:Growth Hormone
keywords: dairy cow; health; performance; somatotropin