Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: March 20, 2003
Publication Date: June 21, 2003
Citation: STRAUCH, T.A., CARROLL, J.A., BERG, E.L., SALFEN, B.E. EFFECTS OF RALGRO IMPLANTATION TO GESTATING SOWS ON SOW AND PIGLET PERFORMANCE AND COMPONENTS OF THE SOMATOTROPHIC AXIS. JOURNAL OF ANIMAL SCIENCE SUPPLEMENT. 2003. V. 81(SUPPL.1):ABSTRACT p. 94. Technical Abstract: Objectives were to determine effects of an estrogenic compound (Ralgro; R) on maternal and neonatal piglet performance and components of the somatotrophic axis. On d 60 of gestation, sows were divided into two groups: R (n=7) and control (C; n=4). Treated sows were administered 36 mg R subcutaneously in the ear, and C sows were administered a sham implant. Sow blood samples were collected on d 60 and 80 of gestation and at parturition. Piglet blood samples and BW were collected within 12 hrs of birth. Thereafter, piglet body weights (BWs) were collected on d 7 and 14 of age. Serum was collected from blood samples and stored at minus 80 degrees C until analyzed for serum concentrations of IGF-I, IGF-II, and growth hormone (GH). Data were analyzed using ANOVA with treatment and pig sex as main effects. There were no differences (P > 0.38) in serum concentrations of IGF-I or GH between C and R sows; however, there was a trend (P < 0.10) for increased serum concentrations of IGF-II in R sows from d 60 of gestation to parturition. There was no difference in litter size (P < 0.14), number born alive (P < 0.33), or piglet survival to weaning (P < 0.21); however, there was a trend (P < 0.11) for greater total litter weight in C sows (19.4 +/- 2.3 vs. 15.4 +/- 1.2 kg; C vs. R). There was no difference (P > 0.47) in piglet BW at birth (1.4 +/- 0.04 kg), but there was a treatment effect (P < 0.002) on average daily gain (ADG) to 7 d of age, with increased ADG in R pigs (0.194 +/- 0.01 vs. 0.162 +/- 0.01 kg/d; R vs. C). There was a tendency (P < 0.07) for increased ADG in R pigs to 14 d of age (0.254 +/- 0.01 vs. 0.231 +/- 0.01 kg/d; R vs. C). Treatment affected piglet serum concentrations of IGF-I (P < 0.006; 52.8 +/- 3.7 vs. 38.4 +/- 3.8 ng/mL; R vs. C) and IGF-II (P < 0.0004; 83.2 +/- 1.5 vs. 74.6 +/- 1.8 ng/mL; R vs. C) at birth; but had no effect (P < 0.18) on serum concentrations of GH (14.4 +/- 1.3 vs. 17.2 +/- 1.9 ng/mL; R vs. C). These data indicate that in utero Ralgro treatment increases circulating concentrations of somatotrophic hormones, and improves piglet ADG during the first 14 d of life.