Author
STERLE, J - UNIVERSITY OF MISSOURI | |
CANTLEY, T - UNIVERSITY OF MISSOURI | |
Carroll, Jeffery - Jeff Carroll | |
Matteri, Robert | |
LUCY, M - UNIVERSITY OF MISSOURI | |
LAMBERSON, W - UNIVERSITY OF MISSOURI |
Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only Publication Acceptance Date: 7/31/1998 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: Crowded uterine conditions were induced by unilateral hysterectomy ovariectomy in 42 gilts to determine the effect of porcine somatotropin on fetal and placental growth. Gilts were randomly assigned across three replicates to one of three treatments: Control (C), daily injections of 1 mL saline d 0 to 64 of gestation; Early (E), 5 mg of rpST/d from d 0 to 30, ,followed by 1 mL saline from d 31 to 64; Late (L), 1 mL saline/d from d 0 to 29, followed by 5 mg of rpST/d from d 30 to 64 of gestation. Gilts were hysterectomized on d 65 of gestation. There was a tendency (P=.06) for L rpST treatment to increase fetal weight (174.76 +/ 4.25 vs 165.14 +/ 5.06, 153.70 +/ 5.66 g, L vs C,E, respectively). Both rpST treatments increased the percentage of placental protein (58.99 +/ 1.30, 63.68 +/ .98 and 62.22 +/ 1.08%; P=.01) and placental dry matter (5.23 +/ .33 vs 6.85 +/ .23, 6.56 +/ .28%; C,E, and L; P=.10). Contact area of uterine/placental interface was increased with both treatments of rpST (.56 +/ .10, .55 +/ .03 vs .37 +/ .04 mm**2; E,L vs C; P=.01). Late rpST treatment numerically increased placental dry weight. Early rpST treatment numerically decreased placenta wet weight (105.42 +/ 21.26, 79.45 +/ 14.83, 124.57 +/ 17.17 g; C,E,L; P=.33), but numerically increased DNA content (P=.30). Fetal weight was positively correlated with both placental wet and dry weight (r=.73;P<.0001 and r=.73;P<.0001) but negatively correlated with dry matter (r=-.45;P<.0001), protein (r=-.20;P<.02), and DNA content (r=-.73;P<.0001) of the placenta. Late rpST treatment numerically increased uterine gland histological variables (total area, lumen area, and nuclei/gland). It is possible that increased placental growth as a result of rpST administration cannot be maintained after cessation of treatment. |