Effect of treatment with and subsequent withdrawal of exogenous porcine somatotropin on growth and reproductive characteristics of gilts.

摘要: Two experiments were conducted to examine responses of gilts treatment with and withdrawal exogenous porcine somatotropin (PST). In Exp. 1, 36 prepubertal (79.7 +/- .9 kg; 159.1 .7 d) allotted randomly receive daily either 0 micrograms PST (C) or 70 PST/kg initial BW for 21 (PST-3) 42 d (PST-6). Gilts examined estrus by a mature boar starting on 22 continuing up 50 d. that expressed mated removed from treatment. PST-treated had higher ADG (P less than .01) lower feed/gain .02) C gilts. Following initiation exposure, (mean interval = 2.0 exhibited earlier PST-3 (24.8 PST-6 (24.0 .07); however, only two observed in compared six 2, 40 (72.6 1.0 141.1 mg 5 30 On 31, half the comingled unfamiliar penmates 45 Estrual treatment.(ABSTRACT TRUNCATED AT 250 WORDS)