Effect of feeding thyrotropin-releasing hormone to lactating sows

摘要: Two experiments were conducted to assess the effects of feeding thyrotropin-releasing hormone (TRH) during lactation on sows. In Exp. 1, sows fed 0, 10, 100 or 1,000 mg TRH d 10.8 +/- .4 (mean SE) after parturition. Blood samples taken from every 30 min -2 h 8 and at 12 18 feeding. Consumption increased mean serum concentrations thyroxine (T4; P less than .001), growth (GH; .06) prolactin (PRL; .01), but insulin (INS; greater .10) was unaffected by TRH. Serum T4 elevated within 2 4 remained for h. Concentrations GH PRL began increase immediately 6 h, respectively. 2, 0 200 111 gestation weaning 27.1 .3 lactation. all stages respiration rate 10 20, heart milk production 20 did not influence number pigs born, born alive, survival lactation, sow body weight, heartgirth, backfat depth, feed disappearance, Piglets nursing similar in weight piglets 5 they heavier (P .07), 15 .001) 27 .0001). Sows took longer return estrus control Results indicated that T4, duration weights, it delayed weaning.