TY - JOUR JO - Journal of Animal and Feed Sciences J2 - J. Anim. Feed Sci. SN - 1230-1388 VL - 1 IS - 3-4 PY - 1992 ID - Wir-Konas1992 TI - The influence of thyrotropin-releasing hormone (TRH) on growth rate and thyroid activity in broiler chicks AB - Twenty-eight-day old broiler chicks were used to determine growth rate and thyroid activity responses to various doses and routes of administration of synthetic thyrotropin-releasing hormone (TRH). In experiment 1, daily intramuscular (im.) injections of 2 µg TRH/chick over 10 or 20 days stimulated the relative body weight gain in cockerels by 5.7 and 10%, respectively, compared with saline injected controls. In experiment 2, TRH administered im. (2 µg/chick) or orally (80 µg/chick) over 10 days significantly increased (P≤0.01) the relative body weight gain of cockerels by 20.3 and 29.6%, respectively and slightly improved feed conversion efficiency. No effect of TRH on the growth rate of female chicks was found. Treatment with TRH induced a marked increase of relative thyroid size, basal metabolic rate and plasma triiodothyronine and thyroxine levels. Our data confirmed earlier reports that improvement in growth rate of TRH-treated chicks appears to be mediated by thyroid hormones. AU - Wir-Konas, E. AU - Ryś, R. AU - Pietras, M. SP - 183 EP - 192 DA - 1992 DO - 10.22358/jafs/69909/1992 UR - https://doi.org/10.22358/jafs/69909/1992 ER -