Improvement of growth in broiler chickens using trilostane

The objective of the present study was to determine whether injecting chicks with trilostane, a beta-hydroxysteroid dehydrogenase inhibitor, affected growth and protein synthesis in muscle and liver. A preliminary study was performed using a total of 72 chicks to determine the dose-response of trilostane (0, 2, 8, 32, 64 and 200 mg trilostane/kg of body weight suspended in .9% saline) on serum corticosterone concentration during a 2 wk and 2 h exposure. A second study was performed using 48 broiler chickens that were assigned at 1 wk of age to receive daily subcutaneous injections of either trilostane (65 mg/kg of body weight; TR) or .9% saline (ST). Six birds from each treatment group were killed at 2 and 3 wk of age. The pectoralis major (PM) and two leg muscles (gastrocnemius and peroneus longus; LM) were dissected and weighed, and concentrations of protein, DNA, and RNA were determined. An additional 6 birds within each time period and treatment group were killed to measure whole body proximate composition. A second experiment was performed using the same experimental design and 20 chicks, in which fractional synthesis rates were measured in 5 birds from each treatment group by infusion and incorporation of radioactive tyrosine. Serum corticosterone concentrations were lower (P less than .05) in the chicks injected with 64 and 200 mg trilostane/kg of body weight during a 2-wk period. The TR chicks gained 8 to 10% faster (P less than .05) than the ST birds.(ABSTRACT TRUNCATED AT 250 WORDS)