“It can be concluded that caffeine supplementation at the levels of 12.5 to 25 mg/kg BW/day increased BWG, decreased FCR and T3 , and significantly altered blood biochemistry parameters.”
“Plasma T4 concentrations were not affected by caffeine (P > 0.05), but plasma T3 concentrations were reduced by caffeine supplementation on d 28 and 42 (P < 0.05).”