Environmental temperature and Turkey performance: the use of diets containing increased levels of protein and use of a choice-feeding system

Female turkeys kept under an 1 8 or 25 °C environmental temperature regime were fed from 72 d of age until the end of the experiment at 100 d of age on one of five diets each containing a different level of protein ( 17 8, 209 , z 40 , 272 , 303 g/kg).Further birds under each temperature regime were offered a high-protein concentrate ( 4 88 g protein /kg) free-choice with whole wheat.Turkeys which received the conventional diets ( 17 8 or 209 g protein/kg) grew significantly faster and consumed food at a significantly greater rate under the IS °C regime compared with the 25 °C regime.Turkeys which received diets 1 , 5 or 6 at i8 °C or diets 5 or 6 at 25 °C exhibited the highest growth rates.Treatment means for body weight, at 72 d prior to feeding the expe- rimental diets, and at the end of the experiment for each diet were markedly lower for the z 5 O C regime.The choice-fed birds apparently overconsumed protein to a considerable extent compared with those fed the 17 8 or 209 g protein /kg diets.The choice-fed turkey appears to meet its lowered dietary energy requirement at higher temperatures by reducing intake of the whole cereal.