Evaluation of a potential cystine response by the turkey poult

An experiment was conducted to determine whether the turkey poult would res pond to Cystine (Cys) supplementation of a corn-soybean meal diet. A 3 x 4 factorial arrangement of treatments was used for the first 4 weeks (.41, .4 4 and .47% Met) and (.43, .45, .47 and .49% Cys). A 2 x 4 factorial arrange ment of treatments was used during weeks 5 to 8 (.39 and .43% Met) and (.38 , .40, .42 and .44% Cys). The poults day-old to 4 wks of age responded to s upplemental Cys when the ratio of Met:Cys was between 48.8:51.2 and 52.2 to 47.8%. The response to Cys was not large enough to assay the poults Cys re quirement. A numerical response was obtained from Cys supplementation from 5 to 8 wk to a diet containing .44% Met and .43% Cys and a Met:Cys ratio of 50.5 to 49.5. Neither feed intake nor feed efficiency was influenced by th e addition of either Met or Cys.