Low vs. High Protein Diets for Turkeys

Two series of corn-soy diets, one high in protein and energy (HPE) and the other low in protein and intermediate in energy (LPE), were fed to 600 male and 300 female Large White poults. The high protein diets, with supplemental methionine, started at 32% crude protein (CP) and were stepped down at 4-week intervals to 16% CP. The energy values of the HPE diets started at 3150 Cal M.E. per kg and were stepped up to 3525 Cal. The LPE diets, supplemented with methionine and lysine, started with 23% CP and were stepped down to 12% CP. The energy values of the LPE diets were held at 2800 Cal M.E. per kg for the duration of the test. The treatments also included three levels of copper, normal (8 to 12 ppm) and two levels of supplemental copper from CuSO, (60 and 120 ppm). The poults were grown intermingled, 50 males and 25 females in each of 12 pens. Crushed corn cob litter was used. The experimental period for the hens ended at 16 weeks, when they were removed from the flock, and the toms continued in the same pens through 24 weeks. The main responses to the treatments are summarized in table 1. The results of the feed density treatments shown were averaged over all of the copper treatments and are shown in table 2. Similarly, the copper treatments were averaged over the feed density treatments. This was done to bring out the main effect of any treatment independent of the other treatments