Our goal was to determine the responses of body weight (BW) and bone hydroxyproline (Hyp) concentration in turkeys fed a corn silage (CS) diet with different values of dietary cation–anion differences (DCADs). The turkeys (n = 90) were divided into five groups and fed as follows: group A (control)—standard diet (SD) (60%) plus CS (40%); group B—SD (60%), CS (40%) plus 240 g of CaCl2 per 100 kg of diet; group C—SD (60%), CS (40%) plus 480 g of CaCl2 per 100 kg of diet; group D—SD (60%), CS (40%) plus 240 g of NaHCO3 per 100 kg of diet; group E—SD (60%), CS (40%) plus 480 g NaHCO3 per 100 kg of diet. The addition of a lesser amount of CaCl2 lowered the DCAD, which ranged between 52.5 ± 4.19 and 91.14 ± 3.14 mEq/kg DM. An increased content of CaCl2 led to high negative values of DCAD. NaHCO3 supplemented in both doses resulted in a significant elevation of DCAD. Compared to each experimental group, feeding birds with a diet supplemented only with CS resulted in a lower BW. Addition of CaCl2 or NaHCO3 to the diet improved BW, but only CaCl2 addition enhanced the bone Hyp amount. In conclusion, we suggest that an anionic diet with low DCAD can prevent bone abnormalities in large turkeys, especially in the final course of production. Keywords: hydroxyproline; body weight; corn silage; diet cation–anion difference; turkey