Effects of Removal of Supplemental Calcium and Phosphorus from Broiler Finisher Diets

Abstract

Meeting the calcium (Ca) and phosphorus (P) needs of broilers contributes significantly to feed cost. If Ca and P levels could be reduced during the 42- to 49-day period without affecting performance adversely, production costs could be reduced markedly. Studies were conducted to investigate whether broilers with properly developed skeletal systems at 42 days of age need supplemental Ca and P during the 42- to 49-day period. Chicks were grown to 42 days on nutritionally complete diets in floor pens with wood shavings. From 42 to 49 days there were fed one of the four following diets: 1) complete diet; 2) diet 1 without limestone (LIME); 3) diet 1 without dicalcium phosphate (DCP); 4: diet 1 without LIME and DCP. Weight gains (WG), feed consumption (FC), feed conversion ratio (FCR), mortality (MORT), and visual leg scores (VLS) were determined. Samples of birds were processed for dressing percentage (DP), abdominal fat content (AFC), tibia length (TL), tibia diameter (TD), and bone breaking strength (BBS). Removal of LIME and DCP from the diet from 42 to 49 days of age had no significant (P < .05) effect on WG, FC, FCR, MORT, VLS, DP, AFC, TL, or TD. Removal of LIME alone, or the combination of LIME and DCP resulted in significant (P < .05) reduction in BBS. However, removal of DCP alone did not reduce BBS significantly.