Comparative Utilization of High Inclusion Rates of Three By-product Feed Resources by Finishing Broilers in the Tropics

Abstract

The comparative utilization of palm kernel meal (PKM), brewers dried grains (BDG) and maize offal (MO) was investigated in a 3x3 factorial combination of PKM, BDG and MO each at 20%, 30%, and 40% in finishing broiler diets. The nine diets were fed to the finishing broilers between 35 to 70 days of age. The results showed that final body weight and daily weight gain were highest (P<0.05) on PKM, then BDG followed by MO based diet. Weight gain decreased significantly (P<0.05) with increasing dietary levels of the by-products, but with significant interactions (P<0.05). The highest feed intake (P<0.05) was on BDG diets followed by MO and PKM, and the consumption increased (P<0.05) linearly without significant (P>0.05) interaction . Feed conversion efficiency was better (P<0.05) on PKM than MO and BDG, and decreased (P<0.05) with increasing levels of the test ingredients. Dry matter and crude protein were apparently better (P<0.05) utilized with MO and PKM than BDG, whereas ether extract was apparently utilized better (P<0.05) on BDG than others. Crude fibre and detergent fibre components were least (P<0.05) utilized with MO based diets. Some significant (P<0.05) interactions in nutrient utilization were observed. The broilers' apparent retention of the eight dietary minerals assayed were similar (P>0.05). Packed cell volume, haemoglobin and erythrocytes in broilers fed PKM tended to be superior to others, but the haematological indices decreased significantly (P<0.05) only at 40% inclusion, especially on MO when compared with the others. Total protein, albumin and globulin were similar (P>0.05) for the treatments, but total protein decreased (P<0.05) at 40% inclusion of the test ingredients. In conclusion, finishing broilers in the tropics tolerated up to 30% of the three by-products without deleterious effects on performance, nutrient retention and haematology, however, the results indicated the order PKM> BDG> MO. Beyond 30% inclusion rate there were demonstrated nutritional and physiological constraints leading to inferior performance.