ABSTRACT
1. The ileal digestible energy (IDE), metabolisable energy (ME) and nitrogen-corrected ME (MEn) of dry fat (DF) and stabilised rice bran (SRB) were determined in two experiments with broiler chickens using the regression method.
2. Chickens were fed a common broiler starter diet from d 0 to 17 and experimental diets from d 17 to 22 post hatching. Three diets were prepared; a maize-soybean meal reference diet (RD) and two test diets containing either DF at 50 or 100 g/kg replacement (Experiment 1) or SRB at 100 or 200 g/kg replacement (Experiment 2) of the energy-contributing ingredients in the RD. In each experiment, 192 chickens were randomly allocated to one of three dietary treatments in a randomised complete block design, comprising eight replicate cages with eight birds per cage.
3. In Experiment 1, the IDE, ME and MEn linearly increased (P < 0.001) with increasing DF concentrations, while in Experiment 2, the IDE, ME and MEn of the diets were not affected by dietary supplemental SRB. The regression-derived IDE concentration for DF and SRB were 25.30 and 14.88 MJ/kg DM, respectively. The respective ME and MEn estimates (MJ/kg DM) were 25.32 and 24.78 for DF; 14.38 and 13.36 for SRB.
4. In conclusion, the current data showed that broiler chickens utilised between 77% and 79% and 68% to 76% of the gross energy (GE) in DF and SRB, respectively, and this suggested a strong potential for these ingredients as dietary energy sources for broiler chickens.
Acknowledgments
The authors would like to thank Patricia Jaynes (Purdue University, West Lafayette, IN, USA) for her technical support during the study.
Disclosure statement
No potential conflict of interest was reported by the author(s).