Energy digestibility in broilers and poult performance when fed palm or soybean oil with or without glyceryl monolaurate

Two trials were conducted to determine interactive effects between lipid source (palm oil, PO versus soybean oil, SO) and emulsifier addition (none versus glycerol monolaurate-GML) on apparent total tract digestibility (ATTD) of gross energy (GE) in broilers and growth performance in poults. In trial 1, 0.05 % GML addition had no impact on the ATTD of GE of SO but improved the ATTD of PO from 77.11 % to 88.21 % (interaction, P=0.03). Without GML addition, PO had a lower ATTD of GE (77.11 %) compared to SO (96.48 %) resulting in an AME of 7,259 versus 9,092 kcal/kg for PO and SO, respectively. In trial 2, the addition of 0.10 % GML reduced ADFI in poults fed diets containing 5 % PO compared to poults fed 0 or 0.05 % GML, while the addition of either 0.05 or 0.10 % GML reduced ADFI in poults fed diets containing 5 % SO compared to poults fed no GML (P=0.01). There was a similar response with ADG (P=0.01) where the addition of either 0.05 or 0.10 % GML reduced ADG in poults fed diets containing SO compared to poults fed no GML, while the addition of GML was largely without effect in poults fed diets containing PO. There was no interaction between lipid source and emulsifier addition on feed efficiency (P>0.10). Poults fed diets containing PO had a poorer feed efficiency compared to birds fed diets containing SO (P=0.01). The main effect of emulsifier was inconsistent in that poults fed the diets containing 0.10 % GML had the greatest feed efficiency compared to poults fed the diets containing 0.05 % GML, with poults fed diets containing no emulsifier being intermediate (P=0.10). In conclusion, addition of GML improved the ATTD of GE for PO but had no effect on the ATTD of GE for SO. This improvement in energy digestibility, did not however, translate to an improvement in poult performance. Broilers and poults fed diets containing SO had a greater feed efficiency compared to birds fed diets containing PO.