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

Authors: Kerr, Brian; Pearce, Sarah; RISLEY, CHAD - Planet Bioscience Pte Ltd; WILSON, BROOKE - Iowa State University; KOLTES, DAWN - Iowa State University

Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/24/2024
Publication Date: 10/28/2024
Citation: Kerr, B.J., Pearce, S.C., Risley, C.R., Wilson, B.A., Koltes, D.A. 2024. Energy digestibility in broilers and poult performance when fed palm or soybean oil with or without glyceryl monolaurate. Poultry Science. 103(12). https://doi.org/10.1016/j.psj.2024.104442.
DOI: https://doi.org/10.1016/j.psj.2024.104442

Interpretive Summary: Energy is a costly component in poultry diets with lipids being an important part of meeting these needs because of their dense energy concentration. Two of the primary vegetable oils produced in the world are palm oil and soybean oil. Literature suggests that palm oil has a lower caloric value to poultry compared to soybean oil because of its greater degree of saturation. Emulsifiers have been shown to improve the caloric value of lipids to an animal due to their ability to improve the digestibility of lipids in an animal's intestine. Two trials were conducted to determine the ability of an emulsifier to improve the digestibility of palm oil or soybean oil and subsequently impact growth performance in young turkeys. The data show that the addition improved the digestibility of palm oil but had no effect on the digestibility of soybean oil. The improvement in digestibility did not, however, translate to an improvement in bird performance. Birds fed diets containing soybean oil grew more efficiently than birds fed diets containing palm oil. Data from this experiment provides a digestible energy value for both palm oil and soybean oil, and the ability of an emulsifier to improve a lipid's digestibility, when tested in growing broilers, thereby proving nutritionists at universities, feed companies, and poultry production facilities a basis from which to assess the economic value of palm oil and soybean oil in combination without or with an emulsifier.

Technical Abstract: Two trials were conducted to determine potential 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. The addition of GML 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. The addition of 0.10% GML reduced ADFI in poults fed diets containing 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 SO compared to poults fed no GML (interaction, P=0.01). There was a similar interaction 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.