Use of re-esterified oils, differing in their degree of saturation and molecular structure, in broiler chicken diets

Abstract

The aim of the present study was to investigate the potential use of re-esterified oils, differing in their degree of saturation and molecular structure, in comparison with their corresponding acid and native oils in broiler chicken diets. For this purpose, 144 one-d-old female broiler chickens were randomly distributed in 48 cages. Birds were fed a basal diet supplemented with 6% of native palm oil (PN), acid palm oil (PA), re-esterified palm oil low in mono- (MAG) and diacylglycerols (DAG) (PEL), re-esterified palm oil high in MAG and DAG (PEH), native soybean oil (SN), acid soybean oil (SA), re-esterified soybean oil low in MAG and DAG (SEL), or re-esterified soybean oil high in MAG and DAG (SEH), which resulted in a 2 × 4 factorial arrangement. Digestibility balances showed that the degree of saturation of fat generally exerted a greater impact than did the fat molecular structure. The dietary utilization of S sources was higher than that of P sources. However, the increased sn-2 saturated fatty acid (SFA) content of EL oils in the starter period and the increased MAG and DAG content of EH oils in the grower-finisher period yielded favorable effects on the SFA apparent absorption, especially in those birds fed re-esterified palm oils. The excreta acylglycerol and free fatty acid composition was mainly composed of free fatty acids, and their amount almost paralleled the results observed for SFA apparent absorption. For growth performance, birds fed S exhibited better feed conversion ratios and lower abdominal fat-pad weights than did those fed P. The fatty acid composition of abdominal adipose tissue was also mainly affected by the degree of saturation of dietary fat sources. We concluded that re-esterified oils, mainly from P sources, can be used in broiler chicken diets as alternative fat sources since they show similar or even higher total fatty acid apparent absorption than do their corresponding native and acid oils, with small changes in abdominal adipose tissue fatty acid composition.