Use of re-esterified palm oils, differing in their acylglycerol structure, in weaning-piglet diets

Abstract

Re-esterified oils are new fat sources obtained from chemical esterification of acid oils with glycerol (both economically interesting by-products from oil refining and biodiesel industries, respectively). The different fatty acid (FA) positional distribution and acylglycerol composition of re-esterified oils may enhance the apparent absorption of saturated fatty acids (SFA) and, thus, their overall nutritive value. The aim of the present study was to investigate the potential use of re-esterified palm oils, in comparison with their corresponding acid and native oils, and also with an unsaturated fat source in weaning-piglet diets. The parameters assessed were: FA apparent absorption, acylglycerol and free fatty acid (FFA) composition of feces, and growth performance. One-hundred and twenty weaning piglets (average weight of 8.50 ± 1.778 kg) were blocked by initial BW (six blocks) and randomly assigned to five dietary treatments, resulting in four piglets per pen and six replicates per treatment. Dietary treatments were a basal diet supplemented with 10% (as-fed basis) of native soybean oil (SN), native palm oil (PN), acid palm oil (PA), re-esterified palm oil low in mono- (MAG) and diacylglycerols (DAG) (PEL), or re-esterified palm oil high in MAG and DAG (PEH). Results from the digestibility balance showed that SN reached the greatest total FA apparent absorption, and statistically different from PN, PA and PEL ( P < 0.05). There were no statistical differences among palm-oil sources ( P > 0.05), but PEH achieved the greatest total FA apparent absorption. Animals fed PEL, despite the fact that PEL oil contained more sn-2 SFA, did not show an improved absorption of SFA ( P > 0.05). Animals fed PA and PN showed similar apparent absorption coefficients ( P > 0.05), despite the high FFA content of PA oil. The acylglycerol and FFA composition of feces was mainly composed of FFA. There were no significant differences in growth performance ( P > 0.05). Results of the present study suggest that, despite the different acylglycerol structure of re-esterified oils, there were no significant differences in digestibility or performance with respect to their corresponding PN and PA oils in weaning-piglet diets.