Does lipidomic serum analysis help in the assessment of digestive efficiency in chickens?

The increasing cost of conventional feedstuffs used in poultry diets has bolstered interest in genetic selection for digestive efficiency (DE) to improve adaptation of birds to various alternative feedstuffs. However, DE measurement through apparent metabolizable energy corrected to zero nitrogen retention (AMEn) is time-consuming and constraining.  To simplify selection for DE, the potential of serum composition to predict AMEn was evaluated based on 40 birds from two broiler lines (D+ and D−) divergently selected on the fecal AMEn of a low digestible wheat-based diet. Differences in serum coloration were suspected between the two lines, a spectrophotometric analysis was thus carried out revealing a significant difference in adsorption between 430 nm and 516 nm corresponding to the signature of orange-red lipophilic pigments such as xanthophylls. To go deeper inside, the liposoluble fraction of the serum was explored for its lipidome by mass spectrometry. Discriminant analysis revealed that a pattern of 10 metabolites, including zeaxanthin/lutein, can explain 82% of the lipidomic differences between both lines. Colorimetry associated to lipidomics studies confirmed the relationship between the digestive efficiency and the serum composition which opens new perspectives for using it as a quick and easy proxy of digestive efficiency.