Impacts of feeding different lipid sources on serum biochemical indices, dietary fatty acid metabolism, raw foie gras quality characteristics and gene expression related to fat deposition in the Landes goose

This study investigated the impacts of feeding different lipid sources on raw goose foie gras quality characteristics. A total of 1080 Landes geese at 60 d old with body weight 3.87 ± 0.13 kg (mean ± SEM) were randomly assigned to three treatments: a corn meal-based diet with 25 g/kg soybean oil, with 25 g/kg goose fat, or with 15 g/kg goose fat plus 10 g/kg soybean oil (MIX). Each treatment was split into 15 pens with 24 geese in each pen. The experiment lasted 30 d, and the daily consumption of the overfeeding diets was recorded. Results showed that geese from MIX had a higher feed consumption (<i>P</i> < 0.001), raw foie gras weight (<i>P</i> = 0.025) as well as serum concentration of high-density lipoprotein-cholesterol (<i>P</i> = 0.012) compared with other treatments. The raw foie gras produced with MIX also had higher contents of monounsaturated fatty acids (<i>P</i> = 0.039), essential amino acids (<i>P</i> < 0.001) and non-essential amino acids (<i>P</i> < 0.001) compared with those of geese fed soybean oil. In addition, MIX promoted the daily retention of dietary C14:0 (<i>P</i> = 0.018), C16:0 (<i>P</i> = 0.045), C18:0 (<i>P</i> = 0.023), C18:1n9c (<i>P</i> = 0.025), C18:2n6c (<i>P</i> = 0.029) and C18:3n6 (<i>P</i> = 0.032). Furthermore, MIX upregulated the relative gene expression of stearoyl-CoA desaturase (<i>P</i> = 0.002), fatty acid synthetase (<i>P</i> < 0.001), acyl-CoA: cholesterol acyltransferase 2 (<i>P</i> < 0.001) and elongation of very long-chain fatty acids protein 1 (<i>P</i> < 0.001) in the fattened liver. In conclusion, including 15 g/kg goose fat mixed with 10 g/kg soybean oil in diets was beneficial to improve the quality characteristics of raw Landes goose foie gras.