Carcass characteristics, meat quality, and functional compound deposition in sheep fed diets supplemented with Astragalus membranaceus by-product

This study was conducted to investigate the effects of dietary supplementation of Astragalus by-product (ABP) on carcass characteristics, internal organ development, meat quality, and functional compound deposition in sheep. Twenty-four Doper x Small Tail Han female lambs (6-7 months of age; 29.07 +/- 2.28 kg initial body weight) were randomly assigned to one of three treatments for a 47 d feeding period. Treatments consisted of dietary supplementation with 0 %, 10 %, or 15 % of ABP (dry matter basis). Bioactive compounds in ABP, liver, and muscle were analysed by the UHPLCQTOF-MS procedure. Dietary ABP supplementation did not affect (P > 0.05) carcass characteristics and internal organ development indicators except kidney weight which increased linearly (P = 0.019). ABP inclusion had no effect (P > 0.05) on moisture, crude protein (CP), and ash composition in the Longissimus dorsi (LD) muscle. Fat content in the LD muscle decreased (P < 0.001) in response to ABP supplementation. Lightness (L*) in the 10 % ABP group was significantly higher (P = 0.002) than that in the 15 % ABP group but did not differ from the control group. Dietary ABP linearly increased (P < 0.001) the redness (a*) of the LD musclebut decreased drip loss at 24 h and 48 h post-mortem (P < 0.05). Among the saturated fatty acids (SFA), undecylic acid (C11:0) showed a quadratic response to dietary ABP supplementation (P = 0.046). Aspartic acid in the LD muscle increased linearly (P = 0.011) in response to dietary ABP inclusion. From the crude UHPLC-MS chromatograms, a total of 20 chromatographic peaks showing different bioactive compounds were detected comprising 5 saponins, 10 flavonoids, 2 phenolic compounds, 1 dicarboxylic acid, and 2 alkaloids in the ABP samples. Among these, 15 compounds were found in the liver and 14 in the muscle of sheep. No significant differences were recorded in bioactive compound contents in both muscle and liver samples between the 10 % and 15 % ABP groups (P > 0.05). The results suggest that dietary inclusion of ABP can be used as a dietary option to develop novel functional meat that may confer certain health benefits to consumers. It provided a firm basis for the scientific exploration of the pharmacological efficacy of herbal medicine by-products.