Evaluation of Waste Mushroom Compost as a Feed Supplement and Its Effects on the Fat Metabolism and Antioxidant Capacity of Broilers

Abstract

Pennisetum purpureum Schum No. 2 waste mushroom compost (PWMC) is the main byproduct when cultivating Pleurotus eryngii. Due to the high mycelium levels in PWMC, it may have potential as a feed supplement for broilers. This study investigated the effects of PWMC supplementation on antioxidant capacity and adipose metabolism in broilers. In the study, 240 broilers were randomly allocated to one of four treatment groups: basal diet (control), 0.5%, 1%, or 2% PWMC supplementation. Each treatment group had 60 broilers, divided into three replicates. The results showed that supplementation with 0.5% PWMC decreased the feed conversion rate (FCR) from 1.36 to 1.28, compared to the control. Supplementation with 0.5% or 2% PWMC decreased glucose and triglyceride levels, compared to the control (p < 0.0001), the concentrations of adiponectin and oxytocin increased from 5948 to 5709, 11820, and 7938 ng/ mL; and 259 to 447, 873, and 963 pg/ mL, respectively. Toll-like receptor 4 was slightly increased in the 0.5% and 1% PWMC groups. Both interferon-γ (IFN-γ) and interleukin-1ß (IL-1ß) were significantly decreased, by about three to five times for IFN-γ (p < 0.0001) and 1.1 to 1.6 times for IL-1ß (p = 0.0002). All antioxidant-related mRNA, including nuclear factor erythroid 2-related factor 2 (Nrf-2) and superoxidase dismutase-1 (SOD-1), increased significantly following PWMC supplementation. Both claudin-1 and zonula occludens 1 increased, especially in the 2% PWMC group. Excitatory amino acid transporter 3 (EAAT3) significantly increased by about 5, 12, and 11 times in the 0.5%, 1%, and 2% PWMC groups. All adipolysis-related mRNA were induced in the PWMC treatment groups, further enhancing adipolysis. Overall, 0.5% PWMC supplementation was recommended due to its improving FCR, similar antioxidant capacity, and upregulated adipolysis.

Keywords: antioxidant; broilers; fat metabolism; mushroom compost.

Figure 1

Intestinal barrier (A) and nutrient absorption-related (B) mRNA expression in the ileum (ILE) for 35-day-old broilers. CLDN: Claudin-1; MUC-2: Mucin2; OCCN: Occludin; ZO-1: Zonula occludens 1; EAAT3: Excitatory amino acid transporter 3; FFAR2: Free fatty acid receptor 2; GLUT2: Glucose transporter 2; SGLT: Sodium-dependent glucose cotransporter 1; PEPT-1: Peptide transporter 1. ^a-c Means within the same rows without the same superscript letter are significantly different (p < 0.05).

Figure 2

Adipolysis- and adipogenesis-related mRNA expression in the liver (L) and adipocytes (F) of 35-day-old broilers. (A) Potassium channel tetramerization domain-containing 15 (KCTD-15), adiponectin, adipose triglyceride lipase (ATGL) and 5′-AMP-activated protein kinase catalytic subunit alpha-2 (AMPK-α2) mRNA expression in L; (B) fatty acid synthase (FAS), fatty acid binding protein 4 (FABP4), CCAAT-enhancer-binding proteins-alpha (CEBPα), and carnitine palmitoyltransferase 1 (CPT-1) mRNA expression in L; (C) adiponectin, KCTD-15, ATGL, and CPT-1 mRNA expression in F; (D) interleukin-6 (IL-6), FAS, FABP4, CEBPα, peroxisome proliferator-activated receptor gamma (PPAR-γ), and peroxisome proliferator-activated receptor alpha (PPAR-α). ^a,b Means within the same rows without the same superscript letter are significantly different (p < 0.05).

Figure 3

Inflammation- (A) and antioxidant-related (B) mRNA expression in the spleen (S) and liver (L) of 35-day-old broilers. TNF-α: Tumor necrosis factor alpha; TLR4: Toll-like receptor 4; NQO-1: NADPH dehydrogenase 1; NFκB: Nuclear factor kappa B p 65; iNOS: Inducible nitric oxide synthases; IFN-γ: Interferon-γ; IL-1ß: Interleukin-1ß; HO-1: Heme oxygenase-1; Nrf-2: Nuclear factor erythroid 2–related factor 2; GCLC: Glutamate-cysteine ligase catalytic; Gpx: glutathione peroxidase; SOD-1: Superoxide dismutase-1. ^a-d Means within the same rows without the same superscript letter are significantly different (p < 0.05).