This study aimed to investigate the effects of supplementing broiler chicken diets with an encapsulated product based on capsicum and other spice (black pepper and ginger) extracts on growth performance, nutrient digestibility, digestive enzyme activity and antioxidant response. To this end, 480 1-day-old male chicks were randomly assigned to two experimental treatments (12 pens/treatment; 20 birds/pen). Dietary treatments included a basal diet with no additives (CONTROL) and a basal diet supplemented with 250 ppm of the spice additive (SPICY; Lucta S.A., Spain). Supplementation of SPICY increased body weight (p < 0.05) compared with CONTROL at 7 d of age and improved (p < 0.01) ADG from 0 to 7 d of age. The apparent ileal digestibility of dry matter, gross energy and crude protein was higher (p < 0.05) in birds fed the SPICY diet compared with the CONTROL diet. Birds fed SPICY showed lower (p < 0.05) plasma catalase (CAT) activity, and the hepatic gene expression of CAT and Nrf2 was down-regulated (p < 0.05) compared with the CONTROL. In conclusion, the inclusion of 250 ppm of SPICY in broiler diets improved growth performance at 7 d of age and positively affected nutrient digestibility and antioxidant response.

The study examines the effect of replacing vitamin E (VE) with a liquid obtained from alpeorujo, an olive oil by-product rich in hydroxytyrosol (HT), as an antioxidant in broiler chicken feeds on the gene expression, lipid profile, and oxidation in the liver. There were five diets that differed only in the substitution of supplemental VE (0 to 40 mg/kg with differences of 10 mg/kg) by HT (30 to 0 mg/kg with differences of 7.5 mg/kg). A linear decrease (p < 0.05) in α-tocopherol concentration in the liver was observed with the replacement of VE by HT. There were no significant changes in triglyceride, cholesterol, or TBARS concentrations. The hepatic transcriptome showed 378 differentially expressed genes between broilers fed HT15 (20 mg/kg VE and 15 mg/kg HT) and HT0 (40 mg/kg VE) diets (p < 0.05 and fold change less or higher than 1.3). Significant changes in cell cycle, cell nucleus activity, neuroactivity, and necroptosis pathways and functions were observed. It is concluded that the olive oil by-product, rich in HT, could be used to spare VE as an antioxidant in broiler diets without affecting liver lipid and TBARS concentrations. The differential gene expression analysis showed a potential role of olive polyphenols in enhancing the chicken immune response.

The aim of this study was to test the in vivo antioxidant capacity in broilers of two phytogenic additives, one derived from olive pomace (OE) and an encapsulated product based on Capsicum sp., black pepper, and ginger (SPICY), in a challenge using oxidized lipids in the feed. A total of 720 one-day-old male Cobb 500 were allocated to 72 pens (8 treatments, 9 replicates, 10 birds/replicate). The treatments were arranged in a 2 × 2 × 2 factorial, the factors being: fat source (4% soybean oil or 4% peroxidized soybean oil); SPICY (0 or 250 ppm); and OE (0 or 3077 ppm). From 1 to 21 days (global period) no significant differences were observed on performance. Broilers fed peroxidized oil showed higher plasma ferric reducing antioxidant power (FRAP; P < 0.05) values and higher catalase (CAT) activity compared to those fed fresh oil except in those birds fed the OE which remained constant with both oil sources (P < 0.05 for the interaction). Broilers fed OE showed a significant lower CAT gene expression in the liver (P < 0.05). Moreover, the heat shock protein 70 (HSP70) gene expression was lower in birds fed fresh oil and OE compared to those fed fresh oil without OE but higher in birds fed peroxidized oil and OE compared to those fed peroxidized oil without OE (P < 0.05 for the interaction). By contrast, broilers fed SPICY upregulated CAT (P < 0.05) and downregulated HSP70 (P < 0.05) gene expression in the liver compared to those not supplemented with SPICY. In conclusion, feeding broilers with peroxidized soybean oil from 1 to 21 days of age did not affect the productive parameters. However, the presence of lipid peroxidation products in the feed triggered both non-enzymatic and enzymatic antioxidant responses to maintain the oxidant/antioxidant balance. In the case of birds fed the OE, the enzymatic antioxidant response was more attenuated, indicating a better control of oxidative stress, likely mediated by HSP70.

Recently, feeding a fungal mycelium from Pleurotus sapidus was found to reduce relative breast muscle weight of broilers. The present study tested the hypothesis that dietary inclusion of P. sapidus mycelium modulates the expression of genes involved in protein anabolic and protein catabolic pathways in breast muscle of broilers. The study included 72 male, 1-day-old Cobb 500 broilers which were randomly assigned to three groups fed three different diets containing either 0 (PSA-0), 25 (PSA-25) and 50 (PSA-50) g/kg diet P. sapidus mycelium in a three-phase feeding system for 35 days. Within the somatropic axis, the mRNA level of GHR was higher and that of IGF1R was lower in group PSA-25 than in group PSA-0 (P < 0.05). Within the mTOR signaling pathway, the mRNA level of S6K1 was higher in group PSA-25 than in group PSA-0 (P < 0.05). Within muscle growth-related genes, the mRNA level of MYOG was lower in groups PSA-25 and PSA-50 than in group PSA-0 (P < 0.05). The relative phosphorylation of proteins involved in protein anabolic pathways (S6K1, RPS6, eIF2a, AKT) did not differ across the three groups. The mRNA of most genes involved in molecular pathways of protein degradation and inhibition of protein synthesis, such as the GCN/eIF2a pathway, the ubiquitin-proteasome pathway, and the autophagy-lysosomal pathway, showed no differences across the three groups. Only the mRNA level of ATG9A was higher in group PSA-25 compared to group PSA-0 (P < 0.05). These observations suggest that a modulation of these signaling pathways is unlikely to explain the reduced relative breast muscle weight in broilers. Nevertheless, future studies are necessary to exclude an effect of feeding P. sapidus mycelium on other less prominent pathways affecting skeletal muscle mass.

Insect meals, which have emerged as a sustainable protein source in animal nutrition, are also rich in calcium and phosphorus and thus might be a valuable source for supplying these minerals in farm animals. The aim of the present study was to determine the apparent total tract digestibility (ATTD) of these minerals from commercially available partially defatted meals of Hermetia illucens (HI) larvae in growing pigs. According to a difference approach, twenty male growing pigs with an average body weight of around 30 kg were divided into five groups of four pigs each and fed either a basal diet or the basal diet blended with one of three HI meals or monocalcium phosphate (MCP, as a positive control) for 14 days. Calcium and phosphorus ATTD were determined, by using the indicator method with acid-insoluble ash as an indigestible marker. Calcium ATTD on average of the three HI meals was 71.2%, ranging from 60.7% to 77.0%, and the ATTD of phosphorus was 80.6%, with a range of 70.8% to 88.9%. Calcium and phosphorus ATTD of MCP were 95.0% and 82.8%, respectively. The study shows that calcium and phosphorus from HI meals exhibit a relatively high ATTD in pigs, similar to that observed from inorganic mineral sources. Thus, HI meal could substantially contribute to the supply of calcium and phosphorus to pigs, thus opening the possibility to conserve scarce minerals resources such as phosphate-rich rocks for pig nutrition.