This study investigates the effects of two-stage fermented feather meal-soybean meal product (TSFP) on growth performance, blood characteristics, and immunity of finishing pigs. Firstly, feather meal-soybean meal is subjected to aerobic fermentation with Bacillus subtilis var. natto N21, B. subtilis Da2 and Da15, B. amyloliquefaciens Da6, Da16 for two days, and anaerobic fermentation with B. coagulans L12 for three days. Then, the fermented product is air-dried into an end product—TSFP. Eighty hybrid pigs (Duroc x KHAPS) with equal numbers of both sexes are randomly assigned into 3% fish meal, 0%, 2.5%, or 5.0% TSFP groups with five replicates per group. Our results show that the average daily feed intake and feed conversion rate of TSFP groups are significantly better than the other groups at 0–3 weeks (p < 0.05). The 5% TSFP group significantly increased HDL-C in the blood (p < 0.05), and decreased LDL-C and blood urea nitrogen content (p < 0.05). The lipopolysaccharide (LPS) and concanavalin A (ConA) in 5% TSFP group and interferon-γ (IFN-γ) content in 2.5% and 5% TSFP groups are significantly higher than the other groups (p < 0.05). The phagocytic oxygen burst capacity and serum IgA content of the 5% TSFP group are significantly higher than those of the fishmeal group (p < 0.05). The CD3, CD4, and CD4 + CD8 + T cells subsets in 2.5% and 5% TSFP groups are significantly higher than the control group (p < 0.05). In conclusion, TSFP has a positive effect on the growth performance and immunity of finishing pigs with the best performance on 5% TSFP.

This study is aimed to select optimum keratin degradation ability from Bacillus strains for feather meal-soybean meal fermentation, and favorably water content for the strain during fermentation of feather meal-soybean meal, and finally investigate the effects of the fermented feather meal-soybean meal product (FFSMP) on growth performance, carcass trait, clinical blood biochemistry, and intestinal morphology of broilers. Thirty-six bacteria strains from soil, sewage pool, and feather waste were screened and selected Bacillus subtilis var. natto N21 (N21), B. subtilis CU14 (CU14), and B. amyloliquefaciens CU33 (CU33) with better keratinase activity and feather-degrading rate. The result of trial 1 showed that the FFSMP produced by CU33 had the optimum physiochemical characterizations, amino acid composition and feeding performance for broilers. Hence the effects of water content (45, 50, 55, and 60%) on FFMSP fermentation of CU33 were investigated in trial 2. Result showed that pH value, counts of Bacillus-like bacteria, γ-PGA, viscosity, surfactin yield and odor all significantly increased according to the water content (P < 0.05). The protease activity reached significantly highest in the 55% and 60% water content groups (P < 0.01). The broilers performance of 55% and 60% water content group were significantly higher than control group (P < 0.05) in weight gain (WG), feed intake (b) at 0 to 21-d-old and the WG, feed conversion ratio (FCR), and production efficiency factor at 0 to 35-d-old, and could reach the similar growth performance as fish meal group (P > 0.05). The fermentation groups significantly decreased urea nitrogen (P < 0.05) and increased creatinine (P < 0.05) in the blood. The fermentation groups also significantly decreased the crypt depth in the duodenum (P < 0.05) and increased villus height to crypt depth ratio of the duodenum (P < 0.05). In conclusion, CU33 shows the best degradation rate for feather and keratinase activity, and the FFSMP with a water content of 50% to 60% during fermentation is suggested. Diets supplemented with 5% FFSMP can promote the growth of broilers by improving the morphology of the duodenum and achieve the feeding effect of high-quality fish meal.

This study aimed to select Bacillus spp. for surfactin production by solid-state fermentation and to investigate the physiochemical characterizations of the fermented product (FP) and its effect on growth performance, carcass trait, intestinal morphology, and clinical blood biochemistry of broilers. Accordingly, the correlations between the functional components of FP and the growth performance of broilers are elucidated. Four hundred eighty 1-day-old Ross 308 broiler chicks were randomly assigned to dietary supplementation of 2.5% fish meal, 2.5% unfermented product, or 2.5% FP produced by Bacillus subtilis LYS1 (LYS1), Bacillus amyloliquefaciens Da16, B. subtilis Lo6 (Lo6), B. subtilis NSN7, B. subtilis subsp. natto N21, or B. subtilis N12. Each treatment had 6 replicates. The experimental period was 5 wk. Results showed that the Lo6 showed the highest protease activity among all fermented groups. The LYS1 showed the highest surfactin yields (10.69 mg/g) among all fermented groups (P < 0.05). The weight gain (WG), feed conversion ratio (FCR), and production efficiency factor (PEF) of LYS1 group were significantly better than unfermented group at 0 to 3 and 0 to 5-wk-old (P < 0.05). The Bacillus-like counts and surfactin content of FP were moderately correlated to WG (0.7 > r > 0.3), FCR (-0.3 > r > -0.7), and PEF (0.7 > r > 0.3) at 0 to 3 and 0 to 5-wk-old (P < 0.05). The protease activity of FP was moderately correlated to WG (0.7 > r > 0.3), FCR (-0.3 > r > -0.7), and PEF (0.7 > r > 0.3) at 0 to 3-wk-old (P < 0.05). The villus height to crypt depth ratio in duodenum and jejunum of fish meal group and LYS1 group were higher than unfermented group (P < 0.05). In conclusion, LYS1 shows the highest surfactin yields. Diets supplemented with 2.5% LYS1 FP can improve the growth performance and the development of intestinal villi in broilers. Moreover, this study proves that the surfactin content, Bacillus-like counts, and protease activity of FP show a correlation to the growth performance of broilers.

This study aimed to investigate the physiochemical characterizations of the fermented product (FP) produced by the high-yield surfactin strain Bacillus subtilis LYS1 (LYS1), as well as its effects on growth performance, carcass traits, intestinal morphology, tibial bone characteristics, and clinical blood biochemistry in broilers. Accordingly, the optimal supplementation of FP for improving growth performance, intestinal villi development, and tibial bone strength in broilers was elucidated using a broken-line quadratic (BLQ) ascending model. Three hundred and sixty 0-day-old Ross 308 broiler chicks, with equal numbers of both sexes, were randomly assigned to dietary supplementation of 2.5% fish meal or 0, 1, 1.5, 2, or 2.5% FP. Each treatment had six replicates, and the experimental period was 5 wk. The LYS1 count, surfactin content, and surfactin composition of the FP were 9.1 log CFU/g, 11.23 mg/g, and C₁₂ to C₁₈, respectively. The FP-supplemented groups improved feed intake, weight gain (WG), and production efficiency factor at 0 to 5 weeks old (p < 0.05) compared with the 0% group. The villus height/crypt depth (V/C) in the jejunum and ileum of the FP-supplemented groups was higher than in the 0% group (p < 0.05). The tibiotarsal index, Ca, and P in the tibia showed a linear effect with increased FP supplementation (p < 0.05). Moreover, the tibiotarsus weight/length index (TWLI) showed a quadratic effect with increased FP supplementation (p < 0.05). The optimal supplementation of FP for WG, V/C in the jejunum and ileum, and TWLI was 1.8, 1.9, and 1.6%, respectively. In conclusion, dietary supplementation with 1 to 2.5% LYS1 FP in broilers can improve their growth performance and the development of intestinal villi. Moreover, 1.9% is the optimal supplementation of LYS1 FP in the diet, based on the fitting results obtained with the BLQ model.

The keratinase-producing microbes can readily change the feather waste into more bioavailable peptides and amino acids. This study aimed to improve two-stage fermented feather meal-soybean meal product (TSFP) quality with five selected Bacillus strains and Saccharomyces cerevisiae Y10, as well as investigate the effects of TSFP on growth performance, blood biochemistry, and immunity of nursery pigs. In trial 1, 100 hybrid piglets (Duroc x KHAPS) were randomly assigned to dietary supplementation of 5% fish meal or 5% TSFP prepared with 0, 32, 40, or 48 h in the first-stage fermentation. The results showed that the body weight (BW), average daily gain (ADG), and feed conversion ratio (FCR) of fermented groups were significantly better than the unfermented group (p < 0.05) at weeks 0 to 3 and 0 to 5. The ADG of 32-hr and 48-hr TSFP groups were better than the unfermented group (p < 0.05) at weeks 3 to 5. In trial 2, 80 hybrid piglets (Duroc × KHAPS) were randomly assigned into 5% fish meal or different supplementation levels of TSFP (32-hr first-stage fermented time) at 0, 2.5, or 5%. The 5% TSFP group had better BW, ADG, FCR, and PEF than the 0% group (p < 0.05) at weeks 0 to 5. Furthermore, the ex vivo mitogen-induced lymphoblastogenesis, the interferon-γ production, the oxidative burst activity, and the IgG production of the 5% TSFP group were higher than the fish meal group (p < 0.05). In conclusion, the first-stage fermentation time can be shortened from 48 h to 32 h using selected Bacillus strains in TSFP production when supplemented at 5% of the diet for nursery pigs shows the best growth performance and immunity.

This study aimed to investigate the effects of a two-stage fermented feather meal-soybean meal product (TSFP) on the performance, clinical blood biochemistry, and immunity of sows and piglets. TSFP was fermented by Saccharomyces cerevisiae Y10 for three days in the second stage, which showed similar results to the five-day fermentation of B. coagulans (p > 0.05). Fifty hybrid sows (Duroc × KHAPS black pig) were randomly assigned into dietary supplementation groups of 2% fish meal or different levels of TSFP at 0%, 1%, 2%, or 3%. The results showed that body weight gain and feed conversion ratio of 2% and 3% TSFP groups were better than the control group and fish meal group during the gestation period (d 80–114) (p < 0.05). During the lactation period, the 3% TSFP group showed the best weaning litter weight (p < 0.05). In sows, interferon-γ and immunoglobulin G (IgG) of 2% and 3% TSFP groups were higher than the control group and fish meal group (p < 0.05). In piglets, in groups of 2% and 3% TSFP blood urea decreased (p < 0.05). The IgG of fermented groups was superior to the control group (p < 0.05). The oxidative burst of phagocytes in the 3% TSFP was higher than those of the control and fish meal groups (p < 0.05). In conclusion, TSFP supplementation exhibits the advantages of performance and immunity of lactating sows and piglets. Furthermore, adding 3% TSFP in the feed showed the best performance.