Growth performance, gastrointestinal and digestibility responses in growing pigs when fed corn-soybean meal-based diets with corn DDGS treated with fiber degrading enzymes with or without liquid fermentation

Monomodular and multifunctional processive endocellulases: implications for swine nutrition and gut microbiome

Poor efficiency of dietary fibre utilization not only limits global pork production profit margin but also adversely affects utilization of various dietary nutrients. Poor efficiency of dietary nutrient utilization further leads to excessive excretion of swine manure nutrients and results in environmental impacts of emission of major greenhouse gases (GHG), odor, nitrate leaching and surface-water eutrophication. Emission of the major GHG from intensive pork production contributes to global warming and deteriorates heat stress to pigs in tropical and sub-tropical swine production. Exogenous fibre enzymes of various microbial cellulases, hemicellulases and pectinases have been well studied and used in swine production as the non-nutritive gut modifier feed enzyme additives in the past over two decades. These research efforts have aimed to improve growth performance, nutrient utilization, intestinal fermentation as well as gut physiology, microbiome and health via complementing the porcine gut symbiotic microbial fibrolytic activities towards dietary fibre degradation. The widely reported exogenous fibre enzymes include the singular use of respective cellulases, hemicellulases and pectinases as well as their multienzyme cocktails. The currently applied exogenous fibre enzymes are largely limited by their inconsistent in vivo efficacy likely due to their less defined enzyme stability and limited biochemical property. More recently characterized monomodular, multifunctional and processive endoglucanases have the potential to be more efficaciously used as the next-generation designer fibre biocatalysts. These newly emerging multifunctional and processive endoglucanases have the potential to unleash dietary fibre sugar constituents as metabolic fuels and prebiotics, to optimize gut microbiome, to maintain gut permeability and to enhance performance in pigs under a challenged environment as well as to parallelly unlock biomass to manufacture biofuels and biomaterials.

The effect of feeding fermented distillers' grains diet on the intestinal metabolic profile of Guanling crossbred cattle

Fermented distiller's grains (FDG)-based diets are nutritious and can improve the growth and intestinal immunity in livestock. However, there is limited research examining the effect of feeding FDG-based diets on changes in intestinal metabolites and related pathways in livestock. In this study, nine Guanling crossbred cattle (Guizhou Guanling Yellow cattle × Simmental cattle) were selected and randomly divided into a basal diet (BD) group and two experimental groups fed with FDG replacing 15% and 30% of the daily ration concentrates (FDG-Case A and FDG-Case B), respectively, with three cattle in each group. Fresh jejunum (J) and cecum (C) tissues were collected for metabolomic analysis. Differential metabolites and metabolic pathways were explored by means of univariate and multivariate statistical analysis. Compared with the J-BD group, 30 and 100 differential metabolites (VIP > 1, p < 0.05) were obtained in the J-FDG-Case A group and J-FDG-Case B group, respectively, and the J-FDG-Case B vs. J-FDG-Case A comparison revealed 63 significantly differential metabolites, which were mainly divided into superclasses including lipids and lipid-like molecules, organoheterocyclic compounds, and organic acids and derivatives. Compared with the C-BD, 3 and 26 differential metabolites (VIP > 1, p < 0.05) were found in the C-FDG-Case A group and C-FDG-Case B group, respectively, and the C-FDG-Case B vs. C-FDG-Case A comparison revealed 21 significantly different metabolites, which were also mainly divided into superclasses including lipids and lipid-like molecules, organoheterocyclic compounds, and organic acids and derivatives. A total of 40 metabolic pathways were identified, with a significance threshold set at p < 0.05. Among them, 2, 14, and 18 metabolic pathways were significantly enriched in the J-FDG-Case A vs. J-BD, J-FDG-Case B vs. J-BD, and J-FDG-Case B vs. J-FDG-Case A comparisons, respectively. Meanwhile, 1, 2, and 3 metabolic pathways were obtained in the C-FDG-Case A vs. C-BD, C-FDG-Case B vs. C-BD, and C-FDG-Case B vs. C-FDG-Case A comparisons, respectively. Furthermore, four significant metabolic pathways, namely insulin resistance, biosynthesis of unsaturated fatty acids, linoleic acid metabolism, and primary bile acid biosynthesis, were significantly enriched in Guanling crossbred cattle fed FDG diets. These results suggest that feeding FDG diets may promote the growth and intestinal immunity of Guanling crossbred cattle by regulating metabolic patterns of lipid compounds and related metabolic pathways. This study sheds light on the potential metabolic regulatory mechanisms of FDG diets and offers some references for their use in livestock feed.

Physiochemical characterization and energy contents of novel corn ethanol co-product streams, with and without inclusion of a multi-carbohydrase enzyme blend, for growing pigs

The physiochemical properties and digestible, metabolizable, and predicted net energy contents in high-protein dried distillers’ grain (HiPro) were determined to assess the nutritive value for growing pigs. Twelve Yorkshire × Landrace barrows (initial body weight 25 ± 0.5 kg) were used in a partially replicated Latin square design over three periods (n = 7 or 8) and assigned to one of five experimental diets. In each period, pigs were adapted to diets for 7 d, followed by 5 d of total urine collection and fecal grab sampling. The experimental diets included a corn- and soybean-meal-based diet (CON) or diets containing dried distillers’ grains with solubles (DDGS) or HiPro to partially replace corn and soybean meal, without or with (i.e., DDGS+ and Hipro+) a multi-carbohydrase enzyme blend (0.05% inclusion). The HiPro ingredient contained half as much starch (2.6% vs. 5.2%; DM-basis), 20% more protein (32.5% vs. 27.1%), and had 14% greater water binding capacity versus DDGS. The digestible, metabolizable, and predicted net energy contents of the HiPro co-product were greater than DDGS for growing pigs (P < 0.05), but fibre-degrading enzymes were ineffective at improving energy values. The greater (available) energy and protein contents of HiPro make it a promising feed ingredient for inclusion in swine diets.

Fiber degrading enzymes increased monosaccharides release and fermentation in corn distillers dried grains with solubles and wheat middlings steeped without or with protease

Treating fibrous feed ingredients with exogenous feed enzymes may improve their utilization in monogastric animals. An in vitro study was conducted to determine the effects of steeping corn distillers dried grains with solubles (DDGS) or wheat middlings (WM) with exogenous feed enzymes. Four treatments were arranged as follows: 1) co-product steeped with water (CON), 2) CON plus 0.5-g fiber degrading enzymes (FDE), 3) CON plus 0.5-g protease (PRO), and 4) CON plus 0.5-g FDE and 0.5 g PRO (FDEPRO). The FDE contained about 62,000, 37,000, and 8,000 U/g of xylanase, cellulase, and β-glucanase, respectively, whereas activities in PRO amounted to 2,500,000, 1,300,000, and 800,000 U/g of acid, alkaline, and neutral proteases, respectively. Briefly, 50 g of DDGS or WM samples (n = 8) were mixed with 500-mL water with or without enzymes and steeped for 0 to 72 h at 37 °C with continuous agitation. The pH, concentration of monosaccharides, and organic acids in the supernatant and apparent disappearance (AD) of fiber in solids were measured at 0, 12, 24, 48, and 72 h. There was treatment and time interaction (P < 0.005) on monosaccharides concentration. At 12 h, arabinose and glucose concentrations were similar (P > 0.05) between FDE and FDEPRO but higher (P = 0.002) than for CON in DDGS. For WM, FDE, and FDEPRO had higher (P < 0.001) xylose concentration than CON and PRO, whereas glucose concentration was higher (P < 0.001) for enzymes than CON at 12 h. However, FDEPRO had higher (P < 0.001) xylose concentration than CON, whereas xylose concentration for FDE and PRO was intermediate at 24 h. There was an interaction (P < 0.05) between treatment and time effect on lactic acid concentration in DDGS and WM (P < 0.005), and acetic acid concentration in WM (P < 0.001). In general, monosaccharide concentration was higher between 12 and 24 h and decreased after 48 h, whereas the pH decreased, and concentration of organic acids increased continuously over time (P < 0.05). The AD of NDF and ADF in DDGS was greater (P = 0.001) for FDE and FDEPRO than CON and PRO at 72 h. In WM, enzymes increased (P = 0.007) AD of NDF relative to CON at 72 h. Nonetheless, greater (P < 0.05) AD of fiber was observed between 48 and 72 h. In conclusion, although there were differences in responses among co-products, fiber degrading enzymes increased release of fermentable monosaccharides from co-products at 12 to 24 h of steeping and these effects were not extended with the addition of protease.

Nutritive value of corn distiller's dried grains with solubles steeped without or with exogenous feed enzymes for 24 h and fed to growing pigs

The use of corn distillers dried grains with solubles (DDGS) in pig diets is limited due to high fiber concentration. Steeping with exogenous fiber-degrading enzymes (FDE) may improve their feeding value. We evaluated apparent ileal digestibility (AID), standardized ileal digestibility (SID), and apparent total tract digestibility (ATTD) of components and DE content in DDGS steeped without or with two commercial FDE (A and B). Mixture of 350 g of DDGS, FDE (none for control), and 1.5 liters of water was incubated at 40 °C for 24 h with 15 min agitation every 40 min. FDE-A (pure combination) supplied 5,500 U of xylanase and 1,050 U of β-glucanase while FDE-B (multienzyme complex) supplied 1,200 U of xylanase, 150 U of β-glucanase, 500 U of cellulase, and 5,000 U of protease per kg of DDGS plus side activities. Samples were taken at time 0, 4, 8, and 24 h for organic acids and pH measurements. Three semi-purified corn starch-based diets were formulated with steeped DDGS as the sole source of CP. The basal mixture contained 0.2% TiO2 as indigestible marker. Six ileal-cannulated pigs (20 kg BW) were fed the three diets in a replicated 3 × 3 Latin square design to give six replicates per diet. Pigs were fed at 2.8× maintenance energy requirements and had free access to water. In each period, pigs were adjusted to diets for 7 d followed by 2 d for grab fecal and 2 d of 8 h continuous ileal digesta collection. There were no (P > 0.05) treatment and sampling time interaction or treatment effects on pH and lactic concentration. Lactic and acetic acids increased, and pH decreased (P < 0.05) over time points. The AID of CP, NDF, and crude fat and SID of CP were not different (P > 0.05) among treatments. Steeping DDGS with FDE-A had lower (P = 0.01) ATTD of NDF than control but higher (P = 0.001) ATTD of crude fat compared with the control or DDGS steeped with FDE-B. Values for DE content in steeped DDGS were not different (P > 0.05) and amounted to 4,095, 4,039, and 3,974 kcal/kg DM for the control, FDE-A, and FDE-B, respectively. In conclusion, under conditions of the study, steeping DDGS with exogenous enzymes did not improve fiber and energy digestibility.