The influence of beta-mannan and xylose on energy metabolism in the pig

Feed ingredient economics are pushing pork producers to increase the use of higher-fiber coproducts while maintaining high production and efficiency goals. To do this, nutritionists utilize beta-mannanase and xylanase enzymes. It is important to evaluate the metabolic impacts of beta-mannan and xylose to accurately estimate enzyme effects on dietary energy availability. Therefore, the overall objective of the work presented in this dissertation was to evaluate the influence of beta-mannan and xylose on energy metabolism in the pig. Beta-mannanase is added to swine diets with the objective of inhibiting an energetically-expensive beta-mannan-induced immune response; however, this rationale was not supported by the experiments presented in Chapters 2 and 3. Research presented in Chapter 2 showed that beta-mannanase did not affect immune status, nutrient digestibility, growth performance, energy balance, or maintenance energy requirements (MEm) of young pigs. These conclusions were further supported by a nursery growth trial that tested the interactions of dietary beta-mannan concentration and beta-mannanase inclusion, presented in Chapter 3. In Chapter 2 it was also found that a lipopolysaccharide-induced innate immune challenge elevated pigs’ MEm by 23.3% which lipid deposition by 30.2% and lead to an 18.3% decrease in ADG during the immune challenge. These novel data directly related decreased ADG to increased MEm independent of changes in feed intake in immune-challenged pigs. Xylose metabolism in the pig was also evaluated and presented in Chapter 4. An improved understanding of xylose metabolism in the pig and its energetic value is essential for effective xylanase utilization. Our data showed that the pig can utilize xylose but does so less efficiently as more xylose is consumed; and only 40 – 60% of xylose was retained. Furthermore, pigs can adapt over time to improve xylose utilization. By applying metabolomic approaches, urinary metabolites of xylose were identified and quantified. This information facilitated construction of a comprehensive pathway for xylose metabolism in the pig. Overall, research presented in this dissertation improved our understanding of how beta-mannanase and xylanase impact pig energy metabolism. This research also furthered the understanding of how immune activation repartitions energy and increases maintenance energy requirements

A STUDY OF THE UNITED STATES INTELLIGENCE COMMUNITY’S ROLE IN INTERNATIONAL HUMANITARIAN ASSISTANCE AND DISASTER RELIEF

The topic of research is an analysis of the intelligence community’s (IC) roles and responsibilities during catastrophic events in overseas locations. The research has involved gathering and studying journal and news articles about IC involvement in disaster relief and national security protection during disastrous events. A comparative analysis was done from the gathered information and examination of two cases -the 2010 Pakistan Floods and the July 7, 2005 London Bombings. Analysis of these events led us to conclude that the IC’s function in HA/DR operations was in line with the IC’s primary function. Further, it played an important role in mitigating suffering while countering potential human threats in the midst of these chaotic events. Finally, we conclude that the IC’s involvement in natural disasters is an effective combination of support to disaster-relief efforts and a furthering of national-security interests because in a man-made disaster, relief and policy efforts are intertwined

Immune System Stimulation Increases Nursery Pig Maintenance Energy Requirements

The objective of this experiment was to determine how immune stimulation and -mannanase supplementation affect nursery pig maintenance energy requirements through changes in serum immune parameters, nutrient digestibility, growth performance, nitrogen and energy balance. While it’s well-known that disease negatively impacts pig performance, the specifics of how immune stimulation affects metabolism and causes these negative effects arenot clearly understood. This experiment demonstrated that an immune response to E. coliLPSdid not impact nitrogen balance or nutrient digestibility, but increased total heat production (19%) and maintenance energy requirements (23%), resulting in decreased lipid deposition (-27%) and ADG (-26%). This is the first experiment in pigs to show a direct relationship between immune stimulation, increased energy use for maintenance purposes, and decreased energy partitioned toward growth. Understanding how immune challenges change energy metabolism in the pig may inform more effective feeding strategies to mitigate negative impacts of disease

Sickness eats into pigs’ energy consumption

Health challenges impair pigs\u27 production efficiency and profitability

Evaluation of the effect of β-mannanase supplementation and mannans on nursery pig growth performance and serum acute-phase protein concentrations

The objective was to evaluate the effects of dietary mannan and β-mannanase supplementation on growth performance and serum acute phase proteins in nursery pigs. Pigs (n = 480) were blocked by initial BW (6.6 ± 0.4 kg) and 12 pens per treatment were randomly assigned to 1 of 4 treatments in a 2 x 2 factorial arrangement for 28 d. Two levels of dietary mannan (0.4% vs 2.8%) were offered with and without 0.05% endo-1,4-β-mannanase. Serum was collected (1 pig/pen) for haptoglobin and C-reactive protein (CRP) analysis on d 0 and d 28. There were no significant interactions between mannan level or β-mannanase supplementation. High mannan decreased ADG (P = 0.027) and ADFI (P = 0.024) compared to low mannan diets with no effect of β-mannanase (P \u3e 0.10). Haptoglobin and CRP were not affected by mannan level or β- mannanase supplementation (P ≥ 0.160). Therefore, dietary β-mannans as high as 2.8% did not induce a systemic innate immune response. Thus the levels of β-mannan found in practical diets (\u3c 2%) are unlikely to induce an immune response, so supplementation with β-mannanase to avoid this response is not warranted

Lipopolysaccharide immune stimulation but not β-mannanase supplementation affects maintenance energy requirements in young weaned pigs

Background: Pathogen or diet-induced immune activation can partition energy and nutrients away from growth, but clear relationships between immune responses and the direction and magnitude of energy partitioning responses have yet to be elucidated. The objectives were to determine how β-mannanase supplementation and lipopolysaccharide (LPS) immune stimulation affect maintenance energy requirements (MEm) and to characterize immune parameters, digestibility, growth performance, and energy balance. Methods: In a randomized complete block design, 30 young weaned pigs were assigned to either the control treatment (CON; basal corn, soybean meal and soybean hulls diet), the enzyme treatment (ENZ; basal diet + 0.056% β-mannanase), or the immune system stimulation treatment (ISS; basal diet + 0.056% β-mannanase, challenged with repeated increasing doses of Escherichia coli LPS). The experiment consisted of a 10-d adaptation period, 5-d digestibility and nitrogen balance measurement, 22 h of heat production (HP) measurements, and 12 h of fasting HP measurements in indirect calorimetry chambers. The immune challenge consisted of 4 injections of either LPS (ISS) or sterile saline (CON and ENZ), one every 48 h beginning on d 10. Blood was collected pre- and post-challenge for complete blood counts with differential, haptoglobin and mannan binding lectin, 12 cytokines, and glucose and insulin concentrations. Results: Beta-mannanase supplementation did not affect immune status, nutrient digestibility, growth performance, energy balance, or MEm. The ISS treatment induced fever, elevated proinflammatory cytokines and decreased leukocyte concentrations (P \u3c 0.05). The ISS treatment did not impact nitrogen balance or nutrient digestibility (P \u3e 0.10), but increased total HP (21%) and MEm (23%), resulting in decreased lipid deposition (−30%) and average daily gain (−18%) (P \u3c 0.05). Conclusions: This experiment provides novel data on β-mannanase supplementation effects on immune parameters and energy balance in pigs and is the first to directly relate decreased ADG to increased MEm independent of changes in feed intake in immune challenged pigs. Immune stimulation increased energy partitioning to the immune system by 23% which limited lipid deposition and weight gain. Understanding energy and nutrient partitioning in immune-stressed pigs may provide insight into more effective feeding and management strategies

Xylanase increased the energetic contribution of fiber and improved the oxidative status, gut barrier integrity, and growth performance of growing pigs fed insoluble corn-based fiber

The experimental objective was to investigate the impact of xylanase on the bioavailability of energy, oxidative status, and gut function of growing pigs fed a diet high in insoluble fiber and given a longer adaptation time than typically reported. Three replicates of 20 gilts with an initial body weight (BW) of 25.43 ± 0.88 kg were blocked by BW, individually housed, and randomly assigned to one of four dietary treatments: a low-fiber control (LF) with 7.5% neutral detergent fiber (NDF), a 30% corn bran without solubles high-fiber control (HF; 21.9% NDF), HF + 100 mg/kg xylanase (HF + XY; Econase XT 25P), and HF + 50 mg/kg arabinoxylan-oligosaccharide (HF + AX). Gilts were fed ad libitum for 36 d across two dietary phases. Pigs and feeders were weighed on days 0, 14, 27, and 36. On day 36, pigs were housed in metabolism crates for a 10-d period, limit fed (80% of average ad libitum intake), and feces and urine were collected the last 72 h to determine the digestible energy (DE) and metabolizable energy (ME). On day 46, serum and ileal and colonic tissue were collected. Data were analyzed as a linear mixed model with block and replication as random effects, and treatment, time, and treatment × time as fixed effects. There was a significant treatment × time interaction for BW, average daily gain (ADG), and gain to feed (G:F; P \u3c 0.001). By design, BW at day 0 did not differ; at day 14, pigs fed LF were 3.5% heavier, and pigs fed HF + XY, when compared with HF, were 4% and 4.2% heavier at days 27 and 36, respectively (P \u3c 0.001). From day 14 to 27 and day 27 to 36, when compared with HF, HF + XY improved ADG by 12.4% and 10.7% and G:F by 13.8% and 8.8%, respectively (P \u3c 0.05). Compared with LF, HF decreased DE and ME by 0.51 and 0.42 Mcal/kg, respectively, but xylanase partially mitigated that effect by increasing DE and ME by 0.15 and 0.12 Mcal/kg, over HF, respectively (P \u3c 0.05). Pigs fed HF + XY had increased total antioxidant capacity in the serum and ileum (P \u3c 0.05) and tended to have less circulating malondialdehyde (P = 0.098). Pigs fed LF had increased ileal villus height, and HF + XY and HF + AX had shallower intestinal crypts (P \u3c 0.001). Pigs fed HF + XY had increased ileal messenger ribonucleic acid abundance of claudin 4 and occludin (P \u3c 0.05). Xylanase, but not AX, improved the growth performance of pigs fed insoluble corn-based fiber. This was likely a result of the observed increase in ME, improved antioxidant capacity, and enhanced gut barrier integrity, but it may require increased adaptation time to elicit this response

Unveiling the influence of adaptation time on xylanase and arabinoxylan-oligosaccharide efficacy: a study on nutrient digestibility, viscosity, and scanning electron microscopy in the small and large intestine of growing pigs fed insoluble fiber

The experiment objective was to evaluate the impact of xylanase over time on viscosity and digestibility in growing pigs fed corn-based fiber. Twenty gilts with an initial body weight of 30.6 ± 0.2 kg (n = 5 per dietary treatment) were fitted with t-cannulae in the medial jejunum and terminal ileum, housed individually, and randomly assigned to one of four dietary treatments: low-fiber control (LF) with 10.4% total dietary fiber (TDF), 30% corn bran high-fiber control (HF; 26.4% TDF), HF + 100 mg xylanase/kg (XY; Econase XT 25P; AB Vista, Marlborough, UK), and HF + 50 mg arabinoxylan-oligosaccharide/kg (AX). Gilts were limit fed for three 17 d periods (P1, P2, P3); each included 5 d adaptation, 2 d fecal collection, 3 d ileal collection, 3 d jejunal collection, and 4 d related rate of passage study. Data were analyzed as repeated measures using a linear mixed model with surgery date as a random effect, and dietary treatment, period, and their interaction as fixed effects. Jejunal and ileal digesta viscosity did not differ among dietary treatments or periods (P > 0.10). There was a dietary treatment × period interaction for the apparent jejunal digestibility (AJD) of dry matter (DM), gross energy (GE), insoluble dietary fiber (IDF), neutral detergent fiber (NDF), total arabinoxylan (T-AX), total non-starch polysaccharide (T-NSP), and TDF (P 0.05). In P1, LF had the greatest AJD of DM (15.5%), and relative to HF and AX, XY decreased it (9.3%, 10.1 %, and 6.3%, respectively). In P2, the AJD of DM in XY was greater than HF (11.7% vs. 9.1%) but did not differ from AX (10.5%). Relative to HF, in P3, XY increased AJD of DM (11.7 vs 15.3%), and AX decreased it (7.2%). For the AJD of NDF, AX performed intermediately in P1; in P2, relative to HF, XY, and AX increased the AJD of NDF (8.4%, 13.1%, and 11.7%, respectively), and in P3, XY, and LF did not differ (13.6 vs. 14.4%). A similar response was observed for the AJD of IDF and TDF, except for XY having the greatest AJD of IDF, T-AX, T-NSP, and TDF in P3 (P This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited

Dietary intake of xylose impacts the transcriptome and proteome of tissues involved in xylose metabolism in swine

Xylose is a primary component of arabinoxylan in swine diets. As arabinoxylan is a significant component of fiber, and fiber is generally rising in practical pig diets globally, the study of arabinoxylan and xylose is of increasing interest. However, the mechanisms by which free xylose may be absorbed and the pathways impacted by xylose have yet to be elucidated in pigs. The objective of this study was to determine the impact of xylose supplementation on gene expression and protein abundance in jejunum, kidney, liver, and muscle tissues which have previously been identified as possible sites of xylose absorption or metabolism. This study aimed to expand the preliminary understanding of dietary xylose metabolism and utilization in pigs. One study, replicated twice with 24 crossbred gilts, was used to assess two dietary treatments: a xylose-free (0%) control and 8% D-xylose. The impact of xylose on growth was monitored by measuring initial and final body weight, serum IGF-1, and liver glycogen concentrations. The rate and efficiency of weight gain were reduced on the xylose diet but not to a level that would occur if xylose was not used at all; the detection of xylose systemically further supports this conclusion. This study confirmed that pigs can utilize dietary xylose. To determine the impact of xylose on tissue metabolism, samples were collected from all four tissues for gene expression analysis by RNA-sequencing, and kidney and liver samples were subjected to proteomic analysis using 2D-DIGE and mass spectrometry. The majority of differentially expressed (DE) genes were identified in the kidney samples (n = 157), with a few identified in the jejunum (n = 16), liver (n = 1), and muscle (n = 20) samples. The DE genes in the kidney were mainly identified as being involved in lipid biosynthesis and fatty acid metabolism. Proteomic results corroborated these findings. Although the inclusion of xylose in a diet at practical levels is shown to impact energy metabolic processes, it has been confirmed that this five-carbon sugar can support levels of growth only slightly below those of glucose, a six-carbon sugar that is more commonly utilized as an energy source in pig diets