Effects of dietary supplementation with a laminarin-rich extract on the growth performance and gastrointestinal health in broilers.

Restriction in antimicrobial use in broiler chicken production is driving the exploration of alternative feed additives that will support growth through the promotion of gastrointestinal health and development. The objective of this study was to determine the effects of dietary inclusion of laminarin on growth performance, the expression of nutrient transporters, markers of inflammation and intestinal integrity in the small intestine and composition of the caecal microbiota in broiler chickens. Two-hundred-and-forty day-old male Ross 308 broiler chicks (40.64 (3.43 SD) g) were randomly assigned to: (T1) basal diet (control); (T2) basal diet + 150 ppm laminarin; (T3) basal diet + 300 ppm laminarin (5 bird/pen; 16 pens/treatment). The basal diet was supplemented with a laminarin-rich Laminaria spp. extract (65% laminarin) to achieve the two laminarin inclusion levels (150 and 300 ppm). Chick weights and feed intake was recorded weekly. After 35 days of supplementation, one bird per pen from the control and best performing (300 ppm) laminarin groups were euthanized. Duodenal, jejunal and ileal tissues were collected for gene expression analysis. Caecal digesta was collected for microbiota analysis (high-throughput sequencing and QPCR). Dietary supplementation with 300 ppm laminarin increased both final body weight (2033 vs. 1906 ± 30.4, P < 0.05) and average daily gain (62.3 vs. 58.2 ± 0.95, P < 0.05) compared to the control group and average daily feed intake (114.1 vs. 106.0 and 104.5 ± 1.77, P < 0.05) compared to all other groups. Laminarin supplementation at 300 ppm increased the relative and absolute abundance of Bifidobacterium (P < 0.05) in the caecum. Laminarin supplementation increased the expression of interleukin 17A (IL17A) in the duodenum, claudin 1 (CLDN1) and toll-like receptor 2 (TLR2) in the jejunum and IL17A, CLDN1 and SLC15A1/peptide transporter 1 (SLC15A1/PepT1) in the ileum (P < 0.05). In conclusion, supplementation with laminarin is a promising dietary strategy to enhance growth performance and 300 ppm was the optimal inclusion level with which to promote a beneficial profile of the gastrointestinal microbiota in broiler chickens.

Seaweed extracts and galacto-oligosaccharides improve intestinal health in pigs following Salmonella Typhimurium challenge.

Pork and pork products are recognised as vehicles of Salmonella Typhimurium infection in humans. Seaweed-derived polysaccharides (SWE) and galacto-oligosaccharides (GOS) have shown to exhibit antimicrobial, prebiotic and immunomodulatory activity. The objective of this study was to assess the effects of dietary GOS and SWE supplementation on reducing S. Typhimurium numbers and intestinal inflammation in vivo. In total, 30 pigs (n=10/treatment, BW 30.9 kg) were randomly assigned to three dietary treatments: (1) basal diet; (2) basal diet+2.5 g GOS/kg diet; (3) basal diet+SWE (containing 180 mg laminarin/kg diet+340 mg fucoidan/kg diet). Following an 11-day dietary adaptation period, pigs were orally challenged with 108 colony-forming units/ml S. Typhimurium (day 0). Pigs remained on their diets for a further 17 days and were then sacrificed for sample collection. The SWE supplementation did not affect S. Typhimurium numbers on days 2 and 4 post-challenge but reduced S. Typhimurium numbers in faecal samples collected day 7 post-challenge (-0.80 log gene copy numbers (GCN)/g faeces) and in caecal and colonic digesta (-0.62 and -0.98 log GCN/g digesta, respectively; P<0.05) compared with the control treatment. Lactobacillus numbers were increased in caecal and colonic digesta after GOS supplementation (+0.70 and +0.35 log GCN/g digesta, respectively; P<0.05). In colonic tissue, both GOS and SWE supplementation resulted in reduced messenger RNA expression levels of interleukin (IL)-6, IL-22, tumour necrosis factor-α and regenerating islet-derived protein 3-γ (P<0.05). It can be concluded that dietary supplementation of SWE reduced faecal and intestinal S. Typhimurium numbers compared with the basal diet, whereas dietary GOS supplementation increased Lactobacillus numbers in caecal and colonic digesta but did not affect S. Typhimurium numbers. Supplementation of GOS and SWE reduced the gene expression of pro-inflammatory cytokines in colonic tissue of pigs after the experimental S. Typhimurium challenge.

Pigs that are divergent in feed efficiency, differ in intestinal enzyme and nutrient transporter gene expression, nutrient digestibility and microbial activity.

Feed efficiency is an important trait in the future sustainability of pig production, however, the mechanisms involved are not fully elucidated. The objective of this study was to examine nutrient digestibility, organ weights, select bacterial populations, volatile fatty acids (VFA's), enzyme and intestinal nutrient transporter gene expression in a pig population divergent in feed efficiency. Male pigs (n=75; initial BW 22.4 kg SEM 2.03 kg) were fed a standard finishing diet for 43 days before slaughter to evaluate feed intake and growth for the purpose of calculating residual feed intake (RFI). Phenotypic RFI was calculated as the residuals from a regression model regressing average daily feed intake (ADFI) on average daily gain (ADG) and midtest BW0.60 (MBW). On day 115, 16 pigs (85 kg SEM 2.8 kg), designated as high RFI (HRFI) and low RFI (LRFI) were slaughtered and digesta was collected to calculate the coefficient of apparent ileal digestibility (CAID), total tract nutrient digestibility (CATTD), microbial populations and VFA's. Intestinal tissue was collected to examine intestinal nutrient transporter and enzyme gene expression. The LRFI pigs had lower ADFI (P<0.001), improved feed conversion ratio (P<0.001) and an improved RFI value relative to HRFI pigs (0.19 v. -0.14 SEM 0.08; P<0.001). The LRFI pigs had an increased CAID of gross energy (GE), and an improved CATTD of GE, nitrogen and dry matter compared to HRFI pigs (P<0.05). The LRFI pigs had higher relative gene expression levels of fatty acid binding transporter 2 (FABP2) (P<0.01), the sodium/glucose co-transporter 1 (SGLT1) (P<0.05), the glucose transporter GLUT2 (P<0.10), and the enzyme sucrase-isomaltase (SI) (P<0.05) in the jejunum. The LRFI pigs had increased populations of lactobacillus spp. in the caecum compared with HRFI pigs. In colonic digesta HRFI pigs had increased acetic acid concentrations (P<0.05). Differences in nutrient digestibility, intestinal microbial populations and gene expression levels of intestinal nutrient transporters could contribute to the biological processes responsible for feed efficiency in pigs.

The effect of algal polysaccharides laminarin and fucoidan on colonic pathology, cytokine gene expression and Enterobacteriaceae in a dextran sodium sulfate-challenged porcine model.

The algal polysaccharides laminarin (LAM) and fucoidan (FUC) have potent anti-inflammatory activities in the gastrointestinal tract. Our objective was to examine the impact of prior consumption of LAM and/or FUC on pathology and inflammation following a dextran sodium sulfate (DSS) challenge in pigs. Pigs (n 7/group) were assigned to one of five experimental groups for 56 d. From 49-55 d, distilled water or DSS was administered intragastrically. The experimental groups were: (1) basal diet + distilled water (control); (2) basal diet + DSS (DSS); (3) basal diet + FUC + DSS (FUC + DSS); (4) basal diet + LAM + DSS (LAM + DSS); and (5) basal diet + LAM + FUC + DSS (LAMFUC + DSS). The DSS group had decreased body-weight gain (P < 0·05) and serum xylose (P < 0·05), and increased proximal colon pathology score (P < 0·05), diarrhoeal score (P < 0·001) and colonic Enterobacteriaceae (P < 0·05) relative to the control group. The FUC + DSS (P < 0·01), LAM + DSS (P < 0·05) and LAMFUC + DSS (P < 0·05) groups had improved diarrhoeal score, and the LAMFUC + DSS (P < 0·05) group had improved body weight relative to the DSS group. The FUC + DSS group (P < 0·001), LAM + DSS group (P < 0·05) and LAMFUC + DSS group (P < 0·001) had lower IL-6 mRNA abundance relative to the DSS group. The LAM + DSS group had reduced Enterobacteriaceae in proximal colon digesta relative to the DSS group (P < 0·05). In conclusion, FUC or a combination of FUC and LAM improved body-weight loss, diarrhoeal scores and clinical variables associated with a DSS challenge in pigs, in tandem with a reduction in colonic IL-6 mRNA abundance.

Maternal supplementation of seaweed-derived polysaccharides improves intestinal health and immune status of suckling piglets.

The experiment investigated the effect of maternal dietary supplementation of seaweed-derived polysaccharides (SDP) (-SDP v. +SDP, n   20) from day 83 of gestation until weaning (day 28) on selected sow faeces and piglet digesta microbiota populations, piglet small-intestinal morphology, and intestinal nutrient transporter and inflammatory cytokine gene expression at birth, 48 h after birth and weaning. The effect of maternal dietary treatment on the piglet gene expression profile of inflammatory cytokines in the colon following a lipopolysaccharide (LPS) challenge was also investigated. Dietary SDP reduced sow faecal Enterobacteriaceae gene numbers at parturition. Small-intestinal morphology, nutrient transporter and cytokine gene expression in newborn piglets did not differ between maternal dietary treatments (P > 0·10). At 48 h after birth, sodium-glucose-linked transporter 1 gene expression was down-regulated in the ileum of piglets suckling the SDP-supplemented sows compared with those suckling the basal sows (P = 0·050). There was a SDP × LPS challenge interaction on IL-1 and IL-6 gene expression in the colon of piglets (P < 0·05). The gene expression of IL-1 and IL-6 was down-regulated in the LPS-challenged colon of piglets suckling the SDP sows compared with those suckling the basal sows (P < 0·05). However, there was no difference in IL-1 and IL-6 gene expression in the unchallenged colon between treatment groups. At weaning, piglets suckling the SDP-supplemented sows had increased villus height in the jejunum and ileum compared with those suckling the basal-fed sows (P < 0·05). In conclusion, maternal dietary SDP supplementation enhanced the immune response of suckling piglets and improved gut morphology, making them more immune competent to deal with post-weaning adversities.

Effect of maternal supplementation with seaweed extracts on growth performance and aspects of gastrointestinal health of newly weaned piglets after challenge with enterotoxigenic Escherichia coli K88.

In the present study, a 2 × 2 factorial arrangement was conducted to investigate the effect of maternal supplementation with seaweed extracts ( - SWE v. +SWE, n 20) from day 83 of gestation until weaning (day 28) on post-weaning (PW) growth performance, faecal score, faecal enterotoxigenic Escherichia coli (ETEC) toxin quantification, intestinal histology and cytokine mRNA of unchallenged and ETEC-challenged pigs. Pigs were ETEC challenged on day 9 PW. There was a maternal treatment × challenge (SWE × ETEC) interaction effect on growth performance and faecal score (P< 0.05). Pigs from SWE-supplemented sows and ETEC-challenged (SE) had higher average daily gain (ADG) during 0-13 d PW and reduced faecal score during 0-72 h post-challenge than those from basal-fed sows and ETEC-challenged (BE) (P< 0.05). However, there was no difference between unchallenged pigs from the SWE-supplemented sows (SC) and basal-fed sows (BC) (P>0.10). Pigs from the SWE-supplemented sows had reduced heat-labile enterotoxin gene copy numbers than those from the basal-fed sows (P< 0.05). Maternal SWE supplementation increased the villus height in the ileum of pigs (P< 0.05). There was a SWE × ETEC interaction effect (P< 0.05) on IL-6 mRNA and a SWE × gastrointestinal (GI) region interaction effect (P< 0.05) on transforming growth factor-ß1 (TGF-ß1) and TNF-α mRNA. IL-6 mRNA was down-regulated in SC pigs than BC pigs (P< 0.05). However, there was no difference in IL-6 mRNA between SE and BE pigs. The mRNA of TGF-ß1 and TNF-α was down-regulated in the colon of pigs from the SWE-supplemented sows compared with those from the basal-fed sows (P< 0.05). However, there was no difference in TGF-ß1 and TNF-α mRNA in the ileum between the pigs from the SWE-supplemented sows and basal-fed sows. In conclusion, maternal SWE supplementation improves ADG and the aspects of GI health of weaned pigs following an ETEC challenge.

Effect of seaweed-derived laminarin and fucoidan and zinc oxide on gut morphology, nutrient transporters, nutrient digestibility, growth performance and selected microbial populations in weaned pigs.

In the present study, two experiments were conducted to (1) evaluate the effect of laminarin and/or fucoidan on ileal morphology, nutrient transporter gene expression and coefficient of total tract apparent digestibility (CTTAD) of nutrients and (2) determine whether laminarin inclusion could be used as an alternative to ZnO supplementation in weaned pig diets. Expt 1 was designed as a 2 × 2 factorial arrangement, comprising four dietary treatments (n 7 replicates, weaning age 24 d, live weight 6·9 kg). The dietary treatments were as follows: (1) basal diet; (2) basal diet+300 ppm laminarin; (3) basal diet+240 ppm fucoidan; (4) basal diet+300 ppm laminarin and 240 ppm fucoidan. There was an interaction between laminarin and fucoidan on the CTTAD of gross energy (GE) (P< 0·05) and the expression of sodium-glucose-linked transporter 1 (SGLT1/SLC5A1) and GLUT1/SLC2A1 and GLUT2/SLC2A2 (P< 0·05) in the ileum. The laminarin diet increased the CTTAD of GE and increased the expression of SGLT1, GLUT1 and GLUT2 compared with the basal diet. However, there was no effect of laminarin supplementation on these variables when combined with fucoidan. Expt 2 was designed as a complete randomised design (n 8 replicates/treatment, weaning age 24 d, live weight 7·0 kg), and the treatments were (1) basal diet, (2) basal diet and laminarin (300 ppm), and (3) basal diet and ZnO (3100 ppm, 0-14 d, and 2600 ppm, 15-32 d post-weaning). The laminarin diet increased average daily gain and gain:feed ratio compared with the basal diet during days 0-32 post-weaning (P< 0·01) and had an effect similar to the ZnO diet. These results demonstrate that laminarin provides a dietary means to improve gut health and growth performance post-weaning.

Effect of the interaction of seaweed extracts containing laminarin and fucoidan with zinc oxide on the growth performance, digestibility and faecal characteristics of growing piglets.

Seaweed extracts (SWE) rich in laminarin and fucoidan have shown promise as a supplement for weaned piglets. However, successful application in pig nutrition depends on their bioactivity in the presence of additives such as ZnO. In the present study, a 2 × 2 factorial experiment was carried out to investigate the effect of the interaction between SWE and ZnO on the growth performance, digestibility and faecal characteristics of 192 weaned piglets (6·5 kg). The piglets were penned in groups of 4 (n 12 pens). The study consisted of two phases after weaning: a starter diet period from the day of weaning (0 d) to 21 d and a transition diet period from 21 to 40 d. The dietary treatments were as follows: (1) control diet; (2) control diet+ZnO; (3) control diet+SWE; (4) control diet+ZnO+SWE. Diets containing ZnO improved the faecal consistency of the piglets throughout the experimental period (0-40 d). An effect of the interaction between ZnO and SWE on several variable was observed. The diet containing only SWE or ZnO improved the feed conversion efficiency of the piglets during the transition diet period; however, this effect was not observed when the diet containing both ZnO and SWE was fed. The diet containing only SWE increased the N and organic matter digestibility of the piglets; however, this effect was not observed in the presence of ZnO. An interaction between ZnO and SWE was observed, whereby the faecal counts of Escherichia coli were decreased when piglets were fed the diet containing only SWE, but not when fed the diet containing both SWE and ZnO. In summary, SWE and ZnO improve growth performance when given alone, but not when given in combination. The biological effect of SWE on selected digestibility and faecal characteristics was markedly different when compared with that of ZnO.

Effect of dietary laminarin and fucoidan on selected microbiota, intestinal morphology and immune status of the newly weaned pig.

A 2 × 2 factorial experiment was conducted to investigate the interactions between laminarin (LAM; 0 and 300 parts per million (ppm)) and fucoidan (FUC; 0 and 240 ppm) levels on intestinal morphology, selected microbiota and inflammatory cytokine gene expression in the weaned pig. There was an interaction between LAM and FUC supplementation on the Enterobacteriaceae population (P< 0·05) and the abundance of attaching and effacing Escherichia coli (AEEC) strains (P< 0·05) in the colon. Pigs offered the FUC diet had a reduced Enterobacteriaceae population compared with pigs offered the basal diet. However, the effect of FUC on the Enterobacteriaceae population was not observed when combined with LAM. Pigs offered the LAM diet had reduced abundance of AEEC strains compared with pigs offered the basal diet. However, there was no effect of LAM on the abundance of AEEC strains when combined with FUC. There was an interaction between LAM and FUC supplementation on villous height (P< 0·01) and the villous height:crypt depth ratio (P< 0·01) in the duodenum. Pigs offered the LAM or FUC diet had an increased villous height and villous height:crypt depth ratio compared with pigs offered the basal diet. However, there was no effect of the LAM and FUC combination diet on intestinal morphology. Pigs offered the LAM-supplemented diets had a lower IL-6 (P< 0·05), IL-17A (P< 0·01) and IL-1ß (P< 0·01) mRNA expression in the colon compared with pigs offered the diets without LAM. In conclusion, supplementation with either LAM or FUC alone modified intestinal morphology and selected intestinal microbiota, but these effects were lost when offered in combination.

Indices of gastrointestinal fermentation and manure emissions of growing-finishing pigs as influenced through singular or combined consumption of Lactobacillus plantarum and inulin.

Conventional dietary strategies to reduce pig manure odor may either be costly, or impede nutrient digestibility. Additionally, the response of manure odor to such measures may be variable, indicating a complex relationship between environmental pollutant and diet. We hypothesized that dietary Lactobacillus plantarum (LP), with or without the inclusion of a purified oligofructose (inulin), may reduce odor without compromising nutrient digestibility. An experiment with a 2 × 2 factorial arrangement of treatments was conducted to investigate effects of dietary inulin (0 and 12.5 g/kg) and LP (0 and 0.5 g/kg) on nutrient digestibility, indicators of gastrointestinal tract fermentation, select fecal bacteria, manure content, and ammonia and odor emissions of 28 growing-finishing pigs (60.3 kg; n = 7/treatment). Dietary treatments had no effect on nutrient digestibility. Dietary treatments containing inulin had decreased Enterobacteriaceae (8.60 vs. 9.67 log gene copy number/g fresh feces; P = 0.03) when compared with unsupplemented diets. There was an interaction between dietary inulin concentration and LP supplementation on estimates of fecal Clostridia (P = 0.01). Pigs offered diets containing both inulin and LP in combination had increased Clostridia when compared with those offered the control diet. However, there was no effect of either LP or inulin fecal Clostridia when offered singularly. An interaction was also noted where diets supplemented with LP or inulin only reduced odor (P = 0.01) compared with the control diet. However, there was no effect of LP on manure odor emissions when offered in combination with inulin. In summary, this study demonstrated that dietary supplementation with either exogenous LP or inulin reduces manure odor but not when offered in combination.

Effect of supplementing different ratios of laminarin and fucoidan in the diet of the weanling piglet on performance, nutrient digestibility, and fecal scoring.

A 3 × 2 factorial experiment was conducted to investigate the effects of different ratios of dietary laminarin (LAM) and fucoidan (FUC) on growth performance and nutrient digestibility in newly weaned piglets. At weaning, 168 piglets (24 d of age; 6.8 kg live weight) were assigned to 1 of 6 dietary treatments (n = 14/treatment): (i) basal diet, (ii) basal diet + 240 mg/kg FUC, (iii) basal diet + 150 mg/kg LAM, (iv) basal diet + 150 mg/kg LAM and 240 mg/kg FUC, (v) basal diet + 300 mg/kg LAM, and (vi) basal diet + 300 mg/kg LAM and 240 mg/kg FUC. Pigs offered 300 mg/kg LAM-supplemented diets had a higher ADG (P < 0.05) throughout the entire experimental period (days 0-35) compared with pigs offered diets with 0 and 150 mg/kg LAM supplementation. There was a significant interaction between LAM and FUC supplementation on G:F (P < 0.05) during the entire experimental period. Pigs offered the 300 mg/kg LAM-supplemented diet had a higher G:F than pigs offered the basal diet. However, there was no effect of the high level LAM on G:F when combined with FUC. There was a significant interaction between LAM and FUC supplementation on the apparent total tract digestibility (ATTD) of GE (P < 0.05). Pigs offered the 150 and 300 mg/kg LAM diet had an increased ATTD of GE compared with pigs offered the basal diet. However, there was no effect of LAM on ATTD of GE when combined with FUC. Pigs offered the 150 and 300 mg/kg LAM-supplemented diets had an improved fecal consistency (P < 0.05) from day 7 to day 14 compared to pigs offered diets without LAM supplementation. In conclusion, the inclusion of LAM improved growth performance of pigs after weaning partially due to an increased ATTD of GE.

The effect of seaweed extract as an alternative to zinc oxide diets on growth performance, nutrient digestibility, and fecal score of weaned piglets.

This study investigated if supplementing the diet with seaweed extracts (SWE) containing laminarin and fucoidan would promote growth performance, nutrient digestibility, and fecal consistency in newly weaned piglets during 2 growth phases as compared with ZnO. The experiment was designed as a 2 × 2 factorial with 2 levels of SWE (0 or 300 mg/kg laminarin + 240 mg/kg fucoidan) and 2 levels of ZnO [0 or added (3.1 g/kg for the starter diet and 2.5 g/kg for the transition diet)]. Dietary treatments were (i) basal diet, (ii) basal diet + ZnO, (iii) basal diet + SWE, and (iv) basal diet + ZnO + SWE. Newly weaned 6.5-kg pigs (n = 12; 4 pigs per pen) were offered supplements in a starter diet from weaning (day 0) to day 21 and in a transition diet from day 22 to day 40. There was an interaction (P = 0.005) between SWE and ZnO on G:F whereby pigs supplemented with SWE and ZnO individually had improved G:F when compared with the combination diet. There was an interaction between SWE and ZnO interaction on digestibility of DM (P < 0.01), N (P < 0.01), and NDF (P < 0.01). Pigs offered the SWE diets alone had a higher digestibility of DM, N, and NDF compared with pigs offered the basal diet. In summary, SWE induced a comparable growth performance pattern as obtained with ZnO inclusion. However, this was negated when supplements were offered in combination. Improvements in growth performance of pigs consuming SWE alone may reflect improvements in nutrient digestibility.

Effects of dietary supplementation with Laminaria hyperborea, Laminaria digitata, and Saccharomyces cerevisiae on the IL-17 pathway in the porcine colon.

An unregulated T(h)17 inflammatory response has been highlighted as a major contributor to the underlying pathology of inflammatory bowel diseases (IBD) whereas regulatory T (T(REG)) cells) have been highlighted as pivotal in suppressing autoimmune and inflammatory responses in the gut. Following dietary supplementation, ß-glucans have been shown to reduce the T(h)17 signature molecule IL-17a in the porcine colon. To expand this observation we examined the effects of supplementing feeds with ß-glucans derived from seaweeds Laminaria hyperborea and Laminaria digitata and the yeast Saccharomyces cerevisiae on gene expression of a range of cytokines, receptors, and signal transducing molecules relevant to the T(h)17 and T(REG) pathways in the porcine colon. All sources of ß-glucans significantly decreased the expression of T(h)17-related cytokines (IL-17a, IL-17F, and IL-22), receptor IL23R, and IL-6. There was no alteration to the T(REG)-related target, Foxp3, or to TGF-ß, although a significant reduction in IL-10 was observed in the L. digitata supplementation group.

Effects of supplementing dietary laminarin and fucoidan on intestinal morphology and the immune gene expression in the weaned pig.

Previous studies have shown the benefit of combining seaweed extracts laminarin (LAM) and fucoidan (FUC) on improving growth in piglets' performance after weaning. A 2 × 2 factorial experiment was conducted to investigate the interaction between FUC (0 and 240 mg/kg) and LAM (0 and 300 mg/kg) levels on gut morphology and colonic cytokine gene expression in the weaned pig. Twenty-eight piglets (6.9 kg BW) were assigned to 1 of 4 dietary treatments for 8 d after weaning and then sacrificed. The dietary treatments were as follows: (i) basal diet, (ii) basal diet + 240 mg/kg FUC, (iii) basal diet + 300 mg/kg LAM, and (iv) basal diet + 300 mg/kg LAM and 240 mg/kg FUC. There was an interaction (P < 0.01) between LAM and FUC supplementation on duodenal villous height and the villus height to crypt depth ratio. Pigs offered the LAM or FUC diet singularly had an increased villus height and villus height to crypt depth ratio compared with pigs offered the basal diet. However, there was no effect of the LAM and FUC combination diet on morphology. Pigs offered the LAM-supplemented diets had a lower IL-6 (P < 0.05), IL-17 (P < 0.001), and IL-1ß (P < 0.001) mRNA expression in the colon compared with pigs offered diets without LAM supplementation. In conclusion, the enhancement in intestinal structure and downregulation of inflammatory cytokine gene expression obtained suggest that LAM may provide a dietary means to improve gut health in weaned pigs.

The effect of protease and nonstarch polysaccharide enzymes on manure odor and ammonia emissions from finisher pigs.

A 2 × 2 factorial experiment was conducted to investigate the effect of dietary protease (0 and 200 mg/kg) and xylanase (0 and 200mg/kg) in reducing manure odor and NH(3) from finisher pigs. Sixteen pigs were assigned to 1 of 4 dietary treatments, (i) basal diet, (ii) basal diet + xylanase, (iii) basal diet + protease, or (iv) basal diet + xylanase + protease, for 24 d. The manure samples from pigs offered diets containing protease showed increased (P < 0.05) molar proportions of isobutyric acid, isovaleric acid, valeric acid, and branched-chain fatty acids in contrast to pigs offered diets without protease supplementation. The pigs offered diets with xylanase inclusion had reduced (P < 0.05) manure odor emissions compared to pigs offered diets without xylanase supplementation [598 vs. 1306 European odor units (OuE)/m(3)]. Pigs offered protease-supplemented diets alone had significantly higher NH(3) emissions compared to basal fed pigs. However, NH(3) emissions were reduced when protease was combined with xylanase. In summary, this study indicates that protease supplementation increased protein-derived VFA in manure and also increased manure NH(3) emissions when offered singularly. Consumption of diets containing xylanase reduced manure odor emissions.

The effect of protease and xylanase enzymes on growth performance and nutrient digestibility in finisher pigs.

Two 2 × 2 factorial experiments were conducted to investigate the interaction between xylanase (0 vs. 200 mg/kg) and protease (0 vs. 200 mg/kg) enzyme supplementation on growth performance (Exp. 1) and coefficient of ileal and total tract apparent digestibility in grower-finisher pigs (Exp. 2). One hundred and twenty-eight individual fed pigs (BW = 34.2 kg; n = 32) were assigned to 1 of 4 dietary treatments: basal diet (T1), T1 + xylanase enzyme (T2), T1 + protease enzyme (T3), or T1 + xylanase + protease enzymes (T4). The pigs offered diets containing protease enzymes had reduced daily gain (0.795 vs. 0.840 kg/d; P < 0.05) and final body weight (96.4 vs. 99.1 kg; P < 0.05) compared to pigs offered diets without protease enzymes. Pigs offered xylanase-supplemented diets had reduced daily gain (0.787 vs. 0.848 kg/d; P < 0.05) compared to pigs offered diets without xylanase enzymes. In Exp. 2, the nutrient digestibility experiment consisted of 24 intact male pigs (n = 6; BW = 78 kg), offered identical diets to that offered in Exp. 1. Following the fecal collections, the pigs were slaughtered and digesta samples were taken from the ileum in order to measure apparent ileal N and GE digestibilities. Pigs offered diets supplemented with protease had increased coefficients of ileal digestibility of N compared to pigs offered diets without protease supplementation (0.583 vs. 0.449; P < 0.05). There was a xylanase × protease interaction (P < 0.05) on the apparent ileal digestibility of GE. Pigs offered diets containing protease only had increased apparent ileal digestibility of GE compared to basal fed pigs; however, the ileal digestibility of GE decreased when protease was combined with xylanase. Neither xylanase nor protease enzymes had any effect on total tract digestibility of GE or N. In conclusion, xylanase and protease enzyme supplementation had no positive effects on grower-finisher pig performance.

Modification of selected bacteria and markers of protein fermentation in the distal gastrointestinal tract of pigs upon consumption of chitosan is accompanied by heightened manure odor emissions.

Previous studies have indicated that reducing dietary CP may improve N utilization and effectively diminish manure ammonia emissions; however, the response of manure odor emissions to such dietary modifications has been inconsistent. The objective of the current experiment was to induce decreased lactobacilli (DL) numbers in the distal gastrointestinal tract (dGIT; cecum + colon) of finishing pigs offered both high- and low-CP diets through consumption of chitosan, and examine the influence of this model on manure ammonia and odor emissions when compared with a positive control diet. It was hypothesized that an DL population would be accompanied by an increase in markers of protein fermentation. When compared with normal lactobacilli populations in the dGIT, generation of an DL population would result in increased manure odor emissions from pigs offered both dietary CP concentrations. A 2 × 2 factorial arrangement of treatments was conducted to investigate the effect of including chitosan [0 (positive control) vs. 20 g/kg of feed] and high or low dietary CP concentration (200 vs. 150 g/kg of feed) on nutrient digestibility, N utilization, selected bacterial populations, and metabolite composition of the dGIT and manure emissions from finisher pigs (60.3 kg). Consumption of chitosan had no influence (P > 0.05) on nutrient digestibility or N utilization. In both high- and low-CP diets, consumption of chitosan decreased the lactobacilli-to-Enterobacteriaceae ratio (P < 0.01), generating an DL population, and increased pH (P < 0.01) in the dGIT and ammonia (P = 0.02) in the cecum compared with diets that supported normal lactobacilli populations. Consumption of chitosan decreased molar proportions of butyric acid (P < 0.01) and increased valeric acid (P < 0.01) in the dGIT compared with unsupplemented diets. Furthermore, consumption of chitosan increased manure odor emissions (P = 0.05) compared with unsupplemented diets. There was no effect (P > 0.05) of chitosan consumption on manure ammonia emissions from 0 to 240 h. The current study demonstrates that dietary chitosan suppressed populations of lactobacilli in the dGIT. In response, a considerable increase in Enterobacteriaceae, markers of protein fermentation, and manure odor emissions was observed compared with the positive control diet. These effects were observed in pigs offered both high-and low-CP diets. The current study indicates a possible role for lactic-acid bacteria in modulating manure odor emissions relatively independent of the proportions of dietary CP available for fermentation in the dGIT.

Comparison of a wheat-based diet supplemented with purified {beta}-glucans, with an oat-based diet on nutrient digestibility, nitrogen utilization, distal gastrointestinal tract composition, and manure odor and ammonia emissions from finishing pigs.

It was hypothesized that supplementation of an oat-extracted mixed-linkage (1 → 3), (1 → 4)-ß-d-glucan (ß-glucans) to a wheat-based diet may beneficially mitigate manure odor and ammonia emissions associated with intensive pig production, without depressing nutrient digestibility as has been observed with oat-based diets. An experiment was conducted to investigate the effect of dietary ß-glucan source and the inclusion of an enzyme composite containing ß-glucanase on energy and nutrient digestibility, N utilization, distal gastrointestinal tract (GIT) fermentation, and manure emissions from finisher boars. Twenty-eight boars (BW = 74.2 ± 3.6 kg) were assigned to 1 of 4 dietary treatments (n = 7/treatment): 1) an oat-based diet (oat), 2) an oat diet + enzyme composite (OE), 3) a wheat-based diet + purified ß-glucans (WG), and 4) a wheat-based diet + purified ß-glucans + enzyme composite. The wheat-based diets containing purified ß-glucans were formulated to contain concentrations of total ß-glucans comparable with the oat-based diet. Consumption of the WG diet resulted in a greater digestibility of GE (P = 0.001) and an increase in the urine:feces N excretion ratio (P = 0.049) compared with the oat diet. In the distal GIT, pigs offered the WG diet contained fewer bifidobacteria (P = 0.027) and lactobacilli (P = 0.050) compared with the oat diet. Pigs offered the WG diet had increased manure odor emissions compared with the oat diet (P = 0.023). In conclusion, although supplementing wheat-based diets with extracted oat-ß-glucan did not reduce nutrient digestibility, there was a negligible effect in beneficially influencing manure emissions from pigs when compared with a conventional oat formulation.

Effect of beta-glucans contained in barley- and oat-based diets and exogenous enzyme supplementation on gastrointestinal fermentation of finisher pigs and subsequent manure odor and ammonia emissions.

The objective of the current experiment was to evaluate the influence of dietary cereal sources of beta(1,3)(1,4)-d-glucan (beta-glucan) and enzyme supplementation on indices of environmental pollution from finisher pigs. An experiment with a 2 x 2 factorial arrangement of treatments was initiated to investigate the effect of dietary source of beta-glucan (barley vs. oats) and enzyme supplementation (no vs. yes) on nutrient digestibility, N utilization, intestinal fermentation, and manure odor and ammonia emissions from finisher boars (n = 4; BW = 73.9 kg; SD = 4.7). Sixteen boars were assigned to 1 of 4 dietary treatments (n = 4/treatment): 1) barley-based diet, 2) barley-based diet + exogenous enzyme, 3) oat-based diet, and 4) oat-based diet + enzyme. The enzyme supplement used contained endo-1,3(4)-beta-glucanase and endo-1,4-beta-xylanase. Experimental diets were formulated to contain similar concentrations of DE (13.5 MJ/kg) and digestible lysine (8.8 g/kg). Pigs offered oat-based diets had reduced digestibility of DM (0.795 vs. 0.849; SEM 0.007; P = 0.001), OM (0.808 vs. 0.865; SEM 0.007; P = 0.001), GE (0.806 vs. 0.845; SEM 0.006; P = 0.002), and NDF (0.233 vs. 0.423; SEM 0.033; P < 0.003) compared with those offered barley-based diets. Oat-based diets increased populations of Bifidobacterium spp. (7.26 vs. 6.38 log cfu/g of digesta; SEM 0.201; P = 0.005) and Lactobacillus spp. (6.99 vs. 6.18 log cfu/g of digesta; SEM 0.234; P = 0.022) in the proximal colon and decreased manure odor emissions [2,179.6 vs. 4,984.6 Ou(E)/m(3) (where Ou(E) refers to European odor units); SEM 653.7; P < 0.011] compared with barley-based diets. There was an interaction between cereal type and enzyme inclusion on manure ammonia emissions from 0 to 96 h (P = 0.050). Pigs offered barley-based diets containing an enzyme supplement had increased manure ammonia emissions compared with those offered unsupplemented barley-based diets. However, there was no effect of enzyme inclusion on oat-based diets. In conclusion, pigs offered oat-based diets harbored increased Bifidobacterium spp. and Lactobacillus spp. populations in the proximal colon and had decreased manure odor emissions compared with those offered barley-based diets. Enzyme inclusion had no effect on manure ammonia emissions from pigs offered oat-based diets.

Effect of crude protein concentration and sugar-beet pulp on nutrient digestibility, nitrogen excretion, intestinal fermentation and manure ammonia and odour emissions from finisher pigs.

A 2 × 2 factorial experiment was conducted to investigate the interaction between high and low dietary crude protein (CP) (200 v. 150 g/kg) and sugar-beet pulp (SBP) (200 v. 0 g/kg) on nutrient digestibility, nitrogen (N) excretion, intestinal fermentation and manure ammonia and odour emissions from 24 boars (n = 6, 74.0 kg live weight). The diets were formulated to contain similar concentrations of digestible energy (13.6 MJ/kg) and lysine (10.0 g/kg). Pigs offered SBP-containing diets had a reduced (P < 0.05) digestibility of dry matter, ash, N, gross energy and an increased (P < 0.001) digestibility of neutral-detergent fibre compared with pigs offered diets containing no SBP. There was an interaction between CP and SBP on urinary N excretion and the urine : faeces N ratio. Pigs offered the 200 g/kg CP SBP-based diet had reduced urine : faeces N ratio (P < 0.05) and urinary N excretion (P < 0.05) compared with those offered the 200 g/kg CP diet without SBP. However, there was no effect of SBP in pigs offered 150 g/kg CP diets. Manure ammonia emissions were reduced by 33% from 0 to 240 h (P < 0.01); however, odour emissions were increased by 41% (P < 0.05) when pigs were offered SBP diets. Decreasing dietary CP to 150 g/kg reduced total N excretion (P < 0.001) and ammonia emissions from 0 to 240 h (P < 0.05). There was an interaction between dietary CP and SBP on branched-chain fatty acids (P < 0.001) in caecal digesta. Pigs offered the 200 g/kg CP SBP-containing diet reduced branched-chain fatty acids in the caecum compared with pigs offered the 200 g/kg CP diet containing no SBP. However, there was no effect of SBP in the 150 g/kg CP diet. In conclusion, pigs offered SBP-containing diets had a reduced manure ammonia emissions and increased odour emissions compared with diets containing no SBP. Pigs offered the 200 g/kg CP SBP-containing diet had a reduced urine : faeces N ratio and urinary N excretion compared with those offered the 200 g/kg CP diet containing no SBP.