Interactive Effects of Dietary Fiber and Lipid Types Modulate the Predicted Production and Absorption of Cecal and Colorectal Short-Chain Fatty Acids in Growing Pigs.

BACKGROUND: High-fiber diets are supplemented with lipids to meet the required energy content, but data on the interactions between dietary fiber (DF) and lipid types on gastrointestinal fermentation in pigs are scant. OBJECTIVES: This study aimed to use a combination of in vivo and in vitro fermentation methodologies to determine the interactive effects of DF and lipid types on short-chain fatty acid (SCFA) production and absorption and organic matter (OM) fermentability in the cecum and colorectal tract of pigs. METHODS: Eight ileal- and cecal-cannulated Yorkshire barrows were fed either pectin- or cellulose-containing diets that were supplemented with either corn oil or beef tallow in 2 independent Youden squares with a 2 × 2 factorial arrangement of treatments (n = 6). Ileal and cecal digesta were collected, freeze-dried, and fermented using inoculum from fresh cecal digesta and feces, respectively, to determine individual SCFA production and absorption and fermentability of OM. RESULTS: Interactions (P < 0.001) between DF and lipid types were observed in which the addition of beef tallow decreased the quantity of cecal and colorectal acetic acid production and cecal acetic absorption, cecal butyric production, predicted cecal OM fermentability, and predicted colorectal propionic acid in pectin diets, but the effects were not observed for cellulose diets. The addition of beef tallow increased (P < 0.001) the production of cecal butyric and propionic acids during in vitro fermentation in cellulose diets and apparent total tract digestibility (ATTD) of OM in pectin diets. CONCLUSIONS: The interactions between DF and lipids on gastrointestinal fermentation largely depend on the degree of saturation of fatty acids in dietary lipids. The addition of beef tallow selectively decreased the production and absorption of individual SCFAs in pectin and cellulose diets but increased cecal butyric and propionic acid production in cellulose diets and the ATTD of OM in pectin diets.

Standardized Ileal Digestibility of Amino Acids in Hybrid Rye Ground to Two Particle Sizes and Fed With or Without Multienzyme Supplement to Young Growing Pigs.

A newly developed hybrid rye with enhanced ergot resistance has potential as an alternative energy source for pigs. An experiment was conducted to evaluate the effects of particle size (PS) and multienzyme supplement (MES) on the apparent total tract digestibility (ATTD) of energy and nutrients and the standardized ileal digestibility (SID) of amino acids (AA) in hybrid rye fed to growing pigs. Bono and Gatano, two hybrid rye varieties, were ground to either a coarse (1111 and 1210 µm) or a fine (594 and 717 µm) PS using a hammer mill. Eighteen ileal-cannulated barrows (initial BW = 18.2 ± 1.0 kg) were randomly assigned to 1 of 9 dietary treatments in a replicated 9 × 3 incomplete Latin square design to give six observations per treatment. Among the nine experimental diets, eight featured two hybrid rye varieties (Bono or Gatano), either coarsely or finely ground, as the only source of AA with or without MES, while an N-free diet was used to estimate the endogenous losses of AA at the distal ileum. All diets contained titanium dioxide as an indigestible marker. Each period lasted 9 days, with the first 5 days being for adaptation followed by 2 days each for faecal and ileal digesta collection. Data were analysed using the MIXED procedure of SAS, with the final model having variety, PS, MES, their two-way interactions, and a three-way interaction. No interactions were noted except that the apparent ileal digestibility and SID of crude protein (CP) and most AA in Gatano had greater effects of MES than Bono (Variety × MES; p < 0.05). The ATTD of dry matter (DM), gross energy (GE) and CP were greater (p < 0.05) in Bono diets than in Gatano diets. Finely ground hybrid rye diets had higher (p < 0.05) ATTD of neutral detergent fibre assayed with a heat stable amylase and expressed inclusive of residual ash (NDF) and ether extract compared to coarsely ground hybrid rye diets. Dietary MES supplementation increased (p < 0.05) the ATTD of DM, GE, CP, NDF, acid detergent fibre expressed inclusive of residual ash, and ash in hybrid rye diets. In conclusion, the nutrients digestibility of hybrid rye can be affected by its variety. PS reduction improved the nutrient digestibility in hybrid rye, and MES supplementation improved the energy and AA digestibility in hybrid rye fed to growing pigs.

Interactive effects of dietary fibre and lipid types modulate gastrointestinal flows and apparent digestibility of fatty acids in growing pigs.

A total of eight ileal and caecal cannulated Yorkshire barrows were used to determine the interactions of dietary fibre (DF) and lipid types on apparent digestibility of DM and fatty acids (FA) and FA flows in gastrointestinal segments. Pigs were offered four diets that contained either pectin or cellulose with or without beef tallow or maize oil in two Youden square designs (n 6). Each period lasted 15 d. Faeces, ileal and caecal contents were collected to determine apparent ileal digestibility (AID), apparent caecal digestibility and apparent total tract digestibility (ATTD) of dietary components. The interactions between DF and lipid types influenced (P <0·05) the digestibility of DM and FA flows. The addition of maize oil decreased (P <0·05) AID of DM in pectin diets, and the addition of beef tallow depressed (P <0·001) ATTD of DM in cellulose diets. Dietary supplementation with beef tallow decreased (P <0·05) the AID of FA in pectin-containing diets but had no effects in cellulose-containing diets. Dietary supplementation with beef tallow increased (P <0·05) AID of SFA and PUFA and the flow of ileal oleic, vaccenic, linolenic and eicosadienoic acids and reduced the flow of faecal lauric, docosatetraenoic and docosapentaenoic acids in pectin- and cellulose-containing diets. In conclusion, the interaction between DF type and lipid saturation modulates digestibility of DM and lipids and FA flows but differs for soluble and insoluble fibre sources, SFA and unsaturated fatty acids and varies in different gastrointestinal segments.

Ammonia-Nitrogen Added to Low-Crude-Protein Diets Deficient in Dispensable Amino Acid-Nitrogen Increases the Net Release of Alanine, Citrulline, and Glutamate Post-Splanchnic Organ Metabolism in Growing Pigs.

Background: Dietary ammonia is rapidly absorbed but poorly used for urea synthesis in pigs fed low-crude-protein (low-CP) diets deficient in dispensable amino acid (DAA)-nitrogen. Objective: We explored the effect of dietary ammonia on net amino acid (AA) balances in portal-drained viscera (PDV) and livers of pigs fed a diet deficient in DAA-nitrogen. Methods: Eight barrows with an initial body weight (BW) of 26.5 ± 1.4 kg (mean + SD) were surgically fitted with 4 catheters each (portal, hepatic, and mesenteric veins and carotid artery). The pigs were restricted-fed (2.8 × 191 kcal/kg BW0.60) for 7 d, and every 8 h a diet deficient in DAA-nitrogen supplemented with increasing amounts of ammonia-nitrogen (CP = 7.76%, 9.27%, and 10.77% for the control and low- and high-ammonia diets, respectively). The treatment sequence was based on a 3 × 3 Latin-square design with 3 consecutive periods. On the last day of each period, blood flows in portal and hepatic veins were determined with a continuous infusion of ρ-amino hippuric acid into the mesenteric vein. Consecutive blood samples were taken for AA concentration in blood plasma, and AA balances were calculated for PDV and the liver. Results: Cumulative release of citrulline (Cit) and proline (Pro) increased with ammonia supplementation in PDV but decreased for glutamine (Gln) and glycine (Gly) (Gln: -19.32 ± 3.56, -32.50 ± 3.73, and -42.11 ± 3.55 mmol/meal for the control and low- and high-ammonia groups, respectively; P ≤ 0.05). Cumulative release of alanine (Ala), glutamic acid (Glu), and Gln increased with ammonia supplementation across the liver (P ≤ 0.05). When combined, PDV+liver, the cumulative release of Ala, Cit, and Glu increased with ammonia-nitrogen supplementation (P ≤ 0.05). Conclusion: Dietary ammonia could be used as a nitrogen supplement to increase the synthesis of Ala, Cit, and Glu across splanchnic organs in pigs fed a diet deficient in DAA-nitrogen.

Ammonia Nitrogen Added to Diets Deficient in Dispensable Amino Acid Nitrogen Is Poorly Utilized for Urea Production in Growing Pigs.

Background: Including ammonia in low-crude protein (CP) diets deficient in dispensable amino acid (DAAs) increases nitrogen retention in growing pigs.Objective: We investigated the absorption and metabolism of dietary ammonia nitrogen in the portal-drained viscera (PDV) and liver of pigs fed a diet deficient in DAA nitrogen.Methods: Eight pigs with an initial mean ± SD body weight (BW) of 26.5 ± 1.4 kg were surgically fitted with 4 catheters each (portal, hepatic and mesenteric veins, and carotid artery). The pigs were fed (2.8 × 191 kcal/kg BW0.60), for 7 d and every 8 h, a diet deficient in DAA nitrogen supplemented with increasing amounts of ammonia nitrogen (CP: 7.76%, 9.27%, and 10.77%; indispensable amino acid nitrogen:total nitrogen ratio: 0.71, 0.59, and 0.50 for control and low- and high-ammonia diets, respectively). The treatment sequence was based on a Latin square design with 3 consecutive periods. On the last day of each period, blood flows in the portal and hepatic veins were determined with a continuous infusion of ρ-amino hippuric acid into the mesenteric vein. Serial blood samples were taken to determine ammonia and urea nitrogen concentration. Net balances of ammonia and urea nitrogen were calculated for the PDV and liver.Results: Cumulative (8 h) ammonia nitrogen appearance in the portal vein increased (P ≤ 0.05) with ammonia intake (433, 958, and 1629 ± 60 mg ammonia nitrogen/meal for control and low- and high-ammonia diets, respectively). The cumulative hepatic uptake of ammonia nitrogen increased (P ≤ 0.05) with ammonia nitrogen supply. The cumulative urea nitrogen appearance in the hepatic vein tended to increase (P ≤ 0.10) only in high-ammonia treatment (-92.5, -59.4, and 209.7 ± 92 mg urea nitrogen/meal for control and low- and high-ammonia diets, respectively) and, relative to the control diet, represented -6.0% and 11% of ammonia nitrogen intake.Conclusion: Dietary ammonia nitrogen is poorly utilized for urea production across splanchnic organs when pigs are fed diets deficient in DAA nitrogen.

Effect of low levels of dietary available phosphorus on phosphorus utilization, bone mineralization, phosphorus transporter mRNA expression and performance in growing pigs.

A study was conducted to examine the effects of different dietary levels of available phosphorus (aP) on P excretion, bone mineralization, performance and the mRNA expression of sodium-dependent P transporters in growing pigs. Sixty-day old growing pigs (n = 54) with an average initial BW of 19.50 ± 1.11 kg were randomly allocated to a control diet (C) containing 0.23% available phosphorus (aP), T1 containing 0.17% aP and T2 containing 0.11% aP. There were 6 pens per treatment with 3 pigs per pen. Body weight and feed intake were measured weekly. At the end of each week, one pig from each pen was housed in a metabolic crate for 24 h to collect fecal and urine samples and then sacrificed to obtain third metacarpal (MC3) bones and jejunal and kidney samples. Bones were scanned by Dual Energy X-ray Absorptiometry (DEXA). Fecal and urine samples were sub-sampled and analyzed for P content. The expression of P transporter mRNA in jejunum and kidney samples was measured using quantitative real-time polymerase chain reaction (qRT-PCR). Data were analyzed using GLM procedure of the Statistical Analysis System (SAS Institute version 9.2). Pigs fed the T2 diet had reduced (P < 0.05) average daily gain (ADG) and gain to feed (G:F) compared to those fed the C diet during week 2. Overall, ADG and G:F were also reduced (P < 0.05) in pigs fed the T2 diet compared to those fed the C and T1 diets. Bone mineral density (BMD) and bone mineral content (BMC) were reduced (P < 0.05) in pigs fed the T2 diet compared to those fed the C diet throughout the experiment. At week 1, jejunal mRNA expression of Na (+)-dependent phosphate transporter 2 (SLC34A2) was increased (P < 0.01) in pigs fed the T2 diet compared to C diet. Renal mRNA expression of Na(+)-dependent phosphate transporter 1 (SLC34A1) and SLC34A3 were increased (P < 0.05) in pigs fed the T2 diet compared to those fed the C diet at week 2 and was accompanied by lower (P < 0.05) urinary P in pigs fed the T2 diet during week 2 and week 3. In conclusion, growing pigs are highly sensitive to low dietary P as shown by reduced ADG, bone mineralization and urinary P level, but moderate reduction in dietary P up to 0.17% aP in the diet has the potential to reduce environmental pollution by reducing P concentration in swine manure and without compromising performance.

Effects of 25-(OH)D3 on fecal Ca and P excretion, bone mineralization, Ca and P transporter mRNA expression and performance in growing female pigs.

A study was conducted to examine the effects of 25-hydroxyvitamin D3 (25-(OH)D3) on fecal Ca and P excretion, bone mineralization, performance and the mRNA expression of intestinal transporter genes in growing female pigs. Sixty-day old gilts (n = 24) with an average initial BW of 23.13 ± 1.49 kg were randomly allocated to a control diet (diet 1) containing wheat/corn/soybean meal and 150 IU kg(-1) of Vitamin D3, diet 1 + 50 µg of 25-(OH)D3 kg(-1) (diet 2) and diet 1 + 100 µg of 25-(OH)D3 kg(-1) (diet 3). The pigs were housed in an individual pen and had ad libitum access to feed and water for 42 days, and BWG and feed intake were measured weekly. Measures of bone mineralization and expression of Ca and P transporters mRNA were analyzed using Dual Energy X-Ray Absortiometry (DEXA) and quantitative real-time polymerase chain reaction (qRT-PCR), respectively. Data were analyzed using GLM procedure of the Statistical Analysis System (SAS Institute version 9.2). Fecal Ca and P concentration were significantly reduced (P ≤ 0.05) in pigs fed diets 2 and 3 compared with the control diet. Supplementation of 25-(OH)D3 did not significantly improve bone mineralization, animal performance and intestinal transporters mRNA expression except for SLC34A1, a sodium-dependent phosphate transporter 1. In conclusion, supplementation of 25-(OH)D3 in swine nutrition may not improve animal performance but has the potential to reduce environmental pollution by increasing dietary Ca and P retention while reducing their excretion.

Chemical composition and digestible and metabolizable energy contents in cold-pressed canola expellers fed to growing pigs.

Cold-pressed canola expellers (CPCE) are a byproduct of canola oil production obtained using the pressing method without thermal and chemical treatment. While CPCE is a valuable source of dietary energy and protein in swine nutrition, the discrepancy in processing conditions leads to variability in the nutritional quality of CPCE from different sources. This study aimed to determine the chemical composition, and digestible energy (DE) and metabolizable energy (ME) values of CPCE when fed to growing pigs. Samples of CPCE were collected from five processing facilities across Western Canada. The physical appearance of the CPCE samples hinted at a potential quality variation. Samples were subjected to a complete chemical characterization. Variations (P < 0.05) were observed in the chemical composition, with the exception of non-phytate phosphorus, xylose, mannose, and galactose. On a g/kg dry matter (DM) basis, CPCE samples ranged as follows: ether extract from 85 to 177; crude protein (CP) from 351 to 419; neutral detergent fiber 231 to 300; total dietary fiber from 326 to 373; glycoproteins from 30 to 76; non-starch polysaccharides from 188 to 204, non-phytate phosphorus from 5.5 to 6.4, and gross energy (GE) in kcal/kg 5,027 to 5,635. The total glucosinolates (GLS) ranged from 5.0 to 9.7 µmol/g DM. Thirty-six (36) growing barrows, with an average initial body weight of 19.2 ±â€…1.0 kg, were individually housed in metabolism crates and assigned to one of the six experimental diets in a completely randomized design, with six pigs per diet. The diets included a corn-soybean meal (SBM)-based basal diet (100%) and five (5) experimental diets in which 18% of the basal diet was substituted with CPCE from different producers. Pigs were fed the experimental diets for 10 d, with 5-d adaptation period, followed by a 5-d period for the total, but separate, collection of feces and urine. Significant differences (P < 0.05) among processing plants were observed in the DE and ME contents of CPCE, which averaged 3,531 and 3,172 kcal/kg DM, respectively. Differences (P < 0.05) were noted in the apparent total tract digestibility of GE, nitrogen (N), as well as in the retention of DM, GE, and N in CPCE samples. In conclusion, while the chemical composition and values of DE and ME in CPCE vary among processors, the byproduct obtained through cold pressing process can be a valuable source of energy and protein for pig nutrition.

Standardized ileal amino acid digestibility and performance indices in pullets and laying hens fed expeller-pressed Canadian prairie soybean meal.

Soybean meals (SBM) from different locations differ in their protein content, subsequently influencing their amino acid (AA) profile. In this study, standardized ileal digestibility (SID) of AA and growth or production performance were evaluated in pullets and hens fed SBM derived from soybean grown in Western Canada, primarily Manitoba (MB) labelled as A-, B- and C-SBM compared with that from Eastern Canada (Ontario, ON-SBM) and contained 38.3 ± 0.44, 38.6 ± 0.61, 39.4 ± 0.49, or 44.0 ± 0.87% CP, respectively. A N-free diet was used to determine basal ileal endogenous losses of AA. The study included the grower, developer, and layer phases (9-12, 13-16, and 44/59-64-wk old birds, respectively). Although a lower (P = 0.029) SID for cysteine was noted in the grower phase for the C-SBM compared with other SBM, the developer phase had higher (P < 0.05) SID for methionine, phenylalanine, cysteine (more by 4.4, 2.4 and 7.2% units, respectively) on average for SBM samples from MB compared with the ON-SBM. Regardless the source of the SBM, no difference in SID of AA was noted in the layer phase. Overall, in all phases the SID values of most AA in the SBM from MB were comparable with the ON-SBM, which may be linked to higher values of these AA per unit of protein content in the former source. In addition, the growth performance including feed intake, BW gain and feed conversion ratio in pullets, and egg production/quality in layers were similar between treatments. These findings show that the MB-SBM have a comparable feeding value with the ON-SBM, hence represent a suitable alternative protein source for poultry.

The role of added feed enzymes in promoting gut health in swine and poultry.

The value of added feed enzymes (FE) in promoting growth and efficiency of nutrient utilisation is well recognised in single-stomached animal production. However, the effects of FE on the microbiome of the gastrointestinal tract (GIT) are largely unrecognised. A critical role in host nutrition, health, performance and quality of the products produced is played by the intestinal microbiota. FE can make an impact on GIT microbial ecology by reducing undigested substrates and anti-nutritive factors and producing oligosaccharides in situ from dietary NSP with potential prebiotic effects. Investigations with molecular microbiology techniques have demonstrated FE-mediated responses on energy utilisation in broiler chickens that were associated with certain clusters of GIT bacteria. Furthermore, investigations using specific enteric pathogen challenge models have demonstrated the efficacy of FE in modulating gut health. Because FE probably change the substrate characteristics along the GIT, subsequent microbiota responses will vary according to the populations present at the time of administration and their reaction to such changes. Therefore, the microbiota responses to FE administration, rather than being absolute, are a continuum or a population of responses. However, recognition that FE can make an impact on the gut microbiota and thus gut health will probably stimulate development of FE capable of modulating gut microbiota to the benefit of host health under specific production conditions. The present review brings to light opportunities and challenges for the role of major FE (carbohydrases and phytase) on the gut health of poultry and swine species with a specific focus on the impact on GIT microbiota.

Effects of particle size and phytase supplementation on apparent and standardized total tract digestibility of phosphorus in hybrid rye fed to growing pigs.

An experiment was conducted to investigate the effects of particle size (PS) and levels of phytase supplementation on the apparent (ATTD) and standardized (STTD) total tract digestibility of P in hybrid rye fed to growing pigs. Thirty-six growing barrows (23.6 ± 1.5 kg initial BW) were individually housed in metabolism crates and randomly allotted to one of six dietary treatments to give six replicates per treatment. The six dietary treatments were arranged in a 2 × 3 factorial with main effects of PS and phytase supplementation levels (0, 500, or 2,500 FTU/kg). Hybrid rye was ground using a hammermill mounted with 4.0- and 3.2-mm screens to obtain material with coarse and fine PS, respectively. Pigs were fed experimental diets for 11 d, including 5 d for adaptation and 6 d for total collection of feces. All data were analyzed using the MIXED procedure of SAS with PS, phytase, and their interaction as fixed effects. Orthogonal polynomial contrasts were used to test linear and quadratic effects of phytase level in both coarse and fine hybrid rye diets. The ATTD and STTD of P were greater (P < 0.05) in diets with fine than in those with coarse hybrid rye. Increasing levels of phytase supplementation linearly (P < 0.01) and quadratically (P < 0.01) improved the ATTD and STTD of P in hybrid rye diets. There were no interaction effects between PS and phytase supplementation on the ATTD and STTD of P in hybrid rye diets. In conclusion, PS reduction improved the digestibility of P in hybrid rye, and supplementing increasing levels of phytase improved P digestibility in linear and quadratic manner in growing pigs fed hybrid rye diets.

Cereal grains such as corn, wheat, and barley are widely used as an energy source in swine diets. However, due to their recent soaring prices, it is necessary to use alternative feedstuffs for swine. New commercial hybrid rye with improved ergot resistance and higher yield has been developed. This hybrid rye contains similar energy content as barley and sorghum, making it a promising ingredient for pigs. Phosphorus is an essential nutrient in swine diets for bone growth and cellular functions. However, most phosphorus in hybrid rye is bound to phytic acid, which is not digested well by pigs. The excessive phosphorus in swine manure may runoff and cause environmental problems such as eutrophication. Increasing phosphorus digestibility can decrease its excretion in pigs. Therefore, in the current study, we formulated six diets including fine or coarse hybrid rye particle size supplemented with three levels of phytase to determine the effects of particle size and phytase supplementation on phosphorus digestibility in hybrid rye. Our results showed that fine particle size and supplementing increasing levels of phytase could improve the phosphorus digestibility in growing pigs fed hybrid rye diets.

Dietary supplementation of red-osier dogwood polyphenol extract changes the ileal microbiota structure and increases Lactobacillus in a pig model.

Red-osier dogwood (ROD) extract contains a lot of polyphenols that have the potential for modulation of gut microbiota. However, little information is available about its prebiotic properties. This study investigated the impact of ROD polyphenol extract on the ileal microbiota with dietary supplementation of ROD polyphenol extract in a pig model. The data indicated that supplementation of ROD polyphenol extract significantly increased class Bacilli, order Lactobacillales and family lactobacillaceae. Within family lactobacillaceae, Lactobacillus was the main responder by increasing from 5.92% to 35.09%. Further analysis showed that ROD polyphenol extract improved two species Lactobacillus delbrueckii and Lactobacillus mucus. The results of this study suggested that ROD polyphenol extract has the potential to play prebiotic role and confer health benefit through modifying gut microbiota.

Ileal digestibility and endogenous flow of minerals and amino acids: responses to dietary phytic acid in piglets.

Effects of phytic acid (PA) on ileal mineral and amino acid (AA) digestibilities and ileal endogenous AA flow in piglets were investigated. Seven ileal-cannulated weanling pigs were fed a casein-maize starch-based diet with PA (as sodium phytate) at 0, 5, 10 or 20 g/kg in 4 x 4 Latin square design with three added columns to give seven observations per treatment. The basal diet was formulated to meet National Research Council energy and AA requirements for piglets. The respective digestibility and endogenous lysine loss were determined by indicator and homoarginine methods. The apparent ileal digestibility (AID) of Na, K and P was linearly and quadratically reduced (P < 0.05) by increased dietary PA concentration, whereas that of Ca and Mg was only linearly reduced (P < 0.05) by the dietary PA. The AID values for Mg and Na were negative ( - 0.03 and - 0.18, respectively) when PA was supplemented at 20 g/kg. The AID of isoleucine, leucine and valine responded quadratically to dietary PA concentration, though the differences between the AID values of the AA due to change in dietary PA concentration were marginal (at most by 1.8 percentage units). Furthermore, dietary PA did not affect (P>0.05) endogenous AA losses. The results suggest that PA has limited effect on the digestibility and endogenous losses of AA in piglets, but can reduce AID of Mg and Na partly by increasing endogenous losses of these minerals as evidenced by their negative AID values.

Effects of in-feed egg yolk antibodies on Salmonella shedding, bacterial antibiotic resistance, and health of pigs.

To determine effects of anti-Salmonella egg yolk antibodies on shedding and antibiotic resistance of Salmonella enterica Typhimurium, newly weaned pigs were randomly assigned to six dietary treatments. These treatment groups were (i) a control (basal) diet without additives and similar diets with (ii) egg yolk powder derived from chickens challenged with Salmonella Typhimurium antigens, (iii) a commercial egg yolk powder control, (iv) apramycin for 14 days followed by carbadox, (v) oxytetracycline, or (vi) spray-dried plasma protein. Treatments were provided beginning on day 3 of the trial, and all pigs were challenged with 5 ml of 10(8) CFU/ml Salmonella Typhimurium on day 7. Fecal samples were collected on days 0, 7, 8, 12, 14, 21, 58, 88, and 118 for isolation of Salmonella and Escherichia coli to determine shedding and antibiotic resistance patterns. Body weights, white blood cell counts, and plasma concentrations of anti-Salmonella immunoglobulin G and porcine interleukin 1beta were analyzed as indicators of animal health. The percentage of pigs shedding Salmonella was lower for antibiotic treatment groups compared with other groups; however, resistance was greater in E. coli from pigs fed antibiotics than in pigs in other treatment groups. Health and performance indicators (pig weight gains, white blood cell counts, and plasma concentrations of anti-Salmonella antibodies) did not differ between treatment groups. These studies indicate that feeding egg yolk containing anti-Salmonella immunoglobulin Y may not be effective in controlling shedding of Salmonella in pigs.

Flaxseed meal and oat hulls supplementation: impact on predicted production and absorption of volatile fatty acids and energy from hindgut fermentation in growing pigs.

A combination of in vivo (ileal cannulated pigs) and in vitro (fecal inoculum-based incubation) methodologies were used to predict the effects of dietary supplementation with soluble or insoluble dietary fiber on hindgut VFA production and absorption. Energy contribution from hindgut VFA and apparent ileal (AID) and total tract (ATTD) digestibility of energy and DM was also investigated. Twelve ileal cannulated Genesus barrows (initial BW: 35.1 ± 0.44 kg) were allocated to 1 of the 3 corn-soybean meal-based diets without (control), or with flaxseed meal (FM) or oat hulls (OH) in a 2-period cross-over design. Flaxseed meal and oat hulls were used as sources of soluble and insoluble fiber, respectively. In each period, 4 pigs were offered 1 of the 3 diets, for 12 d followed by fecal (day 13 and 14) and ileal digesta collection (day 15 and 16) (n = 8). Ileal digesta were collected, freeze-dried, and subjected to in vitro fermentation using fecal inoculum, to predict production and absorption of VFA and energy production, and digestibility of DM and energy. The quantity of acetic, propionic, butyric, and valeric acids produced by in vitro fermentation was higher (P < 0.05) for the diet containing flaxseed meal compared with the control and OH diets. The predicted quantity of VFA produced and absorbed in the hindgut was greater (P < 0.05) in pigs that consumed the FM diet than those fed the control or OH diet. Pigs fed the control diet had greater (P < 0.05) AID and ATTD of DM than pigs offered the OH or FM diet. The determined disappearance of DM was lower (P < 0.05) in pigs fed the control and OH diets than in pigs that consumed the FM diet. The quantity of digested energy in the upper gut was reduced (P < 0.05) more in pigs fed the OH diet than in pigs fed the FM diet. The consumption of the FM diet increased (P < 0.05) the quantity of digested energy, energy produced and absorbed from VFA in the hindgut, and the percentage contribution of VFA from fermentation to total tract digestible energy, compared with the control and OH diets. In conclusion, dietary supplementation with insoluble fiber from oat hulls reduced ileal digested energy more than soluble fiber from flaxseed meal. Addition of soluble fiber to pig diets increased the energy contribution from VFA produced by hindgut fermentation to the total tract digestible energy, compared with dietary addition of insoluble fiber.

Nonstarch polysaccharide hydrolysis products of soybean and canola meal protect against enterotoxigenic Escherichia coli in piglets.

Infectious diarrhea is a major problem in both children and piglets. Enterotoxigenic Escherichia coli (ETEC) infection results in fluid and electrolyte losses in the small intestine. We investigated the effect of nonstarch polysaccharide (NSP) hydrolysis products of soybean meal (SBM) and canola meal (CM) on net absorption of fluid and solutes during ETEC infection. Products were generated by incubating SBM and CM with a blend of carbohydrase enzymes. Following incubation, slurries were centrifuged and the supernatants mixed with absolute ethanol to produce 2 product types: 80% ethanol-soluble (ES) and 80% ethanol-insoluble (EI). Products from SBM and CM were studied in 2 independent experiments in which 2 factors were investigated: product type (EI vs. ES) and time of ETEC infection (before vs. after perfusion). Pairs of small intestine segments, one noninfected and the other ETEC infected, were perfused simultaneously with different products for 7.5 h. Net absorption of fluid and solutes were determined. In both experiments, ETEC-infected segments perfused with saline control had lower (P < or = 0.05) net fluid and solute absorption compared with SBM and CM products. The interaction (P < or = 0.05) between product type and time of infection on fluid absorption was only evident for SBM, in which case perfusing ES products before infection resulted in higher fluid absorption (735 +/- 22 microL/cm2) compared with ETEC infection before perfusion (428 +/- 34 microL/cm2). In conclusion, NSP hydrolysis products of SBM and CM, particularly ES from SBM, were beneficial in maintaining fluid balance during ETEC infection, suggesting potential for controlling ETEC-induced diarrhea in piglets.

Application of resistant starch in swine and poultry diets with particular reference to gut health and function.

The immediate post-weaning period poses a major challenge on the survival of piglets. Similarly, newly hatched chicks face life threatening challenges due to enteric infections. In the past several years, in-feed antibiotics have been used to reduce these production problems and improve growth. However, in-feed antibiotics have been banned in many jurisdictions and therefore the most effective alternatives to in-feed antibiotics must be developed. To date, several studies have been conducted to develop alternatives to antibiotics. One of the potential candidates as alternatives to in-feed antibiotics is resistant starch (RS). Resistance starch is a type of starch that resists enzymatic digestion in the upper parts of the gastrointestinal tract and therefore passes to hindgut where it can be fermented by resident microorganisms. Microbial fermentation of RS in the hindgut results in the production of short chain fatty acids (SCFA). Production of SCFA in turn results in growth and proliferation of colonic and cecal cells, increased expression of genes involved in gut development, and creation of an acidic environment. The acidic environment suppresses the growth of pathogenic microorganisms while selectively promoting the growth of beneficial microbes. Thus, RS has the potential to improve gut health and function by modifying and stabilising gut microbial community and by improving the immunological status of the host. In this review, we discussed the roles of RS in modifying and stabilising gut microbiota, gut health and function, carcass quality, and energy metabolism and growth performance in pigs and poultry.

Barley ß-glucan increases fecal bile acid excretion and short chain fatty acid levels in mildly hypercholesterolemic individuals.

The cholesterol-lowering effect of barley ß-glucan has been proposed to be the result of a pleiotropic effect, which involves several biological mechanisms such as gut fermentation, inhibition of intestinal cholesterol absorption and increased bile acid excretion and its synthesis. However, one of the recent studies from our laboratory indicated that increased bile acid excretion and subsequent increase in its synthesis, but not the inhibition of cholesterol absorption or synthesis might be responsible for the cholesterol-lowering effect of barley ß-glucan. Accordingly, the primary objective of the present study was to investigate the concentration of bile acids (BA), neutral sterols (NS) and short chain fatty acids (SCFA) excreted through the feces by mildly hypercholesterolemic subjects who consumed diets containing barley ß-glucan with varying molecular weights (MW) and concentrations. In a controlled, four phase, crossover trial, 30 mildly hypercholesterolemic but otherwise healthy subjects were randomly assigned to receive breakfast containing 3 g high MW (HMW), 5 g low MW (LMW), 3 g LMW barley ß-glucan or a control diet for 5 weeks. The concentrations of BA, NS and SCFA in the feces were measured at the end of each treatment phase. Compared to the other treatment groups, 3 g day-1 HMW barley ß-glucan consumption resulted in increased lithocholic acid (LCA) excretion (P < 0.001) but not LMW ß-glucan, even at the high dose of 5 g day-1. Increased fermentability of fibre was also evident from a significant increase in fecal total SCFA concentrations in response to the 3 g HMW ß-glucan diet compared to the 3 g LMW barley ß-glucan and control diet (P = 0.0015). In summary, the current results validate our previous report on the role of fecal bile acid excretion in cholesterol lowering through the consumption of barley ß-glucan. In addition, increased SCFA concentrations indicate that an increase in ß-glucan molecular weight promotes hindgut fermentation, which might also be playing a role in attenuating cholesterol levels.

Impact of xylanases on gut microbiota of growing pigs fed corn- or wheat-based diets.

This study investigated the effects of xylanase supplementations with cereal-based diets on nutrient digestibility and gut microbiota of growing pigs. A total of 96 individually penned pigs (initial BW = 22.7 ± 0.65 kg) were allotted to 12 treatments and subjected to a completely randomized block design experiment. Pigs in each treatment were fed an isocaloric wheat-based or corn-based diet with or without 1 of 5 types of xylanase supplements (XA, XB, XC, XD, XE). On d 42, all piglets were euthanized to obtain ileal and cecal digesta for microbial analysis, which involved high-throughput sequencing of the V1 - V3 regions of 16S rRNA gene. Corn- and wheat-based diets differed (P < 0.05) in digestion characteristics. Dietary treatments affected the alpha- and beta-diversities of microbiota in the cecum but not in the ileum. The wheat-based diet increased (P < 0.05) alpha-diversity and clustered separately (P < 0.05) compared with the corn-based diet. Wheat-based diet also promoted the relative abundance of genus (g.) Succinivibrio while corn-based diet promoted the proportion of family (f.) Veillonellaceae in the community. Among xylanases, only XC within the wheat-based diet altered (P < 0.05) the beta-diversity of the cecal microbiota compared with control. For each cereal-based diet and compared with the controls, xylanase treatments affected (P < 0.05) the proportions of 5 bacterial taxa in the ileum (f. Peptostreptococcaceae, order [o.] Streptophyta, f. Clostridiaceae, g. Clostridium and g. Streptococcus) and 8 in the cecum (g. Lactobacillus, g. Streptococcus, class [c.] Clostridia, f. Clostridiaceae, g. Megasphaera, g. Prevotella, g. Roseburia and f. Ruminococcaceae). Network analysis showed that across diets under control treatments, Bacteroidetes was the most influential phylum promoting cooperative relationships among members of the ileum and cecum microbiota. Xylanase treatment, however, reduced the influence of Bacteroidetes and promoted a large number of hub taxa majority of which belonged to the Firmicutes phylum. To maximize the efficiency of xylanase supplementation, our data suggest that xylanase C originated from Bacillus subtilis was more effective when applied to wheat-based diets, while xylanase A originated from Fusarium verticillioides was more beneficial when applied to corn-based diets.

Zearalenone Exposure Enhanced the Expression of Tumorigenesis Genes in Donkey Granulosa Cells via the PTEN/PI3K/AKT Signaling Pathway.

Zearalenone (ZEA) is a natural contaminant existing in food and feed products that exhibits a negative effect on domestic animals' reproduction. Donkeys possess high economic value in China and are at risk of exposure to ZEA. However, few information is available on ZEA-induced toxicity and no report on toxicity in donkeys can be found in scientific literature. We investigated the biological effects of ZEA exposure on donkey granulosa cells (dGCs) by using RNA-seq analysis. ZEA at 10 and 30 µM were administered to GCs within 72 h of in vitro culture. ZEA at 10 µM significantly altered the tumorigenesis associated genes in dGCs. Exposure to 10 and 30 µM ZEA treatment significantly reduced mRNA expression of PTEN, TGFß, ATM, and CDK2 genes, particularly, the ZEA treatment significantly increased the expression of PI3K and AKT genes. Furthermore, immunofluorescence, RT-qPCR, and Western blot analysis verified the gene expression of ZEA-exposed GCs. Collectively, these results demonstrated the deleterious effect of ZEA exposure on the induction of ovarian cancer related genes via the PTEN/PI3K/AKT signaling pathway in dGCs in vitro.