Reducing BW loss during lactation in sows: a meta-analysis on the use of a nonstarch polysaccharide-hydrolyzing enzyme supplement.

A meta-analysis was performed on eight trials, which included a total of 992 parity 1 to 8 lactating sows, to evaluate the effects of feeding xylanase which is the main enzyme activity present in the enzymatic complex (Rovabio Excel, Adisseo, France) supplement throughout lactation on the following sow performance factors: BW loss, feed intake, backfat depth, and piglet growth. Even a short period of enzyme supplementation during lactation led to a reduction in BW loss of approximately 3 kg per sow (P = 0.003). This reduction represented 1-2% of the BW of sows. This effect could be explained by an increase in feed energy intake and enhanced feed digestibility. Sows fed enzyme-supplemented diets exhibited greater DM, OM, and GE digestibilities (3.4, 3.9, and 4.2% increases, respectively; P < 0.001) than sows fed control diets. During lactation, sows lost from 19 to 25 kg of BW (i.e., approximately 10% of their BW), with a difference between parity groups (P < 0.001). Body reserve mobilization was decreased in sows fed enzyme-supplemented diets (-2.9 kg, P = 0.003), with a more pronounced effect in primiparous than multiparous sows when BW loss is expressed relative to total BW (-2.27 vs. -0.59%, respectively; P = 0.058). Enzyme supplementation also increased litter weight gain up to weaning, with a greater effect in litters from multiparous sows than those from primiparous sows (5.4 vs. 0.6 kg, respectively; P = 0.009). These results could be explained in part by the relationship between their NE intake and either variations in BW or litter weight gain (R2 = 0.51 and 0.49, respectively; P < 0.001). Finally, the meta-analysis suggests that there are differences in the partitioning of the NE intake between growth and milk production and in relation to the sow's parity or physiological status. Extra energy released by enzyme is used for one of these functions (i.e., body mobilization reduction or greater milk export for litter gain).

Influence of different carbohydrate composition in barley varieties on Salmonella Typhimurium var. Copenhagen colonisation in a "Trojan" challenge model in pigs.

Based on previously performed in vitro studies, which showed that hulless barley varieties could reduce large intestinal Salmonella Typhimurium var. Copenhagen proliferation in pigs, two in vivo experiments were conducted to prove these observations. In Experiment (Exp.) 1, 126 weaning piglets were randomly allocated into pens of seven animals each and fed one of six experimental diets. Three diets contained (75% as-fed) one of three hulless barley varieties with beta-glucan (BG) contents ranging from 5 to 11% and amylose from 5 to 40%, and two diets contained a low BG and amylose hulless barley supplemented with isolated barley BG or raw potato starch. A hulled barley diet served as a control. Two piglets per pen ("Trojan" pigs) were orally infected with Salmonella Typhimurium var. Copenhagen (ST). The remaining five pigs per pen were designated "Contact" pigs. The ST shedding was determined over one week after infection. On day 6, the two Trojans and two random Contacts from each pen were euthanised and intestinal contents and mesenteric lymph nodes cultured for ST. Intestinal volatile fatty acids and microbial composition were determined. In Exp. 2, 126 piglets were assigned to one of three diets based on hulled or hulless barleys. The timeline, infection, sampling and analyses were similar as in Exp. 1 except samples were taken from four Contact pigs. Hulless barley varieties with high BG and amylose tended to decrease ST persistence in Exp. 1. Clostridia from cluster I in the colon were reduced with high amylose hulless barley or diets supplemented with potato starch (p < 0.05), whereas other microbial groups were not. Propionate increased (p < 0.05) and acetate decreased (p < 0.05) with hulless barley inclusion. Exp. 2 revealed a reduced ST shedding and reduced number of clostridia for high BG hulless barley as compared to common hulled barley and a low BG variety (p < 0.05). In conclusion, high BG hulless barley do not prevent ST colonisation but might help to reduce transmission in pigs, likely by supporting an intestinal environment limiting growth of this zoopathogen.

Nonstarch polysaccharide-degrading enzymes alter the microbial community and the fermentation patterns of barley cultivars and wheat products in an in vitro model of the porcine gastrointestinal tract.

An in vitro experiment was carried out to assess how nonstarch polysaccharide (NSP)-degrading enzymes influence the fermentation of dietary fiber in the pig large intestine. Seven wheat and barley products and cultivars with differing carbohydrate fractions were hydrolyzed using pepsin and pancreatin in the presence or not of NSP-degrading enzymes (xylanase and ß-glucanase) and the filter retentate was subsequently fermented with sow fecal bacteria. Dry matter, starch, crude protein and ß-glucan digestibilities during hydrolysis were measured. Fermentation kinetics of the hydrolyzed ingredients were modelled. Short-chain fatty acids (SCFA) production and molar ratio were compared after 12, 24 and 72 h. Microbial communities were analyzed after 72 h of fermentation using terminal restriction fragment length polymorphism. The results showed an increase of nutrient digestibility (P<0.001), whereas fermentability and SCFA production decreased (P<0.001) with addition of the enzyme. SCFA and bacterial community profiles also indicated a shift from propionate to acetate and an increase in cellulolytic Ruminococcus- and xylanolytic Clostridium-like bacteria. This is explained by the increase in slowly fermentable insoluble carbohydrate and the lower proportion of rapidly fermentable ß-glucan and starch in the retentate when grains were incubated with NSP-degrading enzymes. Shifts were also different for the four barley varieties investigated, showing that the efficiency of the enzymes depends on the structure of the carbohydrate fractions in cereal products and cultivars.

Phaseolin from Phaseolus vulgaris bean modulates gut mucin flow and gene expression in rats.

Dietary protein might modulate mucin flow and intestinal mucin gene expression. Since unheated phaseolin from Phaseolus vulgaris bean is resistant to digestion and increases gut endogenous protein losses, we hypothesised that unheated phaseolin influences mucin flow and gene expression, and that phaseolin heat treatment reverses these effects. The hypothesis was tested using a control diet containing casein as the sole protein source and three other diets with casein being replaced by 33 and 67 % of unheated and 67 % of heated phaseolin. The rats were fed for 6 d and euthanised. Digesta and faeces were collected for determining digestibility and mucin flow. Gut tissues were collected for mucin (Muc1, Muc2, Muc3 and Muc4) and Trefoil factor 3 (Tff3) gene expressions. Colonic mucin flow decreased linearly with increasing the dietary level of unheated phaseolin (P < 0·05). Unheated phaseolin increased N flow in ileum, colon and faeces (P < 0·05), and reduced apparent N digestibility linearly (P < 0·01). Heat treatment reversed all these changes (P < 0·05 to < 0·001), except mucin flow. The expressions of Muc mRNA in gut tissues were influenced by dietary phaseolin level (ileum and colon: Muc3 and Muc4) and thermal treatment (ileum: Muc2; colon: Muc2, Muc3, Muc4 and Tff3) (P < 0·05 to 0·001). In conclusion, phaseolin modulates mucin flow and Muc gene expression along the intestines differentially.

In vitro bile acid binding and short-chain fatty acid profile of flax fiber and ethanol co-products.

Fibers from flaxseed and co-products from ethanol production could be potential sources of dietary fiber in human diet. In vitro fermentation and bile acid binding models were used to investigate the metabolic effects of lignaMax (Bioriginal Food and Science Corp., Saskatoon, SK, Canada) flax meal, spent flax meal, soluble flax gum, wheat insoluble fiber (WIF), and rye insoluble fiber (RIF). Wheat and rye bran were used as reference samples. Bile acid binding of substrates was analysed at taurocholate ([(14)C]taurocholate) concentration of 12.5 mM. Soluble flax gum showed the highest bile acid binding (0.57 micromol/mg of fiber) (P

Effect of carbohydrate composition in barley and oat cultivars on microbial ecophysiology and proliferation of Salmonella enterica in an in vitro model of the porcine gastrointestinal tract.

The influence of the carbohydrate (CHO) composition of cereal cultivars on microbial ecophysiology was studied using an in vitro model of the porcine gastrointestinal tract. Ten hull-less barley cultivars, six barley cultivars with hulls, six oat cultivars, and six oat groats that differed in beta-glucan, nonstarch polysaccharide (NSP), and starch contents and starch type were hydrolyzed enzymatically and incubated for 72 h with pig feces. Fermentation kinetics were modeled, and microbial compositions and short-chain fatty acid (SCFA) profiles were analyzed using terminal restriction fragment length polymorphism and gas chromatography. Cluster analysis and canonical ordination revealed different effects on fermentation and microbial ecology depending on the type of CHO and cultivar. First, in cultivars of barley with hulls and oats, the cellulose and insoluble NSP contents (i) increased Ruminococcus flavefaciens-like and Clostridium xylanolyticum-like phylotypes, (ii) increased acetate production, and (iii) decreased fermentation activity. Second, in hull-less barley cultivars the beta-glucan, amylose, amylopectin, crude protein, and soluble NSP contents determined the microbial community composition and activity as follows: (i) the amylose contents of the hull-less barley varieties increased the butyrate production and the abundance of Clostridium butyricum-like phylotypes, (ii) the beta-glucan content determined the total amounts of SCFA, and (iii) the amylopectin and starch contents affected the abundance of Clostridium ramosum-like phylotypes, members of Clostridium cluster XIVa, and Bacteroides-like bacteria. Finally, the effect of CHO on proliferation of Salmonella enterica in the model was determined. Salmonella cell counts were not affected, but the relative proportion of Salmonella decreased with hull-less barley cultivars and increased with oat cultivars as revealed by quantitative PCR. Our results shed light on the complex interactions of cereal CHO with intestinal bacterial ecophysiology and the possible impact on host health.

Susceptibility of phaseolin (Phaseolus vulgaris) subunits to trypsinolysis and influence of dietary level of raw phaseolin on protein digestion in the small intestine of rats.

The aim of the present work was (a) to investigate trypsinolysis of denatured purified T phaseolin (Phaseolus vulgaris) subunits by MS and (b) to test the effect of raw T phaseolin inclusion level in diets fed chronically to rats on digestion in the small intestine. The diets contained casein as the sole protein source, or casein substituted with 33, 67 and 100 % of purified T phaseolin. Rats were fed for 10 d and then euthanised. Digesta and tissues from the first and second halves of the small intestine were prepared for electrophoresis, immunoblotting and densitometry. alpha-Phaseolin subunit for the T phaseolin was more resistant to trypsinolysis than beta-phaseolin subunit. Nearly intact phaseolin subunits (molecular weight, MW 44-54 kDa) and partially digested phaseolin fragments (MW 17-19 and 20-24 kDa) were identified in small intestinal digesta. The concentration of intact phaseolin and of most undigested phaseolin fragments in digesta increased in the second half of the small intestine with increasing phaseolin intake (P < 0.05-0.01). The concentration of phaseolin fragments of a MW of 21-22.5 and 23-24.5 kDa in the mucosa increased linearly (P = 0.016-0.084) when the level of the T phaseolin was increased in the diet. In conclusion, the present work provides evidence that denatured T phaseolin subunits display different trypsinolysis patterns in vitro. Moreover, a high intake of raw T phaseolin impacts digestion in the small intestine of rats.

Effect of barley and oat cultivars with different carbohydrate compositions on the intestinal bacterial communities in weaned piglets.

This experiment was aimed at comparing the intestinal microbial community composition in pigs fed hulled common barley supplemented with isolated barley mixed-linked beta-glucan, four hulless barley varieties and breeding lines with mixed-linked beta-glucan contents ranging from 41 to 84 g kg(-1) and different amylose/amylopectin ratios as well as two oat varieties. Seventy-two weaned piglets were allocated to one of nine diets composed of 81.5% cereal, 6% whey, 9% soy protein isolate and 3.5% minerals. After 15 days, pigs were sacrificed and ileum and colon contents were collected for quantitative real-time PCR (qPCR) and denaturing gradient gel electrophoresis to evaluate microbial communities. Shifts in intestinal microbial communities were observed with the hulless barley cultivars with a normal to high beta-glucan content and from normal starch toward either high-amylopectin or high-amylose starch. These hulless barleys had the lowest (P<0.05) microbial diversity, whereas oats had intermediate diversity compared with low-beta-glucan hulless cultivars and hulled varieties. Furthermore, hulless varieties favoured xylan- and beta-glucan-degrading bacteria whereas mixed-linked beta-glucan-supplemented hulled barley favoured lactobacilli. Numbers of lactobacilli decreased in the ileum of pigs fed hulless/high mixed-linked beta-glucan barley-based diets. Thus, cultivar differences in both the form and the quantity of carbohydrates affect gut microbiota in pigs, which provides information for future feeding strategies.

Susceptibility of phaseolin to in vitro proteolysis is highly variable across common bean varieties (Phaseolus vulgaris).

A study was conducted to investigate the amino acid (AA) composition and the susceptibility to in vitro proteolysis (pepsin, 120 min and pancreatin, 240 min) of a collection of purified phaseolins ( n = 43) in unheated or heat-treated form. The AA composition of phaseolin varied little across bean varieties. At 360 min of in vitro proteolysis, the degree of hydrolysis varied from 11 to 27% for unheated and from 57 to 96% for heated phaseolins ( P < 0.001). Heat treatment markedly increased the susceptibility of phaseolin to proteolysis ( P < 0.001). The AA scores (AAS) and the protein digestibility corrected for AAS indicated S-containing AA as the limiting AA (39 +/- 3 and 30 +/- 5%, respectively). In conclusion, susceptibility to proteolysis of heat-treated phaseolin rather than its AA composition affects the nutritional value of phaseolin estimated in vitro. Therefore, it should be the criterion of choice in breeding programs aimed at improving the nutritional value of common beans for humans.

Phaseolin type and heat treatment influence the biochemistry of protein digestion in the rat intestine.

The study aimed to investigate the in vivo digestion of Phaseolus vulgaris phaseolin types differing in their subunit pattern composition. Diets contained either casein as the sole source of protein or a mixture (1:1) of casein and pure Sanilac (S), Tendergreen (T) or Inca (I) phaseolin either unheated or heated. Rats were fed for 11 d with the experimental diets. Their ileal content and mucosa were collected and prepared for electrophoresis, Western blotting, densitometry and MS. Differences in digestion among native phaseolin types were observed for intact phaseolin at molecular weights (MW) of 47-50.5 kDa and for an undigested fragment at MW of 19-21.5 kDa in ileal digesta. In both cases, the concentration of these protein bands was lower for I phaseolin than for S or T phaseolin (P < 0.05). In the mucosa, the concentration of a protein band at MW of 20.5-21.5 kDa was lower for S phaseolin as compared to T or I phaseolin (P < 0.001). The presence of phaseolin subunits and their fragments was confirmed by Western blotting. MS analysis revealed the presence of undigested alpha and beta subunit fragments from phaseolin and endogenous proteins (anionic trypsin I and pancreatic alpha-amylase) in ileal digesta. Thermal treatment improved digestion (P < 0.01), acting on both dietary and endogenous protein components. In conclusion, this study provides evidence for differences in intestinal digestion among phaseolin types, S phaseolin being more resistant and I phaseolin more susceptible. These differences were affected by the origin of the phaseolin subunit precursor. Heat treatment enhanced phaseolin digestion.

A protein-free diet alters small intestinal architecture and digestive enzyme activities in rats.

The consequences of feeding a protein-free (PF) diet, as compared to casein, on gut characteristics were studied in slightly energy-restricted rats fed similar amounts of feed for 10 d. The weight and pH of fresh digesta in the stomach were lower (P = 0.045 and P = 0.016). However, the weight of fresh digesta in the other segments and gut tissue weight were not significantly affected by the diet (P > 0.05). Small intestinal crypt depth, width and area were reduced by 13, 23 and 37%, respectively (P = 0.011, P = 0.004 and P = 0.001), and villus width tended to be smaller (P = 0.057), with the PF diet. Villus height to crypt depth ratio was also lower with the PF diet in the duodenum and ileum, respectively (P < 0.05). Finally, the specific activities of alkaline phosphatase and aminopeptidase N were reduced by 36 to 38% at different sites of the small intestine in the rats fed the PF diet (P < 0.05). In conclusion, chronic consumption of a protein-free diet altered the intestinal villus-crypt architecture and enzyme activities in rats.

Influence of the Phaseolus vulgaris phaseolin level of incorporation, type and thermal treatment on gut characteristics in rats.

Phaseolus vulgaris phaseolin has been shown to stimulate faecal losses of endogenous N in rats. Experiments with purified phaseolin were carried out in rats to test the hypothesis that these losses reflect intestinal disorders. Phaseolin composition varies depending on its constitutive subunits. Therefore, three phaseolin types (S, T, I) were tested. Phaseolin T was incorporated in varying levels (0, 33, 67 or 100 % of the dietary protein) as raw material in experiment 1. In experiment 2, the three phaseolin types were incorporated at 50 %, with or without previous thermic treatment. Raw casein was the basal protein source and was also heated in experiment 2. Faecal digestibility of phaseolin and gut integrity were evaluated in both experiments. The incorporation level or type of phaseolin had little effect on gross anatomy of gut segments but these factors influenced the weight and pH of fresh contents of the stomach and caecum (P<0.05). Raw phaseolin T incorporated at various levels led to an enlargement of duodenal villi together with a tendency for increased crypt depth in the jejunum (P=0.06). Activities of both alkaline phosphatase in the duodenum and aminopeptidase N in the ileum decreased (P<0.05) after thermal treatment of casein while they increased (P<0.05) for heat-treated phaseolin S and T, respectively. In conclusion, raw phaseolin had no effect on the tissue weight of gut segments and induced limited alterations in the small intestine. Differences due to phaseolin level or type were limited too.

Effect of pig bodyweight on ileal amino acid endogenous losses after ingestion of a protein-free diet enriched in pea inner fibre isolates.

The present study was conducted to evaluate whether bodyweight and the micronisation of dietary fibre affect the endogenous nitrogen and amino acid losses (ENL and EAAL) in pigs. The effect of the micronising process was tested by providing pigs with 90 g DM x kg(-1) BW0.75 of a N-free diet supplemented with isolated pea inner fibres, presented in native or micronised form and with a water-holding capacity of 12 and 4 g water g(-1) DM, respectively. ENL and EAAL were measured on pigs weighing 24, 62 and 105 kg. In all cases, daily ENL increased linearly (P < 0.05) with BW, for the majority of the AA and total N. As BW increased, daily ENL, total EAAL and the majority of EAAL increased linearly independently of micronisation (P < 0.05). When expressed per kg DMI, total EAAL and the majority of each EAA decreased curvilinearly and reached nadir at around 100 kg BW. For ENL expressed per kg DMI, micronisation resulted in a curvilinear decrease with increasing BW, as compared to a linear decrease for pigs fed the native pea fibre diet (non-micronised). Micronisation of pea inner fibres did not decrease ENL or EAAL daily, except for proline. When the losses were expressed as g x k(-1)g DMI, micronisation did not decrease ENL but decreased (P < 0.05) endogenous losses for a majority of AA as well as for total AA. The results suggest that small pigs excrete more endogenous N per kg DMI than large pigs and that pea fibre micronisation reduces EAAL but not ENL when expressed per kg DMI.

Recommendations by health organizations for pulse consumption.

The present paper aims to study why and how health organizations recommend the consumption of pulses such as beans, chickpeas or lentils. Although it is recognized that frequent pulse consumption may reduce serum cholesterol levels and helps reduce risks of coronary heart disease and diabetes, these advantages are scarcely mentioned by health-promoting associations, i.e. vegetarians and organizations helping people to reduce the risks for chronic diseases. Pulses, especially common beans, are rather considered as whole grains that provide plenty of proteins, starch, dietary fibres, minerals and vitamins. Many organizations refer to the food guide pyramid to advise their members, and place beans either in the third part, together with meat, in the second one with fruits and vegetables, or in the bottom part with starchy foods. Whatever their place, they have acquired the status of staple food for anyone who wants to eat a healthy diet.

Factors influencing pulse consumption in Latin America.

In Latin America, pulse consumption ranges from 1 kg/capita per year (Argentina) to 25 kg/capita per year (Nicaragua). Common beans account for 87 % of the total. The differences between countries, regions or groups of population within the same country can be explained by the following factors: (1) beans are very nutritious; (2) beans and maize are traditional foods and the habit of consuming them is deeply rooted in many people and communities; (3) the rural population eats more pulses than the urban population, due to geographical constraints that limit exchanges and favour consumption of locally produced foods; (4) income level, beans are still the poor man's meat; and (5) other factors, such as consumers' taste, the constraints on cooking beans, etc. The evolution of the consumption level in the future will depend on the urbanization of the population, access to processed foods and income level. Health issues would be an argument for maintaining or increasing the current consumption level.