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Effect of feeding piglets with different extruded and nonextruded cereals on the gut mucosa and microbiota during the first postweaning week



Two trials were conducted to evaluate the effect of different cereals in piglet diets on the jejunal mucosa and the ileal and cecal microbiota during the first postweaning days. In Trial 1, 48 newly weaned pigs (7.95 kg BW; 26 d of age) were individually housed and distributed among 3 experimental diets containing white rice (Oryza sativa), naked oats (Avena sativa), or barley (Hordeum vulgare) as the cereal source. At the start of the trial (weaning; day 0), 12 piglets were slaughtered and sampled to obtain initial reference values for histology and microbiology determinations. Additionally, 4 pigs per treatment per day were slaughtered and sampled at days 1, 2, and 6 postweaning. Villus height (VH), crypt depth (CD), and intraepithelial lymphocytes (IEL) in jejunal mucosa were measured, and microbiota in ileal and cecal digesta were evaluated by RFLP. The Manhattan distances between RFLP profiles were calculated and, for each treatment and sampling day, intragroup similarities (IGS) were estimated. In Trial 2, an additional 48 piglets were used (7.56 kg BW; 26 d of age), and the same experimental procedures were performed except that the 3 experimental diets contained extruded white rice, extruded naked oats, or extruded barley as the cereal source. A reduction in VH was observed in both trials from day 0 to 6 (P < 0.05). In Trial 1 (raw cereals), more IEL and deeper crypts were observed for the barley than for the naked oats based diets (P < 0.05). In Trial 2, no differences among extruded cereals were observed for the histological parameters. In Trial 1, feeding naked oats resulted in lower IGS (increased heterogeneity) of the microbiota in the ileum and in the cecum compared to rice and barley (P < 0.05). In Trial 2, the pigs fed extruded barley had lower IGS in the ileum than those fed extruded naked oats and extruded rice whereas in the cecum, both extruded barley and extruded rice resulted in lower IGS than extruded naked oats (P < 0.05). It is concluded that cereal nature affects the composition of the microbiota and the morphology of the gut mucosa in newly weaned pigs.
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... In Trial 1, pigs fed naked oats had greater ileal and cecal microbiota heterogeneity than pigs fed naked rice or naked barley. 44 In Trial 2, the opposite response was observed, suggesting that extrusion increases the digestibility of oat-based products. 44 Moen et al 45 tested the effects of untreated or extruded oat groats (83.9% of diet) in growing pigs (46.5 kg). ...
... 44 In Trial 2, the opposite response was observed, suggesting that extrusion increases the digestibility of oat-based products. 44 Moen et al 45 tested the effects of untreated or extruded oat groats (83.9% of diet) in growing pigs (46.5 kg). Fecal samples were collected from pigs at baseline (day 0) and after 21 days. ...
... Bacterial populations were measured by 454 pyrosequencing. Similar to the findings of Torrallardona et al, 44 pigs fed extruded grains had lower fecal microbial diversity than those fed untreated grains. 45 Thirty-seven operational taxonomic units were altered in pigs fed untreated grains vs extruded grains, and 27 operational taxonomic units were altered in pigs fed oats vs barley. ...
Oats are uniquely nutritious, owing to their composition of bioactive compounds, lipids, and β-glucan. Scientific research has established that oats can improve diet quality, reduce cholesterol, regulate satiety, and protect against carcinogenesis in the colon; however, determining the effects of oats on gastrointestinal health and the gut microbiome is a newer, evolving area of research. To better understand the effects of oats on gastrointestinal health in humans, a literature review with predefined search criteria was conducted using the PubMed database and keywords for common gastrointestinal health outcomes. Moreover, to examine the gastrointestinal effects of oats across the scientific spectrum, a similar search strategy was executed to identify animal studies. In vitro studies were identified from the reference lists of human and animal studies. A total of 8 human studies, 19 animal studies, and 5 in vitro studies met the inclusion criteria for this review. The evidence in humans shows beneficial effects of oats on gastrointestinal health, with supportive evidence provided by in vitro and animal studies. The effective dose of oats varies by type, although an amount providing 2.5 to 2.9 g of β-glucan per day was shown to decrease fecal pH and alter fecal bacteria. For oat bran, 40 to 100 g/d was shown to increase fecal bacterial mass and short-chain fatty acids in humans. Differences in study design, methodology, and type of oats tested make valid comparisons difficult. The identification of best practices for the design of oat studies should be a priority in future research, as the findings will be useful for determining how oats influence specific indices of gastrointestinal health, including the composition of the human gut microbiome.
... However, some effects of extrusion of the gut microbiota have been indicated in growing pigs. 40,41 The pig has been shown to be a useful model organism for studying how diets affect the human gut microbiota. 42 Both pigs and humans are colon fermenters, and they have similar composition of the colonic microbiota, 43 and mainly consists of the Firmicutes and Bacteroidetes phyla. ...
The effect of extrusion of barley and oat on the fecal microbiota and the formation of SCFA was evaluated using growing pigs as model system. The pigs were fed a diet containing either whole grain barley (BU), oat groat (OU), or their respective extruded samples (BE and OE). 454 pyrosequencing showed that the fecal microbiota of growing pigs was affected by both extrusion and grain type. Extruded grain resulted in lower bacterial diversity and enrichment in operational taxonomic units (OTUs) affiliated with members of the Streptococcus, Blautia and Bulleidia genera, while untreated grain showed enrichment in OTUs affiliated with members of the Bifidobacterium and Lactobacillus genera, and the butyrate-producing bacteria Butyricicoccus, Roseburia, Coprococcus and Pseudobutyrivibrio. Untreated grain resulted in a significant increase of n-butyric, i-valeric and n-valeric acid, which correlated with an increase of Bifidobacterium and Lactobacillus. This is the first study showing that cereal extrusion affects the microbiota composition and diversity towards a state generally thought to be less beneficial for health, as well as less amounts of beneficial butyric acid.
... The harmful effects of heat stress on top of weaning stress can cause lethargy, anorexia, decrease in feed efficiency, weight loss, and high morbidity and mortality in piglets, which in turn leads to prolonged production cycle and enormous economic loss in swine industry (Stahly et al., 1979;Fuquay, 1981;McGlone and Pond, 2003). Furthermore, as is known, environmental and nutritional changes both can dramatically alter the gastrointestinal microbial population (Burkholder et al., 2008;Torrallardona et al., 2012), decrease the immune functions and damage the antioxidant defence system of weanling pigs (Morrow-Tesch et al., 1994). To minimize the harmful effects of weaning and heat stresses on piglet's health and production performance, probiotics and selenium (Se) have been postulated to be alternatives to antibiotic growth promoters. ...
Conference Paper
This study was designed to evaluate the efficacy of selenium-enriched probiotics (SeP) on production performance and intestinal microbiota of piglets raised under high ambient temperature. Forty-eight cross-bred weanling piglets (28 days old), randomly allotted into 12 pens (four piglets/pen) and four dietary treatments (three pens/treatment group), were fed ad libitum for 42 days a basal diet (Con) or the basal diet supplemented with probiotics (Pro), sodium selenite (ISe) or a SeP preparation. Blood and faecal samples were collected on days 0, 14, 28 and 42 post-treatment. The SeP group had higher final BW (p < 0.05), greater ADG (p < 0.05) and lower FCR (p < 0.01) than the Pro, ISe or Con group. The diarrhoea incidence rate of either SeP or Pro group was lower (p < 0.01) than the ISe or Con group. Blood Se concentration and GSH-Px activity were both higher (p < 0.01) in the SeP than in the Pro, ISe or Con group. On days 28 and 42, the serum concentrations of T3 were higher (p < 0.01) and T4 lower (p < 0.01) in the SeP than in the ISe group, and the T3 and T4 concentrations in the ISe group, in turn, were higher (p < 0.05) and lower (p < 0.01), respectively, than in the Pro or Con group. Also on days 28 and 42, the faecal counts of lactobacillus bacteria were higher (p < 0.01) while Escherichia coli lower (p < 0.01) in the SeP or Pro group as compared to the ISe or Con group. The results of RFLP showed that the faecal microbial flora in the SeP group changed the most (numerically) as compared to the Pro or ISe group. These results suggest that the SeP product may serve as a better alternative to antibiotics than the solo probiotics for using as a growth promoter for weanling piglets. Journal of Animal Physiology and Animal Nutrition © 2015 Blackwell Verlag GmbH.
... Since their ban in the European Union, different alternatives to antibiotic growth promoters have been investigated including nonantibiotic natural substances (Lallès et al., 2009). We have shown previously that the nature of the cereal used in the piglet's diet affects the gut microbiota (Torrallardona, et al., 2012). To some degree, this effect of cereal may be due to differences in feed intake related to cereal palatability (Solà-Oriol et al., 2009). ...
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A trial was conducted to evaluate the effect of different cereals on the performance, gut mucosa, and microbiota of weanling pigs with or without previous access to creep feed during lactation. A total of 108 newly weaned pigs (7.4 kg BW; 26 d of age; half with and half without creep feed) were used. Piglets were distributed by BW into 36 pens according to a 2 x 6 factorial arrangement of treatments with previous access to creep feed (with or without) and cereal source in the experimental diet [barley (Hordeum vulgare), rice (Oryza sativa)-wheat (Triticum aestivum) bran, corn (Zea mays), naked oats (Avena sativa), oats, or rice] as main factors. Pigs were offered the experimental diets for 21 d and performance was monitored. At day 21, 4 piglets from each treatment were killed and sampled for the histological evaluation of jejunal mucosa and the study of ileal and cecal microbiota by RFLP. The Manhattan distances between RFLP profiles were calculated and intragroup similarities (IGS) were estimated for each treatment. An interaction between cereal source and previous creep feeding was observed for ADFI (P < 0.05), indicating that whereas creep feeding increased ADFI for the rice-wheat bran diet it reduced it for naked oats. No differences in mucosal morphology were observed except for deeper crypts in pigs that did not have previous access to creep feed (P < 0.05). Cereal source had a significant effect on IGS of ileal and cecal microbiota (P < 0.01). In the ileum oats and corn had the highest IGS (i.e., lowest heterogeneity of the microbiota) followed by rice, naked oats, barley, and rice-wheat bran whereas in the cecum, IGS was highest for rice and oats followed by corn, barley, rice-wheat bran, and naked oats. An interaction between creep feeding and cereal was also observed for the IGS of the cecal microbiota at day 21 (P < 0.05). Access to creep feed reduced IGS in the piglets fed oats or barley but no differences were observed for the other cereal sources. It is concluded that the effect of creep feeding during lactation on the performance and the microbiota of piglets after weaning is dependent on the nature of the cereal in the postweaning diet.
The gastrointestinal tract of piglets is characterized by complex and dynamic interactions between mucosa, intestinal flora and nutrients and is associated with disorders around weaning, resulting in diarrhoea. While there is a need for reducing the use of antibiotics in veterinary medicine, particularly in weaning feeds, alternatives including feeding strategies, feed ingredients and additives have the potential to improve the gut health. The choice of effective substances can only emerge of a prior assessment, based on previous results and in vivo evaluation studies. Such evaluation studies have faced two challenges: to establish experimental models reflecting real farm conditions, and to measure key parameters of the underlying mechanisms of nutritional solutions. This report reviewed and synthesized experimental models and biological indicators used in recent studies evaluating the mechanisms and the effects of alternatives to antibiotics. Interviews with scientists addressing these issues completed the expertise. In this report, the basis of each specific parameter is explained. Data on methodology, limitations and costs are presented. Lastly some examples are given of application of these methods in feeding and additive evaluations. Moreover, tables present the parameters used in recent studies of solutions promoting gut health at weaning, experimental designs and results of other studies measuring the acute phase proteins by piglets, and the biomarkers of morphological and physiological adaptation at weaning. Legislation on feed additives and functional ingredients is considered, mainly about the efficacy studies. The development of evaluation studies is discussed and some recommendations are given. Infectious disease challenges and sanitary status degradation models appeared as two reference experimental approaches to assess effects of dietary treatments on pathogen action in the digestive tract. The challenge model using enterotoxigenic Escherichia coli is appropriate for studying the infectious pathogenic agent which is the most frequently involved in weaning diarrhoea. However, severity of diarrhoea may be lower than that observed in commercial farms. A sanitary status degradation design expose piglets to different pathogens, but the infection pressure is uncontrolled, and the importance of immune stimulation may vary among experiments and experimental herds. The biological parameters were distinguished between those requiring surgery and euthanasia (cannulas, digesta and tissue samples), and those using non-invasive or minimally invasive samplings (blood or faeces). Observation of intestinal villous-crypt architecture is an acute and synthetic indicator of functionality of the intestinal mucosa. Ussing chambers may be used to quantity permeability and absorption capacity of the mucosa. These techniques are both widely used in weaning studies, but they have a significant need for skilled labour. Recently, urinary markers permitted to assess permeability. Adhesion of enterotoxigenic bacteria to intestinal cells is an appropriate indicator for evaluating anti-adhesion agents. Volatile fatty acids support intestinal ecology and epithelial cells. Measurement of its concentrations in gut segments is useful to determine whether feed ingredients favourably influence intestinal fermentations or not. Identification of bacterial populations by microbiological culture methods, or more and more, by molecular techniques provides information on diversity and evolution of the digestive microbiota. Numerous studies have measured effects of raw materials, additives and rearing conditions on the microbiota composition. Enzyme activities are sometimes used to obtain information on digestive capacity around weaning. Weaning is a period of disturbance of the immune system. Several immunity parameters (immunoglobulins, lymphocytes, pro-inflammatory cytokines...) are regularly measured in studies involving prebiotics, probiotics or protein sources as spray-dried animal plasma, that could promote the immune response. The faecal consistency score is an interesting synthetic indicator, frequently used in infectious challenges and sanitary status degradation models. This individual score facilitates comparison of clinical diarrhoea prevalence. Analysis of flora and volatile fatty acids in the faeces are non-invasive and repeatable measurements that provide information on microbiota composition in the lower gut. Acute phase proteins, mainly haptoglobin, are sensitive indicators of infection, inflammation and immune response. They are right biomarkers for challenge and health status studies. Moreover, European Union regulation requires that the efficacy of any product claiming a positive effect on production or animal welfare especially through effects on the intestinal flora, has to be evaluated using short term studies and long-term in vivo studies. This formal evaluation will be helpful for pre-sorting the products. Overall, performances, faecal score and acute phase protein analysis are synthetic and reliable information on digestive health of the piglets, which should be measured whenever possible in evaluation studies. Other biological parameters discussed in this report should be analysed by laboratories on faeces, digesta, blood and tissue samples sent by pig research centres. The use of such additional parameters indicating the mode of action might facilitate the discussion of study results, particularly when performance criteria are not significantly influenced.
The post-weaning period continues to cause problem in rearing piglets, despite sustained research efforts and derived applications in feed industry over the past decades. The present chapter highlights from the scientific standpoint that a significant number of alternatives to in-feed antibiotics have a potential for alleviating postweaning gut disorders in young pigs and provides possible underlying protective mechanisms. A limited number of alternatives are already in use (e.g. zinc oxide, spray-dried animal plasma protein, selected organic acids). However, many studies were conducted in highly controlled experimental facilities and with low numbers of observations. Therefore, the robustness of many other potential alternatives needs to be tested on larger numbers of pigs and in field conditions for confirming their protective effects. Another important point in this chapter relates to interactions among feed components or ingredients and with genetic and environmental factors that are presently poorly understood. The available data reveal the reality and the complexity of these interactions. Obviously, beneficial effects of two or more substances/components evaluated individually are not simply additive or synergistic when combined. Antagonisms have been also disclosed. Therefore, massive work in this field needs to be implemented in order to define and optimize the rules of association of such alternatives into starter diets. Long-term studies are also needed for understanding distant effects of early life events on gut health better.
A trial was conducted to evaluate the effects of extrusion of different cereals on the performance, nutrient digestion, and VFA concentrations in the cecal digestive contents of weanling pigs. Ninety-six weaned piglets (allocated in 48 pens) were fed 12 different cereal-based diets, consisting of 6 cereals (rice, barley, wheat, corn, oats, and sorghum; 55% inclusion) with or without extrusion processing. Piglets’ performance (for 26 d) and nutrient apparent total tract digestibility (ATTD; at d 13) were evaluated. At the end of the trial, the 32 piglets fed the rice and barley diets (with low and high contents of nonstarch polysaccharides, respectively) were slaughtered and samples were obtained to measure apparent digestibility (AD) of nutrients and digesta viscosity in the proximal two-thirds of the small intestine (pSI) and the distal one-third of the small intestine (dSI) and the concentrations of VFA in the cecal contents. Cereal source (CS) or extrusion did not affect piglet performance. Cereal source affected ATTD for all nutrients, whereas extrusion improved ATTD of only GE (86.5 vs. 85.1%) and starch (99.9 vs. 99.8%; P < 0.05). There was a CS × extrusion interaction for ATTD of CP, which was reduced by extrusion but only for rice and oats (84.0 and 84.4 vs. 77.4 and 78.8%, respectively). Extrusion reduced AD of fat in the pSI, whereas a CS × extrusion interaction was observed for AD of starch that was improved by extrusion in barley (88.5 vs. 80.0%) but not rice. Greater AD of DM (72.2 vs. 63.3%) and GE (72.0 vs. 62.7%) in the dSI was observed in rice than in barley, whereas extrusion improved AD of starch (98.6 vs. 96.6%). Interactions (CS × extrusion) were also observed for digesta viscosity in the pSI and dSI (extrusion increased viscosity for barley but not rice). Finally, extrusion reduced (P < 0.05) the concentrations of propionic (20.0 vs. 13.2 μmol/g) and butyric acids (11.0 vs. 4.4 μmol/g) in the cecum. It is concluded that both CS and extrusion affect nutrient digestibility but not performance. Cereal source effects are evident over the whole digestive tract, but the effects of extrusion depend on the nature of the cereal and are more evident in the small intestine. © 2016 American Society of Animal Science. All rights reserved.
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Factors including sub-optimal nutrient and energy intake associated with lowered digestion and absorption, immature immune function, and psychosomatic factors caused by weaning can compromise intestinal barrier function through mucosal damage and alteration of tight junction integrity. As a consequence, pigs at weaning are highly susceptible to pathogenic enteric diseases such as post-weaning colibacillosis (PWC) caused by enterotoxigenic Escherichia coli. Dietary components such as protein, non-starch polysaccharides, and minerals are known to influence microbial growth in the gastrointestinal tract as undigested nutrients then become available for bacterial growth. This article reviews the association between dietary components, intestinal bacterial growth, intestinal barrier function, and enteric disease in weaner pigs with special emphasis on PWC. Evidence presented in this review indicates that the pathogen-originated diseases such as PWC are closely associated with dietary components and intestinal barrier functions can be maintained through manipulation of dietary protein, non-starch polysaccharides (NSP) and mineral levels. Especially, the use of a reduced protein diet for at least 7 days immediately after weaning, limitation of viscosity-increasing soluble NSP content while including 20–80 g/kg insoluble NSP source in the diet, and limitation of iron to 100 mg/kg are important dietary strategies to maintain intestinal barrier function and to minimise PWC.
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The EU ban on in-feed antibiotics has stimulated research on weaning diets as a way of reducing post-weaning gut disorders and growth check in pigs. Many bioactive components have been investigated but only few have shown to be effective. Amongst these, organic acids (OA) have been shown to exert a bactericidal action mediated by non-dissociated OA, by lowering gastric pH, increasing gut and pancreas enzyme secretion and improving gut wall morphology. It has been postulated that they may also enhance non-specific immune responses and improve disease resistance. In contrast, relatively little attention has been paid to the impact of OA on the stomach but recent data show they can differently affect gastric histology, acid secretion and gastric emptying. Butyrate and precursors of butyric acid have received special attention and although promising results have been obtained, their effects are dependent upon the dose, treatment duration, initial age of piglets, gastrointestinal site and other factors. The amino acids (AA) like glutamine, tryptophan and arginine are supportive in improving digestion, absorption and retention of nutrients by affecting tissue anabolism, stress and (or) immunity. Glutamine, cysteine and threonine are important for maintaining mucin and permeability of intestinal barrier function. Spray-dried plasma (SDP) positively affects gut morphology, inflammation and reduces acquired specific immune responses via specific and a-specific influences of immunoglobulins and other bioactive components. Effects are more pronounced in early-weaned piglets and under poorer health conditions. Little interaction between plasma protein and antibiotics has been found, suggesting distinct modes of action and additive effects. Bovine colostrum may act more or less similarly to SDP. The composition of essential oils is highly variable, depending on environmental and climatic conditions and distillation methods. These oils differ widely in their antimicrobial activity in vitro and some components of weaning diets may decrease their activity. Results in young pigs are highly variable depending upon the product and doses used. These studies suggest that relatively high concentrations of essential oils are needed for beneficial effects to be observed and it has been assumed that these plant extracts mimic most of the effects of antibiotics active on gut physiology, microbiology and immunology. Often, bioactive substances protective to the gut also stimulate feed intake and growth performance. New insights on the effects of selected OA and AA, protein sources (especially SDP, bovine colostrum) and plant extracts with anti-bacterial activities on the gut are reported in this review.
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Thirty-six pigs (22 kg of BW) were used to evaluate a carbohydrase preparation, with xylanase and β-glucanase as main activities, added to either wheat-barley-rye- (WBR) or corn-based diets on performance, intestinal environment, and nutrient digestibility. Pigs were offered 1 of 4 different dietary treatments for 27 d according to a factorial arrangement of treatments (a 2 × 2) with 2 cereal types (WBR or corn) and 2 levels of supplemental carbohydrase (0 or 0.01%). Pig growth and feed intake were individually measured every week until the end of the experiment when pigs were slaughtered to obtain samples of digesta and tissues. Cereal type affected performance only during wk 1, in which WBR improved ADG (590 vs. 440 g/d; P = 0.008) and G:F (0.61 vs. 0.43; P = 0.045) compared with corn. The WBR also increased the viscosity of the digestive contents in stomach (1.95 vs. 1.23 mPa·s; P = 0.001) and ileum (6.53 vs. 2.80 mPa·s; P = 0.001) and resulted in greater cecal starch digestibility (95.7 vs. 93.9%; P = 0.012). However, trends for a reduction in digestibility were observed for glucose in the nonstarch polysaccharide (NSP) fraction in the ileum (64.4 vs. 75.8%; P = 0.074) and galactose in the NSP fraction in the cecum (1.4 vs. 1.8%; P = 0.055). The use of the enzyme preparation increased ADFI during wk 2 (1,328 vs. 1,215 g/d; P = 0.028), and increased villus height (423 vs. 390 µm; P = 0.045) and tended to reduce relative pancreas weight (0.16 vs. 0.17% BW; P = 0.079) at d 27. The enzyme also improved cecal starch digestibility (95.5 vs. 94.1%; P = 0.043) and tended to improve ileal energy digestibility (61.3 vs. 53.7%; P = 0.090) and cecal glucose digestibility in the NSP fraction (76.0 vs. 54.5%; P = 0.055). However, it reduced the cecal digestibility of mannose in the NSP fraction (27.0 vs. 50.5%; P = 0.016). Interactions (P < 0.05) between cereal type and enzyme supplementation were observed for ADG and G:F during wk 2, BW and ADG during wk 3, and BW and ADFI over the whole trial; and also for villus-height-to-crypt-depth ratio and for cecal DM digestibility. In all instances, whereas the added enzyme had no effect in the case of the corn diet, improvements were observed with WBR. In conclusion, the multi-enzyme tested had different effects depending on the type of cereal present in the diet.
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The palatability of different cereals was studied in 2 two-way choice (preference) experiments using pigs of 56 d of age and 17 kg of BW. In Exp. 1, the effect of 24 cereals vs. a common reference diet containing white rice on feed preference in pigs was studied. Pigs were offered free choice between the reference diet and a diet with the cereal under study for 4 d. Barley, corn (2 sources), wheat, cassava meal, biscuit meal, rye, sorghum, and 1 source of oats were tested at inclusion rates of 300 and 600 g x kg(-1). Short-grain rice (whole, brown, or extruded white), long-grain white rice (raw and cooked), extruded barley, extruded corn, extruded wheat, oats (2 sources), thick rolled oats, cooked oats, and naked oats (raw, extruded, or micronized) were tested at inclusion rates of 150, 300, and 600 g x kg(-1). Relative preference of cereals (% of total feed intake) was affected by type of cereal and by rate of inclusion. The diets containing extruded rice (150 g x kg(-1)), extruded naked oats (150, 300, and 600 g x kg(-1)), or naked oats (150 and 300 g x kg(-1)) were preferred (P < 0.05) by pigs to the reference diet. However, the reference diet was preferred (P < 0.05) to the diets containing 150, 300, and 600 g x kg(-1) of cooked long-grain rice, oats, or cooked oats, 300 and 600 g x kg(-1) of extruded wheat, wheat, corn, sorghum, or unhulled short-grain rice, and 600 g x kg(-1) of thick rolled oats, extruded corn, rye, extruded barley, micronized naked oats, barley, cassava, or biscuit meal. Extrusion improved (P < 0.05) preference values for corn and naked oats by pigs, but had no effect on barley, rice, or wheat. In Exp. 2, the preferences of pigs for oats and barley were studied using mash and pelleted diets. Diet form did not affect preference in oats diets. However, for barley, greater preference values were obtained when measured in pelleted form compared with mash form. Additionally, direct 2-way choices were also performed between oats and barley diets and between diets presented in mash and pelleted forms. Pigs preferred barley to oats, and preferred diets presented in pelleted form to those presented in mash form. In conclusion, cereal type, inclusion rate, and diet form affected feed preference in pigs. Using cereals with greater preference values may contribute to the formulation of more palatable feeds, which enhance feed intake of piglets at critical stages such as weaning time.
Two experiments were conducted to study the effect of cereal source on the in vitro digestibility of pig feeds. Dry matter and organic matter digestibilities were evaluated using the multi-enzymatic method described by Boisen and Fernández (1997). The rate at which the different diets were digested, was estimated at 3 different time points: (1) after incubation with pepsin for 75min; (2) after incubation with pepsin for 75min and pancreatin for 3.5h and; (3) after incubation with pepsin for 75min, pancreatin for 3.5h and carbohydrases for 18h. In the first experiment, digestibility was evaluated in six diets containing 60% of rice (R), rice supplemented with wheat bran (RW), barley (B), maize (M), oats (O), or naked oats (NO). Diets containing NO and O had the highest digestibility after pepsin incubation, M, R and RW had the lowest and that of B was intermediate. After incubation with pepsin and pancreatin, digestibility was highest for R, RW and NO diets and lowest for M and O diets, B being intermediate. With the complete in vitro digestion procedure (pepsin, pancreatin and carbohydrases), R presented the highest digestibility followed by NO, M, B and O. In the second experiment, the effect of cereal extrusion was also evaluated in diets containing 60% of R, NO or B, either in raw or in extruded form (total of six diets). Following pepsin incubation, R presented a lower digestibility than B and NO; with pepsin and pancreatin incubations, NO presented the highest digestibility followed by R and B; and after incubation with pepsin, pancreatin and carbohydrases, R presented the highest digestibility followed by NO and B. It is concluded that cereals present differences in their in vitro digestion kinetics. This may be a useful tool to estimate possible differences in digestibility kinetics between cereals in the proximal gastrointestinal tract of the pig.
Changes in the rate of passage of digesta may affect feed digestibility and glycaemia, but at the same time glycaemia may also regulate stomach emptying and as a consequence digesta passage rate. The correlations between the glycaemic index (GI) of 12 cereals, the ileal and total tract, dry matter (DM) and organic matter (OM) digestibilities and the ileal digesta flow characteristics of pig feeds containing them were studied. GI for each cereal was calculated as the maximal glucose release rate per minute using an in vitro digestibility system. Pigs fitted with an ileal T-cannula were used to measure the DM and OM digestibilities (ileal and total tract) of the corresponding cereal-based diets, and their ileal digesta flow rate, lag time to initial flow of digesta (Tlag) and mean retention time (MRT). Titanium dioxide (TiO2) was used as indigestible marker. The Spearman's correlations between the GI, the parameters of digesta flow and the digestibility values were estimated. GI was significantly correlated with ileal digestibility of OM (r=0.58; P
Nutrient Requirements of Swine
  • NRC
NRC. 1998. Nutrient Requirements of Swine. 10th rev. ed. Natl. Acad. Press, Washington, DC.
Wheat-barley-rye-or corn-fed growing pigs respond differently to dietary supplementation with a carbohydrase complex
  • J William
  • I Badiola
  • E Devillard
  • P A Geraert
  • D Torrallardona
William, J., I. Badiola, E. Devillard, P. A. Geraert, and D. Torrallardona. 2012. Wheat-barley-rye-or corn-fed growing pigs respond differently to dietary supplementation with a carbohydrase complex. J. Anim. Sci. 90:824-832.