Ileal digestibility of defatted soybean,lupin and chickpea seed meals in cannulated Iberian pigs: I. Proteins

Five castrated male Iberian pigs (100 ± 2 kg body weight) fitted with T‐shaped cannulas at the terminal ileum were used to determine ileal digestibility of legume seed meals. The diets were based on defatted soybean, lupin or chickpea seed meals and contained similar levels of digestible energy (14.2–15.1 kJ g^?1) and protein (107 g kg^?1). Protein‐free and a hydrolysed casein diets were used to study endogenous ileal amino acid flows. Chromium oxide (10 g kg^?1 diet) was added to the diets as an indigestible marker. Ileal flows in pigs fed the hydrolysed casein diet were different (p < 0.05) in amino acid contents and composition from those on the protein‐free diet. Ileal sialic acid flows in pigs fed lupin‐ or chickpea‐based diets were higher (p < 0.05) than those of animals fed soybean or casein diets. Among essential amino acids, only the apparent ileal digestibilities of phenylalanine and valine in lupin meal were lower (p < 0.05) than those in soybean. Apparent ileal digestibilities of lupin aspartate and proline, together with chickpea aspartate, were also lower (p < 0.05) than those of soybean. True ileal digestibility of nitrogen in pigs fed lupin or chickpea meals, calculated according to values from animals fed the protein‐free diet, was lower (p < 0.05) than that for soybean or casein. Among individual essential amino acids, only the true ileal digestibility of phenylalanine in lupin was lower (p < 0.05) than that in soybean. True ileal digestibility of nitrogen calculated according to values obtained with pigs fed a hydrolysed casein diet was not different among soybean, lupin or chickpea meals. Among essential amino acids, only the true ileal digestibilities of isoleucine and lysine in chickpea were lower (p < 0.05) than those of soybean. It is concluded that true ileal nitrogen and amino acid digestibilities of lupin and chickpea meals are comparable to those of defatted soybean in Iberian pigs. The results with protein‐free diets tended to underestimate endogenous protein secretion in pigs fed on diets containing protein. Copyright © 2005 Society of Chemical Industry     

Endogenous lysine and other amino acid flows at the terminal ileum of the growing pig (20 kg bodyweight): The effect of protein-free,synthetic amino acid,peptide and protein alimentation

Twenty-four crossbred pigs of 15 kg initial bodyweight were fed four semi-synthetic diets for 10 days according to a completely randomised design. The study aimed to determine the effects of state of body nitrogen balance and the presence of dietary peptides and protein in the digestive tract on the excretion of endogenous amino acids from the ileum of the pig. Endogenous lysine excretion was determined for pigs given a protein-free (PF) diet, an enzymically hydrolysed casein- (EHC), a zein- (ZN) or a synthetic amino acid- (SAA) based diet. Digesta from the EHC-fed animals were centrifuged and ultrafiltered after collection and the precipitate plus retentate fraction was used to determine the endogenous flows. Such processing excludes unabsorbed dietary amino acids from the measure of endogenous loss. ZN is naturally deficient in lysine and tryptophan and these two amino acids were omitted from the synthetic amino acid-based diet to allow direct measurement of endogenous lysine flow. Pigs given the ZN and SAA diets received free lysine and tryptophan orally throughout the study except for the final 2 days of the study, when these amino acids were infused intravenously. Endogenous flows for amino acids other than lysine were determined for pigs given the PF and EHC diets. On the final day of the study the pigs were given their daily dietary allowance hourly and killed 10 h after the start of feeding. Digesta were collected from the terminal ileum (20 cm anterior to the ileo-caecal junction) and endogenous flows were determined by reference to the marker chromic oxide. The mean endogenous ileal lysine flows for the ZN- and EHC-fed pigs were not significantly different (overall mean, 419 mg kg^?1 dry matter intake), but were higher (P < 0.05) than those for the PF- and SAA-fed pigs (overall mean, 268 mg kg^?1 dry matter intake) whose mean flows were not significantly different from each other. The mean endogenous ileal flows for amino acids other than lysine were higher (P < 0.05) for the EHC-fed pigs compared to the animals on the PF diet, except for proline, glycine and arginine. The similar endogenous ileal lysine excretion for pigs receiving a SAA-based diet and in positive body nitrogen balance, and PF-fed pigs in negative body nitrogen balance, indicates that negative body nitrogen balance per se does not lead to a lowered endogenous ileal excretion. It would appear, however, that the presence of dietary peptides or protein in the gut increases amino acid excretion at the terminal ileum above that found with PF or SAA alimentation. Consequently, endogenous ileal amino acid flow in the pig may be underestimated when determined by the traditional PF method.     

Response of nutrient digestibilities to feeding diets with low and high levels of soybean trypsin inhibitors in growing pigs

Studies were carried out to determine the effect of dietary soybean trypsin inhibitor (SBTI) content on nutrient and energy digestibilities in growing pigs. Six barrows, average initial body weight (BW) 47·8±4·0 kg, were fitted with a simple T-cannula at the distal ileum and fed two diets according to a crossover design. Two maize starch-based diets were formulated to contain 200 g crude protein (CP) kg⁻¹ from either Nutrisoy (a food-grade defatted soy flour) or autoclaved Nutrisoy. The contents of SBTI in the Nutrisoy and autoclaved Nutrisoy diets were 13·4 and 3·0 g kg⁻¹, respectively. The experiment consisted of two periods of 12 days each. The average BW at the start of the first and second experimental periods were 53·3±3·7 and 61·0±5·1 kg, respectively. The average BW at the conclusion of the experiment was 71·8±7·6 kg. The ileal digestibilities of dry matter (DM), organic (OM), energy, CP and all amino acids measured were higher (P<0·01) in pigs fed the autoclaved Nutrisoy diet. The energy digestibility increased from 66·0 to 77·9%, and the CP digestibility increased from 37·4 to 77·1%. The increases in ileal digestibilities of the indispensable amino acids ranged from 27·0 (methionine) to 49·2 (leucine) percentage units. The increases in ileal digestibilities of the dispensable amino acids ranged from 30·2 (aspartic acid) to 50·8 (tyrosine) percentage units. The faecal digestibilities of all criteria measured were also higher (P<0·01) in pigs fed the autoclaved Nutrisoy diet. Furthermore, there was a greater (P<0·01) net disappearance (g kg⁻¹ DM intake) of DM, OM, CP, energy and all amino acids in the large intestine of pigs fed the Nutrisoy diet. In conclusion, feeding diets containing high levels of SBTI decreased both ileal and faecal digestibilities of all criteria measured. The formation of SBTI-enzyme complexes is likely to be responsible for the reduction in protein digestion and amino acid absorption. © 1998 SCI.     

The effect of food dry matter intake on the flow of amino acids at the terminal ileum for rats fed an enzyme‐hydrolysed casein‐based diet

The aim of the study was to determine whether food dry matter intake had an effect on endogenous ileal amino acid flows in the rat when the flows were expressed in units of mg g^?1 dry matter. Eighty 200 g body weight rats were trained for 7 days to consume a casein‐based diet over a daily 3 h feeding period, and then an enzyme‐hydrolysed casein (MW < 5000 Da)‐based diet, with chromic oxide as an indigestible marker, was fed for a further 8 days. The mean ratio of food intake to metabolic body weight over all 80 rats was determined on days 11 and 12. On day 15, food was offered to groups of 10 rats at each of eight intake levels. The intake levels were calculated from the mean food intake value and individual metabolic body weights and scaled in increments of 0.1 by factors ranging from 0.3 to 1.0. Digesta were collected from the terminal ileum 3 h after the start of the meal, and endogenous ileal amino acid flows were determined after amino acid and Cr analyses of the diet and endogenous ileal digesta fractions prepared by centrifugation and ultrafiltration (10 000 Da molecular weight cut‐off). The linear regression relationships between ileal amino acid flows, expressed as mg g^?1 dry matter, and dry matter intakes demonstrated that all slopes were negative but that the slopes for nine of these amino acids were not significantly different from zero (P > 0.05). There were significant slopes (P < 0.05) for the other eight amino acids, although the magnitudes of the effect were small. When the data were re‐examined after removing the lowest feeding level, the slopes for most of these amino acids were no longer statistically significant. The results showed that the measures of amino acid flow (mg g^?1 dry matter), except for isoleucine and cystine, over a wide range of food intakes were not materially affected by food intake. From the perspective of bioassay logistics the results indicate that expressing ileal amino acid flows proportional to dry matter intake is justified over the range of intakes found in practice for determining true ileal amino acid digestibility by the enzyme‐hydrolysed casein method. © 2002 Society of Chemical Industry     

Energy and nutrient digestibilities in wheat dried distillers' grains with solubles fed to growing pigs

The aim of this study was to characterize the nutritional profile and to determine the digestibilities of nutrients in wheat‐based dried distillers' grains with solubles (DDGS) fed to growing pigs. Six ileal cannulated barrows individually housed in metabolism crates were fed experimental diets which consisted of a basal wheat‐based diet or the basal diet with wheat replaced by 400 g kg^?1 mixed wheat or winter wheat DDGS in a replicated 3 × 3 Latin square design. Ileal digesta and fecal samples were collected for determining apparent ileal (AID) and apparent total tract digestibilities (ATTD), respectively. The contents of proximate components and amino acids in DDGS were about three times higher than in wheat. The AID and ATTD of dry matter, nitrogen and energy were lower (P < 0.05) in DDGS compared with wheat. The DDGS samples had lower (P < 0.05) AID of amino acids compared with wheat; average values for lysine, threonine and isoleucine in DDGS were 43.8, 62.9 and 68.0%, respectively. The ileal and fecal digestible energy content in DDGS averaged 9.7 ± 1.18 and 13.5 ± 0.61 MJ kg^?1, respectively. Respective values for wheat were 13.3 ± 0.52 and 14.6 ± 0.22 MJ kg^?1 and both were higher (P < 0.05) than in DDGS. Copyright © 2005 Society of Chemical Industry     

Evaluation of barley and triticale as feed ingredients in growing Iberian pigs: amino acid and carbohydrate ileal digestibility

BACKGROUND: Iberian pig production is linked to the use of the Mediterranean woodland, where the use of local feed resources is of paramount importance for the sustainability of the system. The aim of the present work was to explore the potential of triticale cv. Camarma as compared to barley cv. Esgueva in Iberian pig feeding by studying their respective ileal digestibilities of amino acids and carbohydrates in animals cannulated at the end of the ileum. RESULTS: Leu, Met and Tyr had (P < 0.05) greater standardised ileal digestibilities (SID) in pigs fed triticale diet. There was a trend (P = 0.07) towards greater SID of Thr in pigs fed the barley diet. The least digestible indispensable amino acids were Ile (74.6% SID) for barley and Thr (78.9% SID) for triticale. Except for β‐glucans, apparent ileal digestibilities (AIDs) of individual non‐starch polysaccharide (NSP), sugars and starch were greater in pigs fed triticale (P < 0.05). Nevertheless, total amounts of NSP digested were greater in pigs fed the barley diet (P < 0.05). CONCLUSION: Overall, triticale cv. Camarma had greater amino acid and carbohydrate AID than barley cv. Esgueva and may represent a valuable grain for Iberian pig feeding. Copyright © 2008 Society of Chemical Industry     

Response of pancreatic secretions to feeding diets with low and high levels of soybean trypsin inhibitors in growing pigs

Studies were carried out to determine the effect of soybean trypsin inhibitors (SBTI) on exocrine pancreatic secretions in growing pigs. Six barrows with an average initial body weight (BW) of 27·1±1·4 kg were fitted with permanent pancreatic re-entrant cannulas and fed two diets according to a crossover design. Two maize starch-based diets were formulated to contain 200 g kg⁻¹ crude protein from either Nutrisoy (food grade defatted soy flour) or autoclaved Nutrisoy. The concentrations of SBTI in Nutrisoy and autoclaved Nutrisoy diets were 13·4 and 3·0 g kg⁻¹, respectively. The experiment consisted of two periods of 9 days each. The average BW at the start of the first and second experimental periods was 33·5±2·7 and 37·2±3·7 kg, respectively. The average BW at the conclusion of the experiment was 41·8±3·9 kg. The volume of pancreatic secretion was higher (P<0·01) when the Nutrisoy, as opposed to the autoclaved Nutrisoy diet was fed (3804 vs 2634 ml (24 h)⁻¹). The concen-tration of nitrogen and protein and specific activities (units litre⁻¹) of amylase, chymotrypsin and trypsin were lower (P<0·05) in pancreatic juice of pigs fed the Nutrisoy diet. There were no differences (P>0·05) in the total secretions of nitrogen (g (24 h)⁻¹) and total activities (units (24 h)⁻¹) of amylase, lipase, chymotrypsin and trypsin in pancreatic juice of pigs fed the Nutrisoy and autoclaved Nutrisoy diets. However, the total secretion of protein was slightly higher (25·7 vs 22·8 g (24 h)⁻¹; P<0·05) in pancreatic juice of pigs fed the autoclaved Nutrisoy diet, which corresponded with the increase in the secretion of protein-bound amino acids. There was also an increase in the total secretion of free amino acids in pancreatic juice. These studies show no effect of SBTI on the total enzyme activities in pancreatic juice of growing pigs. © 1998 SCI.     

The effect of food dry matter intake on endogenous ileal amino acid excretion determined under peptide alimentation in the 50 kg liveweight pig

The daily ileal excretion of amino acids was measured at different food dry matter intakes for the 50 kg liveweight pig under conditions of peptide alimentation. The experiment comprised two cross-over design trials each involving four pairs of entire male pigs fitted with simple T-cannulae at the terminal ileum and fed a hydrolysed casein semi-synthetic diet. Each pair of pigs received one of four sequences of food dry matter intake arranged in a Latin square design, namely 0.06, 0.08, 0.10 and 0.12 (Trial 1) and 0.05, 0.07, 0.09 and 0.11 (Trial 2) of metabolic body weight (W^0.75) day^?1. Each pig received the diet at its described level of intake for 8 days, with continuous 24 h collection of ileal digesta on the fifth and eighth days. Chromic oxide was included in the diet to permit correction of ileal flows to complete digesta collection. Pooled digesta from each pig at each level of dry matter intake were centrifuged and ultrafiltered and the high-molecular-weight fraction was analysed for amino acid and nitrogen contents. There were significant (P < 0.05) linear relationships between endogenous ileal amino acid, nitrogen and dry matter excretion (mg day^?1) and food dry matter intake (g day^?1) except for lysine, glutamic acid and phenylalanine which increased in a curvilinear manner (P < 0.05). The results indicate that dietary dry matter intake influences endogenous excretion from the ileum. The relationships, determined under physiological conditions, provide preliminary data on the magnitude of small intestinal amino acid loss in the young growing pig.     

The effect of digesta sampling time and dietary protein source on ileal nitrogen digestibility for the growing rat

The effect of time that digesta were collected on the quantity and representativeness of ileal digesta and on the determination of apparent and true ileal nitrogen (N) digestibility for growing rats was investigated. Semi‐synthetic diets containing chromic oxide as an indigestible marker were given to 200 g live weight rats for 8 days as a single daily meal. The experimental treatments comprised six diets (lactalbumin, soy protein isolate, wheat gluten, fish, protein‐free (PF), enzymically hydrolysed casein (EHC)) and four ileal digesta sampling times (3, 4, 5 and 6 h after the start of feeding). On the eighth day the rats were fed and slaughtered according to treatment, and digesta were sampled from the terminal ileum. Endogenous ileal nitrogen excretion was determined using both the protein‐free and peptide alimentation methods. There was a significant (P = 0.027) effect of experimental diet averaged across sampling times for chromium recovery (CrRec). The CrRec was higher for the rats fed the PF diet than for the other diets. Responses to sampling time varied significantly (P < 0.05) among diets for ileal digesta weight (IDW), nitrogen/chromium (N/Cr) ratio, ileal digesta weight relative to dry matter intake (IDW/DMI), CrRec, N flow, apparent N digestibility and true N digestibility (determined using the protein‐free method). The optimal digesta sampling times for each of the diets were 3 h for PF, EHC, lactalbumin and fish and 4 h for soy protein isolate and wheat gluten. Consequently, 3 or 4 h after the start of feeding is recommended as the optimum ileal digesta sampling time for most purified protein sources when fed to the growing rat as a single daily meal. © 2002 Society of Chemical Industry     

Rice protein concentrate partially replaces dried whey in the diet for early‐weaned piglets and improves their growth performance

BACKGROUND: Recently, rice protein concentrate (RPC), a much cheaper source of dietary protein, has become commercially available for use in the feed industry. Importantly, dietary supplementation with RPC can increase feed intake by early‐weaned pigs. The objective of this study was to determine whether RPC can replace milk protein in the diet for early‐weaned pigs. RESULTS: Neither average daily gain (ADG), average daily feed intake (ADFI), nor the feed/gain ratio differed among the treatment groups in weeks 1 and 2. In week 3, the addition of 5 or 10% RPC to diets increased (P < 0.05) ADFI and ADG of pigs compared to those in the control group fed a 60% dried whey diet. During the entire 21‐day trial, ADFI and ADG were greater (P < 0.05) in pigs fed the 5 and 10% RCP diets than in pigs fed the 60% dried whey and 15% RCP diets. There were no differences in the serum concentrations of growth hormone on days 14 and 21, serum concentrations of insulin growth factor‐I (IGF‐I) on day 14, or IGF‐I gene expression in liver and skeletal muscle on days 14 and 21 among the dietary treatments. Serum concentrations of IGF‐I in pigs fed the 5, 10 and 15% RPC diets were greater than those in pigs fed the 60% dried whey diet. CONCLUSION: Findings indicate that up to 10% RPC can be used to replace dried whey in the diet for 7‐ to 21‐day‐old weaned piglets and can improve their growth performance. Copyright © 2008 Society of Chemical Industry     

Endogenous amino acid flow at the terminal ileum of the rat determined under conditions of peptide alimentation

The study aimed to determine endogenous ileal amino acid excretion in the growing rat fed an enzymically hydrolysed casein (EHC) based diet with subsequent treatment of the digesta using ultrafiltration technology. Comparison was made with endogenous excretions obtained from rats fed an EHC-based or a protein-free diet and without any treatment of the ileal digesta. Preliminary investigations were made to determine the filtration efficiency of the ultrafiltration devices and to examine three alternative prefiltration treatments, trichloroacetic acid (TCA) and perchloric acid (PCA) precipitation, and centrifugation (SPIN). In the preliminary work, 15 purified protein, peptide and amino acid solutions were ultrafiltered using a molecular weight (MW) exclusion limit of 10000 Da, and the recovery of nitrogen indicated an effective filtration (generally >90% separation) on nominal molecular weight. Further, fresh rat ileal digesta samples were treated with either TCA, PCA or SPIN. The resulting supernates were ultrafiltered and the fractions were analysed for nitrogen and amino acids. The precipitates contained 23, 57 and 41% of the total nitrogenous material for the TCA, PCA and SPIN treatments, respectively, indicating that PCA was the most effective precipitant. In the main study, twelve 100-g male rats were fed either an EHC-based diet or a protein-free diet, and samples of ileal digesta were collected after slaughter. The digesta from the six EHC-fed rats were ultrafiltered after centrifugation, and the high molecular weight fraction was added to the precipitate. Endogenous ileal amino acid flows were determined for the total digesta and for the digesta following the centrifugation plus ultrafiltration treatment. The endogenous amino acid flows were generally higher for the total digesta than for the digesta following centrifugation plus ultrafiltration and significantly so (P<0.05) for lysine, glutamin acid and proline. The protein-free fed rats had significantly P<0·05) lower amino acid flows than those rats fed the EHC-based diedt (ultrafiltration treatment), the greatest differences occurring for isoleucine, serine, glutamic acid, valine, leucine, alanine and threonine.     

Diurnal Variation in the Composition of Ileal Digesta and the Ileal Digestibilities of Nutrients in Growing Pigs

Diurnal variation in the chemical composition of digesta and its effect on nutrient digestibilities of diets varying in dietary fibre content was examined in pigs fitted with a PVTC-cannula at the terminal ileum. The pigs were fed three times a day (08:00, 16:00 and 24:00 h). A barley control diet and four barley-based diets containing two levels (100 or 200 g kg^-1 diet) of alfalfa meal or white clover meal and Cr₂O₃ as an indigestible marker were fed according to a 5×5 Latin square design. In each experimental period, digesta were collected for 1 h every third hour on each of two separate sampling days, covering in total a 24 h period. The concentration of dry matter (DM), crude protein (CP), ash and chromium (Cr) in the ileal digesta varied in relation to time of feeding. However, the patterns were similar after all three meals (08:00, 16:00 and 24:00 h) and independent of diet. The maximum DM, CP and ash contents were reached 4–5 h post-feeding. The highest (P < 0·05) DM concentration was found in the ileal digesta of pigs fed the barley control diet. The DM concentration decreased (P < 0·05) as the inclusion level of alfalfa meal and white clover meal was increased. The lowest DM concentration was found for the highest inclusion level of alfalfa meal. The ileal digestibilities of both organic matter and CP were lower 1–2 h post-feeding compared with those recorded 3–5 h later, indicating that the less digestible components of a diet have shorter transit times. The pooled ileal digestibilities of organic matter and CP from the three 8 h periods (08:00–16:00 h, 16:00–24:00 h, 24:00–08:00 h) did not differ (P < 0·05) from each other. Therefore, the estimate of digestibility can be based on digesta samples collected from any interval between two consecutive meals. However, care must be taken to obtain representative samples of digesta between meals. © 1997 SCI.     

Comparison of methods to determine the endogenous amino acid flow at the terminal ileum of the growing rat

The aim was to compare a recently developed peptide alimentation method and the protein-free and regression methods for determining endogenous ileal nitrogen (N) and amino acid excretion in the rat, and to apply the endogenous loss estimates to determine the true ileal digestibility of a meat and bone meal (MBM). Preliminary investigations determined the effect of the time of sampling of digesta after a meal (slaughter method) for rats given a protein-free or an enzymically hydrolysed casein (EHC) based diet, on ileal digesta and endogenous N excretion. There was a significant (P < 0.05) effect of the time of sampling on the amount of digesta collected and the endogenous N excretion for both the EHC and protein-free fed rats. The amount of digesta collected from the terminal 20 cm of ileum and the endogenous N excretion for both the EHC and protein-free fed rats were greatest and least variable at 3 h post-feeding. In the main study, endogenous ileal amino acid excretions were determined in the growing rat fed an EHC-based diet (n = 6) and with subsequent treatment of the digesta using ultrafiltration or in six rats given a protein-free diet or by extrapolation from data for 30 animals given five diets which contained graded levels of MBM as the sole protein source. For the EHC treatment, the ileal digesta precipitate plus retentate was used to determine the endogenous flows. The ultrafiltration step excludes unabsorbed dietary amino acids from the measure of endogenous loss. Chromic oxide was the reference marker in all diets. The endogenous N flows determined by the protein-free and regression methods were similar but both significantly (P < 0.01) lower than those for rats fed the EHC-based diet. The mean endogenous ileal N flows determined by the peptide alimentation method, the protein-free and regression approaches were 1866, 1103 and 1019 μg g^?1 freeze dry matter intake, respectively. The endogenous amino acid flows at the terminal ileum were lower when determined using the traditional protein-free or regression methods. The true ileal digestibility coefficients for MBM were considerably higher based on the EHC versus protein-free endogenous flows.     

Intestinal structure and function of broiler chickens on diets supplemented with a mannan oligosaccharide

A study was conducted to evaluate the response of broiler chickens to a commercial synthetic mannan oligosaccharide, Bio‐Mos? (BM), included in sorghum/lupin‐based diets at 0.0, 1.0, 3.0 or 5.0 g kg^?1 diet. The diets were fed between 7 and 28 days of age, and both the gross response and mechanisms involved were evaluated. The highest level of BM in the diet resulted in longer (P < 0.01) jejunal villi than those observed at other levels of supplementation. The RNA content of the ileal mucosal homogenate was significantly greater (P < 0.05) in chicks raised on diets supplemented with 3.0 and 5.0 g BM kg^?1 diet than in other groups. The protein/DNA ratio of the jejunal mucosal homogenate was also higher (P < 0.05) in chicks fed the 1.0 g BM kg^?1 diet than in chicks fed the other diets. The protein/RNA and RNA/DNA ratios in ileal homogenates were significantly (P < 0.01) influenced by the presence of BM in the diet. There were significantly greater specific activities of maltase (P < 0.01), leucine aminopeptidase (P < 0.05) and alkaline phosphatase (P < 0.001) in the jejunum as a result of supplementation with BM. Digestive enzyme activities in the ileum were unaffected. L ‐Tryptophan uptake by jejunal brush‐border membrane vesicles was significantly higher (P < 0.01) in chicks raised on the 5.0 g BM kg^?1 diet than in the other chicks. The supplement led to minor improvement in body weight but no improvement in feed conversion ratio. These effects were related to changes in digestive enzyme activities and, perhaps, amino acid transport. © 2001 Society of Chemical Industry     

Effects of dietary probiotic supplementation on ileal digestibility of nutrients and growth performance in 1‐ to 42‐day‐old broilers

This study was conducted to determine the effects of dietary probiotic supplementation on the ileal digestibilities of nutrients and growth performance in broilers. Two thousand, eight hundred and eighty male broiler chickens at 1 day of age were randomly allotted to eight treatment groups and fed for 6 weeks the maize–soybean meal‐based diets containing 0, 0.2, 0.4 or 0.6% AgiPro A100® (a probiotic) and 0 or 6 ppm flavomycin (an antibiotic). This well‐established antibiotic was used as a positive control for the efficacy of AgiPro A100®. Dietary supplementation with either the probiotic or the antibiotic alone did not affect (P > 0.05) feed intake or average daily gain (ADG) of broilers between days 1 and 42 of life. However, there was a significant antibiotic × probiotic interaction effect (P < 0.05) in increasing ADG during the entire experimental period. Notably, dietary supplementation with the probiotic or the antibiotic consistently improved (P < 0.05) the ileal digestibilities of crude protein and most amino acids in 21‐ and 42‐day‐old chickens. Supplementing the probiotic to broiler diets also improved (P < 0.05) the ileal digestibilities of dry matter, energy, calcium and phosphate in the birds. Collectively, these results indicated that AgiPro A100® is an effective alternative to flavomycin in chicken production. Copyright © 2007 Society of Chemical Industry     

High apparent ileal digestibility of amino acids in raw and germinated faba bean (Vicia faba)‐ and chickpea (Cicer arietinum)‐based diets for rats

The effects of germinated faba bean (Vicia faba minor var Alameda)‐ and chickpea (Cicer arietinum kabuli var Athenas)‐based diets on performance, N utilisation, amino acid ileal digestibility and plasma concentrations were studied in growing male Wistar rats. Raw and germinated faba bean and chickpea seed meals were incorporated in essential amino acid‐supplemented and energy‐equalised diets as the only sources of protein. A lactalbumin‐based diet equalised in protein (100 g kg^?1) and digestible energy (15.5 kJ g^?1) with the test diets was used as control. Weight gains, gain/feed ratios, N retention and NPU values of animals fed raw or germinated legumes were lower than those of rats given the control (lactalbumin) diet, while faecal dry weights were higher. However, N retention and NPU values of rats fed germinated faba bean diets were higher and faecal dry weights lower than those of animals fed non‐germinated faba bean diets. Liver and thymus fresh and dry relative weights were lower than controls for all legume diets, whilst small intestine, caecum and colon relative weights were higher than controls for non‐germinated faba beans and chickpeas either germinated or not. Caecum and colon fresh and dry relative weights of rats fed germinated faba bean seeds were lower than those of rats fed non‐germinated faba beans and not different from controls. Except for aspartic acid and proline in rats fed raw faba bean diets, apparent ileal digestibilities of amino acids were not different or higher in rats fed legume diets as compared with controls. Except for arginine, apparent ileal amino acid digestibility was higher for germinated than for non‐germinated faba bean seeds. The amounts of glycine, arginine and ornithine in plasma significantly increased whilst those of threonine, alanine, leucine and lysine decreased with respect to controls in faba bean‐ or chickpea‐fed rats, either germinated or not. We conclude that (a) germination of faba bean seeds gave rise to a significant (P < 0.01) but limited improvement in performance, N retention and apparent ileal digestibilities of some amino acids in growing rats compared with non‐germinated seeds, while there was no detectable effect in the case of germinated chickpea seeds, and (b) the apparent ileal amino acid digestibility of essential amino acid‐supplemented diets based on faba bean or chickpea meals, either germinated or not, is similar or even higher than controls. © 2002 Society of Chemical Industry     

Dietary Tryptophan Enhanced the Expression of Tight Junction Protein ZO‐1 in Intestine

Dietary amino acids provide various beneficial effects for our health. The aim of the present study was to assess the effects of tryptophan (Trp) supplementation on barrier function. Ninety‐six healthy finishing pigs (initial body weight 51.49 ± 1.12 kg) were randomly allocated into 2 treatment groups, control group, and 0.2% Trp group. The control group was fed the basal diet, and 0.2% Trp group was fed basal diet plus 0.2% Trp. The trial period is 60 d. Compared with control group, the mRNA abundance of claudin‐3 and zonula occluden‐1 (ZO‐1) in the jejunum in 0.2% Trp group (P < 0.05) was increased. According to immunohistochemistry and immunoblotting test, the expression of ZO‐1 in jejunum in 0.2% Trp group was also significantly increased compared with the control group (P < 0.05). These results revealed that Trp enhanced the expression of tight junction protein ZO‐1 in the intestine of pig model. Trp may be potential and beneficial dietary functional factor for regulating the intestinal development and inhibiting intestinal aging.     

The diurnal pattern of ileal dry matter and endogenous ileal nitrogen flows in the growing pig

The aim was to examine the diurnal pattern of endogenous nitrogen flow at the terminal ileum of the pig. Seven entire male pigs with a mean body weight of 58 kg had post‐valve T‐caecum (PVTC) cannulae surgically implanted for the collection of ileal digesta. The pigs were fed equal‐sized meals (10% of metabolic body weight, W^0.75, per day) twice daily at 08:00 and 17:00. The semi‐synthetic diet included enzyme‐hydrolysed casein (<5000 Da, 100 g kg^?1 diet) as the sole source of nitrogen (N). The diet also contained chromic oxide (6 g kg^?1) as an indigestible marker. The pigs received the diet for an 8 day period, and digesta were continuously collected for 24 h periods (commencing at 08:00) on the fifth and eighth days. Digesta were analysed for dry matter (DM) and chromium (Cr), and endogenous N was determined in the precipitate + retentate fraction of the digesta following centrifugation and ultrafiltration (10 000 Da molecular weight cut‐off). The concentration of Cr expressed on a digesta DM basis and the ratio of endogenous N to Cr in the digesta were relatively constant over the 24 h digesta collection periods, with no statistically significant (P > 0.05) differences found for the latter measure in the digesta collected between 12:00 and 08:00. The endogenous N flow through the terminal ileum is the net effect of the secretion and reabsorption of endogenous N that occurs throughout the digestive tract. The net result of the latter two processes in the small intestine of the pig leads to a relatively constant endogenous N flow over time post‐feeding. © 2002 Society of Chemical Industry     

Effect of duration of the Montanera diet on the hydrocarbon fraction of intramuscular lipids from Iberian dry‐cured ham; characterization by gas chromatography

The characterization and differentiation of Iberian hams was studied as a function of the diet received by animals during the fattening period using a method based on hydrocarbon analysis. Thirty‐one hams were divided into three groups according to fattening diet (1, ‘Concentrate Feed’, fed on an intensive system with concentrates; 2, ‘Short Montanera’, fed on an extensive system with acorns and pasture for 50 days; and 3, ‘Long Montanera’, fed on an extensive system for 75 days). Saturated hydrocarbons in the n‐C₁₄ to n‐C₃₂ range and a large number of branched hydrocarbons were identified in the intramuscular fat of the three groups studied. The diet of the pigs during the fattening period did not affect the n‐alkane and n‐alkene content. The analysis of branched hydrocarbons revealed some significant differences relative to the type of diet. The ‘Concentrate Feed’ group had different concentrations of 2‐butyl‐1,1,3‐trimethylcyclohexane (P < 0.01), 3‐octadecene (P < 0.001), branched hydrocarbon 4 (P < 0.01) and neophytadiene (P < 0.001) than the ‘Montanera’ group. Copyright © 2006 Society of Chemical Industry     

Effectiveness of an ultrafiltration device for use with the enzyme‐hydrolysed protein method for determining endogenous ileal nitrogen and amino acid excretion in the pig

The aim of the work was to perform an in vitro study to determine the effectiveness of Centriprep‐10 concentrator devices for use with the enzyme‐hydrolysed protein method for the determination of endogenous ileal nitrogen and amino acid flows. Different amounts of enzyme‐hydrolysed casein (EHC) were added to tubes containing digesta collected from pigs that had received a protein‐free diet for 5–8 days. The samples were centrifuged and then ultrafiltered using Centriprep‐10 concentrators. The precipitate from the centrifugation step was added to the retentate from the ultrafiltration, and this material was analysed for nitrogen and amino acids. The ultrafiltrates were also analysed for nitrogen. The amount of nitrogen that was deemed to have originated from the EHC and remained in the precipitate plus retentate fraction of digesta after processing, expressed as a percentage of the total amount of nitrogen added to the tubes as EHC, ranged from 1.0 to 5.0%. The overall mean amounts of amino acid in the precipitate plus retentate fractions originating from the EHC, expressed as a percentage of the amino acids added to the tubes as EHC, ranged from 2.4 to 5.8%. The results demonstrate that with Centriprep‐10 concentrators there is a less than complete separation of nitrogen and amino acids originating from EHC from endogenous material in digesta, but for most amino acids this is unlikely to be due to binding of the amino acids to digesta. The incomplete separation of EHC from the endogenous fraction of digesta by Centriprep‐10 concentrators may lead to a small overestimation (approximately 2%) of endogenous ileal nitrogen and amino acid flows. © 2001 Society of Chemical Industry