Dietary α-ketoglutarate supplementation ameliorates intestinal injury in lipopolysaccharide-challenged piglets

Neonates are at increased risk for inflammatory bowel disease, but effective prevention and treatments are currently limited. This study was conducted with the lipopolysaccharide (LPS)-challenged piglet model to determine the effects of dietary supplementation with α-ketoglutarate (AKG) on the intestinal morphology and function. Eighteen 24-day-old pigs (weaned at 21 days of age) were assigned randomly to control, LPS, and LPS + AKG groups. The piglets in the control and LPS groups were fed a corn- and soybean meal-based diet, whereas the LPS + AKG group was fed the basal diet supplemented with 1% AKG. On days 10, 12, 14, and 16, piglets in the LPS and LPS + AKG groups received intraperitoneal administration of LPS (80 μg/kg BW), whereas piglets in the control group received the same volume of saline. On day 16, d-xylose was orally administrated to all pigs at the dose of 0.1 g/kg BW, 2 h after LPS or saline injection, and blood samples were collected 3 h thereafter. Twenty-four hours post-administration of LPS or saline, pigs were killed to obtain intestinal mucosae for analysis. Compared with the control group, LPS challenge reduced (P < 0.05) protein levels, the ratio of villus height to crypt depth, and the ratio of phosphorylated mTOR to total mTOR in duodenal, jejunal, and ileal mucosa. These adverse effects of LPS were attenuated (P < 0.05) by AKG supplementation. Moreover, AKG prevented the LPS-induced increase in intestinal HSP70 expression. Collectively, these novel results indicate that dietary supplementation with 1% AKG activates the mTOR signaling, alleviates the mucosal damage, and improves the absorptive function of the small intestine in LPS-challenged piglets. The findings not only help understand the mode of AKGs actions in the neonatal gut but also have important implications for infant nutrition under inflammatory conditions.     

Proteomic analysis reveals altered expression of proteins related to glutathione metabolism and apoptosis in the small intestine of zinc oxide-supplemented piglets

Zinc is an important dietary factor that regulates intestinal amino acid and protein metabolism in animals. Recent work with the piglet, an established animal model for studying human infant nutrition, has shown that supplementing high levels of zinc oxide (ZnO) to the diet ameliorates weaning-associated intestinal injury and growth retardation. However, the underlying mechanisms are largely unknown. This study tested the hypothesis that zinc supplementation affects expression of proteins related to glutathione metabolism and oxidative stress in the gut. Using two-dimensional gel electrophoresis and mass spectrometry, we identified 22 up-regulated and 19 down-regulated protein spots in the jejunum of weanling piglets supplemented with ZnO (3,000 mg/kg Zn) compared with the control pigs (100 mg/kg Zn). These proteins are related to energy metabolism (increased level for succinyl-CoA transferase and decreased level for creatine kinase M-type); oxidative stress (decreased levels for 78 kDa glucose-regulated protein and glutathione-S-transferase-ω); and cell proliferation and apoptosis (increased levels for A-Raf-1 and calregulin). Consistent with the changes in protein expression, the ratio of reduced glutathione to oxidized glutathione was increased, whereas glutathione-S-transferase and glutathione peroxidase activities as well as the protein level of active caspase-3 were reduced in ZnO-supplemented piglets. Collectively, these results indicate that ZnO supplementation improves the redox state and prevents apoptosis in the jejunum of weaning piglets, thereby alleviating weaning-associated intestinal dysfunction and malabsorption of nutrients (including amino acids).     

Effects of Dietary Supplementation of Recombinant Plectasin on Growth Performance,Intestinal Health and Innate Immunity Response in Broilers

The present study was conducted to evaluate the effects of dietary supplementation of recombinant plectasin (Ple) on the growth performance, intestinal health, and serum immune parameters in broilers. A total of 288 1-day-old male broilers (Arbor Acres) were randomly allotted to four dietary treatments including the basal diet (NC) and basal diet supplemented with 10 mg enramycin/kg (PC), 100 mg Ple/kg (LPle), and 200 mg Ple/kg (HPle) diets. The results indicated Ple increased (P < 0.01) average daily gain and decreased (P ≤ 0.02) feed to gain ratio of broilers. In addition, the supplementation of Ple in the diets increased (P ≤ 0.01) duodenal lipase (day 21) and trypsin (day 42) activities compared with the NC group. Similar as the supplementation of enramycin, Ple also increased villus height and decreased crypt depth in jejunum (day 21), and thus the villus height to crypt depth ratio (P < 0.01) was increased compared to the NC group on day 42. The serum immunoglobulin M (days 21 and 42), immunoglobulin G (day 42), complement 3 (day 21), and complement 4 (days 21 and 42) were significantly increased (P ≤ 0.02) due to the supplementation of Ple and enramycin, while the concentration of malondialdehyde in jejunum was decreased (P < 0.01) in PC, LPle, and HPle groups on day 21 compared with those in the NC group. Furthermore, Ple reduced (P < 0.01) Escherichia coli and total aerobic bacteria population in ileum and cecum of birds on days 21 and 42. These results indicate that the recombinant plectasin has beneficial effects on growth performance, intestinal health, and innate immunity in broilers.

     

Effect of Ascophyllum nodosum extract on growth performance, digestibility, carcass characteristics and selected intestinal microflora populations of grower–finisher pigs

The effects of an extract of the brown seaweed Ascophyllum nodosum (AN) in grower–finisher pigs are reported. In Experiment 1, the effect of dietary supplementation with increasing levels of AN extract (ANE) on growth performance, carcass characteristics and gastrointestinal microflora was investigated. A total of 360 pigs were randomly allocated, based on initial live-weight and sex, to one of four experimental treatments as follows; control diet (no ANE), control diet plus 3 g ANE/kg, control diet plus 6 g ANE/kg and control diet plus 9 g ANE/kg. These diets were fed ad libitum up to slaughter. In Experiment 2, eight male pigs were allocated to a control diet (no ANE) or the control diet plus 2.5 g ANE/kg to determine effects of ANE on coefficient of total tract apparent digestibility (CTTAD) of nutrients and nitrogen (N) balance. Supplementation with increasing levels of ANE in Experiment 1 resulted in reduced daily gain, carcass weight and kill-out yield during the combined grower–finisher period (P<0.05); however, there were no effects of treatment on feed intake, feed conversion ratio or carcass characteristics. Increasing levels of dietary ANE resulted in decreased ileal coliform counts (P<0.05). Increasing dietary ANE also tended to increase adherent lactobacilli in the colon (P=0.080) but caecal bifidobacteria declined (P<0.05). There were trends towards a linear reduction in colonic bifidobacteria (P=0.077) and towards a quadratic effect on rectal lactobacilli (P=0.077). Intestinal pH was unaffected by ANE supplementation (P>0.05). In Experiment 2, the CTTAD was unaffected by the inclusion of ANE (P>0.05). Overall, the intestinal coliform reductions obtained suggest that ANE may provide a dietary means to improve gut health and potentially reduce pathogen carriage in finishing pigs. However, the negative effects on growth performance observed in healthy animals will most likely limit the commercial use of dietary ANE as a feed additive.     

Effects of dietary l-arginine or N-carbamylglutamate supplementation during late gestation of sows on the miR-15b/16, miR-221/222, VEGFA and eNOS expression in umbilical vein

Placental vascular formation and blood flow are crucial for fetal survival, growth and development, and arginine regulates vascular development and function. This study determined the effects of dietary arginine or N-carbamylglutamate (NCG) supplementation during late gestation of sows on the microRNAs, vascular endothelial growth factor A (VEGFA) and endothelial nitric oxide synthase (eNOS) expression in umbilical vein. Twenty-seven landrace?×?large white sows at day (d) 90 of gestation were assigned randomly to three groups and fed the following diets: a control diet and the control diet supplemented with 1.0% l-arginine or 0.10% NCG. Umbilical vein of fetuses with body weight around 2.0?kg (oversized), 1.5?kg (normal) and 0.6?kg (intrauterine growth restriction, IUGR) were obtained immediately after farrowing for miR-15b, miR-16, miR-221, miR-222, VEGFA and eNOS real-time PCR analysis. Compared with the control diets, dietary Arg or NCG supplementation enhanced the reproductive performance of sows, significantly increased (P?<?0.05) plasma arginine and decreased plasma VEGF and eNOS (P?<?0.05). The miR-15b expression in the umbilical vein was higher (P?<?0.05) in the NCG-supplemented group than in the control group. There was a trend in that the miR-222 expression in the umbilical vein of the oversized fetuses was higher (0.05?<?P?<?0.1) than in the normal and IUGR fetuses. The expression of eNOS in both Arg-supplemented and NCG-supplemented group were lower (P?<?0.05) than in the control group. The expression of VEGFA was higher (P?<?0.05) in the NCG-supplemented group than in the Arg-supplemented and the control group. Meanwhile, the expression of VEGFA of the oversized fetuses was higher (P?<?0.05) than the normal and IUGR fetuses. In conclusion, this study demonstrated that dietary Arg or NCG supplementation may affect microRNAs (miR-15b, miR-222) targeting VEGFA and eNOS gene expressions in umbilical vein, so as to regulate the function and volume of the umbilical vein, provide more nutrients and oxygen from the maternal to the fetus tissue for fetal development and survival, and enhance the reproductive performance of sows.     

Dietary alanyl-glutamine improves growth performance of weaned piglets through maintaining intestinal morphology and digestion–absorption function

Alanyl-glutamine (Ala-Gln), a highly soluble and stable glutamine dipeptide, is known to improve gut integrity and function. The aim of this study was to evaluate whether dietary Ala-Gln supplementation could improve growth performance, intestinal development and digestive-absorption function in weaned piglets. A total of 100 purebred Yorkshire piglets weaned at 21 days of age were assigned randomly to four dietary treatment groups and fed a basal diet (control group) or a basal diet containing 0.15%, 0.30% and 0.45% Ala-Gln, respectively. Compared with the control group, piglets fed the Ala-Gln diets had higher average daily gain and lower feed : gain and diarrhea rate (P < 0.05). Moreover, dietary Ala-Gln supplementation increased villous height and villous height : crypt depth ratio in duodenum and jejunum (P < 0.05), as well as the activities of maltase and lysozyme in jejunum mucosa (P < 0.05). In addition, a decrease in serum diamine oxidase activity and crypt depth in duodenum and jejunum was observed in piglets fed the Ala-Gln diets (P < 0.05). Serum cytosolic phospholipase A2 (cPLA2) concentration and gene expression of cPLA2, Na⁺-dependent glucose transporter 1, glucose transporter 2 and peptide transporter 1 in jejunum were increased by feeding Ala-Gln diets relative to control diet (P < 0.05). These results indicated that feeding Ala-Gln diet has beneficial effects on the growth performance of weaned piglets, which associated with maintaining intestinal morphology and digestive-absorption function.     

Dietary arginine supplementation enhances intestinal expression of SLC7A7 and SLC7A1 and ameliorates growth depression in mycotoxin-challenged pigs

This study tested the hypothesis that dietary l-arginine supplementation confers beneficial effects on growing pigs fed a mold-contaminated diet. The measured variables included: (1) the average daily weight gain and feed:gain ratio; (2) activities of total superoxide dismutase, glutathione peroxidase, diamine oxidase, as well as amino acid and d-lactate concentrations in serum; (3) intestinal morphology; (4) expression of the genes for SLC7A7 (amino acid transporter light chain, y^+L system, family 7, member 7), SLC7A1 (cationic amino acid transporter, y⁺ system, family 7, member 1), SLC1A1 (neuronal/epithelial high affinity glutamate transporter, system X_AG, member 1), SLC5A1 (sodium/glucose cotransporter, family 5, member 1) in the ileum and jejunum. Mycotoxins in feedstuffs resulted in an enlarged small intestine mass, oxidative injury in tissues, and reduced growth performance in pigs. Dietary arginine supplementation enhanced (P < 0.05) expression of jejunal SLC7A7 and ileal SLC7A1, in comparison with the control and mycotoxin groups. In addition, supplementing 1 % l-arginine to the mycotoxin-contaminated feed had the following beneficial effects (P < 0.05): (1) alleviating the imbalance of the antioxidant system in the body; (2) ameliorating intestinal abnormalities; and (3) attenuating whole-body growth depression, compared with the mycotoxin group without arginine treatment. Collectively, these results indicate that dietary supplementation with l-arginine exerts a protective role in pigs fed mold-contaminated foods. The findings may have important nutritional implications for humans and other mammals.     

Both Dietary Supplementation with Monosodium L-Glutamate and Fat Modify Circulating and Tissue Amino Acid Pools in Growing Pigs,but with Little Interactive Effect

Background

The Chinese population has undergone rapid transition to a high-fat diet. Furthermore, monosodium L-glutamate (MSG) is widely used as a daily food additive in China. Little information is available on the effects of oral MSG and dietary fat supplementation on the amino acid balance in tissues. The present study aimed to determine the effects of both dietary fat and MSG on amino acid metabolism in growing pigs, and to assess any possible interactions between these two nutrients.

Methods and Results

Four iso-nitrogenous and iso-caloric diets (basal diet, high fat diet, basal diet with 3% MSG and high fat diet with 3% MSG) were provided to growing pigs. The dietary supplementation with fat and MSG used alone and in combination were found to modify circulating and tissue amino acid pools in growing pigs. Both dietary fat and MSG modified the expression of gene related to amino acid transport in jejunum.

Conclusions

Both dietary fat and MSG clearly influenced amino acid content in tissues but in different ways. Both dietary fat and MSG enhance the absorption of amino acids in jejunum. However, there was little interaction between the effects of dietary fat and MSG.     

Dietary N-Carbamylglutamate Supplementation Boosts Intestinal Mucosal Immunity in Escherichia coli Challenged Piglets

N-carbamylglutamate (NCG) has been shown to enhance performance in neonatal piglets. However, few studies have demonstrated the effect of NCG on the intestinal mucosal barrier. This study was conducted to determine the effects of dietary NCG supplementation on intestinal mucosal immunity in neonatal piglets after an Escherichia coli (E. coli) challenge. New-born piglets (4 d old) were assigned randomly to one of four treatments (n = 7), including (I) sham challenge, (II) sham challenge +50 mg/kg NCG, (III) E. coli challenge, and (IV) E. coli challenge +50 mg/kg NCG. On d 8, pigs in the E. coli challenge groups (III and IV) were orally challenged with 5 mL of E. coli K88 (10⁸ CFU/mL), whereas pigs in the sham challenge groups (I and II) were orally dosed with an equal volume of water. On d 13, all piglets were sacrificed, and samples were collected and examined. The results show that average daily gain in the E. coli challenged piglets (III and IV) was decreased (P_E.coli<0.05). However, it tended to be higher in the NCG treated piglets (II and IV). Ileum secretory IgA, as well as IFN-γ, IL-2, IL-4 and IL-10 in ileal homogenates, were increased in E. coli challenged piglets (III and IV). Similarly, ileum SIgA and IL-10 levels, and CD4⁺ percentage in NCG treated piglets (II and IV) were higher than no-NCG treated piglets (P_NCG<0.05). However, the IL-2 level was only decreased in the piglets of E. coli challenge + NCG group (IV) compared with E. coli challenge group (III) (P<0.05). No change in the IL-2 level of the sham challenged piglets (III) was observed. In conclusion, dietary NCG supplementation has some beneficial effects on intestinal mucosal immunity in E. coli challenged piglets, which might be associated with stimulated lymphocyte proliferation and cytokine synthesis. Our findings have an important implication that NCG may be used to reduce diarrhea in neonatal piglets.     

Dietary arginine supplementation enhances antioxidative capacity and improves meat quality of finishing pigs

The present study was conducted to test the hypothesis that dietary arginine supplementation may improve meat quality of finishing pigs. Beginning at ~60 kg body weight, pigs were fed a corn- and soybean meal-based diet supplemented with 0, 0.5 or 1% l-arginine until they reached a body weight of ~110 kg. On the last day of the experiment, pigs were food-deprived for 16 h before blood samples were obtained for analysis of amino acids, insulin, and other metabolites. Immediately thereafter, pigs were slaughtered for determination of carcass composition, muscle biochemical parameters, and meat quality. The result showed that arginine did not affect pig growth performance or carcass traits. However, 1% arginine decreased drip loss of pork muscle at 48 h postmortem, while increasing intramuscular fat content (P < 0.05). Supplementing 0.5 or 1% arginine to the diet increased arginine concentration and decreased cortisol level in serum, while enhancing antioxidative capacity and glutathione peroxidase activity in serum (P < 0.05). Additionally, 1% arginine increased antioxidative capacity in skeletal muscle (P < 0.05). Furthermore, 0.5 or 1% arginine decreased the cortisol receptor mRNA level in muscle (P < 0.05). Collectively, these results indicate that supplemental arginine improved meat quality and attenuated oxidative stress of finishing pigs.     

Effect of High Dietary Copper on Somatostatin and Growth Hormone-Releasing Hormone Levels in the Hypothalami of Growing Pigs

This experiment was conducted to examine the effect of dietary copper supplementation on somatostatin (SS) and growth hormone-releasing hormone (GHRH) mRNA expression levels in the hypothalami of growing pigs. A total of 45 crossbred pigs were randomly assigned to three groups of 15 pigs each; five replicates of three animals comprised each group. Pigs were allocated to diets that contained 5 mg/kg copper (control), 125 mg/kg copper sulfate, or 125 mg/kg copper methionine. At the end of the experiment, five pigs were selected at random from each group and slaughtered, and hypothalami were collected for determination of SS and GHRH mRNA expression levels. The results showed that the SS expression levels were lower and the GHRH levels were higher in pigs fed the diets with 125 mg/kg copper methionine (P < 0.05) and 125 mg/kg copper sulfate (P < 0.05), respectively, than in pigs fed the diet with 5 mg/kg copper. Furthermore, the relationship between SS mRNA and GHRH mRNA abundance had a significantly negative correlation (P < 0.05). The data indicated that high dietary copper could enhance GHRH mRNA expression levels and suppress SS mRNA expression levels in the hypothalami of pigs. High lever dietary copper (125 mg/kg copper sulfate or 125 mg/kg copper methionine) increased pigs’ growth performance and feed efficiency but had no significant effect on daily feed intake; 125 mg/kg copper sulfate or 125 mg/kg copper methionine at the same lever had no difference on growth promoting in pigs.     

Enzymatically modified starch up-regulates expression of incretins and sodium-coupled monocarboxylate transporter in jejunum of growing pigs

Dietary effects on the host are mediated via modulation of the intestinal mucosal responses. The present study investigated the effect of an enzymatically modified starch (EMS) product on the mucosal expression of genes related to starch digestion, sugar and short-chain fatty acid (SCFA) absorption and incretins in the jejunum and cecum in growing pigs. Moreover, the impact of the EMS on hepatic expression of genes related to glucose and lipid metabolism, and postprandial serum metabolites were assessed. Barrows (n=12/diet; initial BW 29 kg) were individually fed three times daily with free access to a diet containing either EMS or waxy corn starch as control (CON) for 10 days. The enzymatic modification led to twice as many α-1,6-glycosidic bonds (~8%) in the amylopectin fraction in the EMS in comparison with the non-modified native waxy corn starch (4% α-1,6-glycosidic bonds). Linear discriminant analysis revealed distinct clustering of mucosal gene expression for EMS and CON diets in jejunum. Compared with the CON diet, the EMS intake up-regulated jejunal expression of sodium-coupled monocarboxylate transporter (SMCT), glucagon-like peptide-1 (GLP1) and gastric inhibitory polypeptide (GIP) (P<0.05) and intestinal alkaline phosphatase (ALPI) (P=0.08), which may be related to greater luminal SCFA availability, whereas cecal gene expression was unaffected by diet. Hepatic peroxisome proliferator-activated receptor γ (PPARγ) expression tended (P=0.07) to be down-regulated in pigs fed the EMS diet compared with pigs fed the CON diet, which may explain the trend (P=0.08) of 30% decrease in serum triglycerides in pigs fed the EMS diet. Furthermore, pigs fed the EMS diet had a 50% higher (P=0.03) serum urea concentration than pigs fed the CON diet potentially indicating an increased use of glucogenic amino acids for energy acquisition in these pigs. Present findings suggested the jejunum as the target site to influence the intestinal epithelium and altered lipid and carbohydrate metabolism by EMS feeding.     

l-arginine supplementation of milk liquid or dry diets fed to pigs after weaning has a positive effect on production in the first three weeks after weaning at 21 days of age

A total of 48, 21-day-old weaned pigs, was used in a 2 × 2 factorial arrangement of treatments with the factors being diet type (milk liquid replacer vs. dry feed) and l-arginine (ARG) supplementation (0 vs. 6 g ARG/kg) to test the hypothesis that dietary supplementation with ARG would increase performance of pigs after weaning. Pigs were fed the experimental diets for 10 d (days) after weaning and then transitioned over a 3-d period to a dry Phase II diet fed in meal form devoid of supplemental ARG. The study ended at d 21. There were five replicates (pens) per treatment (a total of 12 pigs per treatment). Blood samples were collected from two pigs per replicate on d 7 and 16 of the experiment, and free amino acids (AA) and plasma urea nitrogen (PUN) levels analysed. Milk-fed pigs outperformed (P<0.001) dry-fed pigs for the first 10 d of the experiment as well as for the total 21-d period. At d 7, milk-fed pigs had higher (P<0.05) levels of most free indispensable and dispensable amino acids in their plasma. In both the milk-fed and dry-fed pigs supplemented with ARG, average daily feed intake (ADFI, P<0.05) and average daily gain (ADG, P<0.05) were increased during the dietary transition period (d 11–14), when pigs were being changed to the Phase II diet. The difference in production in the transition period caused a tendency for ARG-supplemented pigs to eat more feed (P<0.1) and grow faster (P<0.5) over the 21-d experimental period. Pigs supplemented with ARG had higher plasma ARG levels (P<0.05) at d 7 after weaning and lower plasma urea levels (P<0.05) at both d 7 and 16 after weaning. These data show the benefits of feeding a milk liquid diet as well as of ARG supplementation after weaning on production indices.     

Effects of chitosan‐oligosaccharides on growth performance,digestive enzyme and intestinal bacterial flora of tiger puffer (Takifugu rubripes Temminck et Schlegel, 1850)

The present study was conducted to evaluate the effects of different dietary chitosan oligosaccharide (COS) levels on digestive enzyme activity, intestinal bacteria flora, and growth performance of the tiger puffer (Takifugu rubripes). Some 600 fish (initial body weight 129.2 ± 3.1 g) were randomly allocated into twelve 2,000‐L blue cylinder aquaria with 1,500‐L of sea water and divided into four groups (n = 3 aquaria/diet). The fish were fed experimental diets supplemented with different levels of COS (0% [control, L1], 0.05% [LC1], 0.1% [LC2], and 0.2% [LC3]) for 8 weeks. During the experiment, the water temperature was 18 ± 1°C, salinity 28 ± 0.1, pH 8.0 ± 0.1 (mean ± SD, n = 672); airstones were positioned at the bottom of the tank, dissolved oxygen content was above 7.0 mg/L, with a photoperiod of 12 hr light: 12 hr dark. The results showed that dietary COS significantly increased growth performance, intestinal‐somatic index (ISI), and intestinal protease as well as lipase activity (p < .05). However, dietary COS did not have a significant effect on the condition factor (CF), hepatosomatic index (HSI), viscerosomatic index (VSI), survival, or muscle proximate composition of tiger puffers (p > .05). High‐throughput sequencing analysis showed that COS affected the richness and diversity of intestinal microbial species. The Shannon index of intestinal bacterial flora was significantly higher in the control group than in other groups (p < .05). However, dietary COS supplementation did not alter the phyla species of intestinal bacterial flora. There were significantly more Aliivibrio and Bacillus in LC3 than in other groups, and there were significantly fewer Faecalibacterium, Escherichia, and Bacteroides than in other groups at the genus level (p < .05). It can be concluded that dietary COS can improve the growth performance and intestinal digestive enzyme activity and alter the intestinal bacterial flora in the tiger puffer, Takifugu rubripes.     

Effects of sodium butyrate and salinomycin upon intestinal microbiota,mucosal morphology and performance of broiler chickens

The effect of dietary sodium butyrate (SB) or salinomycin (SAL) or both additives on performance, small intestinal morphology and microbial ecology of broiler chickens was studied. A growth trial was conducted with 96 Ross 308 female broilers from 1 to 30 days of age. Four treatment groups were fed with a non-supplemented control diet or three experimental diets supplemented with i) 300 mg SB (Adimix 30 coated) per kg, ii) 60 mg SAL (Sacox) per kg or iii) both additives in combination. Feed intake and body-weight gain decreased and gain-to-feed ratio increased due to SAL supplementation, while addition of SB did not affect performance in comparison with the control diet but positively affected feed intake and body-weight gain in comparison with birds fed the SAL-supplemented diet. Villus height in jejunum decreased, while crypt depth increased due to SAL supplementation. Addition of SB increased crypt depth in jejunum. No significant effect of either additive was observed in ileum morphology. Total short-chain organic acids concentration in ileal digesta decreased with SAL supplementation, mainly due to lower lactic acid concentration, but no effects were observed in the caeca. The SAL supplementation was accompanied by a pH increase in ileum and a pH decrease in caecum. No significant effect of SB addition was observed for these parameters. Total bacterial numbers and Lactobacillus [lactic acid bacteria (LAB)] counts in ileal and caecal contents were lower in birds fed with SAL-supplemented diet in comparison with birds fed with control or SB diet. DNA fingerprints revealed SAL supplementation to affect the microbial population by suppressing dominating LAB, potentially L. aviarius. The presented results show that dietary SAL, supplemented alone or in combination with SB, suppressed the microbial activity and altered the microbial community structure mainly in ileum. SAL alone negatively affected feed intake and body-weight gain; however, the effect was ameliorated by SB supplementation.     

Performance and total-tract digestibility responses to exogenous xylanase and phytase in diets for growing pigs

Sixty individually housed male pigs (Large White X Landrace, average weight 19.7±0.56 kg) were used in a completely randomised block design having five wheat-based dietary treatments (n=12 pigs per treatment) to study the interactive effects between added xylanase (XYL) and phytase (PHY), either alone or in combination, and days on trial on coefficient of total-tract digestibility (CTTAD) and performance. The diets used were: (i) positive control (PC); (ii) negative control with reduced energy and mineral content (NC); (iii) NC with added XYL (NCX); (iv) NC with added PHY (NCP); and (v) NC with added XYL plus PHY (NCXP). The performance response and CTTAD of dietary components were measured 3 and 7 weeks after commencement of feeding, with the experiment finishing when pigs reached approximately 65 kg live weight.Pigs fed the NC diet decreased average daily gain (ADG) by 13% (P<0.01) and increased feed conversion ratio (FCR) by 11% (P<0.01) compared to pigs fed the PC diet. Addition of PHY in the NC diet increased ADG by 9% (P<0.05) and decreased FCR by 5% (P=0.065), whilst addition of XYL in the NC diet had no effect on the performance indices. Combined addition of XYL and PHY in the NC diet did not improve performance of pigs for the first 21 days but improved FCR by 8% (P=0.008) during the days 22–49. Digestibility measurements showed that combined use of XYL and PHY in the NC diet improved CTTAD of dry matter (DM, P<0.05), gross energy (GE, P<0.05) and crude protein (CP, P<0.01) only during the days 22–49. Independent supplementation of PHY in the NC diet tended to improve CTTAD of GE (P=0.09) only during the days 22–49. In contrast, supplementation of PHY immediately improved CTTAD of P and maintained it to similar levels at 49 days. Results suggested that supplementation of PHY plus XYL in combination in the NC diet improved FCR and CTTAD of DM, GE, CP and P but the beneficial effects other than CTTAD of P were derived mainly during days 22–49.     

Dietary supplementation with <Emphasis Type="Italic">Astragalus</Emphasis> polysaccharide enhances ileal digestibilities and serum concentrations of amino acids in early weaned piglets

Two experiments were conducted to evaluate the effects of dietary supplementation with Astragalus polysaccharide (APS) on growth performance, apparent ileal digestibilities (AID) of amino acids (AA), and their serum concentrations in early weaned piglets. In Exp. 1, 60 pigs were weaned at 21 days of age (BW 7.35 ± 0.23 kg) and allocated to three treatments (20 pigs/treatment), representing supplementing 0.0% (control), 0.02% colistin (antibiotic), or 0.1% APS to a corn- and soybean meal-based diet. Average daily gain (ADG), average daily feed intake (ADFI), and feed/gain ratio (F/G) were measured weekly. Blood samples were obtained from five pigs selected randomly from each treatment for the measurement of serum free AA concentrations on days 7, 14, and 28. In Exp. 2, 12 pigs were weaned at 21 day of age (BW 7.64 ± 0.71 kg), assigned to three treatment groups as in Exp. 1, and surgically fitted with a simple T-cannula at the terminal ileum. Ileal digesta samples were obtained for the measurement of AID of AA on days 7, 14 and 28. Dietary APS did not affect ADFI, but enhanced (P < 0.05) ADG by 11 and 4.4%, and improved F/G by 5.6 and 8.4%, respectively, compared with the control and antibiotic groups. Addition of APS to the diet increased AID and serum concentrations of most nutritionally essential and non-essential AA (including arginine, proline, glutamate, lysine, methionine, tryptophan, and threonine) on days 14 and 28. Circulating levels of total AA were affected by the age of pigs and treatment × time interaction. Collectively, these findings indicate that APS may ameliorate the digestive and absorptive function and regulate AA metabolism to beneficially increase the entry of dietary AA into the systemic circulation, which provide a mechanism to explain the growth-promoting effect of APS in early weaned piglets.     

Effects of dietary copper on growth performance, nutrient digestibility and fiber characteristics in cashmere goats during the cashmere slow-growing period

Thirty-six 2.5-year-old wether Inner Mongolian White Cashmere Goats (IMWG) (BW = 42.7 ± 3.44 kg) were used to determine the effects of dietary copper (Cu) concentration on growth performance, nutrient digestibility and fiber characteristics during the cashmere slow-growing period. Wethers were stratified by weight and randomly assigned to four dietary treatments, which included a control diet containing 5.60 mg Cu/kg DM, the control diet supplied, respectively, with 10, 20 and 30 mg Cu/kg DM (total dietary Cu level of 5.60, 15.6, 25.6 and 35.6 mg/kg DM). The experiment lasted 50 days including a 10-day preliminary trial and 10-day metabolism trial. Average daily feed intake (ADFI) did not differ among treatment groups (P > 0.05), except that the supplement providing 30 mg Cu/kg DM decreased average daily gain and gain efficiency (P < 0.05). Copper supplementation had no influence on digestibility of DM, CP and ADF (P > 0.05), however, NDF digestibility of the treatment group supplemented with 30 mg Cu/kg DM was lower compared with that of other groups (P < 0.05). Length and growth rate of cashmere fiber were higher in the treatment group supplemented with 20 mg Cu/kg DM compared with other groups (P < 0.05), but cashmere diameter was not affected by Cu supplementation (P > 0.05). In conclusion, supplementation of Cu at the levels of 10, 20 and 30 mg/kg DM to the basal diet containing 5.60 mg Cu/kg DM had no influence on ADFI or nutrient digestibility of DM, CP and ADF in cashmere goats, while 30 mg Cu/kg DM supplementation had a negative effect on growth performance and NDF digestibility. However, 20 mg Cu/kg DM supplementation of the basal diet enhanced cashmere growth. Hence, the appropriate supplemental level during the cashmere slow-growing period is deemed to be 20 mg Cu/kg DM (total dietary Cu level of 25.6 mg/kg DM).     

Lactobacillus reuteri KT260178 Supplementation Reduced Morbidity of Piglets Through Its Targeted Colonization,Improvement of Cecal Microbiota Profile,and Immune Functions

Supplementing suckling piglets with Lactobacillus reuteri isolated from a homologous source improves L. reuteri colonization number in the gastrointestinal tract, which can have health benefits. This study investigated dietary L. reuteri supplementation on the growth and health—including immune status—of piglets, as well as its colonization. A total of 60 sows with similar parity and body weight were allocated into one of three groups after secretion (n = 20 each, with 10 neonatal piglets of each): untreated control, L. reuteri supplementation, and antibiotic treatment. The experimental duration was 28 days, from birth of piglets to their group transferred. For the first 7 days after birth, all neonatal piglets were fed by sows. Piglets in the L. reuteri supplementation group were administered with 1.0 ml L. reuteri fermentation broth containing 5.0 × 10⁷ CFU. From 7 to 28 days, piglets were given basal feed (control), basal feed supplemented with L. reuteri (1.0 × 10⁷ CFU/g), or aureomycin (150 mg/kg). L. reuteri colonization in the distal jejunum and ileum was increased in piglets in the L. reuteri-supplemented as compared to the control group after 28 days, as determined by fluorescence in situ hybridization and real-time PCR analysis. Total Lactobacillus and Bifidobacterium counts in the cecum were higher whereas total aerobic bacteria (Escherichia coli and Staphylococcus) counts were lower in the L. reuteri as compared to the control group. L. reuteri supplementation also improved body antioxidant status and immune function relative to control animals. Strain-specific L. reuteri administered to piglets colonizes the intestinal mucosa and improves cecal microbiota profile and whole-body antioxidant and immune status, leading to better growth and lower morbidity and mortality rates.