Intestinal Digestive Enzyme Activities Research Articles

Effect of dietary coated granules containing garlic oil diallyl disulphide and diallyl trisulphide on performance, in vitro digestibility and gastrointestinal functionality in laying hens

This experiment was conducted to investigate the effects of dietary supplementation with coated granules (CG) on performance, in vitro digestibility and the gastrointestinal functionality in laying hens. A total of 40 Hisex Brown laying hens (36weeks of age) were randomly divided into five equal groups; one served as a control and the other four were actual experimental groups supplemented with 0.75, 1.5, 3 or 6g CG per day. All the hens were fed restrictively with target feed intake of 100g basal diet/hen per day. There were no differences in egg production or egg weight among the groups, but feed conversion ratio was significantly improved (linearly, p<0.05) with the dose level of CG in diet. Dietary CG increased the jejunal weight (linear and quadratic terms, p<0.05) but decreased the ileal weight (linearly, p<0.05). There was mostly statistical interaction between dietary CG and specific activity of intestinal digestive enzymes with similar patterns for dietary CG treatments (p<0.05). A positive linear correlation was observed with in vitro protein digestibility by using the crude enzyme extract from dietary CG supplementation. Dietary CG decreased the caecal Escherichia coli population while the Lactobacillus spp.: E.coli ratio increased (quadratic fit, p<0.05). CG supplementation, on the other hand, significantly altered intestinal morphology by increasing the height of duodenal and ileal villi (linearly, p<0.05). Also, duodenal antioxidant capacity observed via remaining reducing power improved linearly (p<0.05). This suggests that CG, unlike garlic oils without encapsulation, may be a good candidate for feed supplementation in commercial egg production. It could be included up to 6g CG per day without any adverse effects on performance, which may relate to improving nutrient digestibility and better utilization of limited feed intake when using a low amount of diet or other observations in this study.

Screening of intestinal probiotics and the effects of feeding probiotics on the digestive enzyme activity, immune, intestinal flora and WSSV resistance of Procambarus clarkii

In this experiment, a potential probiotic strain A23 with high antimicrobial activity against common aquatic pathogens and extracellular enzyme production was isolated from the intestine of healthy Procambarus clarkii. Biochemical and 16S rDNA sequencing analysis identified A23 as Bacillus amyloliquefaciens, and a haemolytic test and antibiotic susceptibility test were carried out on strain A23 to determine its safety. First, the whole genome of B. amyloliquefaciens A23 was determined to explore its mechanism of action. The results showed that the total length of the genome was 3,974,398 bp, the GC content was 46.56%, and 3843 genes were encoded, including 27 rRNA operons and 86 transfer RNA genes. Three bacilysin-related genes and 10 antimicrobial peptide (AMP)-related genes were found through manual inspection. Second, we evaluated the beneficial effects of strain A23 in P. clarkii by performing in vivo feeding experiments. The results showed that probiotic supplementation could effectively enhance the intestinal digestive enzyme activities, innate immune enzyme activities and white spot syndrome virus (WSSV) resistance of P. clarkii. Finally, the intestinal microbial community and diversity of crayfish were compared and analyzed by high-throughput sequencing. At the phylum level, the abundance of Proteobacteria decreased with 108 CFU/g probiotics supplement, while the abundance of Firmicutes and Bacteroides increased. The Shannon index of the intestinal microorganism community of the 108 CFU/g probiotic supplementation group was significantly higher than that of the control group, indicateding that 108 CFU/g probiotic supplementation enhanced intestinal microbial diversity. The results from this study demonstrated that B. amyloliquefaciens A23 is a promising probiotic candidate that provides multiple benefits for crayfish cultivation.

Co-bedding of Preterm Newborn Pigs Reduces Necrotizing Enterocolitis Incidence Independent of Vital Functions and Cortisol Levels.

Background: Preterm infants are born with immature organs, leading to morbidities such as necrotizing enterocolitis (NEC), a gut inflammatory disease associated with adverse feeding responses but also hemodynamic and respiratory instability. Skin-to-skin contact including “kangaroo care” may improve infant survival and health via improved vital functions (e.g., pulmonary, cardiovascular) and endocrine influences by adrenal glucocorticoids. Clinical effects of skin-to-skin contact for newborn siblings (“co-bedding”) are not known. Using NEC-susceptible Preterm pigs as models, we hypothesized that co-bedding and exogenous glucocorticoids improve vital functions and NEC resistance.Methods: In experiment 1, cesarean-delivered, formula-fed Preterm pigs were reared in incubators with (co-bedding, COB, n = 30) or without (single-bedding, SIN, n = 29) a sibling until euthanasia and tissue collection on day four. In experiment 2, single-bedded Preterm pigs were treated postnatally with a tapering dose of hydrocortisone (HC, n = 19, 1–3 mg/kg/d) or saline (CON, n = 19).Results: Co-bedding reduced NEC incidence (38 vs. 65%, p < 0.05) and increased the density of colonic goblet cells (+20%, p < 0.05) but had no effect on pulmonary and cardiovascular functions (respiration, blood pressure, heart rate, blood gases) or cortisol levels. There were limited differences in intestinal villous architecture and digestive enzyme activities. In experiment 2, HC treatment increased NEC lesions in the small intestine without any effects on pulmonary or cardiovascular functions.Conclusion: Co-bedding may improve gut function and NEC resistance independently of cardiorespiratory function and cortisol levels, but pharmacological cortisol treatment predispose to NEC. Preterm pigs may be a useful tool to better understand the physiological effects of co-bedding, neonatal stressors and their possible interactions with morbidities in Preterm neonates.

Evaluation of defatted Hermetia illucens larvae meal for Litopenaeus vannamei : effects on growth performance, nutrition retention, antioxidant and immune response, digestive enzyme activity and hepatic morphology

Defatted black soldier fly (Hermetia illucens) larvae meal (DBSFLM) has been shown an important alternative protein ingredient for fish, but little information is available about the effect of DBSFLM on growth and health of Litopenaeus vannamei. A 56-day feeding trial was conducted to assess the effects of partial replacement of fish meal with DBSFLM on growth performance, body composition, nutrition retention, blood metabolites, antioxidant and immune response, digestive enzyme activities and hepatic morphology of L. vannamei. Six isonitrogenous and isoenergy diets were formulated by replacing 0% (G0), 15% (G15), 30% (G30), 45% (G45), 60% (G60) and 80% (G80) of fish meal with DBSFLM. Each diet was randomly assigned to quadruplicate groups of 40 shrimp per tank. Shrimp were fed three times daily to apparent satiation. Blood samples were collected at the terminal trial to analyse antioxidant and non-specific immune enzyme activities. Hepatopancreas and intestine samples were collected to determine digestive enzyme activities and hepatic morphology. Shrimp fed G80 had lower (p < .05) final body weight, weight gain and specific growth rate, and higher (p < .05) feed conversion ratio than other groups. Crude protein (CP) in the whole body and muscle, coupled with CP and lipid retention of shrimp were decreased (p < .05) as dietary DBSFLM increasing. Shrimp fed G80 had lower (p < .05) serum total cholesterol but higher (p < .05) total antioxidant capacity than other diets, and serum malondialdehyde was lower (p < .05) in shrimp fed G45-G80 than those fed G0-G30. Hepatic and intestinal digestive enzyme activities were not altered by treatments (p > .05). Hepatocytes were shown to have different degrees of vacuolar degeneration, hepatic corpuscle atrophy and starlike lumen lose as observed in G60 and G80. The results demonstrated that up to 60% of fish meal could be replaced by DBSFLM without any adverse effects on growth performance, antioxidant and immune enzyme activities, and digestive enzyme activities of L. vannamei. However, hepatocyte damage was observed when the replacement levels exceeded 60%.

Effects of dietary florfenicol contained feeds on growth and immunity of European seabass (Dicentrarchus labrax) in flow-through and recirculating aquaculture system

Antibiotic growth promoters have been banned in animal husbandry and aquaculture in China, since 2020. Florfenicol (FLO) is the most used antibiotics in aquaculture for controlling various bacterial disease in fish, although its effect on health of farmed fish remains a concern. In the present study, European seabass (Dicentrarchus labrax) reared under flow-through aquaculture system (FAS) and recirculating aquaculture system (RAS), were fed on diets supplemented with FLO for 10 d, followed by a 20-d withdrawal period. The effects of FLO on the growth performance, intestinal digestive enzyme activities, serum biochemical parameters, antioxidant enzymes, and expression of related genes, were evaluated. The results showed that FLO exposure inhibited growth performance of D. labrax although this was recovered after stopping the feeding. Besides, FLO suppressed α-Amylase and trypsin activities in the intestine, and the amounts of nutrition-related indicators were also affected. In addition, FLO exposure upregulated liver cellular damage markers (ALT, ALP, and AST) during the treatment phase, although it did not pose a high potential for liver damage. We also observed elevated levels of SOD, CAT, and MDA in gills, indicative of oxidative stress on the cultured fish. Moreover, integrated biomarker response results indicated that fish in RAS had higher growth performance and immunity in the late post-treatment phase, relative to those in RAS, after FLO exposure. This was attributed to high-efficient water treatment of RAS. Overall, these results indicate that exposure to FLO modulates digestive enzyme activities and antioxidant response in European seabass, thereby affecting their growth performance and immune response under different aquaculture modes.

Dietary glycerol inclusion decreases growth performance and nitrogen retention efficiency in rainbow trout (Oncorhynchus mykiss)

Glycerol is an inexpensive source of dietary energy, although its inclusion in compound feeds has been barely investigated in fish. The effects of dietary refined glycerol inclusion on growth performance, nitrogen and energy balance, as well as its digestibility and intestinal digestive enzyme activities was studied in rainbow trout. Fish (initial BW 20.2 ± 0.1 g, mean ± SE) were divided into nine tanks (1.66 kg m−3), each one assigned to the experimental diets, in triplicates. Fish were fed twice a day to apparent satiation for 60 days three diets including 0, 25, or 50 g kg−1 of refined glycerol (G0, G25, and G50, respectively) with similar digestible protein to energy ratios (22 mg kJ−1). A digestibility trial was conducted in parallel to the growth trial by using a Choubert System to collect feces, in triplicates. Refined glycerol was well digested (ADCglycerol > 99.7%) when included up to 50 g kg−1. Specific growth rate (SGR) decreased as glycerol inclusion levels increased in the diet (P = 0.029). Feed intake was enhanced with increasing dietary inclusion levels of glycerol (P = 0.013). The feed efficiency decreased linearly as the glycerol inclusion levels increased in the diet, reflected in a higher FCR ratio, particularly in the G50 group compared to the G0 or G25 groups (1.04 ± 0.02, 0.90 ± 0.02 and 0.91 ± 0.02, respectively). Total ammonia nitrogen excretion rate (TANER) was measured in trout at the end of the growth trial, displaying increased values with higher dietary glycerol inclusion levels (P < 0.001). As a result, trout fed G25 or G50 diets displayed an increased energy intake, which was not reflected in a reduction of the nitrogen excretion rate. Contrary to expected, glycerol had a negative effect on nitrogen efficiency, indicating that dietary inclusion of this compound does not spare the use of proteins as a metabolic fuel. In addition, amylase, but not proteases and lipase, was altered in the intestine of trout by refined glycerol inclusion, as this digestive enzyme activity increased 6 h post-feeding in trout fed G25 and G50 diets. In conclusion, dietary refined glycerol inclusion on rainbow trout was not reflected in beneficial effects on fish performance or in the quantity of nitrogen waste products excreted to the environment by this carnivorous species.

Feeding sundried cassava leaf meal as a replacement for de‐oiled rice bran in the diets of rohu, L abeo rohita , fingerlings: effect on growth, enzyme activities and gene expression of igf‐i and igf‐bpi

A 75-day feeding trial was conducted to evaluate the nutritional implication of feeding diets containing graded levels of sundried cassava leaf meal (SCLM) to Labeo rohita fingerlings. Four isonitrogenous (300 g/kg crude protein) and isoenergetic (18 MJ/kg) diets were prepared by replacing de-oiled rice bran (DORB) with 0 (diet 1), 130 (diet 2), 260 (diet 3) and 390 g/kg (diet 4) of SCLM. The diets were fed to the triplicate groups of L. rohita fingerlings (average weight, 2.03 ± 0.03 g) in a completely randomized experimental design. At the end of the trial, diet 3 had similar (p > 0.05) percentage weight gain (106.38 ± 4.41%), specific growth rate (1.29 ± 0.04%/day) and feed conversion ratio (2.38 ± 0.08) relative to the control group. Intestinal digestive enzyme activities, hepatic and muscle transaminases and proximate body composition of L. rohita fingerlings were not significantly (p > 0.05) influenced by the dietary treatment. Superoxide dismutase activity of the group reared on diets 3 and 4 was significantly (p < 0.05) higher than that of diet 1. Based on the second-order polynomial regression analysis on the expression of IGF-I and IGF-BPI, it was concluded that as much as 166.5 g/kg DORB can be replaced by SCLM for optimal growth performance, in the diets of L. rohita fingerlings.

High protein intake promotes the adaptation to chronic hypoxia in zebrafish (Danio rerio)

Chronic hypoxia is a common environmental stress factor in aquaculture. Many researchers have illustrated the physiological and metabolic changes under chronic hypoxia, but there are few studies to evaluate the relationship between dietary nutrients and hypoxic adaptation in fish. In the present study, we fed zebrafish with control diet (C), high-carbohydrate diet (HC), high-fat diet (HF) and high-protein diet (HP) at normal dissolved oxygen (DO = 7.0 ± 0.5 mg/L) or low dissolved oxygen (DO = 2.5 ± 0.5 mg/L) environment, respectively. After a 7-week feeding trial, the growth performance, body composition, tissue biochemical indexes, mRNA expressions of hifα isoforms and nutrient metabolism-related genes, intestinal digestive enzyme activities and microbiota composition were measured. The results indicated that only the HP diet could alleviate the reduction of body weight and feed efficiency induced by chronic hypoxia, but the HF diet feeding worsened the adverse effects of chronic hypoxia in zebrafish. At the C groups, hypoxia increased catabolism of lipid and protein, but at the HP groups, hypoxia enhanced utilization of glycogen and protein. Compared to the C-hypoxia group, the HP feeding could activate transcription of hif-1a and its downstream glycolysis genes in chronic hypoxia. Furthermore, at hypoxic state, the HP feeding could alleviate the reduction of intestinal digestive enzyme activities and microbiota dysbiosis induced by the chronic hypoxia, including increasing bacterial diversity and decreasing Cetobacterium genus abundance. This is the first study indicating that high protein intake could strengthen ability of fish in resisting the negative effect of chronic hypoxia.

243 Ileal Terminal Starch Hydrolytic Activity Is Increased in Association with Improved Growth and Feed Efficiency in Weaning Pigs Fed a Therapeutic Multi-antimicrobial-supplemented Diet

Abstract Understanding roles of prescribed in-feed therapeutic multi-antimicrobials in affecting the small intestinal terminal starch digestive enzyme activity in improving weaning pig growth and feed utilization may shed light on developing novel alternative strategies to reduce uses of antimicrobials. A total of 125 crossbred barrows, weaned on d 19–21 with an average initial BW of 6.9 ± 0.1 kg, were randomly assigned to two corn, SBM and dried whey powder based diets for 21 d according to a randomized complete block design. The multi-antimicrobial diet was supplemented with aureomycin 220, tiamulin 31.2 and ZnO 2,358 at mg/kg diet. The growth performances including final BW (control, 13.9 ± 0.2 vs. antimicrobials, 15.0 ± 0.2 kg), ADG (control, 0.307 ± 0.009 vs. antimicrobials, 0.355 ± 0.009 kg/d), ADFI (control, 0.425 ± 0.012 vs. antimicrobials, 0.455 ± 0.013 kg/d) and F:G (control, 1.39 ± 0.03 vs. antimicrobials, 1.28 ± 0.03 kg/kg) were improved (P &amp;lt; 0.05; n = 25 pens; 5 barrows/pen) compared to the non-antimicrobial control diet. The combined enzyme kinetics of the jejunal and the ileal maltase-glucoamylase (MGA) and sucrase-isomaltase (SI) activity were determined with the jejunal and the ileal homogenates by using maltose (0–60 mM in incubation mixture). The combined jejunal and the ileal MGA-SI affinity Km values and the combined jejunal MGA-SI maximal activity Vmax values were not different (P &amp;gt; 0.05) between the two diet groups. However, the combined ileal MGA-SI Vmax (nmol·mg protein-1·min-1) was increased in the antimicrobial diet (P &amp;lt; 0.05; control, 125.6 ± 10.84, n = 13 pigs vs. antimicrobials, 170.8 ± 12.15, n = 11 pigs) in comparison with the control diet. The Pearson’s correlation analyses revealed that the combined ileal MGA-IS Vmax of hydrolyzing maltose was associated with ADG (P = 0.0669; r = 0.38; n = 24 pigs) and feed efficiency (F:G; P &amp;lt; 0.05; r = -0.53; n = 24 pigs). Our results suggest that in-feed therapeutic multi-antimicrobials could improve the distal small intestinal terminal starch digestive enzyme MGA-SI activity, thus improving growth and feed efficiency in weaning pigs.

219 Effects of maternal nutrient restriction and rumen-protected arginine supplementation on post-ruminal digestive enzyme activities of lamb offspring

Abstract To determine the effects of maternal nutrient restriction and rumen-protected arginine supplementation on post-ruminal digestive enzymes in lambs, 31 multiparous, Rambouillet ewes were allocated to one of three dietary treatments at 54 d of gestation. Dietary treatments were 100% of nutrient requirements (control, CON; n=11), 60% of control (restricted, RES; n=10), or RES plus a rumen-protected arginine supplement dosed at 180 mg/kg BW once daily (RES-ARG; n=10). At parturition, lambs were immediately removed from dams and reared independently. Milk-replacer and alfalfa hay + creep feed was offered for ad libitum intake. At day 54 of age, lambs were slaughtered and the pancreas and small intestine were collected. Pancreatic (α-amylase, trypsin) and small intestinal (maltase, glucoamylase, sucrase, isomaltase, lactase) digestive enzyme activities were assayed. Data were analyzed using the GLM procedure of SAS with treatment and fetal sex included in the model statement. Contrast statements were used to determine differences between means for effects of restriction (CON vs. RES and RES-ARG) and rumen-protected arginine supplementation (RES vs. RES-ARG). There was no influence (P≥0.32) of maternal nutrient restriction or rumen-protected arginine supplementation on pancreatic or small intestinal protein concentrations. No treatment effects were observed (P≥0.14) for enzymes involved in starch digestion including pancreatic α-amylase and small intestinal maltase, glucoamylase, and isomaltase. Sucrase activity was undetected in the small intestine of lambs across all treatments. Maternal nutrient restriction tended to increase (P=0.09) pancreatic trypsin specific activity in lambs. Lactase specific activity in the small intestine of lambs tended to decrease (P=0.08) with maternal nutrient restriction. Rumen-protected arginine supplementation to gestating ewes did not influence (P≥0.19) digestive enzyme activities of lamb offspring. These data suggest that maternal nutrient restriction may result in increased pancreatic trypsin activity of lambs to potentially compensate for inadequate pre-natal nutrient supply.

PSIX-7 Grazing toxic endophyte-infected tall fescue does not influence pancreatic or small intestinal digestive enzyme activities in beef steers

Abstract The objective of this experiment was to determine the influence of toxic endophyte-infected tall fescue exposure on pancreatic and small intestinal digestive enzyme activities in steers. Twelve fescue-naive beef steers [693 ± 42.7 kg of body weight (BW)] were stratified by BW and randomly assigned within BW ranks to graze non-toxic endophyte-infected tall fescue (NTE, n = 6; 0.01 ± 0.009 mg ergovaline + ergovalinine/kg) or toxic endophyte-infected tall fescue (TE, n = 6; 0.50 ± 0.048 mg ergovaline + ergovalinine/kg) pastures for 84 d. After the grazing period, steers were weighed and then slaughtered in three groups for tissue collection. A 1-m segment of the small intestine was collected 5-m distal to the pyloric sphincter. Subsamples of the small intestinal mucosa and pancreas were collected, homogenized in saline, and assayed for protein concentration. Pancreatic and small intestinal digestive enzyme activities were assayed. Data were analyzed using the GLM procedure of SAS as a randomized complete block design for effects of treatment and slaughter group (blocking factor). Steers grazing NTE pastures had a greater (P &amp;lt; 0.001) average daily gain (0.282 vs -0.631 kg/d) and final BW at slaughter (739 vs 620 kg) than steers grazing TE pastures. Small intestinal segment mass and mucosal density (P ≥ 0.16) were not influenced by treatment. Grazing TE pasture did not influence (P ≥ 0.21) pancreatic or small intestinal protein concentrations. Pancreatic α-amylase and trypsin activity per gram pancreas (P ≥ 0.21) or per gram pancreatic protein (P ≥ 0.30) were not influenced by fescue treatment. Small intestinal glucoamylase, isomaltase, and maltase activities did not differ between steers grazing NTE or TE pastures when expressed per gram of intestinal tissue (P ≥ 0.47) or per gram of intestinal protein (P ≥ 0.60). These data indicate that decreased gains observed in cattle consuming TE are not a result of decreased pancreatic or small intestinal digestive enzyme activities.

Fatty Acid Composition and Digestive Enzyme Activities of Rainbow Trout in Response to Dietary Docosahexaenoic Acid (DHA) and Eicosapentaenoic Acid (EPA) During Salinity Acclimation

This physiological study aimed to evaluate the effects of dietary docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) on the fatty acid composition and digestive enzyme activities of rainbow trout (Oncorhynchus mykiss) during salinity acclimation. Rainbow trout with an average initial weight of 90.61 g ±9.25 g were fed diets with the quantities of DHA and EPA equaling to 0.54%, 0.95%, 1.40% and 1.79% (abbreviated as DE-0.54, DE-0.95, DE-1.40, and DE-1.79, respectively) for eight weeks, after which the gastric and intestinal fatty acids composition were analyzed. Subsequently, the fish underwent salinity acclimation. On days 1, 4, 7, and 14 after the freshwater was replaced by seawater and at the end of the 8-week period, gastric and intestinal digestive enzyme activities were determined. The results showed that the gastric and intestinal DHA and EPA contents of the fish were positively correlated to their dietary DHA and EPA levels. Low dietary DHA and EPA levels inhibited the protease activity of rainbow trout. Fish in the DE-0.54 group increased the lipase activity to enhance the utilization of lipids maybe due to the inadequate essential fatty acids for fish in this group. Hence, rainbow trout in the DE-0.54 group failed to maintain suitable activities of digestive enzymes after salinity acclimation. Therefore, a diet with minimum 0.95% DHA and EPA levels is necessary for rainbow trout during salinity acclimation.

Partial fishmeal protein replacement with peptides from swine blood modulates the nutritional status, immune response, and intestinal microbiota of hybrid groupers (female Epinephelus fuscoguttatus× male E. lanceolatus)

This study investigated the effects of replacing fish meal (FM) protein with peptides from swine blood (PSB) on the growth, digestion, and absorption capacity of hybrid groupers (female Epinephelus fuscoguttatus × male Epinephelus lanceolatus). It also analyzed their inflammatory-related gene expression, and intestinal microbiota. Four isonitrogenous and isolipidic experimental feeds were formulated to replace 0% (FM), 25% (PSB25), 50% (PSB50), and 75% (PSB75) of the FM protein with PSB. Each experimental diet was fed to triplicate groups of 30 hybrid grouper juveniles for 8 weeks. No significant differences in the weight gain and specific growth rates were found among the FM, PSB25, and PSB50 groups. The intestinal digestive enzyme (lipase, amylase, trypsin, and pepsin) and brush border enzyme (Na+/K+-ATPase, creatine kinase, and γ-glutamyl transpeptidase) activities showed no significant differences among the FM, PSB25, and PSB50 groups. Meanwhile, trypsin, pepsin. Creatine kinase, and γ-glutamyl transpeptidase activities in the PSB group were significantly higher than those of the FM group. No significant differences in the expression levels of the toll-like receptor 21 (TLR21), myeloid differentiation factor 88 (MyD88), and inflammatory cytokines (TNF-α, IL-2, IL-8, and IL-10) were observed among the four groups. The intestinal microbiota results showed no significant differences in alpha diversity among the four groups. At the genus level, at the genus level, Lactobacillus relative abundance was significantly reduced in the PSB10 group compared to that in the FM group. However, no significant differences were found among the FM, PSB50, and PSB75 groups. However, no significant differences were found among the FM, PSB50, and PSB75 groups. These results demonstrated that up to 50% of the FM protein in the feed can be replaced by PSB without adversely affecting the nutritional status and inflammatory response in hybrid groupers. Replacing FM with PSB significantly influences the microbial profile but not the diversity

Effects of Probiotics BaSC06 on Intestinal Digestion and Absorption, Antioxidant Capacity, Microbiota Composition, and Macrophage Polarization in Pigs for Fattening.

This study aimed to compare the effects of BaSC06 and antibiotics on growth, digestive functions, antioxidant capacity, macrophage polarization, and intestinal microbiota of pigs for fattening. A total of 117 pigs for fattening with similar weight and genetic basis were divided into 3 groups: Anti group (containing 40 g/t Kitasamycin in the diet), Anti+Ba group (containing 20 g/t Kitasamycin and 0.5 × 108 CFU/kg BaSC06 in the diet) and Ba group (containing 1 × 108 cfu/Kg BaSC06 in the diet without any antibiotics). Each treatment was performed in three replicates with 13 pigs per replicate. Results showed that BaSC06 replacement significantly improved the ADG (P < 0.05), intestinal digestion and absorption function by increasing the activity of intestinal digestive enzymes and the expression of glucose transporters SGLT1 (P < 0.05) and small peptide transporters PEPT1 (P < 0.05). Besides, BaSC06 supplementation enhanced intestinal and body antioxidant capacity by activating the Nrf2/Keap1 antioxidant signaling pathway due to the increased expression of p-Nrf2 (P < 0.05). Notably, BaSC06 alleviated intestinal inflammation by inhibiting the production of pro-inflammatory cytokines, IL-8, IL-6, and MCP1 (P < 0.05), and simultaneously increasing the expression of M1 macrophage marker protein iNOS (P < 0.05) and M2 macrophage marker protein Arg (P < 0.05) in the intestinal mucosa. Moreover, BaSC06 promoted the polarization of macrophages to M2 phenotype by stimulating the STAT3 signaling pathway. It was also noted that BaSC06 improved microbiota composition by enhancing the proportion of Firmicutes, and reducing that of Bacteroidetes and Proteobacteria. Taken together, our results indicate that dietary supplementation of BaSC06 in pigs for fattening improves the growth, mucosal structure, antioxidative capacity, immune functions (including increasing M1 and M2 polarization of macrophage) and composition of intestinal microbiota, which is much better than antibiotics, suggesting that it is an effective alternative to antibiotics in the preparation of pig feed.

The Impact of Wheat Bran on the Morphology and Physiology of the Gastrointestinal Tract in Broiler Chickens

Simple SummaryRecently, dietary fiber has gained special attention due to its various beneficial effects on poultry. In poultry, moderate amounts of insoluble dietary fiber have been shown to be beneficial to nutrient utilization by improving the physiology of the gastrointestinal tract. Therefore, this study used wheat bran as a source of insoluble fiber to investigate wheat bran on digestive function in broiler chickens. The results indicate that supplementation of 30 g/kg wheat bran enhanced nutrient digestibility by improving antioxidant status, gizzard development, intestinal digestive enzyme activities and morphology in broilers. In conclusion, wheat bran could be used for improving feed efficiency in broilers.There is increasing evidence showing that moderate amounts of insoluble dietary fiber can improve nutrient utilization by positively influencing the physiology of the gastrointestinal tract. The present study was conducted to investigate the effects of wheat bran as a source of insoluble fiber on nutrient digestibility, serum antioxidant status, gastrointestinal development, digestive enzyme activities and intestinal morphology in broiler chickens. A total of 96 one-day-old male Arbor Acre broiler chickens were assigned to two treatments with six replicate cages per treatment and eight birds per replicate for 42 d. Dietary treatments consisted of the control group (CON, control diet) and wheat bran group (WB, 30 g/kg wheat bran). Inclusion of WB increased (p < 0.05) the digestibility of dry matter, organic matter, gross energy and crude protein on Day 42. Birds fed WB had lower (p < 0.05) serum total cholesterol concentration on Day 21, and lower (p < 0.05) serum concentrations of low-density lipoprotein, total cholesterol and total triglyceride on Day 42. Inclusion of WB increased (p < 0.05) serum glutathione peroxidase activity on Day 21 and superoxide dismutase activity on Day 42, but tended (p = 0.07) to decrease serum malondialdehyde concentration on Day 21, and significantly decreased (p < 0.05) serum malondialdehyde concentration on Day 42. Birds fed WB had a greater (p < 0.05) relative weight of gizzard on both Day 21 and 42. Inclusion of WB increased (p < 0.05) activities of amylase and trypsin in pancreas and jejunal mucosa on Day 21, and increased (p < 0.05) amylase activity in pancreas and jejunal mucosa. Birds fed WB had greater (p < 0.05) villus height and villus height to crypt depth ratio in jejunum and ileum on Day 42. In conclusion, supplementation of 30 g/kg WB enhanced nutrient digestibility by improving antioxidant status, gizzard development, intestinal digestive enzyme activities and morphology of broilers.

Effects of substrate on the physiological characteristics and intestinal microbiota of Echiura worm (Urechis unicinctus) juveniles

The effects of environmental factors on the physiological characteristics of Echiura worm Urechis unicinctus have been widely studied, however, the influences of substrate on this species are still unclear. Differences in the growth performance, physiological response, and intestinal microbiota of U. unicinctus juveniles between the sandy and muddy substrates were evaluated in the present study. The results indicated that the weight gain was significantly higher in U. unicinctus juveniles with the sand bottom compared to the mud group, while the survival rate was obviously lower. The activities of intestinal digestive enzymes and the contents of triglyceride, glucose, and total cholesterol in the coelomic fluids had a significant increase in the individuals with the sandy bottom compared to the mud group. The oxidative stress and intestinal inflammatory were induced by the sandy bottom, meanwhile, the antioxidant system and goblet cells were activated to protect the U. unicinctus juveniles. Focused on the intestinal microbiota of U. unicinctus juveniles, Sphingomonadales, Burkholderiales, and Pesudomonadales were more abundant in the mud group. In contrast, Alteromonadales and Rhodobacterales were enriched in the sand group. Moreover, various correlations were observed between the intestinal bacteria and physiological indices, such as Acinetobacter with the lipoprotein- and hepatic-lipase activities, Shewanella with the superoxide dismutase activities, and Cupriavidus with the malondialdehyde contents.

Regulation of growth, intestinal microflora composition and expression of immune-related genes by dietary supplementation of Streptococcus faecalis in blunt snout bream (Megalobrama amblycephala)

A 10-week feeding trial was performed to investigate the effects of Streptococcus faecalis on the growth, intestinal microflora composition and expression of immune-related genes of blunt snout bream (Megalobrama amblycephala). Fish (46.32 ± 0.09 g) were fed four experimental diets containing 0 cfu/g (SF0, control), 1 × 105 cfu/g (SF1), 1 × 106 cfu/g (SF2) and 1 × 107 cfu/g (SF3) of S. faecalis, respectively. Results showed that daily growth index (DGI), feed efficiency ratio (FER), plasma glucose level, plasma contents of total protein and albumin as well as intestinal serous layer (SL), muscular layer (ML), submucous layer (SML), villi thickness (VT) and lamina propria (LP) were all no significant difference among all the treatments, whereas their (except plasma albumin content and intestinal ML) relatively high values were found in the SF2 group. Meanwhile, the intake of the SF2 diets significantly increased plasma globulin content and intestinal digestive enzymes activities, the opposite was true for the activities of plasma aspartate aminotransferase (AST) and alanine transaminase (ALT). In addition, the analysis of the intestinal microbiota showed that fish fed the SF2 diet have the highest values of intestinal alpha diversity and intestinal abundances of Actinobacteria, Chlamydiae, Firmicutes, Planctomycetes, Verrucomicrobia, Clostridium and Synechococcus, while the opposite was true for intestinal abundances of Acinetobacter, Anoxybacillus, Flavobacterium, Planctomyces, Plesiomonas, Pseudomonas, Staphylococcus and Clostridium perfringens. At the molecular level, the expression levels of tumour necrosis factor α (TNF α), interleukin 1β (IL 1β) and heat shock proteins 7 (HSP 70) in head kidney and spleen were all decreased significantly with the increasing S. faecalis levels up to 1 × 106 cfu/g, and then they were increased with further increasing S. faecalis levels. Overall, dietary supplementation of S. faecalis at 1 × 106 cfu/g could improve the intestinal health and innate immunity of blunt snout bream.

Dietary protein and lipid levels affect the growth performance, intestinal digestive enzyme activities and related genes expression of juvenile small yellow croaker (Larimichthys polyactis)

The effects of different dietary protein and lipid levels on juvenile small yellow croaker (Larimichthys polyactis) was experimentally evaluated in 51 days study. Fish (initial weight 16.02±0.50 g) were fed with nine diets contained three levels of protein (430, 470, or 510 g kg−1) and three levels of lipids (60, 90, or 120 g kg−1) in triplicates. Specific growth rate (SGR) and weight gain (WG) of fish on 470 g kg−1 protein and 120 g kg−1 lipid diet were the highest. Protein efficiency ratio (PER) of fish on 120 g kg−1 lipid diet was significantly higher than that of fish on other diets. Intestine lipase activity significantly increased as dietary lipid levels increased, whereas intestine protease activity showed the opposite trend. Relative expression of insulin-like growth factor-1 (IGF-1) and growth hormone receptor (GHR) significantly increased as dietary lipid levels increased. Relative expression of hepatic lipoprotein lipase (LPL) and fatty acid synthase (FAS) were enhanced considerably and decreased by dietary lipid, respectively. In conclusion, a diet containing 470 g kg−1 protein with 120 g kg−1 lipid (protein/energy (P/E) ratio of 24.55 mg protein kJ−1) was found to be optimum for juvenile L. polyactis, which could be a foundation for its nutrition research and large-scale cultivation.

Clostridium butyricum relieves diarrhea by enhancing digestive function, maintaining intestinal barrier integrity, and relieving intestinal inflammation in weaned piglets

The current study aimed to determine how Clostridium butyricum (C. butyricum) relieved diarrhea by evaluating its effects on intestinal digestive enzyme activity, barrier integrity, inflammatory responses, and oxidative stress in weaned piglets. A total of 360 weaned piglets that were 25 days old (180 males and 180 females) were randomly assigned to 5 groups in 6 pens, with 12 pigs per pen, and offered the same antibiotic-free corn-soybean-type basal diet for 30 d. The groups were as follows: no additives (control), basal diet + 250 mg/kg C. butyricum (CB1), basal diet + 500 mg/kg C. butyricum (CB2), basal diet + 1,000 mg/kg C. butyricum (CB3), and basal diet + 2,000 mg/kg C. butyricum (CB4). The incidence of diarrhea decreased quadratically as the amount of C. butyricum supplementation was increased, and this decrease was minimized in the CB2 group. Compared with those in the control group, the duodenal amylase and lipase activities were increased quadratically and maximized in the CB2 group, and the jejunal lipase activity was increased cubically in the CB1 group, while the pancreatic trypsin activity was increased linearly and maximized in the CB4 group. The serum concentration of D-lactic acid responded to the increases in the levels of C. butyricum in a quadratic manner; the minimum level was observed in the CB2 group. Jejunal zonula occludens-1 expression displayed linear and quadratic trends following C. butyricum supplementation, with the maximum response observed in the CB3 group. Quadratic and cubic increases were observed in jejunal alkaline phosphatase activity in the CB3 group. The jejunal IL-10 concentration increased, while the jejunal vascular endothelial growth factor concentration decreased quadratically in response to dietary C. butyricum supplementation in the CB2 group. No significant differences among the groups were observed in terms of the jejunal mucosal concentrations of oxidation-associated enzymes and products. In conclusion, dietary supplementation with appropriate doses of C. butyricum could relieve diarrhea in weaned piglets by enhancing digestive enzyme activity, maintaining intestinal barrier integrity, and relieving intestinal inflammation.

Yeast hydrolysate helping the complex plant proteins to improve the growth performance and feed utilization of Litopenaeus vannamei

Six iso-nitrogenous and iso-lipid experimental diets were formulated to evaluate growth performance, intestinal digestive enzyme activity and the transcript expression of nutrition utilization related genes of the pacific white prawn, Litopenaeus vannamei (initial average body weight: 0.45 ± 0.01 g). The positive control group (LP) contains the 250.0 g/kg fish meal (FM) and 0 g/kg yeast hydrolysate (YH), negative control group (HP) contains the 150.0 g/kg FM and 0 g/kg YH. The 25, 50, 75, and 100 g/kg FM were replaced by plant proteins in the PY1, PY2, PY3 and PY4 groups, respectively, and 30 g/kg YH was supplemented. At the end of the 56-day feeding trial, there were no significantly difference in weight gain rate and specific growth rate between LP and PY1 (P > 0.05). The protein efficiency rate in PY1 was significantly lower than that in LP (P < 0.05). The glucose, total triacylglycerol and total cholesterol concentrations in HP were significantly higher than those in LP, PY1 and PY3 (P < 0.05). The trypsin, amylase and lipase activities in PY1 were significantly higher than those in LP (P < 0.05). In the intestine, the expression levels of fatty acid-binding protein (FABP) and pyruvate kinase (PK) in PY1 were significantly higher than those in LP, PY2, PY3 and PY4 (P < 0.05). In the hepatopancreas, the expression levels of FABP and PK in PY4 were significantly higher than those in HP (P < 0.05). These results revealed that a diet of the 25 g/kg FM were replaced by complex plant proteins, and 30 g/kg YH was fed, had no negative effects on the growth of L. vannamei, and enhanced digestive enzyme activity and transcript expression of metabolic-related genes, improved the ability to utilize carbohydrates and lipids.