Activation of epithelial proliferation induced by Eimeria acervulina infection in the duodenum may be associated with cholesterol metabolism

Effect of Cardamine violifolia on Plasma Biochemical Parameters, Anti-Oxidative Capacity, Intestinal Morphology, and Meat Quality of Broilers Challenged with Lipopolysaccharide

Cardamine violifolia is a newly discovered selenium (Se)-enriched plant rich in MeSeCys and SeCys and has a strong antioxidant capacity. This study aimed to investigate the effects of Cardamine violifolia on plasma biochemical indices, antioxidant levels, intestinal morphology, and meat quality of broilers under acute LPS-induced oxidative stress by comparing it with inorganic Se (sodaium selenite). A total of 240 one-day-old Ross 308 broilers were fed a basal diet and divided into four groups: (1) SeNa-SS, fed a diet supplied with 0.3 mg/kg Se from sodium selenite, and injected with 0.9% sterile saline, (2) SeCv-SS, fed a diet supplied with 0.3 mg/kg Se from Cardamine violifolia, and injected with 0.9% sterile saline, (3) SeNa-LPS, fed a diet supplied with 0.3 mg/kg Se from sodium selenite, and injected with 0.5 mg/kg LPS, (4) SeCv-LPS, fed a diet supplied with 0.3 mg/kg Se from Cardamine violifolia and injected with 0.5 mg/kg LPS. The experiment lasted for 42 days. Sterile saline or LPS was injected intraperitoneally two hours before slaughter, and blood and tissue samples were collected for testing. The results showed that compared with SeNa, SeCv significantly reduced the plasma levels of aspartate aminotransferase, alanine aminotransferase, and urea nitrogen after LPS challenge (p < 0.05), and increased the plasma levels of total antioxidant capacity and glutathione peroxidase, decreased malondialdehyde content in LPS-challenged broilers (p < 0.05). In addition, compared with SeNa, SeCv supplementation increased villus height and the ratio of villus height to crypt depth of jejunum and ileum after LPS challenge (p < 0.05). Additionally, SeCv could increase the redness of breast and thigh muscle, and decrease drip loss, cooking loss, and shear force (p < 0.05). In conclusion, our results indicated that supplementing with 0.3 mg/kg Se from Cardamine violifolia alleviated tissue injury after LPS challenge, increased antioxidant capacity, and improved meat quality of breast and thigh muscle after stress.

Effects of low-crude protein diets supplemented with arginine, glutamine, threonine, and methionine on regulating nutrient absorption, intestinal health, and growth performance of Eimeria-infected chickens

The study was conducted to evaluate the effects of low crude protein diets supplemented with arginine, glutamine, methionine, and/or threonine on apparent ileal digestibility of amino acids, intestinal morphology, intestinal permeability, gene expression of nutrient transporters, and tight junction proteins of broiler chickens challenged with mixed Eimeria spp. A total of five hundred seventy-six, 12-day-old male broiler chickens were allocated into 8 treatments, and 6 replicate cages of 12 chickens per cage. This experiment included a nonchallenged control (NC) fed regular corn-soybean meal-based diet (Regular diet, 19% crude protein), an Eimeria-challenged control (CC) fed Regular diet, an Eimeria challenge group fed low-crude protein diet (LCP, 16% crude protein), 4 Eimeria challenge groups fed low-crude protein diet supplemented with 0.75% arginine, glutamine, methionine, and threonine, respectively (ARG, GLN, MET, and THR), and an Eimeria challenge group fed low-crude protein diet with 0.75% supplemented arginine, glutamine, methionine, and threonine collectively as a combination group (COMB). On d 14, birds in the challenge groups were gavaged with a mixed Eimeria spp. solution containing 12,500 oocysts of E. maxima, 12,500 oocysts of E. tenella, and 62,500 oocysts of E. acervulina. The results showed that the Eimeria challenge reduced overall growth performance, but the LCP had no adverse impacts on intestinal health and growth of Eimeria-infected birds compared to the CC. Additionally, supplementation of crystalline arginine, glutamine, methionine, and threonine improved the apparent ileal digestibility of these specific amino acids on 6 dpi. Moreover, the THR treatment increased villus height in the duodenum. The ARG treatment decreased intestinal permeability and gene expression of amino acid transporters, whereas the GLN and THR treatments both reversed adverse effects of coccidiosis on gene expression of tight junction protein (claudin 1). However, the MET and COMB treatments exacerbated infection severity of coccidiosis. In summary, adding 0.75% of arginine, glutamine, or threonine in a low crude protein diet can improve the intestinal health of birds challenged with a mild coccidia infection.

Effects of riboflavin and Bacillus subtilis on internal organ development and intestinal health of Ross 708 male broilers with or without coccidial challenge

In a companion study, we found that inclusion of different doses of riboflavin affected growth performance of Ross 708 male broilers' responses to coccidial challenge (by 5 Eimeria spp on day 14 of age) and dietary Bacillus subtilis (B. subtilis) supplementation. The current study was conducted to further test whether supplementation of B. subtilis and riboflavin will reduce negative impact and inflammation caused by Eimeria spp proliferation and help proper function of internal organs. A total of 1,248 Ross × Ross 708 male broiler chicks were randomly placed in 96 floor pens (8 blocks, 12 treatments). Treatments were arranged in a 3 (riboflavin) × 2 (B. subtilis) × 2 (Coccidial challenge) factorial arrangement in a randomized complete block design. Coccidial challenge reduced the weight of sampled birds on day 27 and day 36 and increased the relative weights of the internal organs of proventriculus, duodenum, jejunum, ileum, and spleen to BW on day 27, which may be because of inflammation caused by proliferation of Eimeria spp. The increased relative weights of duodenum, jejunum, ileum, and spleen on coccidial challenged birds were lost on day 36. Correlation analysis also indicated that the jejunum weight was positively related to villus height, Eimeria acervulina, and Eimeria maxima on day 27 but was not on day 36. The loss of the positive relationships may be because of recovery of the birds from coccidiosis on day 36. Even though the coccidial challenge and riboflavin interactively affected feed conversion ratio and BW gain and supplementation of dietary B. subtilis reduced mortality from day 35 to 42 in the companion study, the same response of internal organs was not observed in the current study. Coccidial challenge compromised development of internal organs of Ross 708 male broilers at an early age, but the negative effects subsided with age of birds rather than supplementation of riboflavin and B. subtilis at current tested levels under our experimental set up.

2-Nitro-1-propanol improved nutrient digestibility and oocyst shedding but not growth performance of Eimeria-challenged broilers

A 2 × 3 factorial arrangement study was conducted to evaluate 3 dosages of 2-nitro-1-propanol (NP; 0, 150, and 200 ppm) on intestinal health of birds with or without Eimeria challenge. A total of 432 thirteen-day-old male broiler chickens were randomly allocated to 6 treatments with 8 replicate cages of 9 birds per cage. All birds were fed with treatment diets from day 13 to 21. Birds in the challenge groups were gavaged with Eimeria maxima (50,000 oocysts per bird), Eimeria tenella (50,000 oocysts per bird), and Eimeria acervulina (250,000 oocysts per bird) on day 15. Growth performance was evaluated from day 13 to 21, and gut permeability was measured by fluorescein isothiocyanate dextran on day 20. The intestinal lesion, intestinal morphology, and oocysts shedding were determined at the end of the trial. The linear and quadratic orthogonal polynomial contrasts were used to evaluate the effects of increasing NP doses in responses to Eimeria challenge. The results showed that NP was not able to maintain efficient growth performance but improved gut leakage during Eimeria infection period. On the other hand, Eimeria infection increased gut permeability (P < 0.0001) and reduced ileal digestible energy (IDE) and apparent ileal digestibility (AID) of nitrogen. However, the increase of NP linearly enhanced IDE and AID of nitrogen (P < 0.01). Moreover, an interaction between challenge and linear dosage effects was observed for IDE (P = 0.0066) and AID of nitrogen (P = 0.0462). The results indicated that NP improved nutrient digestibility and reduced total oocysts shedding in birds challenged with Eimeria spp. Besides, higher NP doses numerically improved villi height in the intestine. In summary, NP was not able to maintain growth performance of birds but presented positive outcomes on nutrient digestibility and reduced oocysts shedding during mixed Eimeria infection.

Graded Eimeria challenge linearly regulated growth performance, dynamic change of gastrointestinal permeability, apparent ileal digestibility, intestinal morphology, and tight junctions of broiler chickens

This study was conducted to evaluate graded Eimeria challenge on growth performance, apparent ileal digestibility, gastrointestinal permeability, intestinal morphology, gene expression of tight junction protein, and intestinal lesion scores in broiler chickens. There were 5 groups in this study, including a control and 4 different Eimeria treatment doses. A mixed Eimeria spp. solution with 50,000 Eimeria maxima, 50,000 Eimeria tenella, and 250,000 Eimeria acervulina per milliliter was prepared for the high-dose challenge treatment. The 2-fold serial dilution was used to make the medium-high (25,000 E. maxima; 25,000 E. tenella; 125,000 E. acervulina), the medium-low (12,500 E. maxima; 12,500 E. tenella; 62,500 E. acervulina), and the low challenge dose (6,250 E. maxima; 6,250 E. tenella; 31,250 E. acervulina). A total of three hundred sixty 13-day-old male broiler chickens were randomly allocated into 5 treatments with 6 replicated cages. Growth performance was calculated from 0 to 6 D postinfection (DPI). Intestine lesion was scored on 6 DPI. Gastrointestinal permeability was measured on 3, 5, 6, 7, and 9 DPI. The results indicated significant linear reduction in growth performance, intestinal villi height, and ileal nutrient digestibility in response to the increase of Eimeria challenge dose. Furthermore, gene expression of tight junction protein was linearly upregulated by the increasing challenge doses. Significant linear increases of gastrointestinal permeability were found on 5, 6, and 7 DPI (P < 0.01). On 9 DPI, the gastrointestinal permeability was recovered back to normal level in the challenge groups. In conclusion, the higher Eimeria doses birds received, the more severe intestine damage was observed in several gastrointestinal health parameters. The medium-low or medium-high levels of mixed Eimeria oocysts is suggested as an optimum Eimeria-challenge dose to establish a subclinical challenge model for future studies evaluating nutritional strategies. Moreover, it is recommended to measure gastrointestinal permeability on 5 DPI with higher oocysts doses and 6 DPI when using the lower oocysts doses.

Hepatic Inflammatory Response to Exogenous LPS Challenge is Exacerbated in Broilers with Fatty Liver Disease

This study aimed to examine hepatic function and inflammatory response in broilers with fatty livers, following acute lipopolysaccharide (LPS) challenge. One-day-old Lihua yellow broilers were fed a basal diet. Broilers were divided into four groups: control (CON), corticosterone treatment (CORT), LPS treatment (LPS), and LPS and CORT treatment (LPS&CORT). Results show that CORT induced an increase in plasma and liver triglycerides (TGs), which were accompanied by severe hepatic steatosis. The LPS group showed hepatocyte necrosis with inflammatory cell infiltration. Total liver damage score in the LPS&CORT group was significantly higher than that in the LPS group (p < 0.05). Activity levels of plasma alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were similar in the CON and CORT groups, but higher in the LPS group. Gene expression upregulation of the proinflammatory cytokines (NF-κB, IL-1β, IL-6, IFN-γ, and iNOS) was also noted in the LPS group (p < 0.05). In particular, LPS injection exacerbated the gene expression of these proinflammatory cytokines, even when accompanied by CORT injections (p < 0.05). In summary, our results indicate that broilers suffering from fatty liver disease are more susceptible to the negative effects of LPS, showing inflammatory response activation and more severe damages to the liver.

Micro-RNA expression profile of chicken small intestines during Eimeria necatrix infection

Eimeria necatrix is a high pathogenic pathogen second to Eimeria tenella causing chicken coccidiosis. However, the precise underlying molecular mechanisms of interaction between E. necatrix and chickens are not fully understood. Accumulating evidences suggest that micro-RNAs (miRNAs) play pivotal regulatory roles in various diseases, including parasitic diseases. In the present study, the expression profile of miRNAs in Hy-line variety white chicken small intestines infected with E. necatrix was studied by using deep sequencing. A total of 35 miRNAs (including 16 significantly upregulated and 19 significantly downregulated miRNAs) were significantly differentially expressed (DE) in infected tissues at 108 h post-infection (pi). Real-time polymerase chain of 10 miRNAs (including 5 upregulated and 5 downregulated) randomly selected successfully confirmed the effectiveness of deep sequencing. Target prediction showed that 4,568 mRNAs could be regulated by 21 (including 12 upregulated and 9 downregulated) of 35 differentially expressed miRNAs. Functional analysis indicated that target genes of these differentially expressed miRNAs would be involved in pathways related to infection of E. necatrix, including cell differentiation, adhesion, proliferation, and apoptosis (e.g., MAPK signaling pathway and PPAR signaling pathway). To our best knowledge, this is the first study on the miRNA expression profile of small intestines during E. necatrix infection, and the findings in the present study suggested that these DE miRNAs would play important regulatory role in the interaction between E. necatrix and chicken intestines.

Targeted-Release Organic Acids and Essential Oils Improve Performance and Digestive Function in Broilers Under a Necrotic Enteritis Challenge

An experiment was performed to evaluate the effect of four different microencapsulated blends of organic acids (OA) and nature-identical aromatic compounds (AC) on growth performance and gut health of broilers challenged with a recycled NE litter. A total of 600 one-day-old male Ross 308 broilers were randomly assigned to five treatments consisting of a basal diet (as negative control) supplemented with each of the tested microencapsulated blends: OA1 (malic and fumaric acid) + AC; 2.5 g/kg; OA2 (calcium butyrate+fumaric acid) + AC; 1.7 g/kg; MCFA (capric-caprylic; caproic and lauric acid) + AC; 2 g/kg; and MCFA + OA3(calcium butyrate + fumaric and citric acid) + AC; 1.5 g/kg. The AC used was the same for all treatments; including cinnamaldehyde, carvacrol, and thymol (8:1:1), as major compounds. Three tested blends enhanced growth performance by improving intestinal histomorphology (p < 0.001). The tested blends enhanced the abundance of some beneficial families such as Ruminococcaceae and Lachnospiraceae; while reducing that of harmful ones such as Enterobacteriaceae and Helicobacteraceae. A further dose-response experiment showed that 0.5 g/kg of the blend 2 and 2 g/kg of the blend 4 improved growth performance and intestinal histomorphology of chickens on d 42 and decreased fecal Enterobacteriaceae and C. perfringens counts. Similar effects to the previous experiment were observed for cecum microbiota.

Utility of Feed Enzymes and Yeast Derivatives in Ameliorating Deleterious Effects of Coccidiosis on Intestinal Health and Function in Broiler Chickens

Coccidiosis induced necrotic lesions impair digestive capacity and barrier function in concurrence with increased risks for secondary bacterial infections. The industry has been successful in controlling coccidiosis with anticoccidials and vaccination. However, concerns over Eimeria species resistant to anticoccidials, gaps in vaccination and restriction on antibiotics is stimulating research and application of alternative and/or complimentary strategies for coccidiosis control. The aim of this paper is to appraise literature on the utility of feed enzymes and yeast derivatives in modulating coccidiosis. Feed enzymes can complement endogenous enzymes (protease, amylase, and lipase) that may become insufficient in coccidiosis afflicted birds. Coccidiosis in the upper small intestine creates conditions that enhances efficacy of phytase and there are reports indicating supplemental phytase can mitigate the negative impact of coccidiosis on bone quality. Increase in intestinal short chain fatty acids due supplemental fiber degrading enzymes has been linked with reduced survivability of Eimeria. There is evidence whole yeast (live or dead) and derivatives can modulate coccidiosis. Immunomudulation properties of the yeast derivatives have been shown to enhance cellular and humoral immunity in Eimeria challenge models which is critical for effectiveness of coccidial vaccination. Moreover, yeast nucleotides have been shown to be beneficial in stimulating healing of intestinal mucosal surface. Other novel work has shown that certain yeast cells can produce derivatives with anticoccidial compounds effective in attenuating oocysts shedding. Yeast cell surface has also been shown to be an effective oral Eimeria vaccine delivery vehicle. Overall, while further refinement research is warranted to address inconsistencies in responses and commercial application, there is evidence feed enzymes and yeast derivatives could complement strategies for maintaining intestinal function to bolster growth performance in broilers compromised with coccidiosis. However, broilers receive diets containing several feed additives with distinct mode of actions and yet there is dearth of empirical data on the expected responses.Future evaluations should consider combinations of additives to document animal responses and potential synergies.

Dietary supplementation with free methionine or methionine dipeptide mitigates intestinal oxidative stress induced by Eimeria spp. challenge in broiler chickens

Background

This study evaluated the effects of Eimeria spp. challenge and dietary supplementation with free methionine or methionine dipeptide on animal performance; expression of genes associated with the immune system, antioxidant system, and amino acid transport in the jejunum; and redox status of the jejunum of broiler chickens.

Methods

A randomized, 2 × 3 factorial design was used, in which Eimeria spp. challenge was the first factor (Eimeria-challenged, EC, or unchallenged, UC, broilers) and methionine supplementation was the second factor (non-supplemented, NS; free dl-methionine, dl-Met; and methionine dipeptide, dl-methionyl-dl-methionine, dl-MMet). At 14 days of age, chickens were inoculated orally with sporulated oocysts of Eimeria acervulina, Eimeria praecox, Eimeria maxima, and Eimeria mitis. Birds were killed by cervical dislocation 144 h post-inoculation (PI), and the jejunum was collected for biochemical and molecular analyses.

Results

EC broilers had a 13% lower feed intake (FI), 37% lower body weight gain (BWG), and 39% higher feed conversion ratio (FCR) than UC broilers. Chickens fed the dl-Met diet had higher BWG (about 12% higher) and better FCR (about 12% lower) than chickens fed the NS diet. EC chickens had lower relative weight of the bursa of Fabricius (51.8%) and higher relative weights of the spleen and whole intestine (53.6% and 26.3%, respectively) than UC chickens. Eimeria spp. challenge led to an increase in the levels of oxidative substances, such as nitrite and thiobarbituric acid reactive substances (TBARS), in the jejunum of chickens 144 h PI. Among UC chickens, those fed the dl-Met diet had higher total antioxidant capacity (TAC) and lower catalase (CAT) and superoxide dismutase (SOD) activities. EC chickens that received the NS diet had higher carbonylated protein content (CP). This result was associated with their lower TAC and catalase activity. The lower TAC in EC chickens might have been due to reduced expression of catalase (CAT) and superoxide dismutase 1 (SOD1) genes. Chickens fed the dl-Met and dl-MMet diets had lower nitrite content. Eimeria spp. challenge suppressed neutral amino acid transporter 1 (B⁰AT1), peptide transporter 1 (PEPT1), toll-like receptor 5 (TLR5), interleukin 2 (IL2), and occludin (OCLN) gene expression and enhanced cationic amino acid transporter 1 (CAT-1) and interferon gamma (IFNG) gene expression. The highest PEPT1 expression level was observed in broilers fed the dl-MMet diet, and the lowest TLR5 expression level was found in broilers fed the NS diet.

Conclusion

Our results show for the first time that supplementation with methionine as free amino acid or dipeptide helps protect the intestinal cells of broilers under Eimeria spp. challenge from the oxidative damage induced by free radicals, mainly through modulation of the antioxidant system.

Growth performance and gastrointestinal responses of broiler chickens fed corn-soybean meal diet without or with exogenous epidermal growth factor upon challenge with Eimeria

Epidermal growth factor (EGF), a protein known for its mitogenic and anti-apoptotic effects was fed to broiler chickens to evaluate growth performance, gastrointestinal measurements, and apparent retention (AR) of components upon challenge with Eimeria. A total of 216, d old male broiler chicks (Ross 708) were placed in cages (6 birds/cage) and allocated to treatments. The treatments were: 1) control (Lactotobacilli lactis fermentation supernatant without EGF), 2) 80 μg of EGF/kg BW/d, and 3) 160 μg of EGF/kg BW/d. A basal antibiotic-free corn-soybean diet containing TiO2 was used. Birds were offered fresh feed with respective treatments on daily basis and had free access to drinking water for 14 d. On d 5, birds (6 replicates per treatment) were challenged with 1 mL of E. acervulina and E. maxima mixture via oral gavage and the other 6 replicates were given sham. Growth performance was measured in pre- (d 0 to 5) and post- (d 6 to 14) challenge periods. Two birds per cage were necropsied on d 10 for intestinal lesion scores and tissue samples for histomorphology and expression of select intestinal genes. Excreta samples for AR of components and oocyst shedding were taken d 10 to 13 and all birds were necropsied on d 14 for gastrointestinal weight. The EGF linearly (P < 0.05) increased BWG before challenge. There was no EGF and Eimeria interaction (P > 0.05) on growth performance, AR of GE, and intestinal histomorphology; the main effects were such that Eimeria depressed (P < 0.01) BWG, FCR, AR of DM, crude fat, and GE, and villi height to crypt depth ratio. An interaction between EGF and Eimeria (P < 0.05) on indices of gut function was such that EGF improved expression of genes for nutrient transporters and tight junction proteins in Eimeria challenged birds whilst no effect in non-challenged control. In conclusion, Eimeria challenge reduced growth performance and impaired gut function; EGF showed beneficial effects on growth pre-challenge and improved indices of gut function upon Eimeria challenge.

Maternal betaine supplementation in rats induces intergenerational changes in hepatic IGF-1 expression and DNA methylation

SCOPE

Betaine is widely used in animal nutrition to promote growth. Here, we aimed to investigate whether maternal betaine supplementation during pregnancy can exert multigenerational effects on growth across two generations and the possible epigenetic modifications associated to such effects.

METHODS AND RESULTS

In this study, 3-month-old female Sprague-Dawley rats were fed diet supplemented with 1% betaine throughout the pregnancy and lactation. Betaine-supplemented dams produced bigger litter but smaller F1 pups at birth and weaning. However, F2 pubs had higher weaning weight. In accordance with the growth performance, serum insulin-like growth factor 1 (IGF-1) levels were significantly lower in F1 yet higher in F2 pups, so was hepatic IGF-1 mRNA expression. Concurrently, dietary betaine supplementation to F0 dams increased hepatic expression of betaine homocysteine methyltransferase, at both mRNA and protein levels, in F1, but not F2 pups. Moreover, hepatic IGF-1 gene promoter 1 was detected to be significantly hypermethylated in F1 pups, whereas both promoters 1 and 2, together with almost all exons, were found to be hypomethylated in F2 offspring.

CONCLUSION

Maternal betaine supplementation during pregnancy and lactation exerts distinct effects on growth of F1 and F2 rat offspring, probably through differential modification of IGF-1 gene methylation and expression in liver.