Applying I see inside histological methodology to evaluate gut health in broilers challenged with Eimeria

Coccidiosis in Egg-Laying Hens and Potential Nutritional Strategies to Modulate Performance, Gut Health, and Immune Response

Avian coccidiosis, despite advancements in management, nutrition, genetics, and immunology, still remains the most impactful disease, imposing substantial economic losses to the poultry industry. Coccidiosis may strike any avian species, and it may be mild to severe, depending on the pathogenicity of Eimeria spp. and the number of oocysts ingested by the bird. Unlike broilers, low emphasis has been given to laying hens. Coccidiosis in laying hens damages the gastrointestinal tract and causes physiological changes, including oxidative stress, immunosuppression, and inflammatory changes, leading to reduced feed intake and a drastic drop in egg production. Several countries around the world have large numbers of hens raised in cage-free/free-range facilities, and coccidiosis has already become one of the many problems that producers have to face in the future. However, limited research has been conducted on egg-laying hens, and our understanding of the physiological changes following coccidiosis in hens relies heavily on studies conducted on broilers. The aim of this review is to summarize the effect of coccidiosis in laying hens to an extent and correlate it with the physiological changes that occur in broilers following coccidiosis. Additionally, this review tries to explore the nutritional strategies successfully used in broilers to mitigate the negative effects of coccidiosis in improving the gut health and performance of broilers and if they can be used in laying hens.

Epidemiological Survey on Post Mortem Coccidiosis in Broiler Chicken in Bejaia Province, Northern Algeria

AIM

The epidemiological survey was carried out to determine the prevalence of eimeriosis in broiler chickens slaughtered depending the season, to determine the different Eimeria species causing the coccidiosis in poultry farms; and to assess the impact of Eimeria parasite on histomorphological structure and oxidative stress parameters of the intestine.

MATERIALS AND METHODS

The study was conducted from December 2018 to December 2019 in the province of Bejaia, Algeria. The intestines chickens (n = 366) were obtained immediately after slaughter, each cut into different segments (duodenum, jejunum, ileum, and caecum). Microscopic and parasitological examinations were performed according to standard procedures. Histomorphometric measurements of intestine were obtained using Image J software. Oxidative stress parameters were carried out from intestine tissue.

RESULTS

Eimeria spp. were detected in 73.77% (95% CI 71.20-76.34) of broiler gut samples. The prevalence varied significantly according to the season, with the lowest rates in winter (42.81%, 95% CI 40.35-45.27) and the highest in autumn (97.92%, 95% CI 97.6-99.4). All seven Eimeria species were identified, most commonly E. necatrix (27.70%), E. brunetti (26.47%), and E. tenella (20.96%). The mean lesion score ranged from 1.51 ± 0.05 to 1.79 ± 0.04. Significant differences in VH/CD ratio of intestinal epithelium (P < 0.001) were observed in different intestinal portions of infested broiler chickens compared to non-infested. The mean MDA concentration of intestinal segments was significantly higher in Eimeria species infested broilers compared to non-infested (P < 0.05). The results show at least one difference in CAT, SOD, and ABTS-+ concentrations (P < 0.05) in both chicken's groups.

CONCLUSION

Our results revealed that coccidiosis is extremely prevalent in slaughtered broilers, with an abundance of pathogenic Eimeria species. Also, it was concluded that infestation induces tissue structure alterations which coincides with the oxidative damage.

Graded levels of Eimeria infection linearly reduced the growth performance, altered the intestinal health, and delayed the onset of egg production of Hy-Line W-36 laying hens when infected at the prelay stage

The aim of this experiment was to investigate how different levels of Eimeria infection affect the performance, intestinal health, oxidative status, and egg production of Hy-Line W-36 pullets and laying hens. Three hundred and sixty Hy-Line W-36 pullets, aged 15 wk, were randomly distributed into 5 treatment groups, each comprising 6 replicates and a nonchallenged control. At 15 wk, pullets were inoculated with different levels of mixed Eimeria species as high-dose, medium-high, medium-low, and low-dose treatments. The growth performance and average daily feed intake (ADFI) were measured from 0- to 18-days postinoculation (DPI), whereas hen day egg production (HDEP) was recorded from wk 19. The markers of gastrointestinal health and oxidative status were measured at 6 DPI, 14 DPI, and 23 wk of age. The findings revealed a significant linear reduction in growth performance in response to increased Eimeria challenge dosage on 6 and 14 DPI (P < 0.0001, P-L < 0.0001). An interaction between the graded level of Eimeria infection and DPI was observed for ADFI. The challenged pullets showed a reduction in ADFI starting at 4 DPI, which persisted until 14 DPI, when ADFI recovered back to normal. The most significant drop in feed intake was observed in 6 DPI in all the Eimeria-infected groups. The markers of gastrointestinal health (gastrointestinal permeability and tight junction proteins) were upregulated in challenged pullets because of infection, whereas the relative mRNA expression of key nutrient transporters was downregulated following infection on 6 and 14 DPI (P < 0.05). As a result of an infection on 6 DPI, the oxidative equilibrium was shifted toward the oxidative stress, and at the same time, upregulation of proinflammatory and inflammatory cytokines was observed (P < 0.05). An interaction between the Eimeria challenge dosage and bird age was observed for HDEP (P = 0.0427). The pullets infected with Eimeria started to lay eggs later than the Control birds. However, the HDEP of the challenged groups became similar to Control only at wk 22, 3 wk after laying eggs. In conclusion, coccidiosis reduced growth performance, altered gastrointestinal health, induced oxidative stress, and delayed egg production when infected at the prelay stage of pullets and negatively impacted the laying hens' overall performance.

Graded levels of Eimeria infection modulated gut physiology and temporarily ceased the egg production of laying hens at peak production

An experiment was conducted to investigate the changes in gastrointestinal physiology, including intestinal leakage, immune response, oxidative stress, along with performance traits, of Hy-Line W-36 laying hens following Eimeria infection at peak egg production. A total of 360 laying hens, at 25 wk of age, were assigned randomly to 5 treatment groups, each consisting of 6 replicate cages, including a nonchallenged control group. The other 4 groups were inoculated with graded levels of mixed Eimeria species as high, medium-high, medium-low, and low doses, respectively. The body weight (BW) and body weight gain (BWG) of laying hens were measured from 0 to 14 days postinoculation (DPI). Average daily feed intake (ADFI) and hen-day egg production (HDEP) were measured from 0 to 15 and 0 to 28 DPI, respectively. Gut permeability was measured on 5 DPI, whereas oxidative stress, immune response, and expression of nutrient transporter genes were measured on 6 and 14 DPI. A significant linear reduction in BW and BWG was observed with increased Eimeria inoculation dosage on both 6 and 14 DPI (P < 0.001, P-Lin < 0.0001). An interaction between the Eimeria dosages and DPI was observed for ADFI (P < 0.0001). Feed intake in the challenged groups decreased starting at 4 DPI, with the most significant drop occurring at 7 DPI, which did not recover until 15 DPI. Following the challenge, gastrointestinal physiology shifted toward the host defense against the Eimeria infection by upregulating mRNA expression of tight junction proteins and immune responses while downregulating the expression of key nutrient transporters on 6 and 14 DPI (P < 0.05). An interaction between the Eimeria inoculation dosage and DPI was also observed for daily HDEP (P < 0.0001). Overall, HDEP was lower in the challenged groups compared to the control. Daily HDEP in the challenged groups dropped from 8 DPI and became similar to the control birds only after 24 DPI. Egg production temporarily ceased in most of the laying hens infected with the high and medium-high dosages of Eimeria. In conclusion, Eimeria infection activated the host immune response, negatively affecting the gastrointestinal health, growth performance, and temporarily ceased the egg production of Hy-Line W-36 laying hens when infected at peak production.

Distillers dried grains with soluble and enzyme inclusion in the diet effects broilers performance, intestinal health, and microbiota composition

This study tested the effect of distillers dried grains with soluble (DDGS) inclusion in a broiler diet, with or without supplementation of exogenous enzymes, on the microbiota composition, intestinal health, diet digestibility and performance. A total of 288 one-day-old chickens was assigned to 6 treatments (8 replicate of 6 birds each) according to a completely randomized design with a 3 × 2 factorial scheme with 3 DDGS levels (0, 7 and 14%) and 2 inclusions of exogenous enzymes (with or without a multicarbohydrase complex + phytase [MCPC]). The results exhibited that DDGS inclusion up to 14% did not impair broilers performance up to 28 d, however, DDGS-fed animals exhibited significant improvement with the MCPC supplementation. No effects of the enzymes in the ileal digestibility were found at 21 d. DDGS inclusion in the diet affected dry matter and gross energy digestibility. Broilers fed diets with MCPC were found to have less intestinal histological alteration thus better gut health. No effect of DDGS, enzyme or interaction of those were observed for intestinal permeability and in the serum inflammatory biomarker (calprotectin) at 7 and 28 d. The increase of DDGS percentage in the diet reduced the diversity of the ileal microbiota but increased the cecal microbiota diversity. The inclusion of DDGS showed positive effects on microbiota composition due to a reduction of Proteobacteria phylum in the ileum at 28d and a reduction in the presence of Enterococcaceae family in the ileum at 14 and 28d. The inclusion of MCPC complex might promote beneficial changes in the ileal and cecal microbiota due reduce of Proteobacteria, Bacillaceae and Enterobacteriaceae. The supplementation of xylanase, β-glucanase, arabinofuranosidase and phytase to a DDGS diet improves performance and intestinal health allowing the use of these subproduct in the poultry nutrition.

Effects of Feeding Different Levels of Sprouted Barley on Fermentation Characteristics, Bacterial Quantification, and Rumen Morphology of Growing Lambs

The objective of the present study was to investigate the effects of sprouted barley inclusion level on the growth performance, digestibility, volatile fatty acids, bacterial quantification, and rumen morphology of growing lambs. Five dietary treatments with sprouted barley (0, 25, 50, 75 and 100%) and nine replicates per dietary treatment were performed on forty-five Awassi lambs (90 days old). The average weight gain, intake, and digestibility of dry and organic matter were recorded. The pH, color, volatile fatty acids, bacterial quantification, and rumen histomorphometry were also determined. The results showed that the average dry and organic matter intake in T2 to T4 and the average weight gain in T4 decreased linearly. In contrast, the digestibility of dry and organic matter by sprouted barley (T2 to T4) was higher. The pH values and rumen color were not affected. Concentrations of formic acid, acetic acid, butyric acid, and the ratio of acetic acid to propionic acid were increased, while lactic acid and total volatile fatty acids were lower in all levels of sprouted barley. In addition, lambs fed T4 had a higher quantification of Anaerovibrio Lipolytica, Butyrivibrio Fibrisolvens, and Streptococcus Bovis quantification. Selenomonas Ruminantium was higher in T1, T2, and T4, whereas Megashpaera Elsdenii was lower in T1 to T3. The rumen histomorphometric was improved by sprouted barley (T2 and T3). Sprouted barley improved digestibility and rumen histomorphometry and increased the concentration of some volatile fatty acids and rumen bacteria but resulted in a decrease in average dry and organic matter intake, which negatively affected weight gain in lambs fed 100 % sprouted barley. Further studies are required to determine the potential effects on growing lambs fed sprouted barley.

Morphological Assessment and Biomarkers of Low-Grade, Chronic Intestinal Inflammation in Production Animals

Simple Summary

Production animals are continuously exposed to environmental and dietary factors that might induce a state of low-grade, chronic intestinal inflammation. This condition compromises the productive performance and well-fare of these animals, requiring studies to understand what causes it and to develop control strategies. An intestinal inflammatory process is generally associated with alterations in the structure and functionality of its wall, resulting in the release of cellular components into the blood and/or feces. These components can act as biomarkers, i.e., they are measured to identify and quantify an inflammatory process without requiring invasive methods. In this review we discuss the mechanisms of low-grade inflammation, its effects on animal production and sustainability, and the identification of biomarkers that could provide early diagnosis of this process and support studies of useful interventional strategies.

Abstract

The complex interaction between the intestinal mucosa, the gut microbiota, and the diet balances the host physiological homeostasis and is fundamental for the maximal genetic potential of production animals. However, factors such as chemical and physical characteristics of the diet and/or environmental stressors can continuously affect this balance, potentially inducing a state of chronic low-grade inflammation in the gut, where inflammatory parameters are present and demanding energy, but not in enough intensity to provoke clinical manifestations. It’s vital to expand the understanding of inflammation dynamics and of how they compromise the function activity and microscopic morphology of the intestinal mucosa. These morphometric alterations are associated with the release of structural and functional cellular components into the feces and the blood stream creating measurable biomarkers to track this condition. Moreover, the identification of novel, immunometabolic biomarkers can provide dynamic and predictors of low-grade chronic inflammation, but also provide indicators of successful nutritional or feed additive intervention strategies. The objective of this paper is to review the mechanisms of low-grade inflammation, its effects on animal production and sustainability, and the biomarkers that could provide early diagnosis of this process and support studies of useful interventional strategies.

Intestinal health improvement with protected organic acids and essential oils for pullets raised under field conditions

We investigated the dietary supplementation of protected organic acids and essential Oils P(OA+EO) in pullets raised under commercial conditions. A total of 208,000 pullets Lohmann at 2-weeks-old were assigned to receive 1 of 2 treatments: T1, control diet used in the farm; T2, control diet and P(OA+EO) at 300 g/t (fumaric, sorbic, citric and malic acids + thymol, eugenol and vanillin microencapsulated in hydrogenated vegetable fat - Jefo Nutrition Inc. Canada). P(OA+EO) was supplemented from 2 to 18 weeks and the trial lasted 21 weeks. At weeks 6, 12 and 21, 12 pullets/treatment were used for blood sampling and necropsy for ISI – I See Inside. A completely randomized design consisting of 2 treatments, each with 12 replicates of 1 hen/replicate, was used. To evaluate intestinal integrity, birds were inoculated with fluorescein-isothiocyanate labelled dextran (FITC-d) and blood samples were collected after 1.5 h. The macroscopic ISI score of alterations were classified to be presented as: overall health ISI (sum of the scores assigned for intestine, liver, proventriculus, annex glands, locomotor, and respiratory systems) and macro-intestinal ISI (sum of the scores assigned for duodenum, jejunum, ileum, and cecum). The histologic intestinal ISI alterations were evaluated in the ileum. A low ISI index represents better health status. Pullets on P(OA+EO) had lower (P&lt; 0.001) levels of FITC-d recovered in the blood, which is related to reduced leaky gut. They also presented lower overall health ISI score at weeks 6 (P = 0.002) and 12 (P = 0.003), lower macro intestinal ISI score at weeks 6 (P = 0.0001) and 21 (P = 0.004) and, lower histologic intestinal ISI score of alterations at weeks 6 (P = 0.09), 12 (P = 0.0006), and 21 (P&lt; 0.0001), which is associated to better overall health. In addition, at week 21, pullets on P(OA+EO) did not present Eimeria oocysts while the control treatment did (P&lt; 0.0001). In conclusion, the blend of protected organic acids and essential oils evaluated can be used to improve intestinal and overall health status in commercial pullets.

Impact of Dietary Supplementation with Sodium Butyrate Protected by Medium-Chain Fatty Acid Salts on Gut Health of Broiler Chickens

Simple Summary

Nutritional strategies to improve gut health are under research to reduce antibiotic use in poultry production. This study investigated the effect of dietary supplementation with sodium butyrate protected by sodium salts of medium-chain fatty acids as a feed additive on broiler gut health. A first trial was conducted to assess the effectiveness of this feed additive supplemented at a dose range of 0.5, 1, and 2 kg/t to promote a good health status on broilers raised under optimal conditions. Supplementation at 0.5 and 1 kg/t maintained the number of mucin-secretory cells contained in the gut barrier of young chickens, and the use of 1 kg/t improved the intestinal immune system of aged broilers. However, the beneficial effects of some feed additives are not detected under non-challenged conditions. Therefore, the second experiment was performed to evaluate the effect of the feed additive at 1 kg/t in coccidiosis-challenged broilers. In this context, sodium butyrate protected by sodium salts of medium-chain fatty acids restored the number of mucin-secretory cells as well as impacted on the intestinal morphometry and microbiota. The results of the present study suggest that this feed additive could be a useful strategy to reinforce the gut barrier, especially for birds with coccidiosis.

Abstract

Nutritional strategies to improve gut health of broilers are under research. This study investigated the effect of dietary supplementation with sodium butyrate protected by sodium salts of medium-chain fatty acids as a feed additive on broiler gut health. The first experiment was conducted to evaluate the effect of supplementing at 0.5, 1, and 2 kg/t in broilers housed under optimal conditions. Supplementation at 0.5 and 1 kg/t maintained goblet cell counts at 10 days of age (p ≤ 0.05), and supplementation at 1 kg/t decreased intraepithelial lymphocyte counts compared to 2 kg/t at 39 days (p ≤ 0.10). Abdominal fat pad levels of lauric and myristic acids were gradually increased by supplement dose (p ≤ 0.05). In the second experiment, the feed additive at 1 kg/t was evaluated in coccidiosis-challenged broilers. Experimental treatments were as follows: non-challenged, control-challenged, and supplemented-challenged treatments. Coccidiosis negatively impact performance and modify histomorphometry and microbiota (p ≤ 0.05). The feed additive increased crypt depth at 7 days post-inoculation and goblet cell count at 14 days post-inoculation (p ≤ 0.05). Further, supplementation interacted with the microbiota modification led by the coccidiosis (p ≤ 0.05). These results suggest that this feed additive could be a useful strategy to reinforce the gut barrier, especially for birds under coccidiosis-challenge treatments.

Evaluation of gum Arabic (Acacia Senegal) as a natural prebiotic to improve growth performance and health status of broiler chickens

Gum Arabic (GA) is a natural product containing soluble fiber that is indigestible in the gastrointestinal tract and has been used as a traditional medicine to treat many diseases such as intestinal inflammation, kidney disease, and liver disorders, which may be reflected in the improved performance of broiler chickens when used. Therefore, the main objective of the current study was to evaluate the effects of GA on the performance, immune system, visceral organs, functional tests, and histological changes of the ileum, liver, and kidneys of broilers. A total of 432 1-day-old male broilers were allocated to six dietary treatments (0.0, 0.12, 0.25, 0.5, 0.75, and 1.0% GA) for 35 days. Performance, internal organs, and blood biochemical indices were measured. Morphology and histometry of the intestine were also performed. Meanwhile, tissues of the ileum, liver, and kidney were examined and evaluated microscopically to observe histological changes. All levels of GA (0.12 to 1.0%) had a positive effect on growth performance and feed conversion ratio. In addition, GA had no effect on the relative weight of lymphoid and visceral organs, except for a linear response in the bursa and liver. The levels of GA (0.12 and 0.25%) showed the potential to decrease serum uric acid, creatinine, and alanine aminotransferase. The remarkable increase in small intestinal morphology of chickens fed GA and an increase in all histometric values of the ileum. All histological changes in the intestine, liver, and kidneys improved in chickens fed the basal diet containing 0.12 to 0.50% GA. These results provide useful evidence for the potential use of GA powder (Acacia senegal) as a natural prebiotic to improve performance and intestinal, liver, and kidney health in broiler chickens.

Characterization and Evaluation of Colombian Propolis on the Intestinal Integrity of Broilers

Nutritional additives such as propolis seek to improve intestinal health as an alternative to the global ban on in-feed antibiotics used as growth promoters (AGP). The objective of this study was to evaluate the effect of propolis supplementation in diet of broilers. Four hundred and fifty straight-run Ross 308 AP broilers were fed with a basal diet (BD) throughout the whole experimental period. Birds were randomly distributed into 5 groups at d 14: negative control without antibiotics nor propolis (AGP-), positive control 500 ppm of Zinc Bacitracin as growth promoter (AGP+), and 3 groups supplemented with 150, 300, and 450 ppm of propolis. Every group included 6 replicates of 15 birds each. Propolis concentration was increased from d 22 to 42, in experimental groups to 300, 600, and 900 ppm of propolis, and 10% of raw soybean was included as a challenge in all groups during the same period. Analysis of productive parameters, intestinal morphometry, and relative quantification of genes associated with epithelial integrity by qPCR were performed at 21 and 42 d. The groups with the greatest weights were those that consumed diets including 150 (21 d) and 900 ppm (42 d) of propolis compared with all treatments. The lowest score of ISI was found at 300 (21 d) and 600 ppm (42 d). A lower degree of injury in digestive system was seen with the inclusion of 300 ppm (21 d) and 900 ppm (42 d). Up-regulation of zonula occludens-1 (ZO-1) was observed in jejunum of broilers supplemented with 150 and 300 ppm at 21 d. Up-regulation of ZO-1 and TGF-β was also evidenced in ileum at all propolis inclusion levels at 42-day-old compared to AGP+ and AGP-. The beneficial effects were evidenced at inclusion levels of 150 ppm in the starter and 900 ppm in the finisher. According to the results, the Colombian propolis inclusion can improve productive performance, physiological parameters, and gene expression associated with intestinal integrity.

Growth Performance, Histological Changes and Functional Tests of Broiler Chickens Fed Diets Supplemented with Tribulus Terrestris Powder

The current experiment aimed to investigate the effects of TT powder on performance parameters and functional tests, as well as on morphological and histological changes in the liver, kidney and ileum in broiler chickens. Commercial broilers (total = 168 females) were used, equally divided into three dietary treatments (C = 0.0, T1 = 0.75, and T2 = 1.5 g/kg diet). The growth performance (1−35 days of age), absolute and relative weight, liver and kidney functional tests, intestinal morphology (14 and 35 days of age), and histomorphology of the ileum (35 days of age) were evaluated. At 35 days of age, histopathological changes in the ileum, liver, and kidney were also examined. The results showed that the growth performance and absolute and relative weights of the liver and kidney had no negative effects when dietary supplementation with TT powder was given at 0.75 g/kg diet (T1), whereas a decrease was observed at T2 (p < 0.05). Liver and kidney functional tests showed no significant effects in all feed treatments (14 days), while T1 showed lower (p < 0.05) ALT and AST levels (35 days). T1 exhibited higher weights, lengths, and weight-to-length ratios of the small intestine, and relative lengths of the duodenum (p < 0.05). Histomorphometric measurements of the ileum were higher (p < 0.05) in chickens fed the 0.75 g TT/kg diet, and except for in the goblet cell count and epithelial thickness, there were no differences between treatments (p > 0.05). In T1, hepatocytes were more normal but hepatic sinusoids were dilated, whereas in T2, lymphocytes had infiltrated around the central vein and lining endothelial cells had been lost. The kidney was improved in T1 and T2 compared with the control group. Ileal villi were shorter in T2, and some villi fused with enterocyte necrosis and inflammatory cells accumulated in the lumen. We concluded that TT powder (0.75 g/kg feed) has a safe effect and is healthy for broilers.

Influence of Brassica spp. rapeseed and canola meal, and supplementation of bioactive compound (AITC) on growth performance, intestinal-permeability, oocyst shedding, lesion score, histomorphology, and gene expression of broilers challenged with E. maxima

This study was performed to investigate the effect of feeding Brassica spp. including full-fat rapeseed, canola meal, and allyl isothiocyanate (AITC) to broiler chicken challenged with E. maxima. A total of 576 one-day old male broiler chicks were completely randomized to 8 treatments with 6 replicated cages and 12 birds per cage. The treatment diets consisted of nonchallenge control (NC, corn-SBM based diet), challenge control (CC), 10% rapeseed (10RS), 30% rapeseed (30RS), 20% canola (20CLM), 40% canola (40CLM), 500 ppm AITC (500AITC), and 1,000 ppm AITC (1000AITC). At d 14, all birds were challenged, except NC group, with a subclinical dose of E. maxima. Intestinal permeability was conducted on 5 d post-infection (dpi) and for oocyst shedding 5 to 6 dpi feces were pooled and collected. On 6 dpi, growth performance, lesion score, histomorphology, and gene expression were measured. The growth performance result showed that 10RS and 30RS groups had lower BW, BWG, FI, and higher FCR (P < 0.0001). During the challenge and overall periods, NC group had highest BW, BWG, and FI, and lowest FCR. The inclusion of canola meal showed lower performance during prechallenge period but was able to catch up BWG during challenge period. The AITC levels showed similar growth performance to CC group. Intestinal permeability for 20CLM, 40CLM, 500AITC and 1000AITC was similar to NC group, whereas CC, 10RS, and 30RS had higher permeability compared to NC (P < 0.0001). Oocyst shedding was significantly lower for 40CLM and NC, whereas all other treatments had higher oocyst shedding (P < 0.0001). All the challenged treatment groups had higher lesion score and microscore than NC (P < 0.0001). Histomorphology data showed that jejunum villus height (VH) for 1000AITC was similar to NC group, whereas CC group had the lowest VH (P = 0.01). The 30RS group had lower VH: crypt depth (CD) ratio in the jejunum and ileum. The gene expression at 6 dpi for claudin1, occludin, IL2, IL6, GLUT5, EAAT, BoAT, and LAT1 was significantly changed among the treatments. The results suggest that 30RS retards growth performance and deteriorate gut health during coccidiosis and should not be fed to chicken during the starter phase. Canola meal showed decline in growth prechallenge but maintained growth and intestinal health during the challenge period at 40% inclusion. AITC at 1,000 ppm showed similar growth as control group, but with improved gut health during the challenge period. Canola meal could be a good alternative to SBM especially during coccidiosis, whereas AITC needs to be tested vigorously in animal feeding regime.

Protected Organic Acid and Essential Oils for Broilers Raised Under Field Conditions: Intestinal Health Biomarkers and Cecal Microbiota

The objective of the present study was to evaluate the effect of protected organic acids (OA) and essential oils (EO) [P(OA + EO)] on the intestinal health of broiler chickens raised under field conditions. The study was conducted on four commercial farms. Each farm consisted of four barns, two barns under a control diet and two tested barns supplemented with P(OA + EO), totaling 16 barns [8 control and 8 under P(OA + EO)]. The control group was supplemented with antibiotic growth promoters [AGP; Bacitracin Methylene Disalicylate (50 g/ton) during starter, grower and finisher 1, and flavomycin (2 g/ton) during finisher 2]. The tested group was supplemented with 636, 636, 454, and 454 g/ton of P(OA + EO) during starter, grower, finisher 1 and 2, respectively. Eighty birds were necropsied (40/treatment; 20/farm; and 5/barn) to collect blood, jejunal tissue, and cecal contents. The data were submitted to analysis of variance (ANOVA) (P < 0.05) or Kruskal-Wallis' test and the frequency of antimicrobial resistant (AMR) genes was analyzed by Chi-Square test (P < 0.05). It was observed that the supplementation of P(OA + EO) reduced (P < 0.05) the histopathology scores, such as the infiltration of inflammatory cells in the epithelium and lamina propria and tended (P = 0.09) to reduce the serum concentration of calprotectin (CALP). The supplementation of P(OA + EO) reduced the serum concentration of IL-12 (P = 0.0001), IL-16 (P = 0.001), and Pentraxin-3 (P = 0.04). Additionally, P(OA + EO) maintained a cecal microbiota similar to birds receiving AGP. The substitution of AGP by P(OA + EO) reduced (P < 0.05) the frequency of four AMR genes, related to gentamicin (three genes), and aminoglycoside (one gene). Overall, the inclusion of P(OA + EO), and removal of AGP, in the diets of commercially raised broiler chickens beneficially changed the phenotype of the jejunum as shown by the lowered ISI scores which characterizes an improved intestinal health. Furthermore, P(OA + EO) significantly reduced the serum concentration of several inflammatory biomarkers, while maintaining the diversity and composition of the cecal microbiota similar to AGP fed chickens and reducing the prevalence of AMR genes.

Effect of organic acids on growth performance, intestinal morphology, and immunity of broiler chickens with and without coccidial challenge

A total of 360-day-old broiler chicks were allocated into six groups in 2 (Coccidial challenge or not) × 3 (dietary treatments) factorial design. Three dietary treatments including: basic diet, basic diet plus organic acids (OAs) in drinking water, and basic diet plus OAs in the feed with and without coccidial challenge. The OAs in water or feed improved (P < 0.01) average body weight (ABW), average body weight gain (ABWG), and feed conversion ratio (FCR) as compared with the control diet during starter, grower, and whole experimental period. Coccidial challenge decreased BW, ABWG, and average feed intake (AFI), as well as resulted in poor FCR during the starter and whole experimental period (P < 0.05). Though there was no interaction between OAs supplementation and coccidial challenge, the OAs supplementation improved the overall performance with and without coccidial challenge birds on 21 d and 35 d. IgG was found higher (P = 0.03) in broilers fed OAs in feed without the coccidial challenge group. On 18 d, OAs supplementation in feed increased TNF-γ (P = 0.006), whereas the coccidial challenge decreases TNF-γ (P = 0.01) and IL-10 (P =  < .0001), and increases IgM (P = 0.03), IgG (P = 0.04) and IgA (P = 0.02). On 29 d, the coccidial challenge increases IgM and IgA. On 18 d, jejunal lesion score was found significantly higher in the coccidial challenged group as compared to OAs supplementation with coccidial challenged groups on 18 d (P < 0.0001) and 29 d (P = 0.03). Crypt depth was higher, and Villus-height to Crypt depth ratio was lower in the coccidial challenge group on 18 and 29 d. The Goblet cells were found higher in the non-coccidial challenge on 18 d. After 18 d, 16S rDNA gene sequence analysis of ileal chyme has shown that coccidial challenge decreases Lactobacillus_reuteri species as compared to the non-challenged group (P = 0.02). After 29, Cyanobacteria abundance reduced (P = 0.014) in the challenged group than the non-challenged group at the phylum level. At the genus level, Lactobacillus (P = 0.036) and unidentified Cyanobacteria (P = 0.01) were found higher in the non-challenged group than the coccidial challenge group. The results indicate that the OAs supplementation showed improved responses in a pattern similar to the non-challenged control group by neutralizing the negative effects of the coccidial challenge.

Field evaluation of feeding spray-dried plasma in the starter period on final performance and overall health of broilers

The effect of feeding spray-dried plasma (SDP) during the starter period was evaluated with a commercial broiler integrator on performance and overall health of broilers. The I See Inside (ISI) methodology assessing gut health in broilers was used as a tool to evaluate the impact of dietary interventions under commercial conditions. One hundred farms with approximately 1.1 million broilers were used at a Brazilian broiler integrator. Two groups of farms were fed either a control or an SDP diet containing 1% SDP, from 0 to 10 d of age. Diets were formulated to have similar nutritional density, containing zinc bacitracin and CuSO₄ from 0 to 28 d. After 10 d, both groups were fed common commercial diets. Performance data were analyzed together or by type of ventilation system: positive pressure or negative pressure. Birds were sent to market as they reached 3.05 kg; therefore, age at slaughter (AS) was evaluated as a dependent variable along with other performance measures. From the 100 farms in the trial, 35 (16 control and 19 SDP farms) were selected for the assessment of broilers health, biosecurity, and local management. For that, 6 broilers per farm at 14 ± 2 d of age were necropsied and ileum sampled for the ISI methodology evaluation. Biosecurity and management were also evaluated to obtain the influence of those parameters on animal health. SDP-fed birds demonstrated improved feed conversion ratio, reduced mortality, and 1 d less for AS (P < 0.05) vs. control group (P < 0.05) regardless of the type of ventilation. During necropsy, birds fed SDP showed lower coccidiosis and locomotor system lesions as the overall ISI score compared to controls. Histologic intestinal alterations were also lower in SDP-fed broilers (P < 0.05). In conclusion, feeding 1% SDP in the starter period to broilers resulted in improved performance and health under both good and bad management and biosecurity standards independent of the type of ventilation. Overall, there was good agreement between the ISI method and performance improvements observed.

Changes in the Microbial Composition of the Cecum and Histomorphometric Analysis of Its Epithelium in Broilers Fed with Feed Mixture Containing Fermented Rapeseed Meal

This study examined the influence of fermented rapeseed meal (FRSM) on the intestinal morphology and gut microflora of broiler chickens. Limited information is available on the effects of FRSM on the intestinal morphology and the gastrointestinal microbiome population of animals. First, 48 21-day Ross 308 broilers were placed in metabolic cages and randomly assigned to four experimental groups. Group I birds were negative controls and received no additive. Group II birds were positive controls and received a 3% addition of unfermented rapeseed meal. Group III birds received a 3% addition of rapeseed meal fermented with the Bacillus subtilis 67 bacterial strain. Group IV birds received a 3% addition of rapeseed meal fermented with the B. subtilis 87Y strain. After 23 days of experimental feeding, the contents of the birds’ ceca were collected for microorganism determination. The histomorphology of the broilers’ ceca was also determined, and beneficial changes were found in the histology of the broilers’ ceca with the additives. Moreover, these materials inhibited the growth of pathogens and significantly stimulated the growth of probiotic bacteria. These results suggest that the addition of 3% FRSM has a potential probiotic effect and can be used as a material in feed for broilers.

Protected Blend of Organic Acids and Essential Oils Improves Growth Performance, Nutrient Digestibility, and Intestinal Health of Broiler Chickens Undergoing an Intestinal Challenge

The growing restriction of antibiotic growth promoters (AGP) use in farming animals has raised a concern regarding the viability of the animal production system. In this new context, feed additives with proven positive impact on intestinal health may be used as strategy to avoid losses on performance. The aim of this study was to evaluate the effects of a protected blend of organic acids and essential oils [P(OA+EO)] on growth performance, nutrient digestibility, and intestinal health of broiler chickens. A total of 1,080 Cobb × Cobb 500 male broilers were randomly distributed in four treatments with 10 replicates (27 birds/each). Treatments were as follow: non-challenged control; challenged control; AGP (enramycin at 10 g/t); and P(OA+EO) at 300 g/t. All birds on challenged groups were challenged with Eimeria spp. at 1 day and with Clostridium perfringens at 11, 12, and 13 days. Body weight gain (BWG), feed intake and feed conversion ratio (FCR) were evaluated until 42 days. At 17 days, one bird per pen was orally gavaged with fluorescein isothiocyanate-dextran (FITC-d) and blood samples were collected for FITC-d detection to assess intestinal permeability. At 21 days, apparent ileal nutrient and energy (IDE) digestibility, intestinal macroscopic and histologic alterations (ISI) and, expression of mucin2 (MUC2), claudin1 (CLDN1), and occludin (OCLN) genes in the jejunum were evaluated. From 1 to 42 days, birds from the non-challenged and P(OA+EO) groups had greater (P < 0.001) BWG compared to challenged control and AGP groups. The challenged control group presented the worst FCR (P < 0.001). IDE was 106 kcal/kg greater when broilers were fed P(OA+EO) compared to the challenged control group. Broilers supplemented with P(OA+EO) had improved intestinal integrity with lower blood FITC-d concentration and ISI scores, and greater expression of MUC2, CLDN1, and OCLN genes compared to the challenged control group (P < 0.05). In conclusion, the P(OA+EO) and the AGP led to increased growth performance, nutrient digestibility and intestinal health of challenged broilers. A marked difference occurred in favor of the P(OA+EO), suggesting that this blend may be used to improve intestinal health and broiler growth performance in AGP free programs.