Male Cobb Broilers Research Articles

Digestibilidade aparente e valor energético do ovo integral em pó para frangos de corte

Com a necessidade de buscar alimentos alternativos que visam baratear os custos na ração de frangos de corte e reaproveitar os resíduos de incubatório que compreendem material residual do processo de incubação, objetivou-se avaliar a digestibilidade e valor energético do ovo em pó desidratado para frangos de corte. Foram utilizados 300 frangos machos da linhagem COBB, distribuídos em delineamento experimental inteiramente casualizado, composto por dois tratamentos constituídos por cinco repetições, com três animais em cada repetição. O experimento foi composto por um tratamento controle (ração referência) e um tratamento composto por ração referência + 15% de ovo desidratado em pó. Foi utilizado o método de coleta total de excretas para realizar as análises. Nas avaliações foram constatadas 7,010Kcal/kg de energia metabolizável e coeficiente de digestibilidade da proteína bruta e da matéria seca de 86,81% e 72,17%, respectivamente. Conclui-se que o Ovo em pó integral desidratado pode ser utilizado adequadamente na alimentação de frangos de corte, pois possui alto valor energético e boa digestibilidade, assim seguindo os parâmetros nutricionais descritos.

Feeding combination of Lactobacillus casei and extracts of dahlia tuber or garlic on intestinal bacteria, nutrients digestibility and performance of broiler chickens

This study aimed to evaluate the effect of dietary inclusion of 2% synbiotic ( Lactobacillus casei + dahlia tuber extract/LEDT or Lactobacillus casei + garlic extract/LEGT) on intestinal bacteria, nutrient digestibility, and growth of broiler chickens. A total of 150 birds of one-day-old male Cobb broiler were randomly assigned into three groups of treatment with five replications (10 birds each). Dietary treatments applied were T0 = basal ration, T1 = basal ration + 2% LEDT, T2 = basal ration + 2% LEGT. Synbiotics were given to starter chicken (from 2 to 3 weeks old). Parameters observed were intestinal bacteria (total lactic acid bacteria/LAB and coliform counts), nutrients digestibility, and body weight. Data were subjected to analysis of variance and followed by Duncan test. The results showed that the population of intestinal LAB in synbiotic-treated birds significantly (P<0.05) increased while coliform decreased as compared to control group. Protein and crude fiber digestibilities, and growth of broiler chickens given dietary inclusion of synbiotic either LEDT or LEGT were also significantly (P<0.05) higher than those fed control diet. In conclusion, dietary inclusion of 2% synbiotic LEDT increase body weight of broiler chickens through the improved balance of intestinal microbiota and nutrients digestibility.

Isolated and combined organic acids in diets of broiler chickens challenged with Eimeria acervulina

ABSTRACT This study aimed to evaluate the effect of isolated or combined citric and benzoic acids added to the diets of broiler chickens on performance, allometry of the digestive system organs, intestinal pH and quantity of microorganisms in the jejunum. A total of 840 male Cobb broiler chicks were utilized, distributed in a complete random design in 2 × 2 factorial scheme, supplemented or not with citric acid, and sodium benzoate, with seven replications. At 14 days old, 1mL of a solution containing 1 × 105 sporulated oocysts of Eimeria acervulina per bird was inoculated orally. There was no effect of the acids on the broiler’s performance in the 1 to 21-day period. In the total period (1 to 42 days), the broilers fed with a blend of citric and benzoic acid presented greater feed intake, without increment in weight gain. The data of allometry of the digestive system organs and the jejunal pH values were not influenced by the treatments. The citric acid increased the bacterial quantity of gram-positive coccus and total anaerobes in the jejunum. Under the conditions of the present study, we conclude that the citric and benzoic acids, isolated or combined, do not benefit the nutrition of broilers challenged with E. acervulina.

Effects of Inorganic Zn and Cu Supplementation on Gut Health in Broiler Chickens Challenged With Eimeria spp.

An experiment was conducted to evaluate the effect of different levels of inorganic copper and zinc on growth performance, intestinal permeability, intestinal lesion scores, oocyst shedding, antioxidant properties and bone quality in broilers challenged with Eimeria spp. A total of 360 d-old male Cobb broiler chickens were housed in floor cages for 12 days at the Poultry Research Center. At 12 days of age, birds were placed in grower Petersime batteries and distributed in a completely randomized design with 10 birds per cage, six replicates per treatment, and six treatments. There were six corn-soybean meal-based dietary treatments: non-challenged control (NC), challenged control (CC), 100 ppm Cu (100 Cu), 150 ppm Cu (150 Cu), 80 ppm Zn (80 Zn), and 100 ppm Zn (100 Zn). Broilers received the treatment diets for 9 days (12–20d). Birds, except NC, were challenged with Eimeria maxima (50,000 oocysts/bird), Eimeria tenella (50,000 oocysts/bird), and Eimeria acervulina (250,000 oocysts/bird) on 14d. On 20d, the growth performance was recorded, and one bird/cage was used for analysis of intestinal permeability, antioxidant properties and bone quality. Lesion score was recorded at 20 days of age in eight birds/cage. The means were subjected to ANOVA and, when significant, compared by Duncan's test. Intestinal permeability was significantly improved when birds received the 100 Zn diet (P < 0.05). In addition, lesion scores on duodenum were reduced when broilers received diets 150 Cu as compared to CC diet (P < 0.05). However, growth performance was not positively influenced by inclusion of inorganic minerals as compared to the NC diet. Furthermore, activity of superoxide dismutase and bone quality were not affected, whereas glutathione status was improved with mineral supplementation in all groups. This study showed that Cu and Zn supplementation improves intestinal integrity during the Eimeria spp. infection, suggesting that Cu and Zn supplementation would be a potential strategy to reduce detrimental effects of Eimeria infection in broilers.

Longitudinal Characterization of Coccidiosis Control Methods on Live Performance and Nutrient Utilization in Broilers

An experiment was conducted to quantify the timing and magnitude of the effects of coccidiosis vaccination on the growth performance, apparent ileal digestibility (AID) of nutrients and energy, intestinal morphology, and plasma carotenoids and nitric oxide in broilers. Treatment groups consisted of 3 coccidiosis control methods [unvaccinated, unmedicated (NC), in-feed chemical coccidiostat (PC), and live oocyst vaccination (VAC) at day of hatch] administered to male Cobb broilers reared in floor pens. Body weight gain (BWG), feed intake (FI), and feed conversion ratio (FCR) were determined at 12, 16, 20, 28, and 36 d. Blood and ileal digesta were collected from birds in 10 replicate pens of each treatment at 12, 16, 20, and 36 d to evaluate plasma carotenoid and nitric oxide concentrations and determine nutrient AID and IDE. Jejunal samples were taken at 12, 20, and 36 d for morphological measurements. Oocyst shedding in VAC birds was confirmed by increased oocyst counts and decreased carotenoid concentrations (P < 0.05) when compared with PC birds, with no differences (P > 0.05) in nitric oxide concentrations. At 20 d, BWG and FI were lowest (P < 0.05) in VAC birds, intermediate in NC birds, and highest in PC birds, with no differences in FCR (P > 0.05). By 28 and 36 d, FCR was higher (P < 0.05) for VAC and NC birds but BWG and FI of VAC birds were similar (P > 0.05) to PC birds. At d 12, IDE and AID of nitrogen and ether extract were lower (P < 0.05) in VAC birds than PC birds. At d 16, AID of nitrogen was similar (P > 0.05) between PC and VAC birds, whereas AID of ether extract remained lower in VAC birds than PC birds. No differences in AID of nutrients or IDE were observed (P > 0.05) between VAC and PC birds at 20 or 36 d. No differences (P > 0.05) in jejunal morphology were observed at any time point. Overall, VAC elicited a transient reduction in AID and IDE, particularly for lipids, that diminished by d 20.

Effects of encapsulated cinnamaldehyde and citral on the performance and cecal microbiota of broilers vaccinated or not vaccinated against coccidiosis

This study investigated the effects of encapsulated cinnamaldehyde (CIN) and citral (CIT) alone or in combination (CIN + CIT) on the growth performance and cecal microbiota of nonvaccinated broilers and broilers vaccinated against coccidiosis. Vaccinated (1,600) and nonvaccinated (1,600) 0-day-old male Cobb500 broilers were randomly allocated to 5 treatments: basal diet (control) and basal diet supplemented with bacitracin (BAC, 55 ppm), CIN (100 ppm), CIT (100 ppm), and CIN (100 ppm) + CIT (100 ppm). In general, body weight (BW) and feed conversion ratio were significantly improved in birds treated with BAC, CIN, CIT, and CIN + CIT (P < 0.05) but were all decreased in vaccinated birds compared with nonvaccinated birds (P < 0.05). Significant interactions (P < 0.05) between vaccination and treatments for average daily gain during the periods of starter (day 0–9) and BW on day 10 were noted. Broilers receiving vaccines (P < 0.01) or feed supplemented with BAC, CIN, CIT, or CIN + CIT (P < 0.01) showed reductions in mortality rate from day 0 to 28. The incidences of minor coccidiosis were higher (P < 0.05) in vaccinated birds than in nonvaccinated birds. Diet supplementation with BAC or tested encapsulated essential oils showed comparable effects on the coccidiosis incidences. Similar to BAC, CIN and its combination with CIT reduced both incidence and severity of necrotic enteritis (P < 0.05). No treatment effects were observed on the cecal microbiota at the phyla level. At the genus level, significant differences between vaccination and treatment groups were observed for 5 (Lactobacillus, Ruminococcus, Faecalibacterium, Enterococcus, and Clostridium) of 40 detected genera (P < 0.05). The genus Lactobacillus was more abundant in broilers fed with CIT, while Clostridium and Enterococcus were less abundant in broilers fed with CIN, CIT, or CIN + CIT in both the vaccinated and nonvaccinated groups. Results from this study suggested that CIN alone or in combination with CIT in feed could improve chicken growth performance to the level comparable with BAC and alter cecal microbiota composition.

363 Integrated transcriptomic and gut microbiome analysis of the toxic effects of T-2 toxin on the small intestine of chickens

Abstract This study was conducted to reveal the mechanism of T-2 toxin induced small intestine injuries in broilers through a new perspective that combined transcriptomics and microbiology studies. 96-d-old male Cobb broilers were randomly allocated into 4 treatment groups with 4 replicates of 6 birds/cage and all birds were fed a corn-soybean-based diet (Control) and the other 3 groups supplemented with T-2 toxin at 1.0, 3.0 or 6.0 mg/kg, respectively, for 2 weeks. Growth performance and nutrients digestibility were analyzed. Duodenum was collected to assay for histology, transcriptomics and microbiology. Compared with the control, final body weight, body weight gain and feed intake were decreased (P &amp;lt; 0.05) in a dose-dependent manner with increasing dietary T-2 toxin dose. Specially, in dietary T-2 toxin at 6.0 mg/kg, the feed/gain increased (P &amp;lt; 0.05) 11.4% and the apparent metabolic rate of crude protein, calcium and phosphorus were decreased (P &amp;lt; 0.05) by 14.9%, 18.0% and 16.1%, respectively. Meanwhile, T-2 toxin induced severe degeneration, necrosis and desquamation of the villous epithelial cells, increased inflammatory cells. Furthermore, the results of transcriptome drew that 2536 genes showed significant differences and were partially enriched in metabolic pathways, cell growth and death, apoptosis, the metabolism by CYP450, immune response pathways. Gut microbiota play a key role as microbial and duodenum genes and metabolites affected by T-2 toxin shared multiple pathways. Remarkably, Firmicutes and Proteobacteria that related to energy metabolism and inflammatory were seriously affected (P &amp;lt; 0.05). In summary, combined the results of integrated analysis, T-2 toxin partially induced intestine injury, potentially through changing the gene expression and the intestinal micro-ecology or damaging the intestinal mucosal directly, thus inducing inflammatory and apoptotic.

288 Se deficiency aggravates AFB1-induced immunotoxicity in chick spleen via regulating six selenoprotein and redox/inflammation/apoptotic signaling

Abstract This study was designed to reveal the underlying mechanism of Se-mediated protection against aflatoxin B1 (AFB1)-induced splenic injury in broilers. Four groups of day-old Cobb male broilers (n = 5 cages/diet, 6 chicks/cage) were arranged in a 3-wk 2×2 factorial design trial that fed a Se-deficient, corn and soy–based diet (BD, 36 μg Se/kg) or the BD + 1.0 mg AFB1/kg, 0.3 mg Se/kg, or 1.0 mg AFB1/kg with 0.3 mg Se/kg (as 2-hydroxy-4-methylselenobutanoic acid). Serum and spleen were collected at wk 3 to assay for histology, cytokines, redox status, and selected inflammation- and apoptosis-related genes and proteins, and selenogenome. Dietary AFB1 induced the growth retardation and spleen injury, decreasing (P &amp;lt; 0.05) body weight gain, feed intake, feed conversion efficiency, and serum interleukin-1β, increasing (P &amp;lt; 0.05) spleen index and serum interleukin-6, and reduced the splenic lymphocyte number and white pulp region and histiocyte proliferation in Se adequate groups. However, Se deficiency aggravated (P &amp;lt; 0.05) these AFB1-induced changes. Moreover, Se deficiency decreased (P &amp;lt; 0.05) splenic glutathione peroxidases (GPX) activities and glutathione concentration in AFB1 exposed groups. Furthermore, Se deficiency also upregulated (P &amp;lt; 0.05) the antimicrobial (beta defensin 1 and 2) and apoptotic (Caspase 3 and Caspase 9) genes but downregulated (P &amp;lt; 0.05) antiapoptotic (B-cell lymphoma 2) and inflammatory (E3 ubiquitin-protein ligase CBL-B) genes at mRNA and(or) protein levels in AFB1 supplementation groups. Additionally, Se deficiency downregulated (P &amp;lt; 0.05) GPX3, thioredoxin reductase 1 (TXNRD 1), GPX4 and selenoprotein (SELENO) S and upregulated (P &amp;lt; 0.05) SELENOT and SELENOU in spleen in AFB1 administered groups. In conclusions, dietary Se deficiency aggravated AFB1-induced spleen injury in chicks, partially through the regulation of the oxidative stress, inflammatory and apoptotic signaling and six selenoproteins (Supported in part by Chinese Natural Science Foundation Projects 31772636 and 31501987).

The influence of dietary leucine above recommendations and fixed ratios to isoleucine and valine on muscle protein synthesis and degradation pathways in broilers

This study investigated the hypothesis that dietary supplementation of leucine (Leu) above actual recommendations activates protein synthesis and inhibits protein degradation pathways on the molecular level and supports higher muscle growth in broilers. Day-old male Cobb-500 broilers (n = 180) were allotted to 3 groups and phase-fed 3 different corn-wheat-soybean meal-based basal diets during periods 1 to 10, 11 to 21, and 22 to 35 D. The control group (L0) received the basal diet which met the broiler's requirements of nutrients and amino acids for maintenance and growth. Groups L1 and L2 received basal diets supplemented with Leu to exceed recommendations by 35 and 60%, respectively, and isoleucine (Ile) and valine (Val) were supplemented to keep Leu: Ile and Leu: Val ratios fixed. Samples of liver and breast muscle and pancreas were collected on days 10, 21, and 35. The gene expression and abundance of total and phosphorylated proteins involved in the mammalian target of rapamycin pathway of protein synthesis, in the ubiquitin-proteasome pathway and autophagy-lysosomal pathway of protein degradation, in the general control nonderepressible 2/eukaryotic translation initiation factor 2A pathway involved in the inhibition of protein synthesis, and in the myostatin–Smad2/3 pathway involved in myogenesis were evaluated in the muscle, as well as expression of genes involved in the growth hormone axis. Growth performance, feed intake, the feed conversion ratio, and carcass weights did not differ between the 3 groups (P > 0.05). Plasma concentrations of Leu, Ile, and Val and of their keto acids, and the activity of the branched-chain α-keto acid dehydrogenase in the pancreas increased dose dependently with increasing dietary Leu concentrations. In the breast muscle, relative mRNA abundances of genes and phosphorylation of selected proteins involved in all investigated pathways were largely uninfluenced by dietary Leu supplementation (P > 0.05). In summary, these data indicate that excess dietary Leu concentrations do not influence protein synthesis or degradation pathways, and subsequently do not increase muscle growth in broilers at fixed ratios to Ile and Val.

Feed supplementation with inulin on broiler performance and meat quality challenged with Clostridium perfringens: Infection and prebiotic impacts

Following the ban on the use of antibiotics as growth enhancers in 2006 by the European Union, alternative products have been sought. Inulin is a prebiotic that is found naturally in many plants. It reaches large intestine of animals unaltered, where it is fermented by beneficial bacteria that comprise the intestinal microbiota. Inulin also inhibits the growth of pathogenic bacteria. Consumption of inulin in chicken diets improves performance at slaughter; nevertheless, little is known about its effects on poultry meat. Therefore, the objective of this study was to evaluate the effects of inulin on feeding of broilers challenged with Clostridium perfringens (4.0 × 108 CFU) and its consequences on the quality of breast meat. Four hundred Cobb male broiler chickens were distributed in a completely randomized design with four treatments and five replications each, as follows: T1: control treatment, basal diet (DB); T2: DB + 21-day challenged with C. perfringens orally; T3: DB + 21-day challenge with C. perfringens orally +25 mg/kg inulin; T4: DB + 21-day challenge by C. perfringens orally +4.4 mg/kg lincomycin. There were no significant differences between treatments in terms of pH, color parameters (L, a*, b*), water retention capacity, or shear force cooking weight loss. However, we found that the meat of poultry challenged by C. perfringens showed lower lipid peroxidation and increased activity of the antioxidant enzymes SOD and CAT, suggesting improvement in antioxidant profile. Nitrate/nitrite levels were lower with T3 and higher with T4 than with T1. We therefore conclude that inulin can replace antibiotics as growth promoters without causing changes in the physicochemical characteristics of meat. C. perfringens challenge caused lower lipid peroxidation and stimulated antioxidant responses in breast meat.

Changes in cecum microbial community in response to total sulfur amino acid (TSAA: DL-methionine) in antibiotic-free and supplemented poultry birds

The effect of essential total sulfur amino acids (TSAA) like methionine and cysteine on the cecal microbiome of broilers was investigated at 2 different time points (days 21 and 42) of broiler rearing. A total of 360-day-old Cobb male broiler chicks were randomly distributed to 6 dietary treatments in a 2 × 3 factorial arrangement, with 2 levels of antibiotic growth promoters (AGP: 0 and 0.05%) and 3 levels of TSAA (DL-methionine) either for starter (0.7, 0.8, and 0.9%) or finisher chicks (0.52, 0.62, and 0.72%), labeled as diets 1 to 6. Cecal digesta from each replicate (n = 10) were sampled on days 21 and 42. DNA was extracted for the amplification of the V4 region of bacterial 16S rRNA genes and subjected to Illumina sequencing. Bioinformatic analyses were performed using QIIME, Mothur, and ad hoc tools and functional profiles of the inferred metagenome were analyzed using PICRUST. Statistical difference was determined by 2-way ANOVA and PERMANOVA. Clustering of cecal communities using PCoA showed clear separation of microbial communities based on age (P < 0.05) of birds and between low and medium/ high levels of TSAA (DL-methionine). At day 21, bacterial richness and diversity were higher than at day 42 where Clostridium cluster XI and Lactobacillus were found most abundant. No variability in taxonomic richness at the genus level was observed with AGP and DL-methionine supplementation. Interbird variation for richness was greater at day 42 compared to day 21. The mean fold difference of richness was greater (1.5 mean fold) with diets 1 and 6, suggesting interactive effects of AGP and TSAA (DL-methionine) in the diet. KEGG function profiles calculated by PICRUST suggest that the cecal microbiome increased glycolysis and energy generation correlated with increased dietary TSAA (DL-methionine) supplementation levels during the late broiler growth period (day 42). This study increases our knowledge of microbial dynamics and functions that are relevant to host nutrition and performance that may help us tailoring alternative strategies for raising poultry birds under antibiotic-free conditions.

Feeding plans with the use of glycerin for broilers

This study aimed to evaluate the effects of feeding plans with or without addition of glycerin, in different ages, on performance, carcass yield, litter moisture and footpad lesions of broiler chickens. 540 male Cobb broilers were utilized, distributed in a completely randomized design with six treatments (treatments consisted of the inclusion or not of glycerin in diets at all periods or only at different stages: 1 to 7, 8 to 21, 22 to 33 and 34 to 42 days), in six replicates of 15 birds each. Diets were provided ad libitum. At 42 days, the average weight, weight gain, feed intake, feed conversion, carcass yield, litter moisture and footpad lesions were evaluated. There was no effect (p&gt; 0.05) of dietary plans on the performance variables. The feeding plans did not influence (p&gt;0,05) the carcass and cuts parameters at 42 days. However, there was significant effect (p &lt;0.05) of the dietary plans on litter moisture and plantar lesions. Effects were observed (p&gt;0,001) for the feeding plans, were the highest and the lowest incidence of lesions were present in the birds that consume diets with and without addition of glycerin, in the period from 1 to 42 days of age, respectively.

Effects of Extra-Dosing Phytase in Combination with Multi-Carbohydrase on Growth Performance and Bone Mineralization Using Dual-Energy X-Ray Absorptiometry in Broilers

SUMMARY This study aimed to evaluate the effect of the combination of extra-dosing phytase and multi-carbohydrase (MC) on growth performance and bone mineralization in broilers. A total of 640 one-day-old Cobb male broilers were randomly allocated to 8 dietary treatments (4 replicates with 20 birds each) consisting of positive control (PC); negative control (NC; −0.15% Ca and non-phytate-P (nPP)); NC with phytase (500, 1000, and 1500 FTU/kg) with or without MC (500 mg/kg). Feed intake, BW, and FCR were measured at days 7, 21, and 35. At day 35, 3 birds per pen were euthanized to measure body composition using dual-energy X-ray absorptiometry, and right femurs were collected for bone ash. Supplementation of 1000 and 1500 FTU/kg of phytase improved BWG (P

Effect of the use of golden mussel flour contaminated with lead as a source of calcium on the performance of broilers

The objective of this study was to evaluate the use of lead contaminated golden mussel flour (GMF) as a source of calcium for broiler chickens from 14 to 42 days of age and to verify the probable effects on performance, tissue contamination, blood parameters, Pb digestibility, and bone quality. The experiment was conducted in a completely randomized design (DIC), with four levels of Pb contamination (71.33, 147.55, 223.78, and 300 mg kg-1 Pb) in GMF, with five replicates and three birds per experimental unit. Sixty-four-day-old Cobb male broilers housed in metabolism cages were used. GMF was added to rations instead of calcitic limestone. The zootechnical variables were evaluated: feed intake, weight gain, and feed conversion, as well as the digestibility of nutrients. In addition, the serum biochemistry of the birds transaminases, total bilirubin, calcium, and phosphate was studied and the concentration of lead in the tissues and the bone quality of the birds was determined. The tibia was collected for evaluation of bone quality. The levels of Pb contamination in the golden mussel did not change the performance of the birds (P ? 0.05) or the Pb levels in the muscle Pectoralis major, skin, liver, feather, bones, and serum, or the serum levels of ALT, GGT, and total bilirubin, however, there was an effect of Pb levels (P &lt; 0.01) on AST concentrations. Pb levels altered the values (P &lt; 0.01) of the apparent digestible Pb and the coefficient of apparent digestibility of Pb, with an increasing linear effect. There was no effect (P ? 0.05) on bone stiffness, however flexibility and bone strength were altered (P &lt; 0.05). Serum Ca and P concentrations did not show changes (P ? 0.05) due to the use of Pb levels in GMF. In this study, it can be observed that the use of GMF with Pb up to 300 mg kg-1 as a source of Ca in broiler diets does not alter performance, however the use of GMF contaminated with Pb above 73.33 mg kg-1 promotes contamination of the tissues of the animals with Pb, making it impossible to consume the birds. It was concluded that the increase in Pb concentrations in GMF increases the digestibility and metabolism of this metal and causes an increase in the production of AST by the liver. Pb levels in GMF above 214.11 mg kg-1 impair bone strength and flexibility.

Differential Impact of Subtherapeutic Antibiotics and Ionophores on Intestinal Microbiota of Broilers.

Antimicrobial growth promoters (AGPs) are commonly used in the livestock industry at subtherapeutic levels to improve production efficiency, which is achieved mainly through modulation of the intestinal microbiota. However, how different classes of AGPs, particularly ionophores, regulate the gut microbiota remains unclear. In this study, male Cobb broiler chickens were supplemented for 14 days with or without one of five commonly used AGPs including three classical antibiotics (bacitracin methylene disalicylate, tylosin, and virginiamycin) and two ionophores (monensin and salinomycin) that differ in antimicrobial spectrum and mechanisms. Deep sequencing of the V3-V4 region of the bacterial 16S rRNA gene revealed that two ionophores drastically reduced a number of rare bacteria resulting in a significant decrease in richness and a concomitant increase in evenness of the cecal microbiota, whereas three antibiotics had no obvious impact. Although each AGP modulated the gut microbiota differently, the closer the antibacterial spectrum of AGPs, the more similarly the microbiota was regulated. Importantly, all AGPs had a strong tendency to enrich butyrate- and lactic acid-producing bacteria, while reducing bile salt hydrolase-producing bacteria, suggestive of enhanced metabolism and utilization of dietary carbohydrates and lipids and improved energy harvest, which may collectively be responsible for the growth-promoting effect of AGPs.

The response of glandular gastric transcriptome to T-2 toxin in chicks

This study was conducted to determine the effect of T-2 toxin on the transcriptome of the glandular stomach in chicks using RNA-sequencing (RNA-Seq). Four groups of 1-day-old Cobb male broilers (n = 4 cages/group, 6 chicks/cage) were fed a corn-soybean-based diet (control) and control supplemented with T-2 toxin at 1.0, 3.0, and 6.0 mg/kg, respectively, for 2 weeks. The histological results showed that dietary supplementation of T-2 toxin at 3.0 and 6.0 mg/kg induced glandular gastric injury including serious inflammation, increased inflammatory cells, mucosal edema, and necrosis and desquamation of the epithelial cells in the glandular stomach of chicks. RNA-Seq analysis revealed that there were 671, 1393, and 1394 genes displayed ≥2 (P < 0.05) differential expression in the dietary supplemental T-2 toxin at 1.0, 3.0, and 6.0 mg/kg, respectively, compared with the control group. Notably, 204 differently expressed genes had shared similar changes among these three doses of T-2 toxin. GO and KEGG pathway analysis results showed that many genes involved in oxidation-reduction process, inflammation, wound healing/bleeding, and apoptosis/carcinogenesis were affected by T-2 toxin exposure. In conclusion, this study systematically elucidated toxic mechanisms of T-2 toxin on the glandular stomach, which might provide novel ideas to prevent adverse effects of T-2 toxin in chicks.

Modulation of Growth Performance and Intestinal Microbiota in Chickens Fed Plant Extracts or Virginiamycin.

In this study, the effects of plant extracts (PEs) and virginiamycin (VIRG) on broiler growth performance, as well as on host intestinal microbiota composition and function were investigated. A total of 288 one-day-old male Cobb broiler chickens were randomly divided into four treatment groups (with six replicates per group). The duodenal, ileal, and cecal content of six broilers per treatment group after 14 and 28 days of treatment were sampled. This material was used for high-throughput Illumina sequencing of the V3–V4 region of the 16S rRNA gene. The results showed that chickens fed 400 mg/kg plant extracts (HPE group) had significantly higher average body weights at day 28 as compared to the control group (CT; P < 0.05), and lower feed-to-meat ratios over days 15–42 (P < 0.01). Within the HPE group at day 14, the relative abundances of two bacterial phyla and 10 bacterial genera increased significantly in the ileal microbiota, and the relative abundance of three bacterial phyla and four bacterial genera decreased. The relative abundance of the genus Lactobacillus in the cecal microbiota decreased from 21.48% (CT group) to 8.41% (fed 200 mg/kg PEs; LPE group), 4.2% (HPE group), and 6.58% (fed 30 mg/kg virginiamycin; VIRG group) after 28 days. In contrast, Faecalibacterium and unclassified Rikenellaceae increased in abundance in the HPE group (from 18 to 28.46% and from 10.83 to 27.63%, respectively), while Bacteroides (36.7%) and Lachnospiraceae increased in abundance in the VIRG group. PICRUSt function analysis showed that the ileal microbiota of the PE treatment groups were more enriched in genes related to the meolism of cofactors and vitamins. In addition, the cecal microbiotas of the LPE and HPE groups were enriched in genes predicted to encode enzymes within 15 and 20 pathways, respectively. These pathways included protein digestion and absorption, amino acid metabolism, lipid biosynthesis, lipopolysaccharide biosynthesis, the citrate cycle (TCA cycle), and lipoic acid metabolism. Similarly, the VIRG group was enriched in 55 metabolic pathways (17 in the duodenum, 18 in the ileum, and 20 in the cecum) on day 28 (P < 0.05). Thus, the results indicated that the observed increase in broiler growth performance after PE or VIRG supplementation might be attributed to an improvement in intestinal microbial composition and metabolic function.

Selenium Deficiency Aggravates Aflatoxin B1–Induced Immunotoxicity in Chick Spleen by Regulating 6 Selenoprotein Genes and Redox/Inflammation/Apoptotic Signaling

Selenium (Se) plays a protective role in aflatoxin B1 (AFB1)-induced splenic immunotoxicity in chicks. This study was designed to reveal the underlying mechanism of Se-mediated protection against AFB1-induced splenic injury in broilers. Four groups of 1-d-old Cobb male broilers (n=5 cages/diet, 6 chicks/cage) were arranged in a 3-wk 2×2 factorial design trial whereby they were fed an Se-deficient, corn- and soy-based diet [base diet (BD), 36 μg Se/kg], BD plus 1.0 mg AFB1/kg, BD plus 0.3 mg Se/kg, or BD plus 1.0 mg AFB1/kg and 0.3 mg Se/kg (as 2-hydroxy-4-methylselenobutanoic acid). Serum and spleen were collected at week 3 to assay for cytokines, histology, redox status, selected inflammation- and apoptosis-related genes and proteins, and the selenogenome. Dietary AFB1 induced growth retardation and spleen injury, decreasing (P<0.05) body weight gain, feed intake, feed conversion efficiency, and serum interleukin-1β by 17.8-98.1% and increasing (P<0.05) the spleen index and serum interleukin-6 by 37.6-113%. It also reduced the splenic lymphocyte number, the white pulp region, and histiocyte proliferation in Se-adequate groups. However, Se deficiency aggravated (P<0.05) these AFB1-induced alterations by 16.2-103%. Moreover, Se deficiency decreased (P<0.05) splenic glutathione peroxidase (GPX) activity and glutathione-S transferase and glutathione concentrations by 35.6-89.4% in AFB1-exposed groups. Furthermore, Se deficiency upregulated (P<0.05) the apoptotic (Caspase 3 and Caspase 9) and antimicrobial (β defensin 1 and 2) genes, but downregulated (P<0.05) antiapoptotic (B-cell lymphoma 2) and inflammatory (E3 ubiquitin-protein ligase CBL-B) genes at the mRNA and/or protein level in AFB1 supplementation groups. Additionally, Se deficiency downregulated (P<0.05) GPX3, thioredoxin reductase 1 (TXNRD 1), GPX4, and selenoprotein (SELENO) S, and upregulated (P<0.05) SELENOT and SELENOU in spleen in AFB1 administered groups. Dietary Se deficiency exacerbated AFB1-induced spleen injury in chicks, partially through the regulation of oxidative stress, inflammatory and apoptotic signaling, and 6 selenoproteins.

Dietary probiotic form modulates broiler gut microbiota indices and expression of gut barrier genes including essential components for gut homeostasis

The probiotic form (PF) type and its dietary administration in combination or not with avilamycin (AV) were investigated for their effects on broiler gut microbiota and expression of genes relevant for gut barrier and gut homeostasis. Depending on PF type (i.e. no addition, viable, inactivated) and AV addition (no/yes), 450 one-day-old Cobb male broilers were allocated in 6 treatments (CON, CON+A, ViP, ViP+A, InP and InP+A) according to a 3×2 factorial arrangement with 5 replicates of 15 broilers each for 42days. Significant interactions (PPF×AV ≤0.05) between PF and AV administration were shown for the ileal mucosa-associated bacteria, the caecal digesta Lactobacillus spp., the molar ratio of the sum of valeric, hexanoic and heptanoic acids and the gene expressions of ileal and caecal IgA and ileal claudin 1. Avilamycin suppressed ileal digesta Lactobacillus spp. (PAV <0.001) and caecal digesta Clostridium perfringens subgroup (PAV =0.018) and modulated the intestinal fermentation intensity and pattern. The viable PF had the higher levels of ileal digesta Bacteroides spp. (PPF =0.021) and caecal digesta Lactobacillus spp. (PPF =0.038) compared with the other two PF. Probiotic form modulated the microbial metabolic activity in the ileum and caeca with the viable PF being the most noteworthy in terms of effects regarded as beneficial. Furthermore, the viable PF resulted in reduced expression of caecal Toll-like receptors TLR2B (PPF =0.026) and TLR4 (PPF =0.011) and transcription factor NFΚΒ1 (PPF =0.002), which could be considered as essential for limiting inflammation and preserving gut homeostasis. In conclusion, under non-challenge conditions, probiotic function was shown to depend on PF type and to a lesser degree on co-administration with AV. The importance of probiotic viability for the beneficial modulation of important gut components towards a reduced state of physiological inflammation has been highlighted.

Dehydrated citrus pulp in broiler diets

The objective of this study was to evaluate the effects of citrus pulp in diet for broilers on weight of gastrointestinal organs, intestinal morphometry, and quality and lipid oxidation of broiler meat during the storage time. A total of 966 Cobb male broiler chicks were fed six increasing levels of dietary citrus pulp (0%, 2%, 4%, 6%, 8%, and 10%) with seven replications of 23 birds each. The inclusion of citrus pulp in the diet of broilers from 1 to 21 d of age did not significantly affect organ weight and intestinal morphology (P &gt; 0.05). However, the citrus pulp can be used up to 10% inclusion in diets for broilers from 1 to 42 d of age, without impairing broiler performance, carcass yield, intestinal morphometry, and meat quality. For lipid oxidation, samples of thigh were used in a 6 × 4 factorial design (six dietary levels of citrus pulp and four storage periods) with four replications. In the treatments with 10% citrus pulp, the phenolic compounds present in the by-product led to a delayed and reduced oxidation.