Poultry

The present study investigated the effect of supplementing a multi-carbohydrase enzyme complex (MCE) in corn–soy-based diets of Pekin ducks. The treatments were as follows: positive control (PC, 2980 and 3120 kcal/kg for starter and grower, respectively); negative control (NC, −132 kcal/kg energy reduction to PC achieved by reduction of fat and wheat middlings as filler); NC + MCE at 75 ppm (E75); 100 ppm (E100); and 125 ppm (E125) randomly distributed in 10 replicate pens with 25 birds each. Performance was evaluated after 14 and 35 d. On day 36 of the trial, five ducks/pen were processed to evaluate carcass traits. During days 1–14, the PC had a lower (p < 0.01) feed intake compared to all other treatments. At 14 and 35 d of age the NC decreased (p < 0.001) the body weight (BW) of the ducks compared to the PC by −8.3% and −5.3%, respectively. The NC BW was lower (p < 0.001) compared to all MCE-supplemented treatments at 14 and 35 d. The BW of E75, E100, and E125 treatments was not different (p > 0.05) from the PC at both evaluation periods. Cumulatively (1–35 d), the NC resulted in a weight-adjusted FCR increase (p = 0.001) of 9.9% compared to the PC, and the FCR of E75, E100, and E125 were able to recover 72.3%, 66.4%, and 63.5%, respectively, compared to the PC. The carcass and breast weights were lower (p < 0.001) in the NC compared to all other treatments, and no differences (p > 0.05) were observed between the MCE-supplemented treatments and the PC. In conclusion, these results suggest that the MCE supplementation can maintain duck growth performance with no negative effects on carcass traits in energy-reduced corn–soybean meal-based diets. From the results of the trial, 75 ppm MCE delivered the best performance recovery and 125 ppm MCE supplementation had the best % breast yield. Full article

An experiment was conducted to determine the apparent metabolizable energy (AME) and nitrogen-corrected AME (AMEn) of defatted black soldier fly larvae meal (BSM), full-fat dry larvae meal (BSL), and larvae fat (LF) for broiler chickens. The BSM, BSL, and LF contained on a g/kg basis, respectively, crude protein, 459, 399, 0; crude fat, 171, 240, 923; dry matter, 963, 940, 997; neutral detergent fiber, 210, 333, 0; acid detergent fibers, 95, 93, 0; and gross energy (MJ/kg), 22.04, 22.78, 38.16. An AME bioassay was performed wherein broilers were fed four experimental diets (a maize–wheat–soy basal diet and three test diets containing 100 g/kg BSM, BSL, or LF, respectively). The AME of BSM, BSL, and LF was calculated based on the differences between the AME values of basal and test diets (substitution method). The AME and AMEn for BSM, BSL, and LF were determined to be 18.20 and 17.40; 17.60 and 16.50; and 36.50 and 35.60 MJ/kg DM, respectively. There were no significant differences (p > 0.05) between nutrient retention coefficients of dry matter, N, and fat. The results showed that the examined products from black soldier fly larvae are a good source of available energy and crude protein (BSL and BSM) and can be incorporated in broiler diets as alternative protein and energy sources. Full article

Phytogenic additives such as tannins are characterized as polyphenolic compounds known for their antimicrobial, anti-inflammatory, antioxidant, and immunostimulatory properties that have been used to enhance the performance, intestinal health, and meat quality of broiler chickens. The objective of this experiment was to evaluate the effects of increasing dietary supplementation of tannins from Acacia mearnsii on the intestinal morphometrics, litter moisture, and growth performance of broiler chickens. A total of 1400 Cobb 500 one-day-old male chicks were randomly distributed into five dietary treatments with eight replicates (35 birds/pen) until 42 days of age. The treatments consisted of Salmonella Heidelberg-challenged groups supplemented with 0, 300, 500, 700, or 900 mg/kg tannin from Acacia mearnsii. A four-phase feeding program was used with pre-starter, starter, grower, and finisher feeds. At 3 days of age, birds were orally gavaged with an S. Heidelberg culture. Feed intake, body weight gain (BWG), and feed conversion ratio (FCR) were evaluated until day 42. The morphometry of duodenum, jejunum, and ileum was measured at 7 and 42 days of age. From 1 to 28, 1 to 35, and 1 to 42 days of age, tannin supplementation for broilers under S. Heidelberg challenge led to quadratic increases (p < 0.05) in BWG, with optimal responses at 265, 412, and 456 mg/kg, respectively. No effects of tannin were observed on FCR in all periods. Villus height was similar in all segments on day 7 (p > 0.05); however, on day 42, tannin supplementation that improved villus height of the ileum was 600 mg/kg (p = 0.0100). In conclusion, tannins from Acacia mearnsii were able to improve body weight gain and intestinal morphometry of broiler chickens under an imposed challenge of S. Heidelberg. Full article

To tease apart differences between conventional cage (CC) and cage-free (CF) housing systems, this study focuses on the effects of excreta exposure and age by comparing microbial communities, intestinal permeability, and corticosterone in hens in enriched colonies (EC) and CF housing systems during early- and late-lay. Hens were randomly selected from two rooms of CF (n = 20) and EC (n = 20) at 35 and 76 weeks of age. One hour following an oral gavage of fluorescein isothiocyanate dextran (FITC-D), hens were euthanized, and ileal contents and blood were collected. Serum FITC-D using a fluorescent spectrophotometer and corticosterone using a commercial competitive ELISA kit were analyzed. Following DNA isolation from the ileum contents, the V4 region of the 16S rRNA gene was sequenced. Sequence data were filtered in Mothur v1.43.0, followed by de novo operational taxonomic unit (OTU) clustering and classifying with the SILVA SSU v138 reference database. Serum FITC-D was altered by housing type, age of hens, and the interaction between housing type and age of hens (p < 0.001), with 76-week-old hens housed in EC having the highest FITC-D. Corticosterone increased with age (p = 0.023). Microbial community diversity measurements favored hens housed in the CF housing system as ileal contents tended to have increased species evenness (p = 0.008) and greater alpha diversity (p = 0.006). The majority of the over-representation of OTUs were associated with peak lay. Full article

The use of antibiotics in poultry farming has been associated with bacterial resistance in humans, leading to a ban on their inclusion in chicken diets. Therefore, the objective was to evaluate the effects of probiotics and β-mannanase on the growth performance and intestinal health of broiler chickens challenged by Eimeria maxima and Clostridium perfringens. For this, 2100 one-day-old male Ross 308 chicks were used. The treatments were as follows: T1—Negative control (NC) unchallenged birds; T2—Positive control (PC) challenged with E. maxima + C. perfringens; T3—PC + Antibiotic (Enramycin 8%-125 g/ton); T4—PC + β-mannanase (Hemicell^HT; 300 g/ton); T5—PC + probiotic (Protexin^TM; 150 g/ton); T6—PC + β-mannanase + probiotic. Significant differences (p < 0.05) were observed from 1 to 42 days in the variables body weight, body weight gain and feed intake, and the NC treatment presented higher values compared to the PC and PC + probiotic groups. The villus/crypt ratio in the duodenum increased in the PC + β-man + prob treatment, differing from the NC, PC and PC + probiotic (p < 0.05) treatments. The use of β-mannanase, probiotics or both together is effective to mitigate the effects of production challenges, through the maintenance of the intestine by modulating action on the cecum microbiome and intestinal morphometry. Full article

The production of backyard chickens is an activity of great importance in the economy of rural families in Paraguay. The Rustipollos population was created through directed crosses between a commercial meat line and a local population belonging to non-specific breeds but phenotypically assimilated to Creole breeds. The aim of this study was to evaluate the genetic diversity, relationship, and structure of Rustipollos using 29 microsatellite markers. Analysis was performed on 50 Rustipollos animals and 926 other individuals as reference breeds/populations from Europe, Africa, South, and North America. A total of 318 alleles were detected, with a mean of 10.97 per locus. The polymorphic information content indicated that 80% of all loci were highly to moderately informative. Only two breeds/populations showed loci that did not deviate from the Hardy–Weinberg equilibrium. The results of genetic diversity indexes suggested moderate levels of genetic variability in Rustipollos population and low inbreeding level. The genetic differentiation index indicates a high genetic differentiation between populations. The results of the Neighbor-Net tree and STRUCTURE analyses indicate the existence of distinct gene pools, with some genetic relationships between Rustipollos, the commercial chicken strain, and south Spanish breeds. The Discriminant Analysis of Principal Components confirmed the observed genetic distances between breeds/populations. The results will be useful for sustainable use and official recognition of this population. Full article

Two experiments were conducted to assess the efficiency of including the novel protein ingredient Arthrospira platensis or improved soybean meal in a broiler diet. The first experiment aimed to determine the feeding value of soybean meal produced from varieties of soybeans bred for increased amino acid content (SBAA) and improved oil content (SBO) compared to a conventional soybean variety in an ANOVA design fed to Cobb 500 female broilers for 28–42 d. The SBAA and SBO soybeans contained overall higher amino acid content and lower oligosaccharide content compared to the conventional soybean variety in addition to improved oil quality. The second experiment assessed the novel protein ingredient microalgae, Arthrospira platensis (algae), and was conducted to evaluate algae and corn distillers’ grain (DDGS) inclusion on broiler performance for a 28–42 d feeding period in Cobb CF05 male broilers with a 2 × 2 factorial treatment array. Prior to the experimental period, all birds were reared on common feeds. In Experiment 1, birds were fed a diet containing 20% inclusion of an experimental soybean source in the form of full-fat soybean meal. In Experiment 2, the four dietary treatments consisted of diets containing algae at inclusion levels of either 0 or 2% and DDGS at inclusion levels of 0% and 8%. Diets were fed to 288 female broilers (Experiment 1) and 384 male broilers (Experiment 2), placed in eight replicate pens of twelve birds, and live performance was assessed from d 28 to 42. At d 42, six birds from each pen were randomly selected and processed for evaluation of carcass traits and incidence of woody breast. For Experiment 1, all performance data were analyzed using a one-way ANOVA using JMP Pro 16 software with diet as the fixed effect and block as a random effect. Statistical significance was considered at p ≤ 0.05. No significant responses were observed for any recorded measurement for live performance, carcass traits, or woody breast. All data in Experiment 2 were analyzed as a full factorial with a mixed model using JMP software with algae, DDGS, and algae × DDGS as fixed effects and block as a random effect. The F-protected Fisher’s LSD test was used to separate means when p ≤ 0.05. No significant responses were observed for the algae, DDGS, and algae × DDGS influences on BWG, FI, and FCR or processing characteristics; the ingredient source did not affect bird performance. Experimental soybean lines developed at the University of Arkansas were able to be incorporated into broiler diets without decreasing performance. Algae has the potential to be a protein-contributing ingredient for broilers. Full article

Innate immunity is considered the first line of immune defense and is typically an unmeasured response. Here we report a method for evaluating the innate immune response in chickens by using whole blood which has been activated by lipopolysaccharide (LPS) to induce IL-6 release by innate immune cells. It was found that a 24-h LPS activation time interval was the optimum time interval for inducing the IL-6 response. An activation index, defined as the PBS activated control response subtracted from the LPS activated response and then divided by the PBS activated control response and expressed as a percentage, was useful for demonstrating and comparing the magnitude of the innate immune response. Results indicated that there was wide variation between the IL-6 response between individual birds although statistically significant results were obtained for all individual birds at the 24-h activation time interval. The activation indices from all birds were greatest at the 24-h activation time interval. Statistically significant results were achieved when all the data from all birds at the 24-h activation time interval were combined. The cells responsible for the IL-6 response were identified as the peripheral blood monocytes. Full article

This study aimed to determine the ileal digestible energy (IDE), apparent metabolizable energy (AME), and nitrogen-corrected AME (AMEn) of three typical cereals for quail chicks with two age periods (day 15–21 and 22–28). The experimental diets comprised a corn–soybean meal reference diet (RD), and three test diets (TD) that were fed to quail chicks in a completely randomized design with five replicates per diet and 15 birds each. The TD comprised corn, wheat, and barley that partly replaced the RD at 300 g/kg (70% reference diet + 30% test ingredient). Age did not influence the IDE, AME, and AMEn values, while the effect of ingredient type was highly significant on the energy estimates (p < 0.001). The IDE values of corn, wheat, and barley were estimated as 2924, 3440, and 3184 kcal/kg, respectively. The AME values of corn, wheat, and barley were 3519, 2979, and 2710 kcal/kg, respectively. The estimated AMEn values of corn, wheat, and barley were 3255, 2676, and 2281 kcal/kg, respectively. These findings are crucial for optimizing diet formulations to support quail growth and performance effectively, as they provide valuable insights into the energy content of different cereals for quail production. Notably, the high IDE and AME values of wheat suggest its potential as a valuable energy source for quail diets. Understanding these values can aid in formulating diets that meet the energy requirements of quail chicks, leading to improved growth rates, feed efficiency, and overall productivity in quail production systems. Full article

Further reductions of crude protein in broiler diets may cause essential amino acids traditionally considered to be supplied at adequate levels to become limiting. Requirement data for histidine are currently scarce and this amino acid is uniquely able to be stored within the body. Thus, the objectives of this study were to evaluate female Cobb 500 broiler growth performance and carcass characteristic responsiveness to increasing digestible histidine to digestible lysine ratios (dHis:dLys) during a 22- to 42-day feeding period and determine if dHis:dLys in preceding feeds influence the former responses. Starter diets were formulated to contain dHis:dLys of 33% or 38% and grower diets were formulated to contain dHis:dLys of 28%, 33%, 38%, or 43%, which gave rise to a 2 × 4 factorial arrangement of treatments. No interactions (p > 0.05) between the starter or grower diet dHis:dLys occurred. Increasing the dHis:dLys from 22 to 42 days resulted in body weight gain, feed conversion ratio, and total breast meat yield quadratic responses (p ≤ 0.05). Additionally, it appears that dHis:dLys between 33% and 38% fed during the starter phase does not influence broiler responsiveness to different dHis:dLys during the grower phase. Full article

(1) Background: Indigenous chickens (Gallus domesticus) (ICs) are an essential component of agriculture and rural livelihood among 80% of small-scale farmers (SSFs) in Sub-Saharan Africa (SSA). However, in the past decade, significant losses of Indigenous Chicken Animal Genetic Resources (IC-AnGR) resulting from poultry diseases, imported exotic breeds, poor market access, and uncontrolled crossbreeding have been reported. This study aimed to investigate the status of IC-AnGR and assess the major challenges affecting the production of ICs. (2) Methods: We surveyed 358 households in eastern, central, and southern livelihood zones, comprising 81.6% males and 17.6% females. (3) Results: Our study shows that respondents owned 16,112 ICs, 3026 goats, and 5183 herds of cattle. Overall, 77.4% of chicken breeds were ICs and 22.6% were exotic. Across the three zones, 18–44% reported the introduction or adoption of exotic breeds in the past decade, with most households sourcing breeding stock from local communities and family and friends at 45% and 28.6%, respectively. Farmers gave various reasons for adopting new chicken breeds, including fast growth (21.7%), larger mature sizes (21.7%), and resistance to diseases at 15.2%. Overall, 92.5% of farmers agreed or strongly agreed that some IC breeds disappeared in the past decade and nearly 90% were concerned. Some attributed the loss to poultry diseases. (4) Conclusion: Deliberate policies to promote the sustainable use and conservation of ICs are critical in Zambia. Full article

Boron supplementation may improve the musculoskeletal health of pullets before entering the lay phase. This study aimed to evaluate the effects of different boron amounts on the performance, muscle deposition, tibia cross-sectional area (CSA) and mineral density (BMD), ash percent, breaking strength, and bone mineralization (bone-specific alkaline phosphatase [BALP] and pro-collagen type 1 n-terminal propeptide [P1NP]) of a white-feathered strain of pullets. A total of 528 Hy-Line W-36 pullets were distributed across 24 pens and fed basal diets containing varying amounts of boron (C: 0 mg/kg; L: 50 mg/kg; M: 100 mg/kg; H: 150 mg/kg) for 17 weeks. Performance parameters (body weight, average daily weight gain/bird, and average daily feed intake/bird) were measured at weeks 4, 7, 10, 13, and 16, while all other measures were taken at 11 and 17 weeks of age. Performance was not impacted by boron supplementation. Pectoralis major weights were higher in H pullets at 11 weeks of age, and we also observed higher pectoralis major, minor, and leg muscle weights in H pullets at 17 weeks of age. Pullets fed the H diet had larger cortical CSA than the other treatment groups at 11 weeks of age. At 17 weeks of age, both the H and M groups had larger cortical CSA than the L and C groups, but the M group had slightly smaller cortical CSA. Pullets fed the H diet had higher BMD values than the other treatment groups at 11 weeks of age. At 17 weeks of age, pullets fed the H diet had the highest total BMD values compared to the other treatment groups, and cortical BMD increased with increasing boron inclusion. Pullets fed the H diet had the highest tibia ash percentages and concentrations of BALP and P1NP. Pullets fed the M and H diets had greater failure load and maximum bending moment than pullets fed the L or C diet at 11 weeks of age, with H pullets having greater stiffness values than other groups. At 17 weeks of age, pullets fed the H diet had greater failure load and maximum bending moment compared to all other treatment groups. Our results suggest that providing boron within the diet at 150 mg/kg can improve the musculoskeletal characteristics of Hy-Line W-36 pullets up to 17 weeks of age, without impacting performance parameters. Full article

A complex system of neural pathways, collectively known as the microbiota–gut–brain (MGB) axis, interconnects the gut microbiota, the gastrointestinal system, and the brain along with its periphery. Previous studies have demonstrated that modulation of the MGB axis can influence stress-related behaviors such as anxiety. This connection becomes apparent in scenarios like agonistic behavior in laying hens, which is characterized by aggressive head and feather pecks, that can ultimately result in cannibalism and death. The objective was to examine the effects of a dietary synbiotic on agonistic behavior, plasma and brain monoamines, stress parameters, and cecal microbiota counts via modulation of the MGB axis. A total of 396 W36 Hy-Line laying hens were provided at random with a control (CON: basal diet) or treatment (SYN: basal diet supplemented with synbiotic) diet from 50 to 60 weeks old (nine pens/treatment, 22 birds/pen). Blood samples and video recordings (three consecutive days/week) were taken at 50 and 60 weeks. At 60 weeks, three hens/pen were euthanized for brain and cecal microbiota collection. Threatening, fighting, head, body, and feather pecking all occurred less frequently at 60 weeks in the SYN group (p < 0.05). Plasma corticosterone, adrenocorticotropic hormone, dopamine, and serotonin were significantly lower while tryptophan and 5-hydroxyindoleacetic acid were significantly higher in birds from the SYN group (p < 0.05). Significant differences in serotonin, 5-hydroxyindoleacetic acid, dopamine, homovanillic acid, and 3,4-dihydroxyphenylacetic acid were observed in the hypothalamus, hippocampus, and amygdala of the brain. Serotonin and dopamine turnover rates were significantly different in all three regions of the brain (p < 0.05). Cecal counts of Lactobacillus and Bifidobacterium were significantly higher in the SYN group (p < 0.05). Synbiotic supplementation resulted in many significant differences, indicating activation of the serotonergic systems and modulation of both the MGB axis and HPA axis with positive effects on welfare and stress. Full article

Poultry farmers need to consider making adaptations now to help reduce cost, risk, and concern in the future; the industry’s high and unstable input costs, which result in losses, need to incentivize manufacturers to concentrate on efficient management, welfare, and health improvements, thereby creating premium and value-added products. Heat stress, a significant concern, particularly affects broiler chicken, which is vital for global meat supply in the dynamic field of poultry farming. Despite advances in breeding and management, these pressures have a negative influence on avian development, well-being, and overall health, threatening the poultry industry’s long-term viability. This study investigates the physiological reactions and production consequences of various heat conditions in the chicken business. It thoroughly investigates the complicated implications of heat stress, which has a negative impact on broiler performance and causes economic losses. This article investigates various dietary techniques, such as antioxidants, probiotics, amino acid balance, and vitamin supplementation, with the goal of improving chicken thermotolerance as part of a comprehensive stress reduction strategy. This assessment emphasizes the industry’s continuous commitment to sustainable practices by highlighting the need for more research to enhance methodology, investigate creative tactics, and address regional variances in heat stress. Full article

This study evaluated duck growth, health, and welfare in response to water supplementation with organic acid (OA) and oregano oils (OOs) in Pekin duck. The treatments used in this study included a control (CON) treatment with no water additives given, an OA treatment (ProPhorce Exclusive NC^®), and an OO treatment (Nubiotic 4X Concentrate^®). The OA and OO improved the feed conversion ratio (FCR) and body weight (BW) (p < 0.01) compared to the control (CON). Both OA and OO showed differences (p < 0.05) in villus height and crypt depth compared to the CON. But only OA showed an increase (p < 0.01) in villus height and villus height/crypt depth ratio. On D 35, the total plasma corticosterone levels, heterophil-to-lymphocyte ratios, and asymmetry scores for OA and OO were decreased (p < 0.05) compared to CON, indicating lower stress susceptibility. The pH levels of OA ceca and jejunum were lower (p < 0.05) compared to CON. Tibia breaking strength was increased (p = 0.02) for OA compared to CON, while no differences were found with OO (p > 0.05). In conclusion, these experiments indicate that OA and OO can be used to improve duck growth, feed efficiency, stress susceptibility, and bird welfare. Full article

The study aimed to quantify carcass fat and protein retention, and the efficiency of carcass energy utilization (Kre) resulting from feeding broiler chickens diets containing wheat, maize or mixtures of both as the major cereal ingredient. The apparent metabolizable energy (AME) of the four cereal samples was determined in adult cockerels. There was a linear (p < 0.001) increase in AME with increasing amounts of maize within the four cereal mixtures, with analyses indicating that the AME of maize was 1.4 MJ/kg greater than that of wheat. A second bioassay with growing chickens was used to determine Kre in each cereal, measured as carcass fat and protein from 7 to 21d age. Increasing proportions of maize resulted in linear increases in carcass fat and energy retained from fat (p < 0.001). However, the carcass protein and energy retained from protein did not follow the same pattern as fat (p = 0.121), but rather decreased numerically (L = 0.032). The Kre tended (p = 0.060) to increase with greater proportion of maize in a linear fashion (L = 0.009). Although AME values of cereals were confirmed to be additive, this could not be confirmed for Kre. This data can be used for optimizing energy utilization models for growing broilers. Full article

Organic poultry sector needs high-quality proteins sources to meet specific requirements. The EU’s organic regulation forbids synthetic amino acids; therefore, soybean, with its balanced essential amino acid content, has become the most used protein source, though much of it is imported from non-EU countries, with sustainability and crop competition issues; therefore, it should be substituted with a high-protein-value alternative such as insect meal. In this study, 900 Aviagen Savanna broilers were fed with three different organic diets: soybean only (S100), 50% black soldier fly larvae meal (BSL) and 50% soybean (BSL50), and 100% BSL only (BSL100). Broiler performance, welfare, and fatty acids (FA) were analyzed. BSL50 and BSL100 negatively affected growth, while only BSL100 worsened all of the market-related performances. Meat showed a significant increase in saturated FA (SFA) (p < 0.000) and a corresponding decrease in polyunsaturated FA (PUFA), in BSL50 and BSL100, but α-linolenic acid was not affected by BSL50 treatment (p < 0.000). The SFA increase could represent a negative aspect for human health (e.g., cardiovascular diseases), but, as reported by other authors, medium chain SFA, (i.e., lauric acid), may show beneficial effects as well (i.e., antibacterial, anti-inflammatory and antioxidant properties). Full article

This study evaluated the effect of a concentrated yeast fermentation product on the performance and stress response of broiler chickens. Day-old Cobb 500 male broiler chicks were randomly allocated to one of two dietary treatments: Control (CON) or concentrated yeast fermentation product (CSCFP, 0.625 kg/MT). On d18, simultaneous feed withdrawal and heat stress challenges were performed for 12 h. Blood was analyzed for plasma corticosterone (CORT) and heterophil-to-lymphocyte ratio (HL) on d19 and d42. Performance parameters were collected throughout the trial: body weight (BW), feed consumption (FC), and feed conversion ratio (FCR). On d19, the CSCFP birds had lower (p ≤ 0.05) CORT (5320.3 ng/mL) and HL (0.14) than the CON birds (9049.6 ng/mL and 0.21). On d42, the CSCFP birds had lower (p ≤ 0.05) CORT (1623.8 ng/mL) and HL (0.74) than the CON birds (2920.2 ng/mL and 1.05). No differences were observed in mortality (p > 0.05). The CON birds had a higher (p ≤ 0.05) FCR than CSCFP throughout all phases. The CON birds consumed more feed than the CSCFP birds throughout all phases (p ≤ 0.05). In conclusion, CYFP reduced stress and improved feed conversion when compared to CON, making it a viable feed additive to improve welfare and production. Full article

The Salmonella enterica serovars Typhimurium (S. Typhimurium), Heidelberg (S. Heidelberg), and their monophasic variants (S. 1,4,[5],12:i:-, S. 1,4,[5],12:r:- and S. 1,4,[5],12:-:1,2) are highly disseminated in poultry farming and can contaminate chicken meat, eggs, and other foods of avian origin. A time-consuming bacteriological and serological analysis is usually required to identify serovars by traditional methods. Incomplete and inconclusive serological results are frequent in routine analysis, mainly due to the occurrence of bacterial isolates presenting similar antigenic profiles. Molecular biology assays have been developed to improve the detection of specific Salmonella serovars and strains. This study aimed to develop a multiplex real-time PCR (SHTAmp) for the rapid DNA detection of S. Typhimurium, S. Heidelberg, and their monophasic variants from poultry samples. The methodology was used in the analysis of 147 field isolates from Brazilian poultry flocks previously evaluated with serological analysis. The results demonstrated that it was able to specifically and rapidly detect 21 S. Typhimurium and 57 S. Heidelberg isolates with complete antigenic formulae. Furthermore, SHTAmp was able to differentiate nine S. Typhimurium and 44 S. Heidelberg isolates with incomplete serological formulae (monophasic and aphasic variants). The complete methodology was also successfully used to detect these bacteria directly from 34 poultry samples after pre-enrichment in buffered peptone water (BPW). In conclusion, SHTAmp is a fast and accurate method to detect the two frequent and concerning serovars S. Typhimurium and S. Heidelberg directly from poultry samples. Full article