Poultry

The development of effective and innovative vaccination strategies is urgently needed to better control the spread and transmission of the low-pathogenic avian influenza H9N2 subtype (LPAI-H9N2) in poultry. In addition, the enhancement of innate immunity by some of these innovative inactivated vaccines has not yet been investigated. Here, an experiment was conducted in commercial broiler chickens to compare the immune response to two different inactivated H9N2 vaccines. For this, Group 1 (G1) broilers were vaccinated with vaccine 1 [Nobilis^® H9N2-P (pathogen-associated molecular patterns—PAMP) technology], broilers in G2 were vaccinated with vaccine 2 [an inactivated whole H9N2 virus (IWV) autogenous oil emulsion vaccine], while birds in G3 were not vaccinated. The study lasted 34 days. Innate immune parameters (phagocytic activity, nitric oxide, and lysozyme), cytokine signaling (IL-1β, IL-6, IL-8), humoral immunity using the hemagglutination inhibition (HI) test, and the gene expressions of IFN-γ and TLR-21 were assessed. The results showed a significant increase in innate immunity and modulatory cytokines at 24–48 h after the vaccination of G1 broilers, with a continuous increase until the end of the experiment. In addition, a significant increase in geometric mean HI titers was observed in G1 at 11 days post-vaccination (dpv), and a significant (p ˂ 0.05) upregulation of IFN-γ and TLR-21 was observed in the same group, G1, at 31 dpv compared to G2 and G3. Nobilis^® H9N2-P may induce faster and stronger innate and active humoral immunity compared to another IWV, which may contribute to the protection of broilers against early H9N2 infections. However, challenge protection studies for several IWV vaccines, including PAMP-H9N2 against LPAI-H9N2, should be further evaluated in both specific pathogen-free (SPF) and commercial broilers. Full article

Gizzard erosion and ulceration (GEU) is characterized by defects and necrosis in the koilin layer, particularly in broilers. This condition has been associated with growth retardation, runting, and economic implications for poultry producers; nevertheless, its influence on gut microbiota remains unknown. This study investigated the compositional changes in the bacterial community of the ileum of seven-day-old broiler chicks with GEU using next-generation sequencing (NGS) technology. Twenty-two samples were obtained from the ileal mucosa and contents of sixteen chicks with GEU and six without GEU raised in a conventional system located on a farm in southeast Brazil. The results revealed that bacterial phyla in both groups exhibited a similar composition, with Firmicutes representing the most abundant. Porphyromonas, Candidatus Arthromitus, and Limosilactobacillus were statistically more abundant in the group without GEU. The most prevalent genera in the group with GEU were Lactobacillus and Enterococcus, and the relative abundance of Enterococcus in the ilea of some chicks with GEU was considerable. Based on the results of the current study, necrosis in the koilin layer can change the composition of ileal microbiota. Therefore, further studies should be carried out to clarify whether GEU and consequently poor digestibility of the feed cause significant changes in the intestinal microbiota. Full article

Changes in leukocyte populations and immune gene expression associated with attenuated vaccine (SA2) or field (Class 9) strains of infectious laryngotracheitis virus in chicken pullets were observed primarily in the trachea and conjunctiva, while no substantial changes were detected in the Harderian gland. Although there were no significant differences in cellular infiltration in the tissues exposed to Class 9 and SA2, Class 9 induced greater changes in immune gene expression than SA2 in the trachea and conjunctiva and significantly upregulated CD4, CD8A, IRF1, STAT4 and downregulated CXCL12 expression in the trachea. Meanwhile, SA2 significantly upregulated CD14 and downregulated MPO, CCR6 and RAG1 expression in the conjunctiva. In conclusion, gene expression in pullets infected with SA2 and Class 9 were mostly related to inflammatory and tissue-repairing responses in the trachea and conjunctiva. Compared to SA2, Class 9 inoculation was associated with a more robust gene expression of immune markers; however, a larger infiltration of Kul01+, Bu1+ and CD8a+ cells was observed in trachea and conjunctiva after SA2 inoculation. Full article

(a) Introduction: Zambia’s poultry industry comprises commercial chickens and small-scale producers of indigenous chickens (Gallus domesticus) (ICs). Large, integrated entities run the commercial chicken sector, while the indigenous chicken sector (IC sector) is predominantly run by small-scale farmers (SSFs). Increased costs and low access to formal markets for commercial chickens have motivated SSFs to enter the IC sector under the free-range system (FRS) and semi-intensive system (SIS). (b) Objective: This study aimed to highlight the price changes in poultry inputs and outputs and demonstrate that the IC sector has more potential to contribute to farm income than commercial chickens under family poultry production systems. (c) Method: We analysed the prices for inputs and outputs for Zambia’s poultry industry for the first quarter of 2016 to 2023 using data from the Poultry Association of Zambia (PAZ). We also analysed data from the 2021 Qualtrics survey to investigate the crops grown and crops used as feed and feed ingredients, the sources of feed, and the use of minerals and vitamins by SSFs for chickens. The gross profit (GP) and benefit–cost ratio (BCR) were analysed to compare the viability and profitability of ICs and broilers under SSFs. (d) Results: Our study shows that prices for day-old chicks (DOCs) and point-of-lay (POL) pullets increased by 57–125%, broiler and layer feeds increased by 67–96%, and soybean meal (SBM) and fishmeal rose by 143–229%. Prices for live ICs, commercial broilers, and ex-layers increased by 150%, 79%, and 71%, respectively. Egg prices rose by 100–124%. Farmers tried to look for local feed sources. Over 21% of the crops grown was maize, and nearly 43% was used for feed. (e) Conclusion: Our analysis and comparison between the ICs and broilers demonstrated that SSFs could achieve more farm income by producing ICs than commercial broilers. Full article

Laying hens usually have 16 h of light and 8 h of darkness during egg laying, with eggshell formation primarily occurring during darkness when dietary calcium is lacking, leading to bone calcium resorption and osteoporosis. This study examined how interrupting the dark phase affects bone health in 396 Hy-line W36 hens assigned to control (C) or treatment groups (W1 and W2). All hens received 16 h of light and 8 h of darkness daily in different variations of scotophase interruption. Blood samples were taken at weeks 20, 30, 50, and 70, serum calcium was measured during darkness at two timepoints (SRT and END), and bone demineralization markers were examined using enzyme concentrations (TRACP-5b and CTX-I). Across weeks, tibias were CT-scanned for density (mg/cm³) and area (mm²), then used for breakage strength analysis (N) and ash%. No SRT Ca level differences emerged, but C hens had lower END Ca levels compared to W1 and W2 hens across all weeks, while W1 and W2 hens showed no significant differences. C hens displayed higher TRACP-5b and CTX-I concentrations across all weeks compared to W1 and W2 (all p ≤ 0.05). At week 70, C hens had the lowest cortical bone cross-sectional area and mineral density compared to W1 and W2 (all p ≤ 0.05). Tibiotarsi bone breakage strength was lower in C hens compared to W1 and W2. C hens had significantly lower ash% than treatment birds. Interrupting the scotophase period improved overall bone health in Hy-line W36 laying hens. Full article

Currently, there are no guidelines on housing or recommendations for practical environmental enrichments for chickens used for research and teaching purposes. This study was conducted to identify optimal enrichment programs to improve the health and welfare of caged hens used for teaching and research purposes. The 24-week-old Hy-line Brown laying hens (n = 168) were allocated at random to six enrichment programs/treatments with 14 replicate cages of two birds per cage during a 5-week experiment. Hens had physical access to the following treatments: no enrichment provided (control); round, wooden perches provided (perch); scratch pads made of wood and covered with sandpaper provided (scratch pad); hanging CDs provided (hanging CD); all three enrichment forms provided (complex environment); and each enrichment form provided on a 2-week rotation (novelty). While the egg quality was consistent, the complex group had a significantly lower feed intake (p < 0.001) but similar egg mass; thus, they also had a lower feed conversion ratio (p < 0.001). Additionally, hens in the complex treatment group had the leanest average body weight at week 5 (p < 0.01). It should be noted that while some measures of welfare did show significant differences, the biological or practical difference may be negligible, as in the case of the body condition score in this study. The results show that providing three different forms of environmental enrichment had positive effects on the welfare, health condition, and laying performance of laying hens relative to no enrichment or only one enrichment item. Full article

Subclinical necrotic enteritis (NE) is an enteric disease that inflicts significant economic losses in the poultry industry, primarily by reducing performance in commercial flocks but without significant mortality. This study evaluated the effects of a variety of phytogenic blends on broilers’ performance and carcass composition during an induced NE challenge. In this study, 1120 day (d)-old male broilers were allocated to four treatments groups (14 replicate floor pens, 20 birds/pen): the control (CONT) group, fed a basal corn-soybean diet, and three phytogenic blend dietary additives (PHYTO1, PHYTO2, and PHYTO3) added to the basal diet at 150, 250, and 500 mg/kg feed, respectively. Subclinical NE was induced by spraying a concentrated coccidiosis vaccine onto the feed and litter 24 h post-placement. On day 8, two birds/pen were necropsied for NE lesions. On days 8, 14, 28, and 42, the average daily gain (ADG), feed intake (ADFI), and feed conversion ratio (FCR) were calculated. On day 42, two birds/pen were euthanized to assess carcass composition using dual-energy X-ray absorptiometry (DXA). Statistical analyses for all data were performed using the ANOVA procedure (JMP, Pro 16) and significance (p ≤ 0.05) between treatments was determined by the LSD test. There was no effect of treatment on NE lesions. PHYTO1, PHYTO2, and PHYTO3 significantly improved FCR from days 9 to 14, 0 to 14, and 0 to 42 and resulted in greater ADG from days 9 to 14, 29 to 42 and cumulatively on days 0 to 42. Carcass composition data revealed a numerically higher lean-to-fat ratio in the PHYTO groups compared to the CONT group. These results indicate that the dietary supplementation of phytogenic blends could alleviate the adverse effects of NE challenge on broilers’ performance and carcass composition. Full article

Poultry bio-mapping helps identify microbial contamination and process optimization opportunities such as sanitary dressing procedures, equipment adjustments, cross-contamination controls, and chemical intervention applications in commercial poultry processing operations. This study focuses on the development of a preliminary microbiological baseline of microbial indicators, including total viable counts (TVC), Enterobacteriaceae (EB), and the quantification and detection of pathogens such as Salmonella and Campylobacter spp. in four commercial broiler processing facilities in Honduras. Whole chicken and wing rinses were collected from four poultry processing plants at different locations: live receiving, rehanger, post-evisceration, post-chiller, and wings. The MicroSnap^® system was used for the enumeration of microbial indicators, the BAX^®-System-SalQuant^® was used for the quantification of Salmonella, and the BAX^®-System-CampyQuant™ was used for Campylobacter spp. Negative samples after enumeration were tested with BAX^®-System Salmonella and BAX^®-System Campylobacter for prevalence analysis, respectively. The TVC and EB counts were continuously reduced from the live receiving to the post-chiller location, presenting a statistically significant increase (p < 0.01) at the wings location. The Salmonella counts were significantly different between stages (p < 0.01). The prevalence of Salmonella was highest in the live receiving stage, with 92.50%, while that at the post-chiller stage was the lowest, at 15.38%. Campylobacter spp. counts were lower than that at the other stages at wings 1.61 Log CFU/sample; however, Campylobacter spp.’s prevalence was higher than 62.5% in all stages. Microbial bio-mapping using novel technologies suitable for mobile applications was conducted in this study to establish statistical process control parameters for microorganisms. A nationwide microbial baseline for commercial broiler processing facilities in Honduras was developed. In-country data serve as a benchmark for continuous improvement at each facility evaluated and can assist regulatory officers in the development of risk-based performance standards aimed at reducing the risk of exposure to consumers. Full article

Chicken coccidiosis causes annual losses exceeding GBP 10 billion globally. The most pathogenic species for domestic fowls including Eimeria tenella, E. acervulina, and E. maxima, can lead to gastrointestinal issues ranging from mild to fatal. In this study, stages of E. tenella and freshly isolated chicken heterophils were co-cultured for 180 min. These interactions were analyzed using live 3D holotomographic and confocal microscopy. We observed that E. tenella stages were entrapped by heterophils and heterophil extracellular traps (HETs). Notably, different HET phenotypes, specifically sprHETs and aggHETs, were induced regardless of the stage. Furthermore, the quantification of extracellular DNA release from co-cultures of heterophils and sporozoites (ratio 1:1) for 180 min demonstrated a significantly higher release (p = 0.04) compared to negative controls. In conclusion, research on the chicken innate immune system, particularly fowl-derived HETs, remains limited. More detailed investigations are needed, such as exploring the time-dependent triggering of HETs, to establish a standard incubation time for this pathogen defense mechanism. This will enhance our understanding of its role in parasite survival or death during HET confrontation. Full article

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