Impact of adding zeolite to broilers' diet and litter on growth, blood parameters, immunity, and ammonia emission.

This work was designed to assess the impact of varying zeolite concentrations in diet and litter to enhance broiler's growth performance, immunity, and litter quality. A complete random arrangement was used for distributing 525 unsexed "Cobb 500" broiler chicks into seven treatments (75 chick / treatment), each treatment divided into 3 replicates (25 chicks / replicate). The 1st group (control one) received the recommended basal diet. Zeolite has been introduced to the basal diet (ZD) of the second, third, and fourth groups at concentrations of 5, 10, and 15 g/kg, respectively. The 5th, 6th and 7th groups used zeolite mixed with litter (ZL) at 0.5, 1, and 1.5 kg/m2 of litter, respectively. Due to the obtained results, adding zeolite with levels 15 g/kg of diet and 1.5 kg/1 m2 of litter, a significant improvement occurred in live body weight (LBW), body weight gain (BWG), feed intake (FI), feed conversion ratio (FCR) and European production efficiency factor (EPEF). Also, transaminase enzymes (ALT and AST), creatinine, white blood cells (WBCs) and different Immunoglobulins were significantly increased with different zeolite levels, except urea concentrations which showed reduced due to different zeolite treatments. In addition, spleen relative weight hasn't been affected by zeolite treatments, even though thymus and bursa relative weights had been affected significantly. Moreover, the antibodies' production to Newcastle disease virus (NDV) and Avian influenza virus (AIV) had increased significantly with adding zeolite with levels 10 g/kg of diet and 1.5 kg/1m2 of litter. Litter quality traits (NH3 concentration, pH values, and Moisture content) were improved with zeolite addition. So, zeolite could be employed in both feed and litter of broilers to maximize their production, immunity and improve farm's climate.

Dietary Bacillus velezensis KNF-209 supplementation improves growth performance, enhances immunity, and promotes gut health in broilers.

This study aimed to investigate the effects of dietary Bacillus velezensis KNF-209 (BV-KNF-209) on the growth performance, immunity, and gut health of broilers. A total of 540 one-day-old male Cobb-500 broilers were randomly divided into 5 groups of 6 replicates with 18 broilers per replicate. Dietary treatments were corn-soybean meal basal diets supplemented with 0, 50, 100, 200, and 400 mg/kg BV-KNF-209 (CON, BV 50, BV 100, BV 200, and BV 400 groups, respectively) for 42 d. Compared with the CON group, the average daily gains (ADG) at 0 to 42 d in the BV 100 and BV 200 groups were significantly increased (P < 0.01), and the feed-to-gain (F:G) ratios were significantly decreased at 0 to 21 d (P < 0.01) and 0 to 42 d (P < 0.05). The BV 200 and BV 400 groups had higher serum immunoglobulin M (IgM) levels at d 21 and 42 (P < 0.05). The serum levels of tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), and interleukin-6 (IL-6) were significantly decreased in the BV 50, BV 100, and BV 200 groups at d 21 (P < 0.05), and serum IL-1ß and IL-6 levels were also reduced in the BV 100 and BV 200 groups at d 42 (P < 0.05). Meanwhile, increased interleukin-10 (IL-10) levels in the jejunal and ileal mucosa at d 42 were observed in the BV 100, BV 200, and BV 400 groups (P < 0.05), while the IL-1ß and IL-6 levels (P < 0.01) were decreased. The BV 200 and BV 400 groups showed significantly higher activities of lipase and trypsin (P < 0.05) in jejunal digesta as well as higher activities of amylase and trypsin (P < 0.01) in ileal digesta at d 42. The cecal acetic acid and propionic acid levels in the BV groups and lactic acid levels in the BV 50, BV 100, and BV 200 groups (P < 0.05) were significantly higher compared to those in the CON group. Overall, dietary BV-KNF-209 supplementation significantly improved broiler growth performance, an effect that may have been achieved by heightening immunity, increasing digestive enzyme activity, and raising intestinal short-chain fatty acids and lactic acid levels.

Vaccinating parent flocks against colibacillosis reduces broiler mortality - A retrospective observational study from 2016 to 2019 in Finland.

Colibacillosis is one of the most important infectious diseases in modern poultry production. The complex nature of colibacillosis has made it challenging to produce an effective vaccine. As a control measure for colibacillosis outbreak in Finland, a vaccination program with a commercial colibacillosis vaccine and later also an autogenous vaccine was started for parent flocks in 2017. In this retrospective observational study from years 2016-2019, we evaluated first week and total mortality of broiler flocks (n= 6969) originating from parents with different colibacillosis vaccination status. Broiler flocks were divided into three groups according to vaccination status of their parent flocks. First group were flocks from parents with no colibacillosis vaccines; second group was flocks from parents vaccinated with commercial vaccine only; and third group was flocks from parents with both commercial and autogenous vaccine. Bayesian modelling was used to predict posterior distributions of first week mortality and total mortality of the broiler flocks. Results of the modelling revealed that broiler flocks from unvaccinated parents had the highest mortality rates (mean first week mortality 1.40 % and mean total mortality 4.33 %, respectively) whereas flocks from parents with a combination of commercial and autogenous vaccinations had the lowest mortality rates (mean first week mortality 0,91 % and mean total mortality 3,14 %). The mortalities from broilers flocks from parents with only commercial vaccine fell in between these groups. Also, standard deviations of mortality rates were lower in broilers from parents with commercial or both vaccines. This demonstrates that in addition to lowering the mean mortality rates, the vaccinations made high mortality broiler flocks less common. Best performance was obtained when autogenous vaccine was combined to the commercial vaccine. The autogenous vaccine consists of the same type of Escherichia coli strain that was causing most colibacillosis cases during the study period in Finland. This study adds to the evidence of benefits of colibacillosis vaccines during outbreaks. It also demonstrates the importance of the knowledge of the types of APEC strains causing outbreaks to produce effective autogenous vaccines.

Intermittent and mild cold stimulation enhances immune function of broilers via co-regulation of CIRP and TRPM8 on NF-κB and MAPK signaling pathways.

Improving immune function is an important indicator for establishing cold adaptation in broilers. In the study, to explore the effects and molecular mechanisms of intermittent and mild cold stimulation (IMCS) on the immune function of broilers, CIRP and TRPM8, induced by cold stimulation, as well as the NF-κB and MAPK pathways which play an important role in immune response, were selected to investigate. A total of 192 one-day-old broilers (Ross 308) were selected and randomly divided into the control group (CC) and the cold stimulation group (CS). The broilers in CC were raised at normal feeding temperature from d 1 to 43, while the broilers in CS were subjected to cold stimulation from day 15 to 35, with a temperature 3 °C below that of the CC group for 5 h, at 1 d intervals. The results showed that IMCS had little effect on the broiler hearts, and the myocardial structure was not damaged. On d 22, IMCS significantly increased the mRNA levels of CIRP, TRPM8, P65, P38, COX-2, TNF-α, IFN- γ, IL-6, IL-10, and the protein levels of CIRP, P65, P38, IL-1ß and iNOS in the hearts, and the levels of CIRP and all cytokines in the serum (P ≤ 0.05). The mRNA and protein levels of IκB-α were significantly reduced (P ≤ 0.05). On d 36, the mRNA levels of TRPM8, P65, ERK, and IL-10 in the hearts and the content of COX-2 in the serum in CS were increased significantly (P ≤ 0.05), while the mRNA levels of IκB-α, P38, and IL-1ß were decreased significantly (P ≤ 0.05). On d 43, IMCS significantly upregulated the mRNA levels of TRPM8, IFN- γ, IL-4, IL-6, IL-10, and the protein levels of IκB-α, P38, and the levels of iNOS, TNF-α, IL6 and IL10 in the serum (P ≤ 0.05); whereas it significantly downregulated CIRP, JNK, P38, iNOS, TNF-α mRNA levels, and CIRP, P65, ERK, JNK, IL1ß and iNOS protein levels (P ≤ 0.05). Therefore, IMCS can enhance broiler immune function through co-regulation of CIRP and TRPM8 on the NF-κB and MAPK pathways, which facilitate the cold adaptation in broilers.

Comparative genomics of quinolone-resistant Escherichia coli from broilers and humans in Norway.

BACKGROUND: The usage of fluoroquinolones in Norwegian livestock production is very low, including in broiler production. Historically, quinolone-resistant Escherichia coli (QREC) isolated from Norwegian production animals rarely occur. However, with the introduction of a selective screening method for QREC in the Norwegian monitoring programme for antimicrobial resistance in the veterinary sector in 2014; 89.5% of broiler caecal samples and 70.7% of broiler meat samples were positive. This triggered the concern if there could be possible links between broiler and human reservoirs of QREC. We are addressing this by characterizing genomes of QREC from humans (healthy carriers and patients) and broiler isolates (meat and caecum). RESULTS: The most frequent mechanism for quinolone resistance in both broiler and human E. coli isolates were mutations in the chromosomally located gyrA and parC genes, although plasmid mediated quinolone resistance (PMQR) was also identified. There was some relatedness of the isolates within human and broiler groups, but little between these two groups. Further, some overlap was seen for isolates with the same sequence type isolated from broiler and humans, but overall, the SNP distance was high. CONCLUSION: Based on data from this study, QREC from broiler makes a limited contribution to the incidence of QREC in humans in Norway.

Dietary supplementation with Clostridium autoethanogenum protein improves growth performance and promotes muscle protein synthesis by activating the mTOR signaling pathway of the broiler.

The experiment aimed to evaluate the effects of different ratios of Clostridium autoethanogenum protein (CAP) used in the diets on the growth performance, muscle quality, serum indexes, and mTOR pathway of white feather broilers. Four hundred and eighty 1-day-old Arbor Acres (AA) broilers, comprising equal numbers of males and females, were randomly assigned to one of four treatments, and each treatment consisted of 12 replicates of 10 birds. Four diets were formulated based on isoenergetic and isonitrogenous principles. The control group (CAP 0) did not receive any CAP, while the experimental groups received 2% (CAP 2), 3% (CAP 3), and 4% (CAP 4) of CAP for six weeks. Compared with the CAP0, (1) The feed conversion ratio (FCR) was lower (p < 0.05), and the leg muscle yield was higher (p < 0.05) in the CAP3 and CAP4; (2) The serum levels of TP, ALB, T-AOC, and SOD were improved in the CAP3 (p < 0.05); (3) The expression of Lipin-1 gene was down-regulated and AMPKɑ2, Akt, and 4E-BP1 genes were up-regulated in the experiment group (p < 0.05); (4) The inclusion of 3% CAP in the diet increased the levels of 4E-BP1, S6K1, Akt, and AMPKɑ2 phosphorylation by modulating the mTOR signaling pathway (p < 0.05). In conclusion, broiler diets containing 3% CAP can activate the mTOR signaling pathway to promote muscle synthesis and improve growth performance.

Exploring the influence of slaughterhouse type and slaughtering steps on Campylobacter jejuni contamination in chicken meat: A cluster analysis approach.

Campylobacter jejuni (C. jejuni), a foodborne pathogen, poses notable hazards to human health and has significant economic implications for poultry production. This study aimed to assess C. jejuni contamination levels in chicken carcasses from both backyard and commercial slaughterhouses in Chiang Mai province, Thailand. It also sought to examine the effects of different slaughtering practices on contamination levels and to offer evidence-based recommendations for reducing C. jejuni contamination. Through the sampling of 105 chicken carcasses and subsequent enumeration of C. jejuni, the study captured the impact of various slaughtering practices. Utilizing k-modes clustering on the observational and bacterial count data, the research identified distinct patterns of contamination, revealing higher levels in backyard operations compared to commercial ones. The application of k-modes clustering highlighted the impact of critical slaughtering practices, particularly chilling, on contamination levels. Notably, samples with the lowest bacterial counts were typically from the chilling step, a practice predominantly found in commercial facilities. This observation underpins the recommendation for backyard slaughterhouses to incorporate ice in their post-evisceration soaking process. Mimicking commercial practices, this chilling method aims to inhibit C. jejuni growth by reducing carcass temperature, thereby enhancing food safety. Furthermore, the study suggests backyard operations adopt additional measures observed in commercial settings, like segregating equipment for each slaughtering step and implementing regular cleaning protocols. These strategic interventions are pivotal in reducing contamination risks, advancing microbiological safety in poultry processing, and aligning with global food safety enhancement efforts.

Standardized ileal digestible methionine requirements for 22 to 29-d-old male broilers based on the growth performance and feather development.

The aim of the present experiment was to determine the standardized ileal digestible (SID) methionine (Met) requirement during the grower phase (22 to 29 days). A total of 192 Ross 308 male broilers (745 ± 50.5 g) were assigned to six dietary treatments in a randomized complete block design, with eight replicate cages per treatment. The experimental diets were formulated based on corn, soybean meal, and synthetic amino acids (AA), with different levels of dietary SID Met ranging from 0.40% to 0.65%, in increments of 0.05%. Individual body weight and feed intake per cage were measured at the beginning and end of the experimental period. Weight gain (g/bird), feed intake (g/bird), gain-to-feed ratio (g/kg), feather weight (g), and relative feather percentage (% of body weight) were analyzed for linear or quadratic responses using orthogonal polynomial contrasts. Final body weight, weight gain, and feed intake increased quadratically as dietary SID Met concentration increased (p < 0.05). However, the composition of AA in the feathers showed no quadratic or linear effect based on dietary SID Met concentrations, except for Ile (p = 0.05; quadratic). The SID Met requirements for optimum and maximum weight gain of 22 to 29-days-old male broilers were estimated using the broken-line and quadratic-line models to 0.45% and 0.55%, respectively.

Effect of Achyranthes japonica extract on growth, digestibility, microbiota, gas emission, and meat quality in broilers fed different protein diets.

Achyranthes japonica extract (AJE) is a multifuctional products that express anti-inflammatory, antioxidant and anti-microbial properties. This study was aimed to evaluate the effects of AJE addition to standard and low crude protein (LCP) diet on growth performance, nutrient digestibility, excreta bacterial count, excreta noxious gas emissions, breast meat quality, and organ weight of broiler chicken. A total of 340 one-day-old Ross 308 broilers [initial body weight (BW) of 43.10 ± 1.46 g, 5 replicate cages per treatment, and 17 birds per cage] were randomly distributed into 1 of 4 dietary treatment groups for a 35 day trial. The diets were provided based on three age stage of the broiler. In the starter stage broiler were fed basal diet. Experimental diet were fed to broiler from day 8 to 35. In growing (days 8-21) and finishing (days 22-35) stage broiler were fed: Standard crude protein (SCP) diet and LCP diet with 0.025% and 0.05% of AJE supplementation respectively. Here, the SCP and LCP diets were 21.50% and 20.86% CP during days 8-21 and 20.00% and 19.40% CP during days 22-35, respectively. The SCP diets with 0.025% AJE supplementation resulted in higher (p < 0.5) BW gain (BWG) at finishing stage and a tendency to lower feed conversion ratio and BWG in the overall period compared to LCP diets with or without AJE supplemenation. Moreover, dry matter and nitrogen digestibility were increased with SCP diet along with 0.025% of AJE. No significant difference was found in meat quality parameters except for pH. Interestingly, the NH3 gas emission to the environment was found to be less with different levels of CP and AJE supplementation. Therefore, we concluded that the addition of 0.025% AJE to the SCP diet improved broiler growth performance and nutrient digestibility with low fecal NH3 emissions.

Achyranthes japonica extract as phytogenic feed additive enhanced nutrient digestibility and growth performance in broiler.

Achyranthes japonica extract (AJE) is derived from a medicinal plant Achyranthes japonica, known for its anti-inflammatory, antioxidant, and antimicrobial properties. AJE contains multiple bioactive compounds, including saponins, triterpenoids, phytoecdysteroids, 20-hydroxyecdysone, and inokosterone. The aim of this investigation was to examine the impact of AJE as a phytogenic feed additive on growth performance, nutrient digestibility, excreta microbial count, noxious gas emissions, breast meat quality in broilers. About three hundred and sixty, day-old broilers (Ross 308) were assigned into four treatments (five replication cages/treatment, and 18 birds/cage). Dietary treatments: CON, basal diet; 0.02% AJE, basal diet with 0.02%; 0.04% AJE, basal diet with 0.04% AJE, and 0.06% AJE, basal diet with 0.06% of AJE. Body weight gain increased linearly (p < 0.05) through the inclusion of AJE during days 7 to 21, 21 to 35, as well as the entire experimental period. Besides, feed intake increased (p < 0.05) linearly during days 21 to 35 and the entire experiment with the increased AJE doses in broiler diet. Dry matter digestibility was increased (p < 0.05) linearly along with increasing amounts of AJE. With increasing AJE supplementation, nitrogen and energy utilization tended to improve (p < 0.10). In summary, the addition of AJE in the corn-soybean meal diet led to higher body weight gain and increased feed intake as well as enhanced nutrient digestibility, among them the highest improvement was found in 0.06%-AJE indicating the acceptance of AJE as a phytogenic feed additive.

Comparative effects of proteases on performance, carcass traits and gut structure of broilers fed diets reduced in protein and amino acids.

This study aimed to evaluate the effect of supplementing different protease enzymes on growth performance, intestinal morphology, and selected carcass traits in broilers fed diets reduced 3.5% in crude protein (CP) and amino acids (AA). One thousand one-day-old Ross 308 broilers (41 g) were assigned to five dietary treatments with ten replicates of 20 birds each: a positive control (PC) diet formulated to meet Ross 308 AA requirements, a negative control (NC) diet reformulated to provide 3.5% lower CP and AA compared to PC, NC supplemented with a multi-protease (PR1) solution, containing 3 different coated proteases produced from Aspergillus niger, Bacillus subtilis and Bacillus licheniformis, NC supplemented with a serine protease (PR2) produced from Bacillus licheniformis, and NC supplemented with an alkaline protease (PR3) produced from Bacillus licheniformis. At slaughter, 40 birds per treatment were used to assess the effect of the different treatments on carcass traits. At 32 days, samples of the duodenum, jejunum, and ileum of 10 birds per treatment were collected for intestinal morphology evaluation. Birds fed PC and NC supplemented with multi-protease exhibited better (p < 0.05) feed efficiency compared to NC and NC supplemented with all the other protease enzymes. Multi-protease supplementation was linked to the highest (p < 0.05) carcass weight and yield. There were significant differences (p < 0.05) between treatments in all gut segments, with PC, PR1, PR2, and PR3 exhibiting longer villi height (VH) compared to NC. This study demonstrates that 3.5% reduction of CP and AA negatively affected for the overall period feed efficiency, carcass yield, and intestinal morphology. The supplementation of the multi-protease restored feed efficiency and improved carcass yield.

No colonization resistance to Campylobacter jejuni in broilers fed brown algal extract-supplemented diets.

Introduction: Campylobacter jejuni gastroenteritis is the most commonly reported zoonosis within the EU, with poultry products regarded as the primary source of transmission to humans. Therefore, finding strategies to reduce Campylobacter colonization in broilers holds importance for public health. Recent studies suggest that supplementation of broiler feed with brown algal extracts, particularly laminarin, can provide beneficial effects on broiler gut health, growth performance, and gut microbiota. However, its effect on gut microbiota development and subsequent reduction of Campylobacter loads in broiler caeca during the later stages of the birds' lives remains unclear. Methods: Experimental colonization of Ross 308 broilers with two different strains of C. jejuni was conducted, with groups fed either a basal diet or the same basal diet supplemented with 725 ppm algal extract from Saccharina latissima to provide 290 ppm laminarin. Fecal samples were collected for bacterial enumeration, and caecal samples were obtained before and after the C. jejuni challenge for the determination of microbiota development. Results and discussion: No significant differences in fecal C. jejuni concentrations between the groups fed different diets or exposed to different C. jejuni strains were observed. This suggests that both strains colonized the birds equally well and that the laminarin rich algal extract did not have any inhibitory effect on C. jejuni colonization. Notably, 16S rRNA amplicon sequencing revealed detailed data on the caecal microbiota development, likely influenced by both bird age and C. jejuni colonization, which can be valuable for further development of broiler feed formulations aimed at promoting gut health.

Food safety control in poultry industry: prevalence and antimicrobial susceptibility of Escherichia coli isolated from raw chicken and the potential use of Origanum essential oils as alternative to antibiotics.

1. The extensive use of antimicrobials in poultry production may contribute to the emergence of resistant bacteria. This study was conducted to determine the prevalence and resistance of different E. coli strains isolated from raw chicken meat and to investigate the possibility to use Lebanese native oregano essential oils as alternatives.2. In total, 250 chickens from Lebanese markets were examined for the presence of E. coli. Isolates were then screened for susceptibility using 19 antibiotics and two essential oils extracted from oregano plants.3. Of the 250 chickens tested, 80% were contaminated with E. coli. Main resistance was seen against amoxycillin, ampicillin, penicillin, tetracycline, tylosin, streptomycin and erythromycin. The highest rate of sensitivity was found in 86.1% of strains to Amoxycillin/Clavulanic acid, 80.09% to Tilmicosin. Both essential oils from Origanum syriacum (98%) and O. ehrenbergii (97.3%) showed promising potential in inhibiting the growth of the tested bacteria. Oil from O. syriacum exhibited superior efficacy against 200 E. coli strains, inhibiting 46.1% at 200 mg/l and all at 400 mg/l, while O. ehrenbergii oil showed slightly lower inhibition, affecting 41.6% at 200 mg/l and all at 400 mg/l.

The effect of hydroxy-selenomethionine on the productive and reproductive performance of old broiler breeders.

BACKGROUND: Selenium (Se) is a rare essential element that plays a vital role in the health and performance of animals. By interfering in the production of antioxidant enzymes such as glutathione peroxidase, thioredoxin reductase and methionine sulfoxide, Se plays a role in reducing the effects of oxidative stress and animal performance. OBJECTIVES: This study aimed to investigate the effect of hydroxy-selenomethionine (OH-SeMet) in the diet of broiler breeder and old broiler breeder roosters on productive performance, reproduction and sperm quality parameters. METHODS: For this purpose, 260 broiler breeders of the Ross 308 strain were used in a completely randomized design with four treatments and five replications (13 hens and one rooster in each replication). Experimental treatments included: (1) a basal diet without OH-SeMet (T1:control), (2) a broiler breeder diet without OH-SeMet and a rooster diet containing 0.1 mg/kg OH-SeMet (T2), (3) broiler breeder diet containing 0.1 mg/kg OH-SeMet and rooster diet without OH-SeMet (T3) and (4) broiler breeder and rooster diet contained 0.1 mg/kg OH-SeMet (T4). RESULTS: The results showed that T3 and T4 treatments improved egg production, egg weight, egg mass and feed conversion ratio (FCR) compared to the control treatment (p < 0.05). The fertility and hatchability percentages of T4 and T2 treatments increased compared to T1 and T3 treatments (p < 0.05). The rate of embryonic losses in T1 was higher than in other treatments. However, grade one chickens were higher in T4 than in other treatments (p < 0.05). Total motility and viability of sperms were significantly higher in T2 and T4 treatments than in T1 and T3 treatments. The sperm abnormality percentage and sperm MDA concentration decreased in T2 and T4 treatments. CONCLUSIONS: Therefore, using OH-SeMet may be a practical approach to help old broiler breeders' production and reproduction performance.

Synergy of gut microbiota and host genome in driving heterosis expression of chickens.

Heterosis has been widely utilized in agricultural production. Despite over a century of extensive research, the underlying mechanisms of heterosis remain elusive. Most hypotheses and research have focused on the genetic basis of heterosis. However, the potential role of gut microbiota in heterosis has been largely ignored. Here, we carefully design a crossbreeding experiment with two distinct broiler breeds and conduct 16S rRNA amplicon and transcriptome sequencing to investigate the synergistic role of gut microbiota and host genes in driving heterosis. We find that the breast muscle weight of the hybrids exhibits a high heterosis, 6.28% higher than mid-parent value. A notable difference is observed in the composition and potential function of cecal microbiota between hybrids and their parents. Over 90% of the differentially colonized microbiota and differentially expressed genes exhibit nonadditive patterns. Integrative analyses uncover associations between nonadditive genes and nonadditive microbiota, including a connection between the expression of cellular signaling pathway and metabolism-related genes and the abundance of Odoribacter, Oscillibacter, and Alistipes in hybrids. Moreover, higher abundances of these microbiota are related to better meat yield. In summary, these findings highlight the importance of gut microbiota in heterosis, serving as crucial factors that modulate heterosis expression in chickens.

The effects of Artemisia Sieberi, Achillea Fragrantissima, and Olea Europaea leaves on the performance and physiological parameters in heat-stressed broiler chickens.

High temperatures have detrimental effects on the performance and physiology of broiler chickens. Medicinal plants have various biological activities and may enhance the heat resistance of chickens during heat waves. Therefore, this study aimed to explore the potential roles of using specific local medicinal plants to alleviate the negative impacts of heat stress (HS) in broilers. In this study, 180 day-old chicks were used to investigate the effects of HS and dietary indigenous medicinal plants on growth performance, antioxidant biomarkers, and intestinal health. The chicks were assigned to six groups (18 pens with 10 chicks per pen) with three replicates each. In the first group, the chicks were kept under thermoneutral conditions (CON) and fed a basal diet. The other five groups were exposed to recurrent heat stress and fed a basal diet (T1, HS group) or supplemented with Artemisia Sieberi (1.25 g/kg of feed; T2), Achillea Fragrantissima (15 g/kg of feed; T3), Olea europaea (10 g/kg of feed; T4), and all the previous additives (all-in-one) combined at the same dose levels mentioned above (T5). At 21 days of age, the chicks from each group were exposed to two phases of heat stress: phase 1 from days 21 to 34 (34 ± 1°C) followed by phase 2 from days 35 to 39 (37 ± 1°C). The results indicate that HS significantly increased rectal temperature and respiration rate in broiler chickens. Feed intake and body weight gain were improved in all supplemented groups, while the feed conversion ratio was decreased in response to the dietary inclusion of medicinal plants. Additionally, glutathione peroxidase and immunoglobulin G levels were increased in the T3, T4, and T5 groups compared to the other groups. HS induced significant upregulated in the mRNA levels of heat shock protein 70 and interleukin-8, while the mRNA of occludin was decreased. The T3, T4, and T5 showed significantly decreased expression of hepatic HSP70 and ileum IL-8 genes and increased ileum mRNA occludin levels relative to the CON and T1 groups. In conclusion, supplementation with these plants enhances growth performance and maintains intestinal health sustaining the productivity of broiler chickens under HS conditions.

Transcriptomic and epigenomic landscapes of muscle growth during the postnatal period of broilers.

BACKGROUND: Broilers stand out as one of the fastest-growing livestock globally, making a substantial contribution to animal meat production. However, the molecular and epigenetic mechanisms underlying the rapid growth and development of broiler chickens are still unclear. This study aims to explore muscle development patterns and regulatory networks during the postnatal rapid growth phase of fast-growing broilers. We measured the growth performance of Cornish (CC) and White Plymouth Rock (RR) over a 42-d period. Pectoral muscle samples from both CC and RR were randomly collected at day 21 after hatching (D21) and D42 for RNA-seq and ATAC-seq library construction. RESULTS: The consistent increase in body weight and pectoral muscle weight across both breeds was observed as they matured, with CC outpacing RR in terms of weight at each stage of development. Differential expression analysis identified 398 and 1,129 genes in the two dimensions of breeds and ages, respectively. A total of 75,149 ATAC-seq peaks were annotated in promoter, exon, intron and intergenic regions, with a higher number of peaks in the promoter and intronic regions. The age-biased genes and breed-biased genes of RNA-seq were combined with the ATAC-seq data for subsequent analysis. The results spotlighted the upregulation of ACTC1 and FDPS at D21, which were primarily associated with muscle structure development by gene cluster enrichment. Additionally, a noteworthy upregulation of MUSTN1, FOS and TGFB3 was spotted in broiler chickens at D42, which were involved in cell differentiation and muscle regeneration after injury, suggesting a regulatory role of muscle growth and repair. CONCLUSIONS: This work provided a regulatory network of postnatal broiler chickens and revealed ACTC1 and MUSTN1 as the key responsible for muscle development and regeneration. Our findings highlight that rapid growth in broiler chickens triggers ongoing muscle damage and subsequent regeneration. These findings provide a foundation for future research to investigate the functional aspects of muscle development.

Dietary Clostridium butyricum and 25-Hydroxyvitamin D3 modulate bone metabolism of broilers through the gut-brain axis.

Leg disorders have become increasingly common in broilers, leading to lower meat quality and major economic losses. This study evaluated the effects of dietary supplementation with Clostridium butyricum (C. butyricum) and 25-hydroxyvitamin D3 (25-OH-D3) on bone development by comparing growth performance, tibial parameters, Ca and P contents of tibial ash, bone development-related indicators' level, and cecal short-chain fatty acids in Cobb broilers. All birds were divided into four treatment groups, which birds fed either a basal diet (Con), basal diet + 75 mg chlortetracycline/kg (Anti), basal diet + C. butyricum at 109 CFU/kg (Cb), basal diet + C. butyricum at 109 CFU/kg and 25-OH-D3 at 25 µg/kg (CbD), or basal diet + 25-OH-D3 at 25 µg/kg (CD). Our results suggest that the dietary supplementation in Cb, CbD, and CD significantly increased the body weight (BW) and average daily gain (ADG), and reduced the feed-to-weight ratio (F/G) at different stages of growth (P < 0.05). Dietary supplementation in Cb, CbD, and CD prolonged (P < 0.05) the behavioral responses latency-to-lie (LTL) time, reduced (P < 0.05) the levels of osteocalcin (BGP) and peptide tyrosine (PYY), and increased (P < 0.05) serotonin (5-HT) and dopamine (DA). Treatment with Cb increased (P < 0.05) the levels of acetic acid, isobutyric acid, butyric acid, and isovaleric acid compared with those in Con group. The cecal metagenome showed that Alistipes spp. were significantly more abundant in Cb, CbD, and CD groups (P < 0.05). A total of 12 metabolic pathways were significantly affected by supplementation, including the signaling pathways of glucagon, insulin, and PI3K-AKT; primary and secondary bile acid biosynthesis; and P-type Ca 2+ transporters (P < 0.05). Hence, the CbD supplementation modulates bone metabolism by regulating the mediators of gut-brain axis, which may inform strategies to prevent leg diseases and improve meat quality in broilers.

Formic acid as an antibiotic alternative in broiler diets: effects on growth, carcass characteristics, blood chemistry, and intestinal microbial load.

This study explored the ability of formic acid (FA) to replace antibiotics in broiler chicken diets. It examined how FA affected the chickens' growth, carcass characteristics, blood chemistry, and gut bacteria. The experiment randomly assigned 300 one-day-old (Ross 308) broiler chicks to 5 groups, each divided into 6 replicates with 10 unsexed chicks. The following were the treatments: 1st group, negative control (NC): only received a basal diet; 2nd group, positive control (PC): received a basal diet supplemented with 0.5 grams of Colistin antibiotic per kilogram of diet; 3rd, 4th, and 5th groups (FA2, FA4, and FA6) these groups received a basal diet along with formic acid added at increasing levels: 2, 4, and 6 Cm3 per kilogram of diet, respectively. Results found no significant differences in live body weight (LBW) or body weight gain (BWG) between treatment groups, except for LBW at one week and BWG at 0 to 1 and 4 to 5 wk of age. No significant variations were found in feed intake (FI) and feed conversion ratio (FCR) among the treatment groups, excluding FI and FCR at 1 to 2 wk of age. The treatments significantly impacted carcass traits, dressing percentage, breast meat, thigh meat, spleen, giblets, blood levels of urea, creatinine, total protein, globulin, and albumin, as well as the activity of enzymes alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in chicks fed different diets compared to control groups. The addition of FA to the diet significantly impacted antioxidant levels. Also, the FA2 group had the highest total bacterial count (TBC). However, the FA6 group was the opposite; it had the lowest levels of harmful bacteria, such as E. coli and Coliform. Supplementing broiler diets with formic acid improves blood parameters, antioxidant activity, and gut bacteria counts, with 4.0 cm³ formic acid/kg diet supplementation promoting optimal broiler health and product quality.

Distinct patterns of feed intake and their association with growth performance in broilers.

Improving feed utilization is a vital strategy to meet the growing global demand for meat and promote sustainable food production. Over the past few decades, significant improvements in the feed intake (FI) and feed utilization efficiency of broilers have been achieved through advanced breeding procedures, although dynamic changes in FI and their effects on the feed conversion ratio (FCR) have remained unclear. In this study, we measured individual weekly FI and body weight of 274 male broilers to characterize the dynamic FI patterns and investigate their relationship with growth performance. The broilers were from 2 purebred lines and their crossbreed and measurements were collected from 4 to 6 wk of age. Overall, a continuous increase in the weekly FI occurred from 4 to 6 wk of age, whereas the body weight gain (BWG) reached an inflection point in wk 5. The dynamic change in weekly FI was observed to follow 3 distinct FI patterns: pattern 1, a continuous weekly increase in FI; pattern 2, an increase followed by a plateau; pattern 3, an increase followed by a decrease. The prevalence of these patterns was similar in the purebred and crossbred populations: pattern 2 was most frequent, followed by a moderate proportion of pattern 1, and the lowest proportion of pattern 3. Broilers following pattern 1 displayed significantly better growth performance and feed utilization efficiency than those following pattern 3, emphasizing the importance of maintaining good appetite in the last stage of broiler production. In summary, this study has characterized the dynamic patterns of FI and their association with growth performance. Our results offer a new foundation for improving feed utilization efficiency and investigating feeding regulation in broilers.