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.

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.

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.

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.

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.

Review: Myopathies in broilers: supply chain approach to provide solutions to challenges related to raising fast growing birds.

This review is a summary of a Poultry Science Association symposium addressing myopathies in broilers' breast meat, focusing on the interactions between genetics, nutrition, husbandry, and meat processing. The Pectoralis major myopathies (woody breast [WB]; white striping [WS]; spaghetti meat [SM]) and Pectoralis minor ("feathering") are described, followed by discussing their prevalence, potential causes, current and future ways to mitigate, as well as detection methods (in live birds and meat) as well as ways to utilize affected meat. Overall, breast myopathies remain an important focus across the poultry industry and whilst a lot of data and knowledge has been gathered, it is clear that there is still a lot to understand. As there are multiple factors impacting the occurrence of breast myopathies, their reduction relies on a holistic approach. Ongoing balanced breeding strategies by poultry breeders is targeting the longer-term genetic component but comprehending the significant influence from nongenetic factors (short-term solutions such as nutrition) remains a key area of opportunity. Consequently, understanding the physiology and biological needs of the muscle through the life of the bird is critical to reduce the myopathies (e.g., minimizing oxidative stress) and gain more insight into their etiology.

Sodium butyrate and rosemary herb improve growth performance, biochemical profile, immunity, and carcass traits in broiler chickens.

Background: Feed additives are products used in poultry nutrition to improve the quality of feed and the safety of food byproducts from animal origin. They are promising antibiotic alternatives for the production of broilers. Aim: This study aimed to investigate the effect of sodium butyrate (SB) and RL on growth performance, biochemical profile, immunity, and carcass traits of broilers. Methods: Five hundred-one-day-old chicks of the Hubbard breed were reared on floor pens in a privet farm, Giza. The chicks were weighed on arrival (each chick weighted 43-45 gm) and randomly assigned into five equal groups, with four replicates each (25 chicks/replicate). Group 1 was fed on a broiler diet without any additions (control). The diets of groups 2 and 3 were supplemented with 500 g/ton SB and 4 kg/ton RL, respectively. In group 4, the diet was enriched with 250 g/ton SB plus 2 kg/ton RL. Chicks in group 5 were fed on a diet fortified with 500 g/ton SB plus 4 kg/ton RL. Results: Supplementation of broiler diet with 500 g/ton SB plus 4 kg /ton RL increased body weight gain (BWG) and feed efficiency ratio (FER) of birds. It decreased serum levels of aspartate aminotransferase, alanine aminotransferase, total cholesterol triglycerides, and malondialdehyde, but increased superoxide dismutase, catalase, and immunoglobulins, phagocytic activity, lysozyme activity, and nitric oxide concentrations. Antibody titers against the Newcastle disease virus were also elevated. Conclusion: Supplementation of broiler diet with 500 g/ton SB plus 4 kg/ton RL gives the best result regarding productive efficiency and immunity of broiler chickens.

Nutraceuticals vs. antibiotic growth promoters: differential impacts on performance, meat quality, blood lipids, cecal microbiota, and organ histomorphology of broiler chicken.

The main goal of this study was to evaluate the effect of nutraceuticals vs. in-feed antibiotics on performance, blood lipids, antioxidant capacity, cecal microbiota, and organ histomorphology of broiler chickens. A total of 320 one-day-old male broiler chickens were distributed into 5 treatment groups with 8 replicates each. The control group was fed on a basal diet without any additives (NC); the antibiotic group was fed on a basal diet supplemented with 100 mg kg-1 avilamycin (PC); the algal group was fed on a basal diet supplemented with a mixture of Spirulina platensis and Chlorella vulgaris (1.5 g + 1.5 g/kg feed) (SP+CV); the essential oil group was fed with a basal diet containing 300 mg/kg feed rosemary oil (REO); and the probiotics group (a mixture of 1 × 1011 CFU/g Bacillus licheniformis, 1 × 1011 CFU/g Enterococcus facieum, 1 × 1010 CFU/g Lactobacillus acidophilus, and 2 × 108 CFU /g Saccharomyces cerevisiae) was fed with a basal diet supplemented with 0.05% probiotics (PRO). The experiment lasted for 35 d. A beneficial effect of SP+CV and PRO (P < 0.01) was noticed on final body weight, body weight gain, feed conversion ratio, and breast yield. The dietary supplementation with SP+CV, REO, and PRO increased (P < 0.001) broilers' cecal lactic acid bacteria count compared to the control. Lower cecal Clostridium perfringens and Coliform counts (P < 0.001) were noticed in chickens fed the PC and supplemental diets. Malondialdehyde (MDA) concentration was decreased, while glutathione peroxidase (GPx), superoxide dismutase, and catalase enzymes were increased in the breast and thigh meat (P < 0.001) of broiler chickens fed SP+CV, REO, and PRO diets. Dietary SP+CV, REO, and PRO supplementation decreased (P < 0.001) serum total lipids, cholesterol, triglycerides, low-density lipoprotein, and MDA, but increased serum high-density lipoprotein and GPx compared to PC and NC. No pathological lesions were noticed in the liver, kidney, or breast muscle among broilers. The SP+CV, REO, and PRO groups had greater (P < 0.001) intestinal villi height and crypt depth while lower goblet cell densities (P < 0.01) than the control. The present findings suggest that PRO and SP+CV, followed by REO could be suitable alternatives to in-feed antibiotics for enhancing the performance, health, and meat quality of broiler chickens.

Effects of finisher diet nutrients density and slaughter age on energy and protein efficiency, productive and economic performance and meat quality of broilers.

BACKGROUND: The current broilers have been greatly optimized for weight gain and breast yield, which necessitates the provision of nutrients-dense diets for maximum potential. OBJECTIVES: The current study aimed to evaluate the effect of finisher diet nutrients density (ND) on energy and protein efficiency, productive and economic performance and breast meat quality of broilers raised until different slaughter age. METHODS: A total of 600 23-day-old broiler male chicks (Cobb-500) were assigned to 10 treatments with six replicates and 10 birds each. Experimental treatments were included factorial arrangement of five increment (2.5%) levels of finisher diet ND (92.5%, 95%, 97.5%, 100% and 102.5% as strain recommendation) and slaughtered at 38 or 46 days of age. The relative difference in the energy level of experimental diets was used to increase ND levels at the same ratio. RESULTS: Feed intake (FI) and breast meat quality traits exception water holding capacity (WHC) were not affected by finisher diet ND. In response to increasing finisher diet ND, energy and protein efficiency, productive traits, bio-economic index (BEI) and breast relative weight (BRW) linearly improved. However, residual feed intake and breast meat WHC improved with a quadratic trend. By using broken-line regression analysis, the optimum dietary ND was obtained at 97.5%-102% of strain recommendation. Energy and protein efficiency, feed conversion ratio and BEI deteriorated by prolonging rearing period. The BRW, meat lightness (L*), redness (a*), hue angle (h*) and WHC values for the birds slaughtered at 46 days of age were significantly higher, and cooking loss was lower than those slaughtered at 38 days old. CONCLUSIONS: Broilers during the finisher period are not able to regulate their FIs with diet ND. The energy and protein efficiency, productive and economic performance were reduced when broilers were fed diluted diet or the rearing period was prolonged.

Oleuropein has hypophagic effects in broiler chicks.

Oleuropein, a phenolic compound derived from olives, has known glucoregulatory effects in mammalian models but effects in birds are unknown. We investigated effects of dietary supplementation and exogenous administration of oleuropein on broiler chick feed intake and glucose homeostasis during the first 7 days post-hatch. One hundred and forty-eight day-of-hatch broiler chicks were randomly allocated to one of four dietary treatments with varying oleuropein concentrations (0, 250, 500, or 1,000 mg/kg). Body weight and breast muscle and liver weights were recorded on day 7. In the next experiment, chicks received intraperitoneal (IP) injections of oleuropein at doses of 0 (vehicle), 50, 100, or 200 mg/kg on day 4 post-hatch, with feed intake and blood glucose levels measured thereafter. Lastly, chicks fed a control diet were fasted and administered intracerebroventricular (ICV) injections of oleuropein at doses of 0, 50, 100, or 200 µg, after which feed intake was recorded. Results indicated that IP and ICV injections led to decreased feed intake, primarily at 60 min post-injection, with effects diminishing by 90 min in the IP study. Blood glucose levels decreased 1-h post-IP injection at higher oleuropein doses. These findings suggest that oleuropein acts as a mild appetite suppressant and influences energy metabolism in broiler chickens.

Bacillus subtilis fmbj ameliorates lipopolysaccharide-induced intestinal dysfunction in broilers by enhancing the SIRT1/PGC1α pathway.

This study aimed to explore the impact of dietary Bacillus subtilis fmbj (BS) supplementation on acute intestinal dysfunction induced by lipopolysaccharide (LPS) in broilers. One hundred and eighty 1-day-old male Arbor Acres broilers were randomly divided into three treatment groups, each comprising ten replicates of 6 birds. On d 20, LPS-challenged (LPS group and LPS-BS group) and LPS-unchallenged (CON group) broilers received intraperitoneal injections of 1 mg/kg body weight LPS solution and an equivalent volume of sterile saline, respectively. Compared to the CON group, LPS disrupted (P < 0.05) the morphology of the small intestine (jejunum or ileum), exacerbated (P < 0.05) serum, small intestinal, and small intestinal mitochondrial antioxidant capacity, induced (P < 0.05) small intestinal oxidative damage, and altered (P < 0.05) the expression of genes and proteins related to antioxidants, cell adhesion, and mitochondrial function in the jejunum. The LPS-BS group exhibited a tendency towards improvement in small intestinal morphology, serum, small intestinal, and small intestinal mitochondrial antioxidant capacity, small intestinal oxidative damage, and the expression of genes and proteins related to antioxidants, cell adhesion, and mitochondrial function in the jejunum when compared to the LPS group. In conclusion, BS supplementation may confer protection against LPS-induced acute intestinal dysfunction in broilers by enhancing the activation of SIRT1/PGC1α, suggesting its potential as a valuable additive for the poultry industry.

Effects of Dietary Inclusion of a Proprietary Combination of Quillaja saponaria and Yucca schidigera on Intestinal Permeability and Immune Response in Broiler Chickens during a Coccidia Challenge.

This study assessed the impact of Magni-Phi Ultra (MPU) inclusion on intestinal integrity and immunity in broiler chickens challenged with coccidia during peak and recovery phases. A total of 128 male Ross 708 broiler chicks were randomly allotted to one of four treatment groups (four chicks/cage). Treatments included an uninfected control (UUC); a coccidial challenge (CC) infected control (IUC); a CC fed salinomycin at 66 ppm (SAL); and a CC fed Magni-Phi Ultra at 0.11 g/kg of diet (MPU). At 16 days post-hatch, all birds in the CC groups were orally gavaged with a 3× dose of a live coccidia vaccine. At 5 dpi, the birds fed MPU and SAL showed decreased plasma FITC-d, oocyte shedding, and lesion scores and higher BWG compared to the IUC birds (p < 0.05). Jejunum IL-17, IL-10, and IFN-ϒ mRNA expression was higher in the IUC compared to the UUC (p < 0.05) group at 5 dpi. At 12 dpi, the birds fed MPU or SAL had lower plasma FITC-d and jejunum IFN-ϒ and IL-10 mRNA expression compared to the IUC birds (p < 0.05). This study indicates that MPU supports intestinal integrity and mucosal immune responses during the peak and recovery phases of infection, which may lead to improved health and performance.

The Association between Broiler Litter Microbiota and the Supplementation of Bacillus Probiotics in a Leaky Gut Model.

Probiotics provided from hatch have a major influence on microbiota development, and together with environmental and bedding microbiota, shape the microbial community of the litter. We investigated the influence of probiotic supplementation and a leaky gut challenge induced using dexamethasone (DEX) on the litter microbial community and litter parameters. The probiotic product was a mix of three Bacillus amyloliquefaciens strains. The litter microbiota were compared to the microbial communities from other gut sections. The litter samples had higher microbial diversity compared to the caecum, gizzard, jejunum, and jejunal mucosa. The high similarity between the litter phylum-level microbiota and gizzard microbiota detected in our study could be a consequence of ingested feed and litter passing through the gizzard. Moreover, the litter microbial community is fundamentally distinct from the intestinal microbiota, as evidenced by the number of genera present in the litter but absent from all the intestinal sections and vice versa. Furthermore, LEfSe analysis identified distinct microbial taxa across different groups, with specific genera associated with different treatments. In terms of litter quality, the birds in the DEX groups had a significantly higher moisture content, indicating successful leaky gut challenge, while probiotic supplementation did not significantly affect the moisture levels. These findings provide comprehensive insights into the distinct microbiota characteristics of litter.

Effect of Triticale Grain in Diets on Performance, Development of Gastrointestinal Tract and Microflora in Crop and Ileum of Broiler Chickens.

The purpose of the research was to determine the effect of the use of a diet containing 30% triticale grain. In an experiment lasting 28 days, 180 one-day Ross-308 chickens (sex ratio 1:1) with an average initial body weight in treatment of 44.6 g were randomly assigned to 30 metabolic cages/replications, 6 birds in each. To compare the results between treatments, a one-way ANOVA was used with uneven replication numbers. The control group (I) received a standard diet containing maize and soybean meal. In the other treatments, 30% of different cereals were used: II-wheat, III-barley, and IV-triticale. Significant differences in body weight (BW) and feed conversion ratio (FCR) were observed on the 4th day of the life of broiler chickens (p < 0.05). Differences were determined between the control group (90.7 g BW and 1.32 kg of feed/kg BWG in the case of FCR) and birds receiving barley (93.0 g BW and 1.29 kg of feed/kg BWG in the case of FCR), compared to chickens fed diets with a 30% share of wheat grain (86.2 g BW and 1.53 kg feed/kg BWG in the case of FCR) and triticale (86.6 g BW and 1.53 kg feed/kg BWG in the case of FCR). Later, the differences in performance of birds between treatments did not occur (p > 0.05). In the nutrition of broiler chickens, control or 30% of the triticale diet caused a significant reduction (p < 0.01) of the number of Escherichia coli (E. coli) in the crop of broiler chickens (0 log cfu/g), compared to birds obtaining feed with 30% of wheat (1.78 log cfu/g). The diet containing triticale also reduced the number of E. coli (p < 0.05) within the ileum (0.78 log cfu/g) compared to chickens obtaining barley grain in the diet (2.12 log cfu/g). As a result of the use of triticale grain (p < 0.05), the total length of the bird intestines (199.64 cm) was compared to 30% of barley grain (209.76 cm). The increase in the length of the large intestine of broiler chickens in treatments was positively correlated (r = 0.613, p < 0.05) with the number of Lactobacillus sp. in the ileum. Triticale increased the pH in the crop of broilers chickens. The research results indicate that triticale, after longer storage, can be used in amounts of 30% of the diet without significant effect on the performance of broiler chickens, with a reduction in E. coli in crop in comparison with wheat and in ileum with barley.

The relationship between phosphorus retention and fibroblast growth factor 23 in broiler breeders.

Previous studies with broiler breeders indicate a P retention threshold when fed daily dietary levels of non-phytate P (NPP) exceeding 320 mg. Fibroblast growth factor 23 (FGF23) is a hormone secreted by osteocytes which modulates P retention and could be the biological agent which controls the P threshold in breeders. To evaluate the relationship between FGF23 and the P retention threshold, a 4-wk study with 32-wk-old breeders was conducted with 6 dietary treatments with daily NPP intake of 216 to 576 mg/d/h with increments of 80 mg/kg diet. The goals were 1) to elucidate how plasma FGF23 corresponds with the P retention threshold in broiler breeders and 2) to determine the amount of P for optimal egg production and bone health. Results showed that between daily 288 mg and 360 mg dietary NPP intake, P retention decreased from 33 to 26% but FGF23 levels increased from 130 pg/mL to 220 pg/mL with increasing NPP. The elevation of plasma FGF23 between the range of 288 mg to 360 mg dietary NPP/d intake suggests that FGF23 is related to the P retention threshold and may be the major hormone for regulating physiological P levels when intake of daily dietary P levels are increased above 288 mg NPP.

Research Note: Effects of high barn temperature on group-level dispersion and individual activity in broiler chickens.

Heat stress in broilers is a pressing issue in the changing climate. Data on broiler behavior might be useful for early detection of heat stress and subsequent intervention, and may provide potential indicators for heat tolerance that can be used in broiler breeding programs. Here, we used bird location data collected in a previous study during which broilers were inadvertently exposed to high ambient temperatures due to a local heat wave. We examined whether broiler behavior changed with increasing ambient temperatures, focusing on group-level dispersion behavior and individual-level locomotor activity. We observed that birds moved closer together with increasing temperatures up to 9 °C above the desired level, and remained in similar proximity or moved further apart at temperatures above that threshold. The activity level decreased or remained stable with increasing temperature during most parts of the day, but increased at the end of the day. Possibly, the birds exhibited compensatory behavior (such as drinking and eating) during the periods when the barn cooled down after a hot day, but that could not be confirmed as no behavioral observations were available. The difference in activity levels between individuals accounted for 8.4% of the total variation, suggesting that activity might be an interesting indicator trait for heat tolerance in broiler chickens. Overall, the results of this study can inform the development of behavior-based 1) early-warning systems for heat stress and 2) heat tolerance indicators, although data on behaviors that are more specific to heat stress are probably required.

The effect of Limosilactobacillus fermentum 2i3 and 0.6% addition of humic substances on production parameters and the immune system of broilers.

The widespread use of antibiotics in the poultry industry as growth promoters has led to the emergence of bacterial resistance, which poses a significant health risk to humans and animals. Substances of natural origin, such as probiotic bacteria and humic substances, can be a promising solution. The aim of this experiment was to study the effect of the administration of a probiotic strain of Limosilactobacillus fermentum 2i3 and/or a new formula of humic substances specifically designed for detoxification on the production parameters, including gene expression of myogenic growth factors and selected parameters of the immune response. We found that production parameters such as feed conversion ratio and weekly weight gain, as well as gene expression of mucin-2 and immunoglobulin A, were positively influenced mainly by the administration of L. fermentum 2i3. Similarly, the percentage of active phagocytes and their absorption capacity as well as the proportions of CD8+ and CD4+CD8+ T-lymphocyte subpopulations were significantly increased. The addition of humic substances, either alone or in combination with probiotics, significantly reduced the aforementioned parameters compared to the control. On the other hand, the relative gene expression for all myogenic growth factors was the highest in the humic group alone. Based on the results obtained, we can confirm the immunostimulating effect of L. fermentum 2i3 administered in drinking water, which also had an impact on important production parameters of broiler meat. On the other hand, in the combined group there was no expected potentiation of the positive effects on the observed parameters.

Mix it-cograzing with cattle reduces broiler losses and increases broiler range use.

Pasture access allows broilers to perform a wide range of behaviors and is a prerequisite in organic poultry production, but exposes broilers to various potential hazards including predators. Co-grazing broilers with cattle can reduce land use and could offer protection from avian predation. Thus, we aimed to assess the effects of co-grazing on broiler losses, range use, performance, contact dermatitis and broilers' manipulation of cow pats. To this end, across 5 replicates we compared each a treatment group of 54 to 61 broilers co-grazing with 10 young cattle and a similar sized control group of broilers on a pasture which had been grazed by cattle 2 weeks prior. Broilers had pasture access during civil daylight and were locked in the coop overnight. Continuous video recordings of the pastures were used to identify the cause when broilers were missing or found dead. On 2 days per week in 4 replicates, broiler distribution in the pasture and maintenance behaviour (i.e. foraging, standing, lying, locomotion) were observed directly using instantaneous scan sampling. Based on the broilers' distance to the coop we calculated a group Ranging Distance Index (RDI). Cow pats were assessed weekly and contact dermatitis was scored before slaughter. Broilers in the treatment groups ranged further (p = 0.003) and higher percentages of birds tended to be outside (p = 0.09) compared to the control groups. Broiler losses due to predatory birds were consistently lower in treatment (median, range: 1, 0 to 3) than in control groups (3, 2 to 5, p = 0.025). Live weight before slaughter was slightly higher (p = 0.035) in treatment groups than in control groups. Feed conversion ratio (p = 0.174), maintenance behaviors and prevalence of contact dermatitis were not affected. No manipulation of cow pats by broilers was found or observed. Overall, co-grazing with cattle positively affected broiler range use, losses due to avian predation and weight gain.

Impact of in ovo feeding of grape pomace extract on the growth performance, antioxidant status, and immune response of hatched broilers.

Delivering natural antioxidants via in ovo feeding holds promise for enhancing the antioxidant status and performance of chickens. Therefore, The objective of this study was to evaluate the impacts of in ovo feeding during early embryonic development using grape pomace extract as a natural antioxidant on hatchability, productive performance, immune response, and antioxidant status in broilers. A total of 900 fertile broiler eggs from the Arbor Acres strain were utilized. Each egg was individually weighed, with egg weights ranging from 61.88 ± 3 g. On the 17.5th d of incubation (DOI), the fertile eggs were divided into 6 groups. The first treatment group was untreated and designated as the control (C). The second group was the sham group (Sh), receiving a simulated injection. The third group, designated as the vehicle group (V), was injected with 100 µl of dimethyl sulfoxide (DMSO). The fourth group received an injection of 100 µL of grape pomace dissolved in DMSO at a concentration of 2 mg (T2). Similarly, the fifth and sixth groups were injected with 100 µL of grape pomace dissolved in DMSO at concentrations of 4 mg and 6 mg, (T4), (T6) respectively. Subsequently, all groups were raised under uniform conditions in terms of management, environment, and nutrition till 5 wk of age. The grape pomace extract (GPE), obtained is rich in total phenolic content (16.07 mg/g), total flavonoid content (7.42 mg/g), and total anthocyanin (8.37 mg/g). Grape pomace extract has exhibited significant antioxidant properties as evidenced by its effectiveness in DPPH scavenging and reducing power assays. Significant improvements in body weight at hatch were observed with in ovo feeding of grape pomace extract, particularly at the 4 mg level, surpassing the effectiveness of the 2 mg and 6 mg grape pomace levels, and this enhancement in body weight continued until the age of 5 wk. GPE injection also led to a significant reduction in cholesterol levels, with the lowest levels recorded for the T4 group. Plasma total Antioxidant Capacity (TAC) levels were significantly elevated in groups treated with T4, T6, and T2 compared to the control group. Conversely, the control group showed a significant increase (P < 0.01) in plasma malondialdehyde (MDA) levels. The immune response of hatched chicks from grape pomace extract-injected groups, especially the T4 group, exhibited improvement through increased IgM and IgG. These findings demonstrate that in ovo feeding of GPE, particularly at a dosage of 4 mg, enhances growth performance, immune response, and antioxidant status in hatched chicks. Thus, administering natural antioxidants, such as grape pomace extract, to developing broiler embryos via in ovo feeding could serve as a valuable strategy for enhancing the subsequent post-hatch productive performance, as well as bolstering the antioxidant and immunological status of broiler chicks.