Growth Performance Of Poultry Research Articles

Targeted sequencing analysis of Mycoplasma gallisepticum isolates in chicken layer and breeder flocks in Thailand

Mycoplasma gallisepticum (MG) is one of the most economically important pathogens worldwide. MG affects the respiratory system and impairs growth performance in poultry. In developing countries, the most widely used technique to identify MG is the conventional PCR assay. In this study, 24 MG isolates collected from Thailand farms with unvaccinated chickens during 2002–2020 were characterized by gene-targeted sequencing (GTS), followed by phylogenetic analysis using unweighted pair group method with arithmetic mean. These 24 Thai MG isolates differed from vaccine strains, including the F, ts-11 and 6/85 strains. One isolate showed 99.5–100% genetic similarity to the F strain with 4 partial gene analyses. This result may have been due to contamination from vaccinated flocks because the F strain is the most commonly used vaccine strain in Thailand. However, the GTS analysis using the partial MG genes in this study showed that the isolates could be grouped into different patterns based on individual gene sequences. The phylogenetic analysis of partial mgc2, gapA, pvpA and lp gene sequences classified the Thai MG isolates into 7, 11, 7 and 2 groups, respectively. In conclusion, at least 2 partial MG genes, especially partial gapA and mgc2 genes, are needed to differentiate MG isolates.

164 Awardee Talk: Influence of Ingredient Quality and Diet Formulation on Amino Acid Digestibility and Growth Performance of Poultry and Swine

Abstract Ingredient varieties and heat processing can influence nutrient utilization for monogastric species. Objective 1 determined the influence of SBM quality on AA digestibility and growth performance of broilers. Treatments consisted of 1 of 4 soybean sources varying in CP content and processed into SBM; 2 sources from a similar region were either commercially or experimentally solvent extracted. Broilers fed commercially processed SBM had improved (P < 0.05) AA digestibility compared with experimentally processed SBM from a similar region. Increasing CP content increased AA digestibility. Broiler d18 BW improved (P<0.05) in broilers fed conventionally processed SBM compared with experimentally processed SBM. Feed intake improved (P < 0.05) when broilers were fed conventionally processed SBM compared with experimentally processed SBM with experimentally processed SBM from a similar source intermediate. Objective 2 determined the effects of diet formulation and pelleting on AA digestibility and growth performance of swine. Diets were fed in mash or pelleted form and formulated with low or high crystalline AA and low or high RS (reducing sugars; DDGS and bakery meal). There was no feed form × crystalline AA × RS interaction observed for SID of AA. For main effects of feed form, the SID of total AA, CP, and indispensable AA increased (P < 0.042) in pigs fed pelleted diets compared with mash diets. Average daily feed intake decreased (P = 0.001) and G:F and caloric efficiency improved (P = 0.001) in pigs fed pelleted diets compared with mash diets. Pigs fed diets with high crystalline AA had increased (P < 0.024) ADFI compared with those fed diets with low crystalline AA. Pigs fed high RS diets had decreased (P <0.041) ADG, ADFI, G:F, and caloric efficiency compared with those fed low RS. Results concluded that pelleting diets with increased crystalline AA or RS did not lead to a reduction in AA digestibility or affect the pigs’ response to pelleting.

Immunoproteomic analysis of the sporozoite antigens of Eimeria necatrix

Eimeria necatrix, an apicomplexan protozoa of the genus Eimeria, causes intestinal coccidiosis that can reduce growth performance of poultry and result in high mortality in older chickens. In this report, the whole sporozoite proteins of E.necatrix were studied by two-dimensional electrophoresis (2-DE) and Western blotting using hyper-immune chicken serum containing E.necatrix-specific antibodies. Approximately 680 protein spots for E.necatrix sporozoite were detected by 2-DE with silver staining, where 98 spots were cross-reacted with the E. necatrix-specific immune sera. Out of the 56 spots that were selected for MALDI-TOF-MS/MS analysis, 50 unique proteins were identified using the MASCOT software, 8 proteins were identified as known E.necatrix proteins and the rest were all putative proteins. These proteins have a wide range of known or predicted structures, cellular locations and functions, including proteins in category nuclear location & function, multifunctional- or multifunctional motifs-containing proteins, cellular transport and structure-related proteins, proteins of enzymatic activities, motor proteins-related, cell surface and organelle-related proteins. These new findings will enhance our understandings of parasite immunogenicity and immune evasion mechanisms of E. necatrix and facilitate the discovery phase of highly effective vaccine candidates.

The effect of natural feed additive on productive performance of broiler chickens

The effect of natural feed additive on productive performance of broiler chickens

Multi-Omics Characterization of Host-Derived Bacillus spp. Probiotics for Improved Growth Performance in Poultry

Microbial feed ingredients or probiotics have been used widely in the poultry industry to improve production efficiency. Spore-forming Bacillus spp. offer advantages over traditional probiotic strains as Bacillus spores are resilient to high temperature, acidic pH, and desiccation. This results in increased strain viability during manufacturing and feed-pelleting processes, extended product shelf-life, and increased stability within the animal’s gastrointestinal tract. Despite numerous reports on the use of Bacillus spores as feed additives, detailed characterizations of Bacillus probiotic strains are typically not published. Insufficient characterizations can lead to misidentification of probiotic strains in product labels, and the potential application of strains carrying virulence factors, toxins, antibiotic resistance, or toxic metabolites. Hence, it is critical to characterize in detail the genomic and phenotypic properties of these strains to screen out undesirable properties and to tie individual traits to clinical outcomes and possible mechanisms. Here, we report a screening workflow and comprehensive multi-omics characterization of Bacillus spp. for use in broiler chickens. Host-derived Bacillus strains were isolated and screened for desirable probiotic properties. The phenotypic, genomic and metabolomic analyses of three probiotic candidates, two Bacillus amyloliquefaciens (Ba ATCC PTA126784 and ATCC PTA126785), and a Bacillus subtilis (Bs ATCC PTA126786), showed that all three strains had promising probiotic traits and safety profiles. Inclusion of Ba ATCC PTA12684 (Ba-PTA84) in the feed of broiler chickens resulted in improved growth performance, as shown by a significantly improved feed conversion ratio (3.3%), increased of European Broiler Index (6.2%), and increased average daily gain (ADG) (3.5%). Comparison of the cecal microbiomes from Ba PTA84-treated and control animals suggested minimal differences in microbiome structure, indicating that the observed growth promotion presumably was not mediated by modulation of cecal microbiome.

129 Maternal Nutrition and in Ovo Feeding Affect Gut Health and Performance of Poultry

Abstract Maintaining a healthy gastrointestinal tract (GIT) is critical for better nutrient utilization, optimum performance, and overall health of poultry. Thus, several nutritional strategies have been tried to improve poultry’s gut health. More recently, different nutrients and feed additives are being used in poultry diets with some success when antibiotic growth promoters (AGP) are not an acceptable option anymore. However, effective modulation of gut health depends on the methods and timing of the compound being available to host animals. Routinely, the alternatives to AGP like prebiotics, probiotics, symbiotic, enzymes, and other nutrients are provided in feed or water to poultry. However, the GIT of the newly hatched poultry is functionally immature, despite going through significant morphological, cellular, and molecular changes toward the end of incubation. Thus, the early growth and development of GIT are of critical importance to enhance nutrients utilization and optimize the growth performance of poultry. Maternal nutrition and in ovo feeding have been used and found to be effective in improving gut health but with inconsistent results. The effects of maternal nutrition on the development and viability of embryo and post-hatch growth performance of birds are documented. However, there is limited information on how maternal nutrition affects the gut health of chicks. In contrast, information on the same from in ovo feeding of nutrients and feed additives has increased in recent years. The results show that in ovo feeding can be a good tool to modulate gut health of post-hatch birds positively. However, more information is needed on the proper route and time of inoculation, optimum doses, and effective combination of different compounds to maximize the benefits of in ovo feeding technique in poultry production.

Immunomodulatory, behavioral, and nutritional response of tryptophan application on poultry

Tryptophan is an essential amino acid for all animals that was discovered through casein hydrolysis. The use of tryptophan as feed additives has been attracting the attention of many nutritionists because it cannot be synthesized enough in an animal’s body. Tryptophan or precursor to the vitamin niacin in the diet is important, and its supplementation for poultry is determined to improve the amino acid balance and promote the poultry’s growth performance through enhancing appetite, feed efficiency, and protein synthesis. Moreover, poultry in different growth phases, breeding, and conditions require various amounts of tryptophan. In addition, supplemented tryptophan also improves the immune response or the immunomodulatory activity of poultry to various diseases through the kynurenine pathway, especially diseases in the bursa. Furthermore, tryptophan also has a strong relationship with lysine (the ideal tryptophan/lysine ratio) in improving growth performance. However, tryptophan deficiency could affect the behavioral responses (e.g. pecking behavior and poultry stress) because tryptophan serves as a precursor for the neurotransmitter serotonin and the pineal hormone melatonin in the diet. This paper tried to summarize all information about applying tryptophan in the diets and illustrate the roles of tryptophan in the poultry industry.

Cinnamon: A Natural Feed Additive for Poultry Health and Production-A Review.

Simple SummaryDue to restrictions on antibiotics in chicken production in recent years, the poultry industry has looked towards alternatives such as plant-derived feed additives. Plant bioactive compounds, such as phytochemicals, in poultry diets, are gaining popularity due to their potential antioxidant and anti-microbial activities. Some plant derivatives improve the immune system, reduce the stress response, and exert positive effects on health and performance. The dietary supplementation of cinnamon in poultry feed as a natural feed additive has beneficial impacts on nutrient digestibility, hypocholesterolaemic, blood biochemical profile, gene expression, immunity, and particularly on gut health to alleviate the impact of disease and heat stress by maintaining water and electrolytic balance and feed intake. It is clearly demonstrated that cinnamon can be used as an alternative to antibiotics in the poultry industry offering greater animal health, food safety, and economic aspects of poultry production.The increased bacterial resistance to synthetic antibiotics and consumer awareness about the health and food safety concerns have triggered the ban on the use of antibiotic growth promotors (AGPs) in the poultry industry. This situation encouraged the poultry sector and industry to explore safe alternatives to AGPs and focus on developing more sustainable feed management strategies to improve the intestinal health and growth performance of poultry. Consequently, phytogenic feed additives (PFAs) have emerged as natural alternatives to AGPs and have great potential in the poultry industry. In recent years, cinnamon (one of the most widely used spices) has attracted attention from researchers as a natural product with numerous health benefits for poultry. The essential oils in cinnamon, in particular, are of interest because of their antioxidant, anti-microbial, anti-inflammatory, antifungal, and hypocholesterolaemic effects, in addition to their ability to stimulate digestive enzymes in the gut. This review mainly emphasizes the potential impact of cinnamon as a natural feed additive on overall gut health, nutrient digestibility, blood biochemical profile, gene expression, gut microbiota and immune response.

Climate change and heat stress: Impact on production, reproduction and growth performance of poultry and its mitigation using genetic strategies.

Heat stress is an important environmental determinant which adversely affects the performance of poultry worldwide. The present communication reviews the impact of heat stress on production, reproduction and growth performance of poultry, and its alleviation using genetic strategies. The adverse effects of high environmental temperature on poultry include decrease in growth rate, body weight, egg production, egg weight, egg quality, meat quality, semen quality, fertility and hatchability, which cause vast financial losses to the poultry industry. High ambient temperature has an antagonistic effect on performance traits of the poultry. Thus, selection of birds for high performance has increased their susceptibility to heat stress. Additionally, heat burden during transportation of birds from one place to another leads to reduced meat quality, increased mortality and welfare issues. Molecular markers are being explored nowadays to recognize the potential candidate genes related to production, reproduction and growth traits for selecting poultry birds to enhance thermo-tolerance and resistance against diseases. In conclusion, there is a critical need of formulating selection strategies based on genetic markers and exploring more genes in addition to HSP25, 70, 90, H1, RB1CC, BAG3, PDK, ID1, Na, F, dw and K responsible for thermoregulation, to improve the overall performance of poultry along with their ability to tolerate heat stress conditions.

Ecofriendly Alternatives to Antibiotics for Improving Growth Performance in Poultry

Background: Poultry farming has become an integral part of animal husbandry and has been developed rapidly during the last few decades. Antibiotics have been used and adopted as growth promoters for improving feed efficiency and performance in poultry industry. The prolonged use of antibiotics has led to the development of resistant bacteria and destruction of beneficial bacteria. Search on additives that can replace antibiotics without causing any negative impact in productivity and quality has been progressed. Objective: To review the various growth promoters available alternate to antibiotic, that can perform better in the existing condition according to their genetic potential and keep up health, growth, and performance of poultry. Materials and Methods: Our study relies on the literature analysis; clinical and biological data were collected from different literatures and reports. Result of Study: A brief description of alternatives and their efficaciousness, use, and advantage for enhancing production and safeguarding the health of poultry is presented. Although the beneficial activities of the developed alternative are well demonstrated, their mode of actions is not well defined. Conclusions and Recommendations: The article is useful to the researchers to enhance their idea on poultry birds and perform further research on antibiotics and other alternatives without sacrificing birds.

Effect of rearing temperature on physiological measures and antioxidant status of broiler chickens fed stevia (Stevia rebaudiana B.) leaf meal and exogenous xylanase

• Rearing birds at high ambient temperature reduced feed intake but did not influence weight gain and feed efficiency. • Dietary xylanase increased hepatic vitamin E and stevia increased the hepatic carotenoid content in birds. • Incorporating stevia and xylanase into diets for broilers reared at high ambient temperatures reduces oxidative stress. The global climate is warming. Heat stress, as a result of high ambient temperatures, may negatively impact physiology and reduce growth performance of poultry. Stevia is a perennial shrub indigenous to South America where its phytochemical extracts have been used as a natural sweetener for hundreds of years. Its physiological effects, including antioxidant properties, on poultry are well known, however, the translation of these to improved growth performance is variable. Combining stevia with a commercial xylanase to enhance feed digestibility could therefore form a feeding strategy to partially mitigate the negative impact of rearing birds under high ambient temperatures. The study aimed to compare the growth performance, dietary energy and nutrient availability, oxidative status, gastrointestinal tract development, and caecal short chain fatty acid concentration; at two ambient rearing temperatures, when feeding diets containing stevia and exogenous xylanase, alone or in combination, to broiler chickens. Study design/Methods : Day-old chicks (n = 105) were reared in a single floor pen following breeder recommendations for the first 7 days, whereupon birds (n = 96) were randomly allocated to one of four experimental diets (negative control, stevia at 20 g/kg diet, xylanase at 100 FXU/kg diet, stevia at 20 g/kg diet + xylanase at 100 FXU/kg diet), in one of two environmental conditions (high ambient temperature at 32 ± 2 °C or regular rearing at breeder recommendations), in a 2 × 2 × 2 factorial design. Rearing birds at high ambient temperature reduced daily feed intake (p = 0.02). Birds fed stevia and reared at regular temperature had similar weight gain to birds reared in high ambient temperatures, although birds on the control diet housed at regular temperatures had the greatest weight gain (P < 0.05). Exogenous xylanase improved overall dietary metabolisable energy and improved nitrogen retention in the high ambient temperature group only (P < 0.05). Dietary stevia reduced caecal digesta butyric acid: acetic acid at regular temperature, but xylanase increased the butyric acid concentration at high ambient temperature (P < 0.05). Dietary stevia increased (P < 0.001) the hepatic carotenoid concentrations and xylanase improved (P < 0.05) hepatic vitamin E concentrations. Rearing temperature is an important environmental factor in broiler production. Exogenous xylanase supplementation can increase feed efficiency and dietary metabolisable energy. Feeding xylanase or stevia improves hepatic antioxidant status in broilers by increasing hepatic vitamin E and carotenoids, respectively, suggesting that either may be effective in counteracting oxidative stress.

In vitro immunomodulatory effects of thymol and cinnamaldehyde in a pig intestinal epithelial cell line (IPEC-J2)

Thymol and cinnamaldehyde are phytogenic feed additives developed to improve gut health and growth performance in poultry and swine. This study evaluated the in vitro immune modulating effects of thymol and cinnamaldehyde blend (TCB) in a porcine gut epithelial cell line (IPEC-J2), with or without cellular damage caused by challenge with lipopolysaccharides. Cytotoxicity, permeability, wound-healing and bacteria adhesion assays were recorded. The expression of cytokines, tight junctions and polymeric immunoglobulin receptor (pIgR) were measured by RT-PCR. The IPEC-J2 cells were cultured in the presence of TCB at concentrations ranging from 1 ng/ml to 1 μg/ml and displayed high viability (&gt;90%). TCB increased barrier integrity (13.8% less in lipopolysaccharide challenge which induced gut epithelial leakage, P&lt;0.05) and accelerated the initial speed of wound recovery (day 1, 26% wound recovery in TCB treated vs 7% in control, P&lt;0.05; day 2, 54 vs 39%, P&lt;0.001). The RT-PCR analysis of cell culture showed that TCB upregulated anti-inflammatory cytokine interleukin (IL)-10 (73.3%, P&lt;0.05) in non-stimulated IPEC-J2 cells, while, when stimulated, pIgR (9.7%, P&lt;0.05) and tight junctions claudin-4 (9.4%, P&lt;0.05) were upregulated by TCB. Furthermore, TCB significantly increased Lactobacillus acidophilus adherence to gut epithelial cells (285.0%, P&lt;0.05). Overall, the current in vitro study showed that TCB can induce various immune responses, which may explain its in vivo benefits as feed additive.

Immunomodulatory effects of thymol and cinnamaldehyde in chicken cell lines

Thymol and cinnamaldehyde are phytogenic feed additives that have been developed to improve gut health, immunity and growth performance in poultry and swine. This study evaluated the immune modulating effects of a thymol and cinnamaldehyde blend (TCB) in the intestinal system of poultryin vitro, using two chicken cell lines, LMH (liver cell line) which has been used to mimic epithelial cell responses, and HD-11 (monocyte/macrophage-like). Cells with high viability (&gt;95%) from established cell lines were cultured in the presence of TCB at concentrations ranging from 1 ng/ml to 100 ng/ml. The viability, transepithelial electrical resistance (TEER) and phagocytic capacity of co-cultured LMH cells, with or without stimulation with lipopolysaccharide (LPS), was subsequently evaluated. The expression of cytokines, chemokines and pattern recognition receptors by HD-11 monocytes/macrophages was measured by RT-PCR and by proteomic analysis. TCB was well tolerated by both cell lines (cell viability &gt;90% after co-culture with TCB at 100 ng/ml for 48 h with or without LPS). Epithelial integrity of LMH cells (as assessed by TEER) was increased by TCB (10 ng/ml) after 4 h incubation, versus untreated controls, and phagocytic capacity of HD-11 cells was increased, in a dose-dependent manner (P&lt;0.05). In HD-11 cells, TCB (10 ng/ml) downregulated the relative expression of pro-inflammatory cytokines interleukin (IL)-1β, IL-6, IL-8 and the transcription factor cyclooxygenase-2 and upregulated expression of anti-inflammatory IL-10, versus untreated controls (P&lt;0.05). In summary, under the tested conditions, TCB enhanced the epithelial barrier integrity of poultry hepatocytes, increased phagocytic activity and production of anti-inflammatory cytokines by monocytes and macrophages. These results indicated how supplementing TCB in poultry diets can increase bird performance, by increasingin vivo cell membrane integrity (especially important in the gut) and assisting in immune responses, which can liberate energy for growth.

Effect of arginine supplementation on growth performance, lipid profile, and inflammatory responses of broiler chicks challenged with coccidiosis

Avian coccidiosis causes inflammation and decreases growth performance in poultry. Arginine alleviates inflammation and improves growth performance. This study aimed to evaluate the effects of different levels of arginine on growth performance, lipid profile, and inflammatory responses in broiler chicks challenged with Eimeria spp. A total of 384 one-d-old broiler chicks were assigned into eight groups and six replications per group. At 21 days of age, a mixture of Eimeria species was used for induction of challenge in the broiler chicks. Broiler chicks were divided into infected and uninfected groups and received arginine at 85, 100, 125, and 150 % of recommended level. Growth performance, serum nitric oxide (NO), pro-inflammatory cytokines, lipid profile, and faecal oocyst were further assessed. Broiler chicks challenged with coccidiosis showed lower growth performance compared to non-challenged broiler chicks in grower and finisher periods; however, those fed diets containing 125 and 150 % arginine showed better growth performance compared to broiler chicks fed with 85 and100 % levels. The challenged broiler chicks showed higher concentrations for serum NO, lipid profile, and pro-inflammatory cytokines in comparison to uninfected ones. Nevertheless, adding arginine into diet at 125 and 150 % levels increased the levels of serum NO and decreased the concentration of pro-inflammatory cytokines. In conclusion, higher levels of arginine caused anti-inflammatory effects in broiler chicks challenged with coccidiosis.

Dietary Supplementation With Magnolia Bark Extract Alters Chicken Intestinal Metabolite Levels.

Magnolia bark extract administered as a dietary supplement to poultry confers a performance and health benefit, but the mechanisms are unknown. Here, a metabolomics approach was used to identify changes in intestinal metabolite levels in chickens fed an unsupplemented diet or a diet supplemented with magnolia bark extract. Total body weight gains of chickens fed magnolia bark-supplemented diets were increased 2% (from 861 to 878 g/chicken), compared with chickens fed an unsupplemented diet. Compared with unsupplemented controls, the levels of 278 intestinal biochemicals (metabolites) were altered (165 increased, 113 decreased) in chickens given the magnolia-supplemented diet. Data for biochemicals of intestinal contents of chickens fed the unsupplemented diet clustered on the left side of the PCA score plot, while those of the magnolia-supplemented diet were separated and clustered on the right side. The biochemicals included changes in the levels of amino acids, fatty acids, peptides, and nucleosides, which provided a distinctive biochemical signature unique to the magnolia-supplemented group, compared with the unsupplemented group. These results provide the foundation for future studies to identify naturally-produced biochemicals that might be used to improve poultry growth performance.

Dietary Supplementation With Bacillus subtilis Direct-Fed Microbials Alters Chicken Intestinal Metabolite Levels.

Direct-fed microbials (DFMs) are dietary supplements containing live microorganisms which confer a performance and health benefit to the host, but the mechanisms are unclear. Here, a metabolomics approach was used to identify changes in intestinal metabolite levels in chickens fed an unsupplemented diet or a diet supplemented with B. subtilis strain 1781 or strain 747. Body weight gains of chickens fed the B. subtilis-supplemented diets were increased up to 5.6% in the B. subtilis 1781 group and 7.6% in the B. subtilis 747 group compared with chickens fed the unsupplemented diet. Compared with unsupplemented controls, the levels of 83 metabolites were altered (p < 0.05) (25 increased, 58 decreased) in chickens given the B. subtilis 1781-supplemented diet, while 50 were altered (p < 0.05) (12 increased, 38 decreased) with the B. subtilis 747-supplemented diet. Twenty-two metabolites were altered (p < 0.05) (18 increased, 4 decreased) in the B. subtilis 1781 vs. B. subtilis 747 groups. A random forest analysis of the B. subtilis 1781 vs. control groups gave a predictive accuracy of 87.5%, while that of the B. subtilis 747 vs. control groups was 62.5%. A random forest analysis of the B. subtilis 1781 vs. B. subtilis 747 groups gave a predictive accuracy of 75.0%. Changes in the levels of these intestinal biochemicals provided a distinctive biochemical signature unique to each B. subtilis-supplemented group, and were characterized by alterations in the levels of dipeptides (alanylleucine, glutaminylleucine, phenylalanylalanine, valylglutamine), nucleosides (N1-methyladenosine, N6-methyladenosine, guanine, 2-deoxyguanosine), fatty acids (sebacate, valerylglycine, linoleoylcholine), and carbohydrates (fructose). These results provide the foundation for future studies to identify biochemicals that might be used to improve poultry growth performance in the absence of antibiotic growth promoters.

Single components of botanicals and nature-identical compounds as a non-antibiotic strategy to ameliorate health status and improve performance in poultry and pigs.

In the current post-antibiotic era, botanicals represent one of the most employed nutritional strategies to sustain antibiotic-free and no-antibiotic-ever production. Botanicals can be classified either as plant extracts, meaning the direct products derived by extraction from the raw plant materials (essential oils (EO) and oleoresins (OR)), or as nature-identical compounds (NIC), such as the chemically synthesised counterparts of the pure bioactive compounds of EO/OR. In the literature, differences between the use of EO/OR or NIC are often unclear, so it is difficult to attribute certain effects to specific bioactive compounds. The aim of the present review was to provide an overview of the effects exerted by botanicals on the health status and growth performance of poultry and pigs, focusing attention on those studies where only NIC were employed or those where the composition of the EO/OR was defined. In particular, phenolic compounds (apigenin, quercetin, curcumin and resveratrol), organosulfur compounds (allicin), terpenes (eugenol, thymol, carvacrol, capsaicin and artemisinin) and aldehydes (cinnamaldehyde and vanillin) were considered. These molecules have different properties such as antimicrobial (including antibacterial, antifungal, antiviral and antiprotozoal), anti-inflammatory, antioxidant, immunomodulatory, as well as the improvement of intestinal morphology and integrity of the intestinal mucosa. The use of NIC allows us to properly combine pure compounds, according to the target to achieve. Thus, they represent a promising non-antibiotic tool to allow better intestinal health and a general health status, thereby leading to improved growth performance.

Growth performance and small intestinal morphology of native chickens after feed supplementation with tryptophan and threonine during the starter phase.

Background and Aim:The amino acid content of feed can affect growth performance of poultry during the first 6 weeks of life or the starter phase. Unlike for broiler and layer chickens, there is no information concerning standard requirements for tryptophan and threonine during the starter phase. This study aimed to determine the amount of threonine and tryptophan that should be supplemented in chicken feed to maximize growth performance and small intestinal morphology of native chickens during the starter phase.Materials and Methods:A total of 128 day-old native chickens were divided into four treatment groups with four replications based on a completely randomized design. The treatment diets were as follows: T0 (control feed); T1 (T0+0.10% L-tryptophan+0.35% L-threonine); T2 (T0+0.17% L-tryptophan+0.68% L-threonine); and T3 (T0+0.25% L-tryptophan+1.00% L-threonine).Results:The feed intake was highest for the T2 and T3 groups (123.06 and 124.18 g/bird/week, respectively). The T3 group had the highest body weight gain (49.35 g/bird/week) and carcass weight (201.44 g/bird) relative to the other groups, while the T2 and T3 groups showed similar, significant (p<0.05) increases in feed conversion ratio (2.57 and 2.51, respectively) and carcass percentage (60.88 and 60.99%/bird, respectively) compared to the other groups. This study showed villi height, crypt depth, and villi width of duodenum, the highest jejunum and ileum of T3 (1109.00±27.26, 1325.50±75.00, 1229.50±101.68, 225.50±17.52, 236.00±24.81, 219.75±17.25, 192.25±14.41, 191.75±4.79, and 184.75±6.40, respectively) compare to other treatment.Conclusion:These results indicate that supplementation of feed with 0.17% L-tryptophan and 0.68% L-threonine positively affected the growth performance and small intestinal morphology of native chickens during the starter phase.

Effects of Direct Fed-Microorganisms and Enzyme Blend Co-Administration on Growth Performance in Broilers Fed Diets With or Without Antibiotics

SUMMARY Direct-Fed Microorganisms (DFM) and exogenous enzymes have been demonstrated to improve growth performance in poultry and are potentially important components of management programs for antibiotic-free (ABF) poultry production. In this study, we evaluated the effect of a feed additive composed of a DFM product containing spores of 3 Bacillus amyloliquefaciens strains and a multi-enzyme complex of xylanase, amylase, and protease on the performance of broilers with or without an antibiotic growth promoter (AGP), either bacitracin methylene disalicylate (BMD) or virginiamycin. Growth performance of broilers fed one of 6 treatments arranged in a 3 (AGP) × 2 (additive) factorial was evaluated over a 42 d production period. Overall, administration of the feed additive improved body weight, body weight gain, and feed conversion ratio. Administration of either antibiotic significantly reduced cumulative FCR when compared to the control, while BMD administration reduced foot pad lesions as compared to the control. Our results suggest the co-administration of DFM and enzymes may be an important component of ABF poultry production programs and the benefits of their use are not dependent on the presence or absence of AGP.

Assessment of the role of silver nanoparticles in reducing poultry mortality, risk and economic benefits

The paper reports a study conducted in two poultry farms of West Medinipur district, West Bengal, India with a target to reduce the prevalence of pathogenic bacteria, Escherichia coli (E. coli) in the poultry drinking water by the application of a formulation of silver nanoparticles (AgNPs). The lab-synthesized AgNPs had an average size of 15 nm. The minimum inhibitory concentration (MIC) of AgNPs for the farm water was considered 50 mg/L. Two poultry farms A and B were selected as case and control groups, respectively, for sampling. The study was designed with three replications. In the case group, the supplied water, generally used for the poultry in both the cases, was dosed with synthesized AgNPs throughout the study period, while in the control group the untreated water was supplied for drinking by the poultry. The study also included the impact of AgNP dose on factors of standard poultry growth performance like mortality count, feed intake (FI), body weight (BW) and food conversion ratio (FCR). The observations revealed that, compared to the control, in the case group the percentage mortality rate was reduced significantly (p 0.05). The results of average 4.92% mortality of case poultry, compared to the average 14.13% mortality in control, would potentially provide substantial economic benefit to the farmers. Moreover, the consumption risk assessment surmised that a 1.2 µg/g of silver retained on the poultry and hazard quotient (Ag) was 0.34 (< 1) which is considered non-toxic on the poultry, and the poultry is fit for human consumption. A cost–benefit analysis weighs in favour of AgNP use by the farmers to particularly deal with the effects of E. coli.