Control Birds Research Articles

A probiotic and mixed-enzymes combination reduces the inflammatory response, faecal shedding and systemic spread of Campylobacter jejuni in broilers

Recent research has questioned the notion that Campylobacter jejuni is a harmless resident of the avian gastrointestinal tract (GIT). The following trial examined the effect of dietary supplementation with a mixture of enzymes and Bacillus-based probiotics on growth performance, C. jejuni colonisation, GIT immune responses, faecal shedding and extra-intestinal spread in broilers. Fifty-eight, Ross 308 d-old broilers were randomly assigned to one of four treatments, giving 14 or 15 birds/pen. Birds were given nutritionally complete, complex, phased diets unsupplemented (two treatments) or supplemented (two treatments) with a multi-enzyme containing 2,000 U/kg xylanase, 200 U/kg amylase and 4,000 U/kg protease, and 75,000 cfu/g of a combination of three strains of Bacillus amyloliquefaciens. One control and one supplemented diet group contained birds orally challenged with 105 cfu C. jejuni strain M1 on d 21 of age. Among challenged birds, the mixed-enzymes and probiotic combination numerically reduced faecal C. jejuni shedding (-98% vs challenged control) three days-post-infection (d.p.i.), and at 7 d.p.i. numerically reduced C. jejuni colonisation of the ileal mucosa (-1000-fold vs control) and totally inhibited systemic spread of C. jejuni to the liver, compared to the control (P<0.05). It suppressed early pro-inflammatory chemokine response seen in the ileum, caecum and caecal tonsil tissues (at 3 d.p.i.) in challenged control birds (-18 to -46-fold; P<0.05) and altered expression of pro-inflammatory (IL-1β, IL-6, IL-17A and IL-17F) and regulatory (IL-10 and TGF-β) cytokines. The data demonstrated inhibition of a sustained pro-inflammatory response to C. jejuni infection and improved intestinal barrier integrity in supplemented birds. This highlighted the importance of looking beyond simple measurements of feed conversion and body weight gain when seeking to understand the effects and mode of action of poultry dietary interventions. Achieving a favourable balance between the gut, immune function, microbiome and nutrition should be the goal for achieving good gastrointestinal health and optimal performance.

POSTRELEASE SURVIVAL OF CALIFORNIA BROWN PELICANS (PELECANUS OCCIDENTALIS CALIFORNICUS) FOLLOWING OILING AND REHABILITATION AFTER THE REFUGIO OIL SPILL.

Oil spills represent a continued threat to marine wildlife. Although the public expects, and the State of California, US requires, oiled animals to be rescued for rehabilitation and release, scientists have questioned the welfare and conservation value of capture and rehabilitation of oiled wildlife, based on poor postrelease survival documented in the few available studies. In May 2015, Plains Pipeline 901 spilled >100,000 gallons of oil near Refugio State Beach, California. Many California Brown Pelicans (Pelecanus occidentalis californicus) were oiled; capture and rehabilitation efforts began within 1 d. Ultimately, 65 live birds were captured, including 50 pelicans. Forty-six pelicans survived and were released. Of these, 12 adults (six male, six female) were fitted with solar-powered GPS satellite Platform Terminal Transmitters (PTT) and released in June 2015. In early July, we captured eight adult (three male, four female, one unknown), unoiled pelicans from the Ventura, California area. These control birds were similarly instrumented and released immediately. At 6 mo after release, PTTs from nine of 12 oiled pelicans and six of eight control pelicans were still transmitting; at 1 yr, those numbers decreased to two of 12 and two of eight, respectively. Survival analysis revealed no difference in survival between oiled and control birds. Although our sample size is limited, these data demonstrate that most oiled and rehabilitated pelicans can survive for 6 mo following release, and some individuals can survive over 1 yr.

Learning about construction behaviour from observing an artefact: can experience with conspecifics aid in artefact recognition?

Observation of or interaction with the enduring products of behaviour, called 'social artefacts' (e.g. an abandoned nest) is a potential source of social information. To learn from an artefact, that artefact needs to be recognized as the product of a behaviour that can provide relevant information (i.e. the artefact should be recognized as a nest). We used zebra finches (Taeniopygia guttata) to experimentally test whether observing a conspecific using a nest facilitates recognition of a future artefact as a source of social information. We manipulated the opportunity to form an association between a conspecific and their nest: half the subjects observed a pair of birds incubating eggs in a nest, the control subjects did not get this opportunity. Then, subjects observed an artefact made of their non-preferred colour and finally were allowed to build a nest. We predicted that the subjects given the opportunity to associate a nest with conspecifics would copy the colour of the artefact (i.e. use social information). We found that subjects who had the opportunity to learn what a nest is used social information obtained from the artefact by increasing their use of the artefact-material colour after artefact observation, while control birds did not. These data suggest that forming an association between conspecifics and their nest facilitates recognition of an artefact as a nest affecting how first-time builders use social information. This finding is important because it demonstrates that social learning is not limited to observing behaviour, but rather inferring behaviour from an artefact.

Immune Responses Induced in Chickens by Capsular Extract of P. Multocida Isolated From Farm Rat

An experiment was conducted to investigate the immune response induced in chickens by capsular extract of Pasteurella multocida isolated from rats wandering in and around the poultry farms. The rat isolate of P. multocida was isolated and identified by cultural, morphological, and biochemical characteristics, followed by capsular extract preparation and experimental vaccine development. The isolated P. multocida was found Gram-negative, non-motile, non-spore forming rod occurring singly or pains and occasionally as chains or filaments in Gram’s-staining method. The isolates consistently produced acid from dextrose, sucrose and mannitol but not fermented maltose or lactose. The Capsular antigen was extracted and confirmed by acriflavine test. Finally, experimental fowl cholera vaccine was prepared. Primary vaccination was performed at the dose rate of 5.6×107 CFU/ml through intramuscular and subcutaneous routes in birds of group A (10 birds) and group B (10 birds) and group C (10 birds) were control birds. Secondary vaccination was similarly performed after 15 days of primary vaccination in groups A and B. The levels of pre-vaccination and post-vaccination sera were determined by passive haemagglutination test. The passive haemagglutination antibody titre was recorded on 15 and 35 days of post vaccination in groups A and B. It was demonstrated that experimental capsular extract fowl cholera vaccine conferred 100% protection (p<0.01) against challenge infection and found to be safe. It could be suggested that after thorough field trial, the experimentally prepared capsular extract FC vaccine using rat isolate of P. multocida may be used side by side with conventional FC vaccine.
 Res. Agric., Livest. Fish.8(1): 117-124, April 2021

Eat yourself sexy: how selective macronutrient intake influences the expression of a visual signal in common mynas.

Producing colored signals often requires consuming dietary carotenoid pigments. Evidence that food deprivation can reduce coloration, however, raises the question of whether other dietary nutrients contribute to signal coloration, and furthermore, whether individuals can voluntarily select food combinations to achieve optimal coloration. We created a two-way factorial design to manipulate macronutrient and carotenoid access in common mynas (Acridotheres tristis) and measured eye patch coloration as a function of the food combinations individuals selected. Mynas had access to either water or carotenoid-supplemented water and could either eat a standard captive diet or choose freely between three nutritionally defined pellets (protein, lipid or carbohydrate). Mynas supplemented with both carotenoids and macronutrient pellets had higher color scores than control birds. Male coloration tended to respond more to nutritional manipulation than females, with color scores improving in macronutrient- and carotenoid-supplemented individuals compared with controls. All mynas consuming carotenoids had higher levels of plasma carotenoids, but only males showed a significant increase by the end of the experiment. Dietary carotenoids and macronutrient intake consumed in combination tended to increase plasma carotenoid concentrations the most. These results demonstrate for the first time that consuming specific combinations of macronutrients along with carotenoids contributes to optimizing a colorful signal, and point to sex-specific nutritional strategies. Our findings improve our knowledge of how diet choices affect signal expression and, by extension, how nutritionally impoverished diets, such as those consumed by birds in cities, might affect sexual selection processes and, ultimately, population dynamics.

Effect of New Feed Additive on Growth Performance and Immunoglobulin of Broilers

Recently postbiotics and inulin combinations used as a new feed additives. Within current study, we examined the effect of new feed additives on growth performance and immunoglobulin of broiler. 216 one day-old male chicks were distributed into six treatments, six replicates/six birds in cage system, negative control (NC) without additive, positive control (PC) basal diet + antibiotic, Basal diet + 0.15% postbiotic + 1.0% inulin (T1), Basal diet + 0.3% postbiotic + 1.0% inulin (T2), Basal diet + 0.45% postbiotic + 1.0% inulin (T3), Basal diet + 0.6% postbiotic + 1.0% inulin (T4) and nourished for six weeks. Results demonstrated that birds that fed T3 and T1 had greater (p<0.05) body weight in the starter and finisher phase than negative control birds. The outcomes from the current study exhibited that the immune response increased especially at the starter phase for both types of immunoglobulin. We conclude that combinations of postbiotic and inulin are potential substitutes for antibiotic in poultry industry as growth promoters.

Capromorelin, a ghrelin receptor agonist, increases feed intake and body weight gain in broiler chickens (Gallus gallus domesticus)

Ghrelin is a hormone that induces orexigenic effects in mammals. However, in avian species, there is scant and conflictive results on the effect of ghrelin on feed intake (FI). Therefore, we evaluated the effect of a ghrelin receptor agonist (capromorelin) on FI, ADG, water intake (WI), animal behavior and concentrations of ghrelin, glucose, growth hormone (GH) and insulin in broiler chickens. One-day-old male broilers were reared as recommended by the industry. At 4 wk of age (experimental day 0; D0), birds were blocked by weight and randomly assigned to 3 treatments in 2 identical trials. Control birds received a vehicle control solution containing 0 mg/kgBW/d of capromorelin. Birds in treatments 2 and 3 received capromorelin at target doses of 6 or 12 mg/kgBW/d of capromorelin (n = 27). FI and WI were measured 3 times a day at 0700 h (Period 1; P1), 1200 h (P2) and 1700 h (P3), while BW was recorded daily. Blood samples were collected on D-1 and D5. Bird behavior (pecking, sitting and standing) was evaluated for 9 h on D2. Data were analyzed using a randomized complete block design with repeated measures over time. Orthogonal polynomial contrasts were used to determine linear and quadratic effects of increasing levels of capromorelin. Polynomial contrasts showed that capromorelin doses linearly increased FI (P = 0.002) and ADG (P = 0.019). There were no treatment, day or treatment x d interactions on glucose, ghrelin and GH concentrations. However, there was a treatment x d interaction (P = 0.041) on insulin concentrations. Concentrations of insulin were higher on D5 for the 0 and 12 mg/kgBW/d treatments as compared with D-1. Polynomial contrasts showed that capromorelin doses linearly increased number of pecks/h (P = 0.018). Per hour FI and WI was higher during P1 (i.e., 0700−1200) as compared to P2 and P3 (P < 0.001). Our observations suggest that capromorelin linearly increases feed intake; thus, the same effect of that reported in mammalian species.

Antimicrobial, immunomodulatory and hepatomodulatory effects of aqueous extracts of Petiveria alliacea root and leaf on growing pullets

Aim of study: To evaluate antimicrobial, immunomodulatory and hepatomodulatory effects of aqueous extracts of Petiveria alliacea L. (Guinea hen weed) root and leaf on growing pullets.Area of study: Abeokuta, Nigeria.Material and methods: Two hundred and eighty eight eight-weeks-old Isa-brown pullets were divided into eight treatments which consisted in birds administered root extracts or leaf extracts at four different concentrations (0, 15, 30 and 45 ɡ/L). Each treatment was replicated three times with 12 pullets per replicate.Main results: Oocyst counts was lower (p&lt;0.05) in pullets administered root extract (78.42 opɡ) compared with leaf extract (103.58 opɡ). Oocyst counts was lower (p&lt;0.05) in pullets administered 30 and 45 ɡ/L root or leaf extract compared with other treatments. Bacteria counts reduced (p&lt;0.05) in pullets administered root extract compared with leaf extract. Pullets administered 45 ɡ/L root extract recorded lowest (p&lt;0.05) bacteria count. Bursa and thymus weights increased in pullets administered root or leaf extract compared with the control. Pullets administered 30 and 45 ɡ/L root or leaf extract had highest (p&lt;0.05) antibody titre against Newcastle disease vaccine 8.80, 8.86, 8.74 and 8.80 (log2) respectively. There was fatty infiltration in liver of control birds, while hepatocytes appeared normal in liver of pullets administered P. alliacea extracts.Research highlights: P. alliacea root and leaf extracts at 45 ɡ/L performed best as antimicrobial, immune-stimulating and hepato-protective agent in pullets. This study highlights P. allicaea as a valuable antimicrobial and immunostimulating agent in poultry production.

Transcriptome Analysis Revealed Ameliorative Effects of Bacillus Based Probiotic on Immunity, Gut Barrier System, and Metabolism of Chicken under an Experimentally Induced Eimeria tenella Infection

In this study, we performed transcriptome analysis in the cecum tissues of negative control untreated non-challenged (NC), positive control untreated challenged (PC), and Bacillus subtilis (B. subtilis) fed challenged chickens (BS + ET) in order to examine the underlying potential therapeutic mechanisms of Bacillus based probiotic feeding under an experimental Eimeria tenella (E. tenella) infection. Our results for clinical parameters showed that birds in probiotic diet decreased the bloody diarrhea scores, oocyst shedding, and lesion scores compared to positive control birds. RNA-sequencing (RNA-seq) analysis revealed that in total, 2509 up-regulated and 2465 down-regulated differentially expressed genes (DEGs) were detected in the PC group versus NC group comparison. In the comparison of BS + ET group versus PC group, a total of 784 up-regulated and 493 down-regulated DEGs were found. Among them, several DEGs encoding proteins involved in immunity, gut barrier integrity, homeostasis, and metabolism were up-regulated by the treatment of probiotic. Functional analysis of DEGs also revealed that some gene ontology (GO) terms related with immunity, metabolism and cellular development were significantly affected by the exposure of probiotic. Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis showed that the DEGs in the cecum of B. subtilis-fed challenged group were mainly participated in the pathways related with immunity and gut barrier integrity, included mitogen-activated protein kinase (MAPK) signaling pathway, toll-like receptor (TLR) signaling pathway, extracellular matrix (ECM)–receptor interaction, tight junction, and so on. Taken together, these results suggest that Bacillus based probiotic modulate the immunity, maintain gut homeostasis as well as barrier system and improve chicken metabolism during E. tenella infection.

Training level reveals a dynamic dialogue between stress and memory systems in birds

Chronic stress profoundly affects forms of declarative memory, such as spatial memory, while it may spare non-declarative memory, such as cue-based memory. It is known, however, that the effects of chronic stress on memory systems may vary according to the level of training of an individual was submitted. Here, we investigated, in birds, how chronic stress impact spatial and cue-based memories according to training level. For that, control and chronically stressed Japanese quail were trained in a task that could be solved using spatial and cue-based memory and tested for their memory performance after 5 and 15 training days (initial training and overtraining, respectively) and following an emotional challenge (exposure to an open field). Our results showed that, compared to control quail, chronic stress impacted negatively spatial memory performances in stressed birds after initial training, but these differences were lowered after overtraining. Control birds seemed to shift from spatial to cue-based memory to solve the task across overtraining. However, an emotional challenge before testing reinstated the negative impact of chronic stress on spatial memory performances between the groups, revealing that chronic stress/overtraining did not eliminate the spatial memory and differences caused by stressors can reemerge depending on the individual’s immediate psychological state. Contrary to spatial memory, cue-based memory was not affected in chronically stressed birds compared to control birds in any test occasion, confirming its resistance against the negative effects of chronic stress. Altogether these findings reveal a dynamic dialogue between stress, training level, and memory systems in birds.

THE USE OF TWO EMPIRICAL METHODS OF SUBSTITUTION OF FEEDSTUFFS: PARBOILED CASSAVA PEEL MEAL VERSUS MAIZE IN THE DIETS OF GROWTH COCKERELS

The effect of two empirical methods of substituting maize with parboiled cassava peel meal (PCPM) in the diets of 168, 11-week old Isa Brown cockerels were examined in a 3-week experiment. The control diet A contained 40% maize while the proportion of maize in the control diet was replaced with PCPM at the graded levels of 20% of diets B and C, 30% of diets D and E and 40% of diets F and G with and without regard to the energy content of PCPM respectively. Consequently, diets A, B, D and F contained metabolisable energy (ME) content of about 2600s kcal/kg while diets C, E and G contained ME of about 2400, 2300 and 2200 kcal/kg respectively. The calculated crude protein (CP) contents of all diets were similar (17% CP). The results on the performance characteristics studied did not reveal any adverse effect of the two empirical methods of substitution of maize with PCPM in the diets of growing cockerels. The growth rate and feed conversion ration of birds fed on diets containing 50 and 75% of PCPM at the expense of maize using the two substitution methods were similar to those of the control birds. However, there was depression in feed intake at the replacement levels beyond 50%. Thus, it was concluded that the two substitution methods could be used to replace maize with PCPM at the level of 75% of the former without adverse effect on weight gain and feed conversion ratio in the growing cockerels during the early stage of growth.

Direct Evidence That Sunbirds' Gut Microbiota Degrades Floral Nectar's Toxic Alkaloids.

Orange-tufted sunbirds (Cinnyris osea) feed on the nectar of the tobacco tree (Nicotiana glauca) which contains toxic pyridine alkaloids characterized by high concentrations of anabasine and much lower concentrations of nicotine. We aimed at determining whether the gut microbiota of sunbirds harbors bacterial species that enable the birds to cope with these toxic alkaloids. An in vivo experiment that included 12 birds showed that inducing dysbiosis in sunbirds’ guts by the addition of sulfamethoxazole and trimethoprim, significantly reduced the birds’ ability to degrade anabasine (n = 3) compared to control birds (n = 3) with undisturbed microbiota. Sunbirds whose gut bacterial communities were altered by the antibacterial agents and who were fed with added nicotine, also showed a lower percentage of nicotine degradation (n = 3) in their excreta compared to the sunbirds with undisturbed microbiota (n = 3), though this difference was not significant. In an in vitro experiment, we studied the ability of Lactococcus lactis, Enterobacter hormaechei, Chryseobacterium gleum, Kocuria palustris, and Methylorubrum populi that were isolated from sunbirds’ excreta, to degrade anabasine and nicotine. By using gas chromatography-mass spectrometry (GC-MS) analysis, we successfully demonstrated, for the first time, the ability of these species to degrade the focal secondary metabolites. Our findings demonstrate the role of gut bacteria in detoxifying toxic secondary metabolites found in the N. glauca nectar. The degradation products may supply the birds with nitrogen which is scarce in nectar-rich diets. These findings support another role of bacteria in mediating the interactions between plants and their pollinators.

Dose-related morphological changes in the epididymal region of sexually active adult male Japanese quail treated with di-n-butyl phthalate (DBP) commencing during the pre-pubertal stage

Di-n-butyl phthalate (DBP) is widely used as a plasticizer in personal care and medical products and is known to induce toxicity in the male reproductive organs in both mammals and birds. In this study, there was investigation of the effects of DBP on the epithelium of the rete testis, proximal, and distal efferent ductules and epididymal duct of adult Japanese quail (Coturnix japonica) following treatment with varying doses during the pre-pubertal and peri-pubertal periods. Pre-pubertal quail (n = 25) 4 weeks post-hatching were dosed orally with 10, 50, 200 and 400 mg DBP/kg/d, for 30 days and control birds were administered corn-oil only (n = 5 per group). Histo-metrically, there was lesser (P < 0.001) epithelial heights of the rete testis and efferent ductules in all quail DBP-treated groups, but not in the epididymal duct epithelium. There were no morphological change effects as a result of DBP treatments in the rete testis epithelium, while there were epithelial cytoplasmic vacuoles detected in the distal efferent ductule and epididymal duct of birds treated with 50, 200 and 400 mg DPB/kg/d. There were several lesions, including degenerative changes, cytoplasmic vacuoles, apoptosis and autophagy in the epithelium of the proximal efferent ductule in quail treated with 200 and 400 mg DBP/kg/d. Overall, the results indicate that treatment with DBP during the pre-pubertal period induced dose-dependent histometric and morphological changes in the epithelium of the epididymal region. It is concluded that the proximal efferent ductule was a highly sensitive component of the epididymal tissues of Japanese quail following treatment with DBP during the pre-pubertal period.

Effect of oxidized β-carotene on the growth and feed efficiency of broilers

Fully oxidized β-carotene (OxBC) containing β-carotene-oxygen copolymers is proposed as an alternative to antimicrobial growth promoters. Two trials were conducted to determine the efficacy of OxBC in enhancing growth and feed intake (FI) in male and female Ross × Ross 308 broilers in Ontario, Canada, and in Ross 308 male broilers in the United Kingdom. In the first trial, 0, 1, 2, or 5 ppm OxBC were added to diets in a 20% cornstarch premix, whereas in the second trial, 0, 2, or 5 ppm OxBC were added in a 1% cornstarch or 1% corncob grits premix. In trial 1, 2, and 5 ppm OxBC improved bird final body weights (BW) compared with the unsupplemented, nonmedicated (no bacitracin methylene disalicylate included), negative control birds after 39 d of feeding under commercial conditions (P < 0.05). All levels of OxBC improved feed conversion (FCR) during the finisher period (P < 0.05), whereas 2 and 5 ppm OxBC enhanced FCR relative to the negative control group during the full production cycle (P < 0.05). Average daily FI was not affected by OxBC, whereas 2 and 5 ppm OxBC increased broiler average daily gain (ADG) (P < 0.05). Oxidized β-carotene did not affect bird mortality. The optimal OxBC dose was 2 ppm under the conditions used. In trial 2, 2 or 5 ppm OxBC on cornstarch and 5 ppm OxBC on corncob grits improved ADG, BW, and FI when fed for 35 d, as compared with the negative, nonmedicated control (P < 0.05). Feed conversion was not improved in the OxBC groups compared with the control group (P > 0.05). There were no differences among the 3 OxBC groups (P > 0.05). When birds were fed 2 ppm OxBC on corncob grits, the overall ADG, BW, and FI were lower than the respective control values (P < 0.001). Overall bird mortality was higher than expected for all groups, including the control group, but no dose effect was evident. Cornstarch was the preferred carrier for OxBC, and 2 ppm OxBC was the optimal dose under the conditions used.

Expeller-Pressed Canola (Brassica napus) Meal Modulates the Structure and Function of the Cecal Microbiota, and Alters the Metabolome of the Pancreas, Liver, and Breast Muscle of Broiler Chickens.

Simple SummaryThe impact of a broiler chicken diet that is supplemented with canola meal (CM) on the cecal microbiota, growth, and metabolome of broiler chickens was examined. CM did not affect feed consumption, weight gain, nor the richness, evenness, or diversity of the cecal bacterial community. However, CM affected the structure of the bacterial microbiota, the concentrations of short-chain fatty acids (SCFAs) were elevated, and the abundance of bacterial taxa known to ferment dietary fiber were more abundant in the ceca of birds fed the CM diet. Nuclear magnetic resonance spectroscopy metabolomics was applied, and a number of metabolites that were associated with SCFA metabolism were differentially regulated in cecal digesta. The supplementation of diet with CM also affected the metabolic profiles of the pancreas, liver, and breast muscle (e.g., metabolites that are associated with energy production, protection against oxidative stress, and pathways of amino acid and glycerophospholipid metabolism). In summary, broiler chickens that were fed a diet supplemented with CM showed equivalent feed consumption and growth, but CM affected the composition and function of the cecal microbiota, and the metabolome of the pancreas, liver, and breast muscle of birds indicating the possibility of an increased disease risk. The study also demonstrated the utility of using metabolomics to ascertain impacts of diet on the microbiota and host tissues, and identified biomarkers to facilitate subsequent evaluation in production settings.The inoculation of one-day-old broiler chicks with the cecal contents from a mature broiler breeder resulted in a highly diverse and uniform cecal bacterial community. CM did not affect feed consumption, weight gain, nor the richness, evenness, or diversity of the cecal bacterial community. However, the structure of the bacterial community was altered in birds fed the CM diet. Although the CM diet was formulated to contain equivalent metabolizable energy to the control diet, it contained more dietary fiber. The abundance of bacterial families, including those that are known to contain species able to metabolize fiber was altered (e.g., bacteria within the families, Methanobacteriaceae, Atopobiaceae, Prevotellaceae, Clostridiales Family XIII, Peptostreptococcaceae, and Succinivibrionaceae), and concentrations of SCFAs were higher in the ceca of birds fed the CM diet. Moreover, concentrations of isoleucine, isobutyrate, glutamate, and 2-oxoglutarate were higher, whereas concentrations of phenyllactic acid, indole, glucose, 3-phenylpropionate, and 2-oxobutyrate were lower in the digesta of chickens that were fed CM. The metabolic profiles of pancreas, liver, and breast muscle tissues of birds fed the CM diet differed from control birds. Metabolites that were associated with energy production, protection against oxidative stress, and pathways of amino acid and glycerophospholipid metabolism had altered concentrations in these tissues. Some of the observed changes in metabolite levels may indicate an increased disease risk in birds fed the CM diet (e.g., pancreatitis), and others suggested that birds mounted metabolic response to offset the adverse impacts of CM (e.g., oxidative stress in the liver).

Bacillus amyloliquefaciens TL Downregulates the Ileal Expression of Genes Involved in Immune Responses in Broiler Chickens to Improve Growth Performance.

Bacillus amyloliquefaciens TL promotes broiler chicken performance by improving nutrient absorption and utilization and reducing intestinal inflammation. In this study, RNA-sequencing (RNA-seq)-based transcriptomes of ileal tissues collected from probiotic-fed and control broiler chickens were analyzed to elucidate the effects of the probiotic B. amyloliquefaciens TL, as a feed additive, on the gut immune function. In total, 475 genes were significantly differentially expressed between the ileum of probiotic-fed and control birds. The expression of genes encoding pyruvate kinase, prothymosin-α, and heat stress proteins was high in the ileum of probiotic-fed birds (FPKM > 500), but not in the control group. The gene ontology functional enrichment and pathway enrichment analyses revealed that the uniquely expressed genes in the control group were mostly involved in immune responses, whereas those in the probiotic group were involved in fibroblast growth factor receptor signaling pathways and positive regulation of cell proliferation. Bacillus amyloliquefaciens TL downregulated the expression of certain proinflammatory factors and affected the cytokine–cytokine receptor interaction pathway. Furthermore, B. amyloliquefaciens TL in broiler diets altered the expression of genes involved in immune functions in the ileum. Thus, it might contribute to improved broiler growth by regulating the immune system and reducing intestinal damage in broilers.

Comparative immunogenicity of local and imported infectious bursal disease (IBD) vaccines administered to chicks at different days of age

A comparative immunogenicity and efficacy study of local and imported infectious bursal disease (IBD) vaccines administered to chicks (cockerels) at varying regimes (10 and 18, 10 and 28, 14 and 35 days of age) was carried out. The test birds were challenged seven days after the booster dose of the IBD vaccine by administering six drops of 20% suspension of infected Bursa of Fabricius homogenate in saline intraocularly. The results showed that the control (unvaccinated) birds as well as those that were vaccinated on the 14 and 35" days of life showed signs of IBD and up to 80% of the birds in these two categories died two days post-challenge. The birds that were vaccinated on the 10% and 18and 10and 28 days of life were apparently protected from clinical infection as there was no morbidity or mortality among them as a result of the IBD virus challenge. The results of the study suggest that both local and imported vaccines are immunogenic and vaccination of chicks on the 10h and 184 and 10h and 28 days of life is effective and protective.

Comparative immunogenicity of local and imported infectious bursal disease (IBD) vaccines administered to chicks at different days of age

A comparative immunogenicity and efficacy study of local and imported infectious bursal disease (IBD) vaccines administered to chicks (cockerels) at varying regimes (10 and 18, 10 and 28, 14 and 35 days of age) was carried out. The test birds were challenged seven days after the booster dose of the IBD vaccine by administering six drops of 20% suspension of infected Bursa of Fabricius homogenate in saline intraoccularly. The results showed that the control (unvaccinated) birds as well as those that were vaccinated on the 14th and 35th days of life showed signs of IBD and up to 80% of the birds in these two categories died two days post-challenge. The birds that were vaccinated on the 10th and 18th and 10th and 28th days of life were apparently protected from clinical infection as there was no morbidity or mortality among them as a result of the IBD virus challenge. The results of the study suggest that both local and imported vaccines are immunogenic and vaccination of chicks on the 10th and 18th and 10th and 28th days of life is effective and protective. Keywords: Chickens, IBD, vaccines, vaccination, Immunogenicity

Anthelmintic drugs modulate the acute phase immune response but not the microbiota in wild Song Sparrows

Abstract Co-infection with microparasites (e.g., bacteria) and macroparasites (e.g., helminths) is often the natural state for wild animals. Despite evidence that gut helminths can bias immune responses away from inflammatory processes, few field studies have examined the role that helminths, or their potential interactions with internal microbial communities, play in modulating immunity in free-living, wild birds. Here, we used anthelmintic drugs to treat wild Song Sparrows (Melospiza melodia) for helminth infections and measured markers of systemic inflammation (heterothermia and locomotor activity) in response to an immune challenge with lipopolysaccharide (LPS), a cell wall component of gram-negative bacteria. Using birds from a population that previously showed high helminth prevalence, we monitored skin temperature and activity remotely using automated radio telemetry. We also collected cloacal swabs to determine whether drug treatment was associated with changes in the cloacal microbiota, and whether cloacal microbial community structure was associated with the severity of birds’ immune responses. Because helminths can reduce the severity of inflammatory immune responses in other species, we predicted that in comparison with untreated control birds, anthelmintic-treated birds would be more lethargic and display higher fevers when challenged with LPS. Consistent with these predictions, anthelmintic-treated birds expressed higher fevers in response to immune challenge. However, all LPS-challenged birds decreased locomotor activity to a similar degree, regardless of anthelmintic treatment. Although several individual indicator bacterial taxa were strongly associated with anthelmintic treatment, this treatment did not alter overall bacterial alpha- and beta- diversity. Similarly, we did not find evidence that bacterial community diversity influenced the severity of immune responses to LPS. These results suggest that under field conditions, natural helminth infection can reduce the severity of songbirds’ thermoregulatory responses (fever) during an immune challenge, without major impacts on internal microbial communities or behavioral responses to infection.

Performance of laying birds fed diets containing forage meal of Tithonia diversifolia (Hemsl A. Gray) and antibiotics

A study was conducted to evaluate the effects of dietary inclusion of the forage meal of Tithonia diversifolia with or without antibiotic on the laying performance and egg quality of birds for a period of eleven weeks. T. diversifolia is also known as wild sunflower leaf. Wild sunflower leaf meal (WSFLM) was incorporated in the diets at 75g/kg (basal diet). Streptomycin and penicillin were added to basal diet at 100 ppm each. Mixture of penicillin and streptomycin, each at 100 ppm added to the fourth diet. Control diet neither contained WSFLM nor antibiotic. The results of weekly performance at first week of the study, showed that there were significant (P&lt;0.01) increases for egg production, hen day production and feed efficiency for birds fed diets containing WSFLM, while egg weight and feed intake were not affected. Haugh Unit (P &lt;0.05) and egg breadth (P &lt;0.01) 8th week, whereas food consumption at second (P &lt;0.05), fourth and fifth weeks (P &lt;0. 01) were all significantly influenced by the dietary treatments. Yellow pigmentation of egg yolks was significantly (P &lt;0.01) enhanced by WSFLM throughout 77 days. The summary of the data at the end of the study indicated that WSFLM significantly (P &lt;0.01) enhanced egg. Weight, egg production, Egg yolk and hen day production (P &lt; 0.05). Control birds and those fed basal diets with antibiotic significantly (P &lt;0.05) retained protein and ether extract than those fed basal diet. Supplementation of basal diet with either penicillin or streptomycin positively affected the egg production and egg weight at 77th day, whereas the mixture of the two antibiotics adversely affected the performance of the birds. It is therefore advisable that WSFLM at 75 g kg-1 in combination with either penicillin or streptomycin at 100ppm may be included in the diet of laying birds