Commercial Layer Research Articles

Effect of Organic Selenium-Enriched Yeast on Relieving the Deterioration of Layer Performance, Immune Function, and Physiological Indicators Induced by Heat Stress.

Heat stress (HS) induces deleterious effects on the performance of laying hens and causes economic losses for poultry industry. This study was carried out to investigate the organic effect of selenium-enriched yeast (SY) on relieving the performance, immunity and physiological deterioration induced by heat stress in laying hens. A total of 324, 28-week-old, Hy-Line Brown commercial chicken layers were randomly distributed into 4 treatments according to a 2 × 2 factorial design, with 9 hens × 9 replicates per treatment (n = 81). From 30 to 34 weeks of age, layers were exposed to 2 temperature treatments (the HS treatment groups): a thermoneutral temperature at 24°C and a heat stress at 35°C. Layers were further assigned into the 2 subgroups according to dietary supplementation with organic selenium-enriched yeast (the SY treatment groups) at either 0 or 0.4 mg/kg diet. Results indicated that all the aspects of the layer performance during the experimental period were impaired by exposure to HS, while SY supplementation improved the layer performance in both the HS and non-HS layers. Intestinal villi disruptions and liver necrotic hepatocytes were observed in the layers exposed to HS, while villi integrity and hepatocytic normality were enhanced by SY treatment. A significant (P < 0.05) decrease in the total leukocyte count, sheep red blood cell (SRBC) antibody titer, and T- and B-lymphocyte proliferation along with an increase in the heterophils/lymphocytes (H/L) ratio were observed in the HS layers compared to non-HS layers. On the contrary, SY treatment significantly (P < 0.05) improved the immune function traits in both the HS layers and non-HS layers. Furthermore, the SY treatment plays an important role in mitigating the oxidative stress and inflammation induced by HS, displaying lower levels of plasma corticosterone, lipid peroxidation, interleukin-1β, and tumor necrosis factor-α in HS layers supplemented with SY compared to HS layers without SY supplementation. These results conclude that addition of SY to the diet of laying hens could be applied as a potential nutritional approach to relieve the deterioration effects of heat stress on the immunity, physiological status, and productive performance of laying hens.

Practices and issues of moulting programs for laying hen: A review

ABSTRACT 1. Moulting is a natural physiological process in birds when they shed their old feathers and replace them with new ones, and is followed by reproductive quiescence resulting in reduced egg production. Different birds undergo moulting at different points in their life. Some birds have seasonal moulting while some moult at the end of their breeding cycle. This review will mainly focus on moulting practices associated with commercial layer birds because, in all other bird types, this is not managed. 2. Commercial farms commonly analyse the cost-benefit ratio to decide the time and method to adopt for moulting. Commercial layer farms adopt different practices to force birds out of moult and restart the production cycle. Animal welfare groups consider this as stressful and against animal welfare, raising questions about the ethics of this practice. 3. Many studies have been conducted using complete or partial feed withdrawal and non-feed withdrawal programs to measure their effectiveness in maintaining animal welfare, economy, and post-moult performance in mind. 4. Animal welfare should not be compromised during moulting. The United States Egg Producers and other such groups from the United Kingdom and Europe have decided to sell eggs produced only through a non-feed withdrawal moulting programs.

Development of Polymer-Ceramic-Metal Graded Acoustic Matching Layers via Cold Sintering.

A family of three phase, polymer-ceramic-metal (Poly-cer-met) electrically conducting composites was developed via cold sintering for acoustic matching application in medical ultrasound transducers. A range of acoustic impedance ( Z ) between MRayl with low attenuation (<3.5 dB/mm, measured at 10 MHz) was achieved in composites of zinc oxide, silver, and in thermoplastic polymers like Ultem polyetherimide (PEI) or polytetrafluoroethylene (PTFE) at sintering pressure less than 50 MPa and temperature of 150 °C. Densities exceeding 95% were achieved, with resistivities less than 1 Ω -cm. The acoustic velocity was homogeneous across the part (variations <5%). The acoustic velocities exceeded 2500 m/s for Z above 12 MRayl. The experimentally measured acoustic impedance of ZnO/Ag/PEI composites was observed to be in close agreement with the theoretical logarithmic model developed for different volume fractions of individual phases at the percolation limit for Ag. Thus, the acoustic properties of this family of matching layers (MLs) can be predicted to a good approximation before experimental realization. Additionally, a non-conducting low Z (5 MRayl MRayl) with acoustic velocities exceeding 2000 m/s was achieved using hydrozincite as the ceramic component. Scaling of the composites to 2'' diameter was demonstrated. A -6 dB bandwidth greater than 85% was measured for a three ML ultrasound transducer, fabricated using a single cold sintered layer ( Z = 19 MRayl) and two other commercial layers in the stack. Finally, a co-cold sintered graded prototype consisting of three tape-casted formulations corresponding to Z = 5 , 9, and 19 MRayl, while still retaining the correct distributions of the components was demonstrated.

Comparative effects of feeding single- and multi-strain probiotics to commercial layers on the productive performance and egg quality indices

This experiment investigated the effects of dietary supplementation of single-strain probiotic ( SSP ) containing Bacillus subtilis 2 × 10 9 cfu/g and multi-strain probiotic ( MSP ) containing Lactobacillus acidophilus 3 × 10 7 –10 8 cfu/g, Bacillus subtilis 3 × 10 7 -10 8 cfu/g, and Saccharomyces cerevisiae 10 6 –10 7 cells/g on ISA Brown layers' productive performance and egg quality traits for 26 to 51 wk. Eighty-four birds were reared in cages of an open-sided house. SSP was fed either at 0.375, 0.50, or 0.625 g/kg feed or MSP either at 0.75, 1.00, or 1.25 g/kg feed, and a control group were maintained. Each dietary treatment was replicated 6 times, having 2 birds each. Egg production increased linearly with dose increment in the MSP-fed birds. Both SSP and MSP caused an improvement in egg weight, egg mass, and FCR. Feed intake and body weight gain were not affected by probiotic feeding. At 37 wk, MSP-fed birds had a higher shell percentage, whereas the value was higher for both SSP and MSP at 49 wk. Shell thickness rose linearly by MSP at 37 wk and followed a similar trend at 49 wk along with SSP. Haugh unit also increased in both weeks with SSP and MSP. Due to MSP feeding, the predicted yolk index dose was 0.67g/kg at 37 wk and increased linearly at 49 wk. The yolk percent varied with doses of SSP and MSP, while albumen percent with MSP doses at 37 wk. In conclusion, MSP increased egg production, and both SSP and MSP positively influenced other laying performances and egg quality, notably shell and albumen quality.

Hierarchical titanium nitride nanostructured thin film gas diffusion electrodes for next generation PEM fuel cells

Durability of the catalyst support in polymer electrolyte membrane fuel cell (PEMFC) is still one of the main obstacles to its full deployment. In fact, despite the high peak performances achieved by state of the art membrane electrode assemblies (MEA), the degradation of their performances is still a major issue. Since engineering solutions proposed to overcome this issue increase the complexity and the cost of the system, the development of a stable catalyst support capable to stabilize the Pt nanoparticles is a preferable strategy. For this reason, in this work a highly durable, high surface area support has been developed by growing an array of hierarchical nanostructures of an extremely oxidation resistant material, i.e., titanium nitride (TiN) directly on the microporous layer of a commercial gas diffusion layer. Pt was successively deposited to obtain a hierarchical titanium nitride nanostructured thin film gas diffusion electrode (HTNTF-GDE). It resulted capable to withstand the harsh conditions of the accelerated stress tests (AST) with a degradation of the electrochemically active surface area (ECSA) of to 31% after 15,000 cycles in the rotating disk electrode (RDE) setup and of 34% degradation after 5000 cycles in a fuel cell set-up, exceeding in both cases the DOE target for support durability. Besides durability, we investigated the HTNTF-GDE also in an ionomer free catalyst layer configurations.

Investigation of Serotype Prevalence of Escherichia coli Strains Isolated from Layer Poultry in Greece and Interactions with Other Infectious Agents.

Colibacillosis is the most common bacterial disease in poultry and it is caused by avian pathogenic Escherichia coli (APEC), which is assigned to various O-serogroups. Previous studies have shown that APEC strains are more often related to certain O-serogroups such asO78, O2 and O1. E. coli has been reported to act either as a primary or secondary agent in complicating other infections. The aim of this study was to investigate the occurrence of and characterize the O-serogroups of E. coli strains isolated from commercial layer and layer breeder flocks showing macroscopic lesions of colibacillosis and increased or normal mortality in Greece. Furthermore, we attempted to assess the interaction between infectious agents such as Mycoplasma gallisepticum (MG), Mycoplasma synoviae (MS), infectious bronchitis (IBV) and infectious laryngotracheitis (ILT) with E. coli infections in layer flocks with increased mortality. Our study revealed that in addition to the common serogroups (O78, O2), many other, and less common serogroups were identified, including O111. The O78, O111 and O2 serogroups were frequently detected in flocks with lesions of colibacillosis and increased mortality whereas O2, O88 and O8 were reported more commonly in birds with colibacillosis lesions but normal mortality rates. These data provide important information for colibacillosis monitoring and define preventative measures, especially by using effective vaccination programs because E. coli vaccines are reported to mainly offer homologous protection. Finally, concerning the association of the four tested infectious agents with E. coli mortality, our study did not reveal a statistically significant effect of the above infectious agents tested with E. coli infection mortality.

Genetic Parameter Estimation and Whole Sequencing Analysis of the Genetic Architecture of Chicken Keel Bending.

Bone health is particularly important for high-yielding commercial layer chickens. The keel of poultry is an extension of the abdomen side of the sternum along the sagittal plane and is one of the most important bones. In this study, the keel phenotype of White Leghorns laying hen flocks showed significant individual differences. To clarify its genetic mechanism, we first estimated the heritability of keel bend (KB) in White Leghorn, recorded the production performance of the chicken flock, examined the blood biochemical indexes and bone quality in KB and keel normal (KN) chickens, and performed whole-genome pooled sequencing in KB and KN chickens. We then performed selection elimination analysis to determine the genomic regions that may affect the keel phenotypes. The results show that KB is a medium heritability trait. We found that cage height had a significant effect on the KB (p < 0.01). At 48 weeks, there were significant differences in the number of eggs, the number of normal eggs, and eggshell strength (p < 0.05). The content of parathyroid hormone was lower (p < 0.01) and that of calcitonin was higher (p < 0.01) in KB chickens than in KN chickens. The differences in bone mineral density, bone strength, and bone cortical thickness of the humerus and femur were extremely significant (p < 0.01), with all being lower in KB chickens than in KN chickens. In addition, the bones of KB chickens contained more fat organization. A total of 128 genes were identified in selective sweep regions. We identified 10 important candidate genes: ACP5, WNT1, NFIX, CNN1, CALR, FKBP11, TRAPPC5, MAP2K7, RELA, and ENSGALG00000047166. Among the significantly enriched Kyoto Encyclopedia of Genes and Genomes pathways found, we identifed two bone-related pathways, one involving “osteoclast differentiation” and the other the “MAPK signaling pathway.” These results may help us better understand the molecular mechanism of bone traits in chickens and other birds and provide new insights for the genetic breeding of chickens.

Divergent selection for natural antibodies in poultry in the presence of a major gene

BackgroundNatural antibodies (NAb) are antibodies that are present in a healthy individual without requiring previous exposure to an exogenous antigen. Selection for high NAb levels might contribute to improved general disease resistance. Our aim was to analyse the genetic background of NAb based on a divergent selection experiment in poultry, and in particular the effect of a polymorphism in the TLR1A gene.MethodsThe study population consisted of a base population from a commercial pure-bred elite white leghorn layer line and seven generations of birds from a High and Low selection line. Birds were selected for total KLH-binding NAb titer (IgTotal). An enzyme-linked immunosorbent assay was performed to determine NAb titers in blood plasma for IgTotal and the antibody isotypes IgM and IgG. NAb titers were available for 10,878 birds. Genotypes for a polymorphism in TLR1A were determined for chickens in generations 5, 6 and 7. The data were analysed using mixed linear animal models.ResultsThe heritability estimate for IgM was 0.30 and higher than that for IgG and IgTotal (0.12). Maternal environmental effects explained 2 to 3% of the phenotypic variation in NAb. Selection for IgTotal resulted in a genetic difference between the High and Low line of 2.4 titer points (5.1 genetic standard deviation) in generation 7. For IgM, the selection response was asymmetrical and higher in the Low than the High line. The frequency of the TLR1A C allele was 0.45 in the base population and 0.66 and 0.04 in generation 7 of the High and Low line, respectively. The TLR1A polymorphism had large and significant effects on IgTotal and IgM. Estimated genotypic effects suggest full dominance of the TLR1A C allele. Significant TLR1A by generation interactions were detected for IgM and IgTotal.ConclusionsThe effect of a polymorphism in the TLR1A gene on IgTotal and IgM NAb was confirmed. Furthermore, we provide experimental verification of changes in allele frequencies at a major gene with dominant gene action on a quantitative trait that is subjected to mass selection. TLR1A by generation interactions indicate sensitivity to environmental factors.

Chitosan-based formulation of hemagglutinin antigens for oculo-nasal booster vaccination of chickens against influenza viruses

Avian influenza viruses (AIVs) and especially highly pathogenic (HP) AIVs of the H5 and H7 subtypes are of both veterinary and public health concern worldwide. In response to the demand for effective vaccines against H5N1 HPAIVs, we produced recombinant protein based on hemagglutinin (HA), a protective viral antigen. A fragment of the HA ectodomain, with a multibasic cleavage site deletion, was expressed in Escherichia coli, refolded, and chromatographically purified from inclusion bodies. Finally, the protein was formulated in Tris-HCl buffer of pH 8.0 or PBS of pH 7.4 to obtain antigens denoted rH5–1 and rH5–2, respectively. The systemic prime and boost immunizations proved that rH5–1 adsorbed to aluminum hydroxide induces anti-H5 HA neutralizing antibodies and protective immune responses against H5N1 HPAIVs in chickens. The present studies were aimed at stimulating immune responses via the mucosal routes using the systemic prime-mucosal boost strategy. Efficacy trials were performed in commercial layer chickens. For systemic and mucosal immunizations, H5 HA antigens were adjuvanted with aluminum hydroxide and chitosan glutamate, respectively. The first dose of rH5–2 was administered subcutaneously, while its second dose was administered subcutaneously, intraocularly, oculo-nasally, or intranasally. rH5–1 was delivered to the subcutaneously primed chickens by the intranasal route. Post-vaccination sera were analyzed for anti-H5 HA antibodies, using homologous ELISA and heterologous FluAC H5 and hemagglutination inhibition tests. Intraocularly and oculo-nasally delivered rH5–2 mixed with chitosan glutamate was capable of stimulating anti-H5 HA IgY antibody responses in the subcutaneously primed chickens; however, it was ineffective when administered by the intranasal route. Efficient intranasal boosting was achieved using rH5–1. The enhanced production of antigen-specific antibodies was reflected in the development of H5-subtype specific and hemagglutination inhibiting antibodies. Conclusively, the subcutaneous prime and oculo-nasal boost vaccination is proposed as the target strategy for future optimization.

Development of innovative scorecard for assessment of welfare and production performance of commercial layer birds reared at different stocking densities in cages

A methodology to assess the welfare of laying birds maintained in cages was developed using innovative scorecardmethod without compromising the production and economics in Indian scenario. To develop scorecard, specific keyparameters such as production, economics, egg quality, welfare and behaviour were considered. The scores for these key parameters were assigned on the basis of the performance of the commercial laying hens maintained in different stocking densities in cages (387, 484, 548 and 645 cm2/b) for an experimental period of 20 weeks. The range for each parameter was decided and based on it four groups were formed and the treatment with the best performance received the highest weightage, that is how scoring of each treatment was done according to the range they fitted in. The scoring, weightage and guidelines were devised by Delphi technique, by a panel of national experts from the academics and experts working in the poultry industry. At the end of the experimental period, laying birds maintained at stocking density of 548 cm2/b scored the highest weightage with 84 out of total 100; 48 weightage for production and economics, 12 weightage for egg quality and 40 weightage for welfare and behaviour. From all above results, it could be summarized that this innovative scorecard can be used to determine the best performance of laying birds taking welfare into consideration.

Detection of Newcastle disease virus and assessment of associated relative risk in backyard and commercial poultry in Kerala, India.

BackgroundNewcastle disease (ND) is an economically important viral disease affecting the poultry industry. In Kerala, a state in South India, incidences of ND in commercial and backyard poultry have been reported. But a systematic statewide study on the prevalence of the disease has not been carried out.ObjectivesA cross‐sectional survey was performed to detect the presence of Newcastle disease virus (NDV) in suspect cases and among apparently healthy commercial flocks and backyard poultry, in the state and to identify risk factors for NDV infection.MethodsReal‐time reverse transcription‐PCR (RT‐PCR) was used to detect the M gene of NDV in choanal swabs and tissue samples collected from live and dead birds, respectively and the results were statistically analysed.ResultsThe predominant clinical signs of the examined birds included mild respiratory signs, huddling together and greenish diarrhoea. Nervous signs in the form of torticollis were noticed in birds in some of the affected flocks. On necropsy, many birds had haemorrhages in the proventriculus and caecal tonsils which were suggestive of ND. Of the 2079 samples tested, 167 (8.0%) were positive for the NDV M‐gene by RT‐PCR. Among 893 samples collected from diseased flocks, 129 (14.5%), were positive for M gene with pairwise relative risk (RR) of 15.6 as compared to apparently healthy flocks where 6 out of 650 (0.9%) samples were positive. All positive samples were from poultry; none of the ducks, pigeons, turkey and wild birds were positive. Commercial broilers were at higher risk of infection than commercial layers (RR: 4.5) and backyard poultry (RR: 4.9). Similarly, birds reared under intensive housing conditions were at a higher risk of being infected as compared to those reared under semi‐intensive (RR: 6.7) or backyard housing (RR: 2.1). Multivariable analysis indicated that significantly higher risk of infection exists during migratory season and during ND outbreaks occurring nearby. Further, lower risk was observed with flock vaccination and backyard or semi‐intensive housing when compared to intensive housing. When the M gene positive samples were tested by RT‐PCR to determine whether the detected NDV were mesogenic/velogenic, 7 (4.2%) were positive.ConclusionsIn Kerala, NDV is endemic in poultry with birds reared commercially under intensive rearing systems being affected the most. The outcome of this study also provides a link between epidemiologic knowledge and the development of successful disease control measures. Statistical analysis suggests that wild bird migration season and presence of migratory birds influences the prevalence of the virus in the State. Further studies are needed to genotype and sub‐genotype the detected viruses and to generate baseline data on the prevalence of NDV strains, design better detection strategies, and determine patterns of NDV transmission across domestic poultry and wild bird populations in Kerala.

An in vitro evaluation of the sensitivity and responses of Dermanyssus gallinae to selected acaricides

Dermanyssus gallinae is an obligatory ectoparasite of birds which feeds on blood and significantly compromise the well-being of commercially raised laying hens. In this study, the mortality rates and responses of D. gallinae to 2 acaricides with a physical mode of action (Dergall and Mite Max) and 2 acaricides with a chemical mode of action (Milben Ex and Bio PK) were evaluated in tree dilutions (S1–3) and compared at 8-time intervals after application. The evaluation involved a novel method that simulates real-world conditions in a commercial poultry farm. Tested products have shown high efficacy (84.3–100%) against D. gallinae in the producer recommended solution (S1). Acaricides with a physical mechanism of action were as effective as chemical agents in eradicating poultry red mites. The compared preparations differed only in the onset of action which was longer in acaricides with a physical mode of action (1–6 h for chemical 24 h for physical in S1). An increase in the concentration of the active ingredient did not significantly speed up the onset of action of the evaluated preparations. However, the efficacy of Dergall and Bio PK decreased when the applied dose was halved, to 12% and 0% respectively. A decrease in the dose Mite Max led to a somewhat smaller, but not statistically significant decrease in mite mortality rates (74%). The proposed method for evaluating acaricide efficacy can be helpful in selecting the most effective preparations and the optimal concentration of the working solution to be applied in commercial layer farms, thus reducing the costs associated with the eradication of D. gallinae. The developed method enables a reliable evaluation of acaricides with both a physical and chemical mode of action, and it supports observations of the parasites’ responses to the applied treatment.

Prevalence and Intensity of Ectoparasitic Infestations in Commercial Layer Chickens reared under Elevated Cage System

Prevalence and Intensity of Ectoparasitic Infestations in Commercial Layer Chickens reared under Elevated Cage System

Prevalence of Newcastle disease and associated risk factors in domestic chickens in the Indian state of Odisha.

Newcastle disease (ND), caused by Newcastle disease virus (NDV), is a contagious disease that affects a variety of domestic and wild avian species. Though ND is vaccine-preventable, it is a persistent threat to poultry industry across the globe. The disease represents a leading cause of morbidity and mortality in chickens. To better understand the epidemiology of NDV among commercial and backyard chickens of Odisha, where chicken farming is being prioritized to assist with poverty alleviation, a cross-sectional study was conducted in two distinct seasons during 2018. Choanal swabs (n = 1361) from live birds (commercial layers, broilers, and backyard chicken) and tracheal tissues from dead birds (n = 10) were collected and tested by real-time reverse transcription polymerase chain reaction (RT-PCR) for the presence of matrix (M) and fusion (F) genes of NDV. Risk factors at the flock and individual bird levels (health status, ND vaccination status, geographical zone, management system, and housing) were assessed using multivariable logistic regression analyses. Of the 1371 samples tested, 160 were positive for M gene amplification indicating an overall apparent prevalence of 11.7% (95% CI 10.1–13.5%). Circulation of virulent NDV strains was also evident with apparent prevalence of 8.1% (13/160; 95% CI: 4.8–13.4%). In addition, commercial birds had significantly higher odds (75%) of being infected with NDV as compared to backyard poultry (p = 0.01). This study helps fill a knowledge gap in the prevalence and distribution of NDV in apparently healthy birds in eastern India, and provides a framework for future longitudinal research of NDV risk and mitigation in targeted geographies—a step forward for effective control of ND in Odisha.

Commercial Free-Range Laying Hens' Preferences for Shelters with Different Sunlight Filtering Percentages.

Simple SummaryAustralian sunlight is intense, and may impact range use by free-range hens. Range design and management are important for optimising commercial layer farms where artificial shelters may offer protection for ranging hens. This study investigated preferences among 34–40-week-old hens for artificial shade cloth shelters of different densities, using two flocks on a commercial farm during the summer. Three types of sunlight-filtering shade cloth shelters, i.e., blocking 50%, 70%, and 90% of ultraviolet (UV) light, each with three replicates, were placed on the range for each flock. The number of hens under each shelter was counted at 30-min intervals using image snapshots from video recordings for 14 to 17 days. An on-site weather station recorded sunlight intensity across different spectra, ambient temperature, and relative humidity. During the day, hens generally preferred the 90%, followed by 70% and 50% sunlight-filtering shelters. However, fewer hens were observed underneath shelters during times of peak sun intensity. Shelter preferences were mostly impacted by ambient temperature in both flocks, with all sunlight spectra having different degrees of effect depending on the shelter type and flock. Overall, shelters comprising higher densities of sunlight-filtering artificial cloth were preferred by hens on the range, but these may not be sufficient to attract more hens outside during intense sunlight and hot climatic conditions.Extreme sunlight might be aversive to free-range laying hens, discouraging them from going outside. Range enrichment with artificial shelters may protect hens from sunlight and increase range use. The preferences of 34–40-week-old Hy-Line Brown laying hens for artificial shelters were assessed by counting the number of hens under three densities of individual shelters (three replicates/density) from video recordings for 14 to 17 days for two flocks. The artificial shelters used shade cloth marketed as blocking 50%, 70%, and 90% of ultraviolet light, although other sunlight wavelengths were also reduced. Different sunlight spectral irradiances (ultraviolet radiation (UVAB) (288–432 nm), photosynthetically active radiation (PAR) (400–700 nm), and total solar radiation (TSR) (285 nm–3000 nm), ambient temperature, and relative humidity were recorded with an on-site weather station. There was a significant interaction between sunlight-filtering shelter and time of day (both Flocks, p < 0.0001), i.e., hens preferred shelters with the highest amount of sunlight-filtering at most time points. Regression models showed that the most variance in shelter use throughout the day resulted from the ambient temperature in both flocks, while sunlight parameters had different degrees of effect depending on the shelter type and flock. However, fewer hens under the shelters during the midday period suggest that during periods of intense sunlight, hens prefer to remain indoors, and artificial structures might not be sufficient to attract more hens outside.

Seroprevalence of Mycoplasma gallisepticum in apparently healthy layer chickens in commercial farms in Ibadan

Mycoplasma gallisepticum (MG) is a common poultry infection that causes chronic respiratory disease in chickens and turkeys, resulting in significant financial losses for poultry farmers and affecting the entire country. The primary goal of this study was to establish the seroprevalence of Mycoplasma gallisepticum in commercial layer birds in several local government in Ibadan namely; Afijio, Akinyele, Lagelu, Ido, Egbeda, Ona ara and Ibadan South west, between March and July, 2021. A total of 140 blood samples were obtained at random from commercial layer chickens (ISA brown) of various ages and flock sizes. The presence of antibodies against MG was detected using an indirect enzyme linked immunosorbent test (iELISA). Overall prevalence of 74.3% was recorded during this study with Deborah farm having the highest MG prevalence of 85%, Agboola, 80%, Brian, Betty and Cornerstone had 75%, Rehoboth had 70% and Abol farm had the lowest prevalence of 60%. The highest seroprevalence of MG antibody was 85% in 18-21 weeks, followed by 80% in 22-25 weeks, and lowest with 60% in 8-11 weeks. In the farm chosen, there was no significant change in relative flock size at p &lt; 0.05. Moreover, because the disease is transmitted vertically, these findings suggest that commercial layers in Ibadan should be frequently examined for MG infection and carrier birds should be culled. Efforts should be focused on educating poultry producers on how to effectively control MG in layer farms in Nigeria through proper management and the use of appropriate preventive or therapeutic methods.

Monitoring the Effect of Disinfection Methods on Mycoplasma gallisepticum in Commercial Layer Farms

Monitoring the Effect of Disinfection Methods on Mycoplasma gallisepticum in Commercial Layer Farms

Artificial Neural Networks to Predict Egg-Production Traits in Commercial Laying Breeder Hens

In recent years, egg production has had an intense growth in Brazil, and Brazilian egg consumption per capita has significantly increased in the last decade. To reduce sanitary and financial risks, decisions regarding the production and health status of the flock must be made based on objective criteria. Our aim was to determine the main “input” variables for the prediction of egg production performance in commercial laying breeder flocks using an ANN model. The software NeuroShellClassifier and NeuroShell Predictor were used to build the ANN. A total of 26 egg-production traits were selected as input variables and eight as output variables. A database of 44,120 Excel cells was generated. For the training and validation of the models, 74.9% and 25.1% of the data were used, respectively. The accuracy of the ANN models was calculated and compared using the analysis of coefficient of multiple determination (R2), mean squared error (MSE), and an assessment of uniform scatter in the residual plots. The models for the outputs “weekly egg production,” “weekly incubated egg,”, “accumulated commercial egg,” and “viability” showed an R2 greater than 0.8. Other models yielded R2 values lower than 0.8. The ANN predicts adequately eight egg-production traits in the breeders of commercial laying hens. The method is an option for data management analysis in the egg industry, providing estimates of the relative contribution of each input variable to the outputs.

Seropositivity of Mycoplasma synoviae by ELISA in commercial broiler and layer chickens

Seropositivity of Mycoplasma synoviae by ELISA in commercial broiler and layer chickens

Effects of Supplemental 2-Hydroxy-4-Methyl(Thio) Butanoic Acid and DL -Methionine on Productive Performance, Egg Quality and Redox Status of Commercial Laying Ducks

Effects of Supplemental 2-Hydroxy-4-Methyl(Thio) Butanoic Acid and DL -Methionine on Productive Performance, Egg Quality and Redox Status of Commercial Laying Ducks