Genetic variability of Mycoplasma synoviae detected in commercial layers in southeastern Brazil / Variabilidade genética de Mycoplasma synoviae detectado em poedeiras comerciais do sudeste do Brasil

Este estudo teve como objetivo caracterizar genótipos de M. synoviae circulantes em poedeiras comerciais, na Região Sudeste do Brasil. Para estabelecer a relação evolutiva entre as cepas de MS, foi analisada a sequência genética do gene vlhA de 11 cepas de MS identificadas no Rio de Janeiro e em São Paulo, de 10 outras cepas de MS identificadas no Brasil e cujas sequências foram depositadas no banco de dados GenBank, e da cepa vacinal MSH. O método da máxima verossimilhança e o modelo de Kimura com dois parâmetros foram utilizados para comparar as cepas. As sequências obtidas foram depositadas no Genbank, sob os números de acesso OP279775 a OP279785. Foi possível verificar a presença de diferentes cepas circulantes no Brasil, com alta similaridade entre as cepas do Rio de Janeiro pela análise do gene vlhA. As duas cepas paulistas detectadas no presente estudo possuem o baixo percentual (68%) de similaridade, demonstrando a variabilidade das cepas dessa localidade.

Effect of monochrome light with different wavelengths on biochemical parameters of hens

Artificial light, as one of the environmental factors, plays a significant role in regulating the synthesis and secretion of hormones related to the coordination of parameters of life, growth, immunity, and reproductive functions of hens. The article aims to study the influence of monochrome light with different wavelengths on the biochemical parameters of hens` blood serum. Four groups of "Hy-Line W-36" crossbred hens were formed. Hens of the 1st group were kept using monochrome light with different wavelength lamps with a wavelength of ~ 460 nm, the 2nd group ~ 600 nm, the 3rd group ~ 630 nm, and the 4th group ~ 650 nm. It was found that the use of light with different wavelengths for keeping hens in cages of multilevel batteries affects hen' biochemical parameters, according to the research results. It was established that when using light with a wavelength of ~ 630 and ~ 650 nm, the indicators of clinical biochemistry of hens' blood serum were within the normal physiological values. Whereas, with the use of light with a wavelength of ~ 600 nm, an increase in the level of glucose, creatinine, total protein, total bilirubin, and phosphorus, a decrease in the ratio of calcium to phosphorus, in the activity of alkaline phosphatase, aspartate aminotransferase, and lactate dehydrogenase, were observed in the hens' blood serum. The use of light with a wavelength of ~ 460 nm was accompanied by a further increase in the level of glucose, creatinine, total protein, urea, total bilirubin, phosphorus, the activity of alkaline phosphatase, aspartate aminotransferase, lactate dehydrogenase, and gamma-glutamyltransferase, a decrease in the ratio of calcium and phosphorus.

Economic Feasibility in Commercial Egg Production in a Conventional and Cage-Free Systems with Different Stocking Densities

Adapting existing laying facilities to meet animal welfare certifications is not a simple task. It causes higher expenses to producers, who are often hesitant to accept the need for changes. Considerations of their financial situation make them insecure to make assertive decisions in this area, as they seek to maintain the economic efficiency of laying poultry. This study aims to analyze the economic viability of laying systems (conventional cages and Cage-Free) with different housing densities. The data source was a systematized literature review. Five articles were found containing reports on systems. Further data sources were the lineage handbook and a survey with companies specializing in poultry farming. An analysis of economic viability was performed in the multiple scenarios. Densities in each system were used to compose different scenarios: Conventional: 1,500 cm²/bird, 750 cm²/bird, and 398 cm²/bird; and Cage-Free:7 birds/m² and 13 birds/m². The scenarios were evaluated in terms of Net Present Value, Internal Rate of Return, Modified Internal Rate of Return, Discounted Payback Method, Profitability Index, Equivalent Uniform Annual Value, and Monte Carlo Simulation. The best scenario was the Conventional, with 398 cm²/bird, presenting a higher NPV. The Cage-Free system, with seven birds per square meter, had a lower NPV compared to conventional systems. All scenarios had satisfactory chances of success. The risks of negative or null financial return were low according to Monte Carlo simulations. Conventional and Cage-Free production are economically viable when using densities of 1,500 cm²/bird, 750 cm²/bird, or 398 cm²/bird (conventional), and 7 birds/m², or 13 birds/m² (Cage-Free).(AU)

Thermal environment characterization of laying hen-housing systems

This study systematically collected data on variables that influence the thermal environment characteristics in poultry houses. Laying poultry farming is a relevant economic activity in Brazilian agriculture and has been expressively growing mainly regarding genetics and nutrition. Thermal comfort in poultry houses is needed to achieve poultry's maximum productive potential. Therefore, laying aviaries previously naturally ventilated (positive pressure) are starting to be equipped with cage batteries and designed with lateral closures, using negative pressure ventilation and in some cases associated with adiabatic cooling. However, negative pressure ventilation systems' thermal efficiency in tunnel mode and its distribution in different cage levels is still slightly known. Consequently, this system's thermal efficiency needs to be investigated to ensure adequate climate indices recommendations and avoid costs and losses due to inadequate handling and facilities.

The Effect of Dietary Glucose Oxidase Supplementation on Production Performance, Egg Quality and Nutrient Digestibility in Laying Hens

The study was conducted to investigate the effect of GOX on performance, egg quality, and nutrient digestibility in laying hens. In total, 432, 50-week-old Hy-Line brown breeder hens were assigned into four treatments, and fed a basal diet with GOX at 0, 100, 200 and 300 units for 10 weeks, respectively. A Quadratic decrease in FI in week 3 (p<0.05) and linear increase in egg production in week 6 to 10 and overall experiment period (p<0.05) and Quadratic increase in egg production in week 7 (p<0.05), a linear decrease in broken egg rate in week 6 (p<0.05) a quadratic increase in egg weight on day 14 (p<0.05), alinear increase in egg weight on day 28 (p<0.05), and linear decrease in yolk color on day 7 (p<0.05), a linear increase in yolk color on day 42 and day 70 (p<0.05), and linear increase in haugh unit on day 28 and 70 (p<0.05), a linear increase albumen height on day 28 and day 56 (p<0.05), and linear decrease in shell color on day 14 (p<0.05) and day 28(p<0.05), a linear and quadratic increases in eggshell strength and eggshell thickness on day 56 (p<0.05), and linear increase in eggshell strength and eggshell thickness on day 70 (P0.05) were observed with the addition of GOX the the diet. Conclusion: This study suggested that the supplementation of GOX may have beneficial effects on feed intake and egg quality in laying hens.(AU)

Efficacy of Aluminum Sulfate Addition to Poultry Litter on Productive Performance of Laying Hens, Ammonia Emissions, and Litter Quality

The objective of this research was to examine whether different types of litter (New, used, and mixed) and alum could interfere in litter quality, thereby also influencing the productive performance of laying hens. A total number of 450 Inshas chickens aged 24 weeks were randomly distributed into six groups (5 replicates, each with 15 hens) of floor litter. The groups included (G1) new wheat straw litter, (G2) used wheat straw litter, (G3) mixed wheat straw litter (50% new+50% used) and (4, 5 and 6) the same litter types in groups 1, 2 and 3 supplied with 500g of alum /m2 litter. The experiment lasted 16 weeks. Laying hens productive parameters, blood parameters, carcass parameters, respiratory rate, coliform count and pH, as well as ammonia emission, litter quality were assessed.The results showed that the litter type significantly affects the level of ammonia emission, litter characteristics, carcass characteristics, intestinal pH and coliform count, blood characteristics (T3, cholesterol, uric acid, total protein, albumin, globulin, hemoglobin, and PCV), as well as the body weight gain. In general, we found that reused litter followed by the mixed litter without added alum resulted in the lowest efficiency on the studied traits, as compared to the same types of litter treated with alum and the new litter. We therefore conclude that the addition of alum reduces ammonia emission and improves the characteristics of the litter, which is reflected in enhancement of productive performance and properties of blood and carcass.(AU)

Effect of Modified Clinoptilolite to Counteract the Deleterious Effects of Ochratoxin A on Egg Production and Quality

The objective of this study was to evaluate the efficacy of modified clinoptilolite as mycotoxins adsorbent in preventing negative effects of ochratoxin A (OTA) on egg production and egg quality of laying hens exposed to this mycotoxin. Forty-eight (n=48) laying hens (27 weeks old) were used in this study. The hens were randomly divided into six equal groups and were fed for 7 weeks with a standard diet in addition to: E-I group - 1 mg/kg OTA; E-II group 0.25 mg/kg OTA; E-III group 1mg/kg OTA + 0.2% of MZ; E-IV group 0.25 mg/kg OTA + 0.2% of MZ. MZ group of hens was fed with standard diets containing 0.2% of the adsorbent (MZ). The control group of hens was fed with standard diet, without any addition of OTA or MZ. The present study showed that laying hens fed with 1 mg/kg of OTA (E-I), had a significant decrease (p<0.05) of all performance parameters during the trial, while group fed with 0.25 mg/kg OTA have shown no adverse effects on egg production and egg quality. Addition of modified clinoptilolite (0.2%) to the diet containing the OTA, minimized these effects bringing values not significantly different from the control diet for most of the parameters. These findings clearly indicate the protective potential of modified clinoptilolite against the toxic effects of OTA in laying hens.(AU)

The Effect of Supplementing Tea Polyphenols on Yolk Cholesterol and Production Performance of Laying Hens During the Egg-laying Period

This study aimed to investigate the effect of supplementing 300 mg/kg tea polyphenols (TP) on yolk cholesterol content and production performance of laying hens during the egg-laying period. A total of 600 Roman laying hens aged 24 weeks were randomly divided into two dietary treatment groups. The feeding experiment lasted for 48 weeks. Layers fed basal diet supplemented with 0 (control group) and 300mg/kg TP (TP group) diet, respectively. The yolk cholesterol content, laying performance, and egg quality were determined at 28, 38, 48, 58, and 68 weeks of age. The yolk cholesterol content in the TP group was significantly decreased at 28-68 weeks of age (p<0.01), compared to the control group. There was a significant increase in laying rate in the TP group at 38 weeks of age (p<0.05), compared to the control group, while no significant differences during the other laying periods were obtained (p>0.05). The FCR significantly decreased in the TP group at 38 weeks of age whereas AEW significantly increased in the TP group at 58 weeks of age (p<0.05). Similarly, the eggshell thickness and eggshell strength in the TP group significantly increased (p<0.05), compared with the control group at 38 weeks of age. The albumen height and Haugh unit significantly increased at 28 weeks of age (p<0.05). In conclusion, the results showed that the diet supplemented with 300 mg/kg TP had positive effects on production performance of layers during the egg-laying period, and could lessen yolk cholesterol content significantly at 28-68 weeks of age.(AU)

Effects of Vitamin A and K3 on Immune Function and Intestinal Antioxidant Capacity of Aged Laying Hens

This study was conducted to investigate effects of vitamin A (VA) and vitamin K3 (VK3) on immune function and intestinal antioxidant capacity of aged laying hens. In a 3 × 3 factorial arrangement, the diets of 1080 Roman Pink laying hens (87 weeks old) was formulated with deficient, adequate and excess VA and VK3, including 0, 7000 and 14000 IU/kg VA and 0, 2.0 and 4.0 mg/kg VK3 for 8 weeks. Interactive effects between VA and VK3 were observed that VA and VK3 decreased the splenetic mRNA expression of inducible nitric oxide synthase (iNOS) and tumour necrosis factor α (TNF-α), but increased the plasma immunoglobulin G (IgG) content and jejunal mRNA expression of nuclear factor-like 2 (Nrf2). Hens fed adequate or excess VA had higher spleen index, mRNA expression of interleukin-10 (IL-10) in spleen, sIgA content, catalase (CAT), glutathione peroxidase and total dismutase (T-SOD) activity, and mRNA expression of polymeric immunoglobulin receptor (pIgR) in jejunum and lower mRNA expression of IL-1ß in jejunum and iNOS, TNF-α in spleen. Furthermore, adequate or excess VK3 significantly increased plasma IgG content, the CAT, T-SOD and total antioxidant capacity activities, up-regulated the mRNA expression of pIgR, Nrf2, SOD1 and CAT in jejunum and down-regulated the mRNA expression of iNOS and TNF-α in spleen.(AU)

Protease Supplementation in the Diet of Light Laying Hens

This work was developed to evaluate the impact of the addition of proteases on the performance characteristics, egg quality, relative weight of digestive organs, and intestinal morphometry of laying hens. 390 Hy Line W36® hens were allocated into five treatments and six replicates with 13 animals. The treatments were: 1) Control (standard formulation), 2) Negative control A - NCA (nutritional reduction according to protease A matrix), 3) Negative control B - NCB (nutritional reduction according to protease B matrix), 4) NCA+protease A (0.250 g/kg of feed) and 5) NCB+protease B (0.125 g/kg of feed). Hens fed the NCA, NCB, and NCA+protease A diets showed reductions in feed intake and egg mass. The addition of protease B provided better results for egg production in both percentage and per dozen as compared to the group fed with the NCA+protease A diets. The hens subjected to diets NCA and NCB showed eggs with a reduced eggshell and thickness percentage. However, supplementation with proteases A and B improved these parameters to values similar to the controls. There was no significant effect of the treatments on the relative weight of the liver, proventricle, gizzard, pancreas, and small intestine. However, the addition of protease A resulted in a decreased value for the relative weight of the large intestine. The jejunum and ileum crypt depths were, respectively, smaller in hens fed the control diet in relation to the NCB diet and the NCA and NCB diets. As it can be concluded, Protease B supplementation provided the best performance results.(AU)

Eficácia do caldo de fumo (Nicotiana tabacum) no controle do Menacanthus stramineus (phthiraptera: menoponidae) em galinhas poedeiras no município de salinas, Minas Gerais / Efficacy of tobacco broth (Nicotiana tabacum) in the control of Menacanthus stramineus (phthiraptera: menoponidae) in laying hens in the municipality of salinas, Minas Gerais / Eficacia del caldo ahumado (Nicotiana tabacum) en el control de Menacanthus stramineus (phthiraptera: menoponidae) en gallinas ponedoras del municipio de salinas, Minas Gerais

Em granjas de postura, infestações por ectoparasitas são um problema que gera gastos e diminui a produção dos animais, pelo aumento do estresse. O piolho Menacanthus stramineus é apontado como um dos principais parasitas na avicultura comercial. Há um interesse crescente no uso de abordagens de controle de parasitos na produção de aves minimizando o uso de pesticidas sintéticos tradicionais. Objetivou-se avaliar a eficácia do caldo de fumo (Nicotiana tabacum) no controle do Menacanthus stramineus (Phthiraptera: Menoponidae) em galinhas poedeiras no município de Salinas, Minas Gerais. Para isso, 30 galinhas poedeiras naturalmente infestadas por piolhos, oriundas dos Setor de Zootecnia I do Instituto Federal do Norte de Minas Gerais - Campus Salinas (IFNMG), foram selecionadas aleatoriamente e divididas em três grupos, mantidos em galpões distintos e separados: Grupo I- Tratado com caldo de fumo, conforme Sagrilo e colaboradores (2007); Grupo II- Tratado com Colosso Pulverização®, diluídos 11ml em nove litros; Grupo III- Controle, tratado com água, sendo todos os grupos submetidos ao tratamento por imersão em balde com nove litros de solução. Espécimes de piolhos foram coletados manualmente através de inspeção visual, juntamente com penas contendo ovos em sua base e encaminhados ao Laboratório de Parasitologia Veterinária (LPV) do IFNMG, para realização do diagnóstico parasitológico através de chaves de identificação. Os espécimes foram clarificados em hidróxido de potássio a 10% e observados em microscopia óptica nas objetivas de 4x e 10x. Os ovos foram observados em microscópio estereoscópico, no aumento de 4x. Todas as galinhas foram diagnosticadas com infestação por ovos e adultos de M. stramineus. Para o banho de imersão, as aves foram seguradas pelo pescoço e pelas asas, mergulhando todo seu corpo em balde plástico. Sete dias após a realização dos tratamentos, as aves foram novamente examinadas em uma inspeção visual pelos mesmos examinadores. O Grupo I não apresentou ovos e nem adultos de M. stramineus em nenhuma ave, revelando 100% de eficácia. O Grupo II não apresentou adultos, mas foram observados ovos aderidos à base das penas, friáveis ao toque, em nove aves. Posteriormente, verificou-se que se tratava de cascas de ovos vazias. E, o Grupo III estava ainda intensamente parasitado por ovos e adultos de M. stramineus. Conclui-se que o caldo de fumo (Nicotiana tabacum) preparado conforme descrito na metodologia do presente trabalho, é eficaz no controle do piolho Menacanthus stramineus (Phthiraptera: Menoponidae) em galinhas poedeiras no município de Salinas, Minas Gerais.(AU)

In laying hens barns, ectoparasite infestations are a problem that generates expenses and decreases animal production due to increased stress. The Menacanthus stramineus louse is considered one of the main parasites in commercial poultry. There is growing interest in the use of parasite control approaches in poultry production while minimizing the use of traditional synthetic pesticides. The objective of this study was to evaluate the efficacy of tobacco broth (Nicotiana tabacum) in controlling Menacanthus stramineus (Phthiraptera: Menoponidae) in laying hens in the municipality of Salinas, Minas Gerais. Thus, 30 laying hens naturally infested with lice, housed at the Zootechnics Sector I at the Federal Institute of Northern Minas Gerais ­ Campus Salinas (FINMG) were randomly selected and divided into three groups, which were kept in different and separated barns: Group I- Treated with tobacco broth, according to Sagrilo et al (2007); Group II- Treated with Colosso Pulverização®, diluted 11ml in nine liters; Group III- Control, treated with water. All groups were elaborated for treatment by immersion in a bucket with nine liters of solution. Lice specimens were manually collected through visual inspection including feathers containing eggs at their base and then sent to the Veterinary Parasitology Laboratory (VPL) at the FINMG for parasitological diagnosis by using identification keys. The specimens were clarified in potassium hydroxide 10% and observed under optical microscopy at 4x and 10x objectives. The eggs were observed under a stereoscopic microscope at 4x magnification. All chickens were diagnosed with infestation of adult and egg stages of M. stramineus. For the immersion bath, the animals were held by the neck and wings, dipping their entire bodies in a plastic bucket. Seven days after the treatments were carried out they were again examined in a visual inspection by the same examiners. Group I did not show any eggs or adults of M. stramineus, which presented efficacy of 100%. Group II did not have adults, but friable eggs when touched adhered to the base of the feathers were observed in nine animals. Later on, it was found that they were empty egg shells. And, Group III was still intensely parasitized by eggs and adults stages of M. stramineus. It is concluded that tabocco broth (Nicotiana tabacum) prepared as described in the methodology of the present study is effective in controlling the lice Menacanthus stramineus (Phthiraptera: Menoponidae) in laying hens in the municipality of Salinas, Minas Gerais.(AU)

En las gallinas ponedoras, las infestaciones de ectoparásitos son un problema que genera gastos y disminuye la producción animal, debido al aumento del estrés. El piojo Menacanthus stramineus se considera uno de los principales parásitos de las aves comerciales. Existe un interés creciente en el uso de enfoques de control de parásitos en la producción avícola mientras se minimiza el uso de pesticidas sintéticos tradicionales. El objetivo fue evaluar la eficacia del caldo de tabaco (Nicotiana tabacum) en el control de Menacanthus stramineus (Phthiraptera: Menoponidae) en gallinas ponedoras del municipio de Salinas, Minas Gerais. Para ello, 30 gallinas ponedoras naturalmente infestadas de piojos, del Sector I de Zootecnia del Instituto Federal del Norte de Minas Gerais - Campus Salinas (IFNMG), fueron seleccionadas al azar y divididas en tres grupos, mantenidos en galpones separados y separados: Grupo I - Tratado con caldo de humo, según Sagrilo et al. (2007); Grupo II- Tratado con Colosso Pulverização®, diluido 11ml en nueve litros; Grupo III- Control, tratado con agua, con todos los grupos sometidos a tratamiento por inmersión en un balde con nueve litros de solución. Las muestras de piojos se recolectaron manualmente mediante inspección visual, junto con plumas que contenían huevos en su base y se enviaron al Laboratorio de Parasitología Veterinaria (LPV) del IFNMG, para el diagnóstico parasitológico mediante claves de identificación. Las muestras se clarificaron en hidróxido de potasio al 10% y se observaron bajo microscopía óptica en objetivos 4x y 10x. Los huevos se observaron bajo un microscopio estereoscópico, con un aumento de 4x. Todos los pollos fueron diagnosticados con huevos de M. stramineus e infestación de adultos. Para el baño de inmersión, se sujetó a las aves por el cuello y las alas, sumergiendo todo su cuerpo en un balde de plástico. Siete días después de que se llevaron a cabo los tratamientos, las aves fueron examinadas de nuevo en una inspección visual por los mismos examinadores. El grupo I no presentó huevos ni adultos de M. stramineus en ninguna ave, mostrando una efectividad del 100%. El grupo II no presentó adultos, pero se observaron huevos adheridos a la base de las plumas, friables al tacto, en nueve aves. Posteriormente, se encontró que se trataba de cáscaras de huevo vacías. Y, el Grupo III todavía estaba intensamente parasitado por huevos y adultos de M. stramineus. Se concluye que el caldo de tabaco (Nicotiana tabacum) elaborado según lo descrito en la metodología del presente trabajo, es efectivo en el control de los piojos Menacanthus stramineus (Phthiraptera: Menoponidae) en gallinas ponedoras del municipio de Salinas, Minas Gerais.(AU)

Effects of ZooBioR2 product as feed supplement in laying hens on the morphofunctional state of intestinal mucosa / Efeitos do produto ZooBioR2 como suplemento alimentar em galinhas poedeiras sobre o estado funcional da mucosa intestinal

Spirulina platensis is a microalga with biological activity used to produce nutritional supplements rich in proteins, essential fatty acids, vitamins, and minerals. The current study aims to prove the impact of the product ZooBioR2 (obtained from Spirulina platensis) on health, and on the histology of duodenum, jejunum, ileum, and cecum in laying hens. The experiment was performed in duplicate on 5 groups of hens (14 birds/group), one control and four experimental, in which the feed was supplemented with ZooBioR2 in different doses (5.0; 10.0; 15.0; 20.0mg active substance/kg of fodder). Inclusion of the supplement in the diet have determined a significant decrease of height of intestinal villi, the depth of the crypts and the thickness of muscular layer of mucosa in the experimental groups receiving 15.0 and 20.0mg/kg. The decrease of crypts depth is an indicator of a higher rate of turn-over of epithelial tissue. The morphological changes of intestinal mucosa could be involved in a better digestibility of the fodder.

Spirulina platensis é uma microalga com atividade biológica utilizada para produzir suplementos nutricionais ricos em proteínas, ácidos graxos essenciais, vitaminas e minerais. O estudo atual visa provar o impacto do produto ZooBioR2 (obtido da Spirulina platensis) na saúde e na histologia do duodeno, jejuno, íleo e ceco em galinhas poedeiras. O experimento foi realizado em duplicata em cinco grupos de galinhas (14 aves/grupo), um controle e quatro experimentais, nos quais a ração foi suplementada com ZooBioR2 em diferentes doses (5,0; 10,0; 15,0; 20,0mg de substância ativa/kg de forragem). A inclusão do suplemento na ração determinou uma diminuição significativa da altura das vilosidades intestinais, da profundidade dos crypts e da espessura da camada muscular da mucosa nos grupos experimentais que receberam15,0 e 20,0mg/kg. A diminuição da profundidade das criptas é um indicador de maior taxa de rotação do tecido epitelial. As alterações morfológicas da mucosa intestinal podem estar envolvidas em uma melhor digestibilidade da forragem.

Detection of Mycoplasma Synoviae and Other Pathogens in Laying Hens with Respiratory Signs in the Rearing and Production Phases

The present study aimed to investigate the occurrence of Mycoplasma synoviae (MS), M. gallisepticum (MG), Ornitobacterium rhinotracheale (OR), Avibacterium paragallinarum (AP), Pasteurella multocida (PM) and Infectious Bronchitis Virus (IBV) in laying hens with respiratory clinical signs in two phases of production. 140 tracheal swabs and 140 blood samples were collected from laying hens in the rearing and production phases, the chickens belonged to six farms (A-F) located in the state of São Paulo, Brazil. The samples were analyzed by PCR for MG, MS, OR, AP, PM and IBV and by ELISA for MG and MS. The highest frequencies observed by PCR were for MS at farms B and C with 95 and 100% positivity, followed by MG at farms D and E with 35% and 65%, IBV with 35% at farm F and ORT with 15% at farm A. All flocks were positive for MG and MS in serology. Although MG and IBV have been detected, this can be explained by the vaccination protocols, since live attenuated vaccines are widely used for immunization against these pathogens. It was also possible to detect OR and AP thorugh PCR in some flocks. The occurrence of several etiological agents that cause respiratory diseases in laying hens was confirmed by PCR and serology, with MS being the most prevalent and being present in all farms studied.(AU)

Production Performance and Egg Quality of Laying Hens as Influenced by Genotype and Rearing System

ABSTRACT The aim of this study was to evaluate the effect of rearing systems and genotypes on production performance and egg quality. Isa Brown and New Hampshire genotypes were used in this study. These two genotypes were housed in floor and organic rearing systems. During the experimental period, which lasted one year (52 weeks), the following production performance parameters were recorded: egg production, daily egg mass, feed consumption, feed conversion efficiency, and mortality. Fifteen eggs per group were collected for analysis at 64 weeks of hen age. These samples were evaluated for external parameters (egg weight and egg shape index), internal parameters (albumen height, Haugh unit, and the proportions of albumen, yolk and shell), eggshell quality parameters (shell thickness, shell deformation and shell breaking strength), and eggs chemical composition (dry matter, minerals, protein and lipids). Generally, Isa Brown hens had better production performance than New Hampshire hens. At the same time, organic New Hampshire layers performed better than floor-reared ones. Genotype had a significant effect on all ten egg quality parameters (external, internal and eggshell quality), rearing system independently affected only egg weight, and the interaction of the observed factors significantly influenced seven parameters. Genotype had a significant effect on three of the four chemical composition parameters, while no significant effect of the rearing system was established on the chemical composition of eggs. The rearing system x genotype interaction significantly affected the eggs protein content.

Detection of Mycoplasma Synoviae and Other Pathogens in Laying Hens with Respiratory Signs in the Rearing and Production Phases

The present study aimed to investigate the occurrence of Mycoplasma synoviae (MS), M. gallisepticum (MG), Ornitobacterium rhinotracheale (OR), Avibacterium paragallinarum (AP), Pasteurella multocida (PM) and Infectious Bronchitis Virus (IBV) in laying hens with respiratory clinical signs in two phases of production. 140 tracheal swabs and 140 blood samples were collected from laying hens in the rearing and production phases, the chickens belonged to six farms (A-F) located in the state of São Paulo, Brazil. The samples were analyzed by PCR for MG, MS, OR, AP, PM and IBV and by ELISA for MG and MS. The highest frequencies observed by PCR were for MS at farms B and C with 95 and 100% positivity, followed by MG at farms D and E with 35% and 65%, IBV with 35% at farm F and ORT with 15% at farm A. All flocks were positive for MG and MS in serology. Although MG and IBV have been detected, this can be explained by the vaccination protocols, since live attenuated vaccines are widely used for immunization against these pathogens. It was also possible to detect OR and AP thorugh PCR in some flocks. The occurrence of several etiological agents that cause respiratory diseases in laying hens was confirmed by PCR and serology, with MS being the most prevalent and being present in all farms studied.

Production Layer Salmonella Enteritidis Control through Dry Fed Pre & Probiotic Products

ABSTRACT Increasing interest in multiple strain Bacillus probiotics and parietal yeast fractions as feed ingredients for egg laying hen diets has also led to food safety questions. This study was undertaken to evaluate the ability of these products to reduce Salmonella Enteritidis colonization. Sixty Hy-Line hens aged 56 weeks were placed in individual cages and fed a mash diet containing one of the following treatments, control, Bacillus spp. probiotic, yeast cell wall, or a combination of yeast cell wall and Bacillus probiotic. At 60 weeks of age all hens were challenged orally with 7 x 107 CFU/bird of Salmonella Enteritidis. At 61 weeks of age, birds were humanely euthanized, by cervical dislocation and the ceca aseptically removed and cultured for S. Enteritidis prevalence and number by the Most Probable Number method. There was no significant difference in prevalence of Salmonella Enteritidis between the control and any treatments. The control birds had 4.37 log10 MPN/g of S. Enteritidis detected in the ceca. The Probiotic group had 2.96 MPN/g, a reduction of 1.41(p 0.05) and the yeast cell wall group had 2.89 MPN/g a reduction of 1.48 (p 0.05). The combination had 3.60 MPN/g a numerical reduction of 0.78 (p=0.14). The yeast cell wall and Bacillus probiotic groups significantly reduced the amount of Salmonella Enteritidis in the ceca of the laying hens.

Dietary Supplementation with Ferula Improves Productive Performance, Serum Levels of Reproductive Hormones, and Reproductive Gene Expression in Aged Laying Hens

This study investigated the effects of dietary Ferula supplementation on productive performance, egg quality, follicular development, serum levels of reproductive hormones, and reproductive gene expression in aged laying hens. A total of 300 Dawu pink laying hens (65 weeks old) were assigned to four treatments with six replicates per treatment and 10 hens per replicate. The birds were individually housed in wire cages and fed a corn-soybean meal-based diet with added Ferula at doses of 0, 50, 100, and 200 mg/kg for 12 weeks. The results showed that the laying rate in the 100 mg/kg Ferula-supplemented group was higher than in birds of the control group during weeks 1 to 12 (p<0.05). The average egg weight in the 100 mg/kg Ferula-supplemented group was significantly higher than in the other groups (p<0.01), while the feed-to-egg ratio was significantly lower than in other groups (p<0.01). The numbers of small yellow follicle, middle white follicle, and small white follicle were higher in the 100 mg/kg Ferula-supplemented birds than in the other groups (p<0.01). On weeks 69, the serum levels of estradiol, follicle-stimulating hormone, and luteinizing hormone were significantly higher in the 100 mg/kg Ferula-supplemented group than in the other groups (p<0.05). Additionally, expressions of ERα, FSHR, and LHR in the ovarian tissue were up-regulated by Ferula supplementation, especially in the 100 mg/kg group (p<0.01). These results indicate that the Ferula supplementation can significantly improve productive performance, egg quality, reproduction of hormonal profile, and reproductive gene expression of aged laying hens.(AU)

The Effect of Supplementing Tea Polyphenols in Diet of Laying Hens on Yolk Cholesterol Content and Production Performance

This study was conducted to evaluate the influence of supplementing tea polyphenols (TP) in diet of laying hens on yolk cholesterol content and production performance. A total of 1800 Lohmann laying hens aged 48 weeks were randomly allocated to 6 groups. Each group consisted of 6 replicates with 50 layers. The feeding experiment was 4 weeks including one-week acclimatization. Layers fed basal diet supplemented with 0, 150, 200, 250, 300 and 350 mg TP/kg diet, respectively. The results showed that average daily feed intake (ADFI), feed conversion ratio (FCR), average egg weight (AEW), laying rate and the indicators of egg quality were not significantly affected by the diet supplemented with 300 mg/kg TP (p>0.05). However, yolk cholesterol content decreased by increasing TP concentration (p 0.01), with 18.06% reduction in layers fed diet supplemented with 300 mg TP/kg. Also, the diet supplemented with 300 mg/kg TP significantly decreased plasma triglyceride (TG), total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-C) level (p 0.05). The activity of serum glutathione peroxidase (GSH-Px) was enhanced by increasing TP concentration, while the content of serum methane dicarboxylic aldehyde (MDA) was decreased by increasing TP concentration. The highest activity of GSH-Px and the lowest serum MDA content were both determined in 300 mg/kg TP group (p 0.01). In conclusion, this study suggests that the addition of 300 mg TP/kg basal diet had no negative effect on the production performance laying hens, yet decreased the egg yolk cholesterol content and enhanced the antioxidant capacity of laying hens at the same time.(AU)

The Effect of Supplementing Tea Polyphenols in Diet of Laying Hens on Yolk Cholesterol Content and Production Performance

This study was conducted to evaluate the influence of supplementing tea polyphenols (TP) in diet of laying hens on yolk cholesterol content and production performance. A total of 1800 Lohmann laying hens aged 48 weeks were randomly allocated to 6 groups. Each group consisted of 6 replicates with 50 layers. The feeding experiment was 4 weeks including one-week acclimatization. Layers fed basal diet supplemented with 0, 150, 200, 250, 300 and 350 mg TP/kg diet, respectively. The results showed that average daily feed intake (ADFI), feed conversion ratio (FCR), average egg weight (AEW), laying rate and the indicators of egg quality were not significantly affected by the diet supplemented with 300 mg/kg TP (p>0.05). However, yolk cholesterol content decreased by increasing TP concentration (p 0.01), with 18.06% reduction in layers fed diet supplemented with 300 mg TP/kg. Also, the diet supplemented with 300 mg/kg TP significantly decreased plasma triglyceride (TG), total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-C) level (p 0.05). The activity of serum glutathione peroxidase (GSH-Px) was enhanced by increasing TP concentration, while the content of serum methane dicarboxylic aldehyde (MDA) was decreased by increasing TP concentration. The highest activity of GSH-Px and the lowest serum MDA content were both determined in 300 mg/kg TP group (p 0.01). In conclusion, this study suggests that the addition of 300 mg TP/kg basal diet had no negative effect on the production performance laying hens, yet decreased the egg yolk cholesterol content and enhanced the antioxidant capacity of laying hens at the same time.

Dietary Supplementation with Ferula Improves Productive Performance, Serum Levels of Reproductive Hormones, and Reproductive Gene Expression in Aged Laying Hens

This study investigated the effects of dietary Ferula supplementation on productive performance, egg quality, follicular development, serum levels of reproductive hormones, and reproductive gene expression in aged laying hens. A total of 300 Dawu pink laying hens (65 weeks old) were assigned to four treatments with six replicates per treatment and 10 hens per replicate. The birds were individually housed in wire cages and fed a corn-soybean meal-based diet with added Ferula at doses of 0, 50, 100, and 200 mg/kg for 12 weeks. The results showed that the laying rate in the 100 mg/kg Ferula-supplemented group was higher than in birds of the control group during weeks 1 to 12 (p<0.05). The average egg weight in the 100 mg/kg Ferula-supplemented group was significantly higher than in the other groups (p<0.01), while the feed-to-egg ratio was significantly lower than in other groups (p<0.01). The numbers of small yellow follicle, middle white follicle, and small white follicle were higher in the 100 mg/kg Ferula-supplemented birds than in the other groups (p<0.01). On weeks 69, the serum levels of estradiol, follicle-stimulating hormone, and luteinizing hormone were significantly higher in the 100 mg/kg Ferula-supplemented group than in the other groups (p<0.05). Additionally, expressions of ERα, FSHR, and LHR in the ovarian tissue were up-regulated by Ferula supplementation, especially in the 100 mg/kg group (p<0.01). These results indicate that the Ferula supplementation can significantly improve productive performance, egg quality, reproduction of hormonal profile, and reproductive gene expression of aged laying hens.