Apparent calcium retention and digestibility coefficients of limestone with different particle sizes in laying hens

Apparent calcium (Ca) retention and digestibility coefficients are affected by limestone particle size in the diet of laying hens. This study aimed to determine the apparent retention and digestibility coefficients of Ca in limestone of different particle sizes in laying hens. The study comprised 288 Lohmann Brown laying hens (50 weeks of age; 1,964 ± 98 g) distributed in a completely randomized experimental design with a 3 × 2 factorial arrangement [three Ca concentrations (10, 20, and 30 g kg-1) × two limestone particle sizes (480 and 1,978 µm)] with eight repetitions per treatment and six birds per experimental unit. The experiment included five days for adaptation and five days for total excreta collection. All birds were slaughtered at the end of the ten days to collect the ileal contents. The total or ileal Ca content was plotted against the Ca of diets concentration using linear regression analysis. The regression line slope represented the apparent retention (CaR) and digestibility coefficients of Ca (CaD) in limestone. There was interaction between Ca concentration in the diet and limestone granulometry on CaD (p = 0.001) and CaR (p < 0.001). The CaD and CaR of fine- and coarse-grained limestone increased linearly with increasing Ca concentrations in the diet. The apparent digestibility coefficients estimated for laying hens fed with fine-grained and coarse-grained limestone were 0.72 and 0.35, respectively. The apparent retention coefficients estimated for laying hens fed fine-grained and coarse-grained limestone were 0.96 and 0.47, respectively.

Effects of amylin on egg quality traits of hens during the early laying period

This study was conducted to investigate the effects of amylin, a pancreatic hormone polypeptide, on egg quality traits in laying hens. A total of 40 birds (14 wk of age) were randomly divided into two treatments with two replicates, 10 birds in each replicate. Twenty birds were subcutaneously injected with amylin at 75 µg/kg every other day (treatment 1), and the remaining animals (20 hens) were given only water as the control group (treatment 2). Eggs collected from the two groups (140 eggs per group) were examined for several quality performance traits such as egg weight, specific gravity, shape index, eggshell strength, eggshell thickness, eggshell ash, eggshell weight, Haugh unit (HU), albumen index, yolk index, yolk color, and albumen height. The results indicated that amylin had a positive effect on some egg quality traits in laying hens. Specific gravity, eggshell thickness, eggshell weight, HU, albumen index, yolk index, and albumen height, which are all considered as important quality parameters from the consumer point of view, especially HU, were relatively improved in the amylin treatment group. These results showed that the injection of 75 µg/kg amylin has a significant effect on some egg quality traits. Considering that egg quality characteristics are crucial for the egg industry, this study can be a reference for the detailed investigation of the use of amylin in the different stages of egg production.

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.

Effects of dietary fiber on performance and egg quality of laying hens at pre-laying and laying peak

This study aimed to evaluate the effects of different levels of dietary fiber on the performance and egg quality of laying hens at pre-laying and laying peak periods. The experimental period was divided into three periods: pre-laying (16 to 19 weeks of age), the start of laying (20 to 22 weeks of age) and laying peak (23 to 28 weeks of age). The experimental design was completely randomized with treatments constituted by five levels of fiber (2.00, 2.50, 3.00, 3.50, and 4.00%) in the diets, with five replicates (pens) of six birds each, totalling 180 hens. Performance and egg quality results were evaluated by polynomial regression at 5%. Fiber levels were not influenced (p >0.05) the first laying of the hens. However, levels above 2.50% of fiber provided worst (p <0.05) performance results, regardless of the period evaluated. Shortly after the start of laying, higher levels of fiber also caused a linear reduction (p <0.05) on egg weight and percentages of yolk and albumen, and an increase (p <0.05) on eggshells. Higher fiber levels caused a linear reduction (p <0.05) in the quality of the eggs, regardless of the period evaluated. It was concluded that the fiber levels did not influence the start period of the laying. Both pre-laying and start of the laying, levels above 2.5% of fiber caused a gradual worsening in performance. From the start of laying up to laying peak, levels above 2.5% of fiber also caused a gradual worsening in egg quality.(AU)

Identical thermal stress coupled with different temperature and humidity combinations affects nutrient digestibility and gut metabolites of laying hens

The present study investigated whether the same temperature-humidity index (THI) values under different conditions of air temperature and relative humidity (RH) would affect the thermoregulatory, nutritional, and behavioral responses of laying hens. One hundred twenty Hy-Line Brown laying hens (60-weeks-old) were divided equally in two environmental chambers: 26 °C with 70% RH (hRH75) and 30 °C with 30% RH (hT75) for 28 days. The two ambient environments (hRH75 and hT75) had an identical THI value of 75, calculated using an empirical formula for laying hens. Neither hRH75 nor hT75 affected rectal and body-surface temperatures and heart and respiratory rates. The concentration of volatile fatty acids in fecal excreta were altered by the thermal treatments. hT75 vs. hRH75 decreased the proportion of acetate and increased the proportion of propionate in fecal samples. hT75 vs. hRH75 lowered the digestibility of dry matter, crude protein, and neutral detergent fiber at 14 days. Thermal treatments did not affect heat stress-associated behavioral responses including feeding, drinking, panting, and wing elevation at any stage. Laying hens exposed to the same THI at different temperatures and RH exhibit equal physiological responses including rectal and body-surface temperatures, heart and respiratory rates, and behavioral responses. Nonetheless, high-temperature treatment (hT75; 30 °C and 30% RH) vs. low temperature treatment (hRH75; 26 °C and 70% RH) affects nutrient digestibility and gut metabolites, suggesting that there are negligible but discernable responses to temperature in the gut physiology.(AU)

Diferentes densidades de alojamento de galinhas poedeiras em gaiolas e suas respectivas produção, qualidade de ovos e escore de penas / Different housing densities of laying hens in cages and their production, egg quality andfeather score

As poedeiras criadas em sistema degaiolas tem seu bem-estar afetado devido ao menor espaço disponível para elas, o que vai de encontro da crescente pressão por grande parte de consumidores preocupados com as condições em que essas aves são criadas. A consequência dessa menor densidade de alojamento sobre a produtividade, e a qualidade de vida da ave e dos ovos por elas produzidos deve ser avaliada. O objetivo desse estudo é avaliar a produção, qualidade de ovos, e bem-estar de galinhas poedeiras criadas em diferentes densidades de alojamentos em gaiolas. Às 28 semanas de idade, foram distribuídas, em delineamento inteiramente casualizado, 120 poedeiras leves da linhagem Novogen White, após debicagem, em 24 gaiolas com dimensões de 45 cm x 50cm, em três diferentes densidades de alojamento: 562,5 cm² /ave (quatro aves/gaiola), 450 cm² /ave (cinco aves/gaiola) e 375 cm² /ave(seis aves/gaiola), com 8 repetições cada. As dietas experimentais foram isoproteicas e isoenergéticas, formuladas à base de milho e farelo de soja. O período experimental será compreendido por seis ciclos de 28 dias cada. As variáveis analisadas foram: peso do ovo, índice de gema, unidade Haugh, pigmentação da gema, porcentagem dos componentes dos ovos e espessura de casca (em milímetros). Quando as aves atingiram 44 semanas de idade, foi realizada a medição do escore de penas. Foram avaliadas 40 galinhaspor tratamento, em quatro regiões: peito, dorso, asas e posterior. Essa análise consiste emcategorizar as aves de acordo com três diferentes escores, de acordo com o tamanho da área de ausência de penas em cada região. Espera-se que a redução da densidade de alojamento das galinhas nas gaiolas propicie maior produção com melhor qualidade dos ovos, promovendo também melhor bem-estar das aves.(AU)

The well-beingof laying hens raised in cages is affected due to the smaller space available for them,which is in line with the growing pressure from a large number of consumers concerned about the conditions in which these birds are raised.The consequence of thislower housing density on productivity and the quality of life of the bird andthe eggs produced by them must be evaluated. The aim of this study is to evaluate the production, egg quality, and welfare of laying hens reared in different housing densities in cages. At 28 weeks of age, 120 light Novogen White laying hens were distributed, after beak trimming, in24 cages measuring 45 cm x 50 cm, in three different housing densities: 562.5 cm²/bird (four birds/cage), 450 cm²/bird (five birds/cage) and 375 cm²/bird (six birds/cage), with 8 repetitions each. The experimental diets were isoproteic and isoenergetic, based on corn and soybean meal. The trial period will comprise six cycles of 28 days each. The variables analyzed were: egg weight, yolk index, Haugh unit, yolk pigmentation, percentage of egg components and shell thickness (in millimeters). When the birds reached 44 weeks of age, the feather score was measured. Forty chickens per treatment were evaluated in four regions: chest, back, wings and hindquarters. This analysis consists of categorizing the birds according to three different scores, according to thesize of the area without feathers in each region. It is expected that the reduction in the hen housing density in the cages will lead to higher production with better egg quality, also promoting better hen welfare.(AU)

Threonine-to-lysine ratio in laying hens: physiological parameters and organ weight

The objective of this study was to evaluate the effect of threonine:digestible lysine ratio in the diet on the physiological variablesand weight of organs of light laying hens. Two hundred and ten 47 week-old Dekalb White laying henswere distributed in a completely randomized design, with five levels of threonine (0.507; 0.552; 0.597; 0.642 and 0.677%) and seven replicates of six birds each. The experimental period was 10 weeks, totaling 62 days and more eight days for the animals to adapt. The physiological parameters of cloacal temperature (CT), respiratory rate (RR) and average surface temperature (AST) were recorded weekly (7:00 am, 10:00 am, 1:00 pm, 4:00 pm, and 7:00 pm); after solid and water fasting,the birds were slaughtered to assess the absolute weight of the organs. The time of day influenced (p < 0.05) the physiological parameters RR and AST, and CT showed a significant effect (p < 0.05) of increasing levels of digestible threonine. The total weight of the pancreas, proventriculus and lung showed a significant effect (p < 0.05) of the increase in the levels of digestible threonine. The respiratory rate is affected by the levels of threoninein the diet. The 0.687% level promoted hypertrophy of the pancreas, proventriculus and lung, promoting more significant activity of these organs.(AU)

Performance, physical egg quality, and economic index of laying hens under different rearing systems / Desempenho, qualidade do ovo e índice econômico de poedeiras em diferentes sistemas de criação

The objective was to evaluate the performance, physical egg quality (weight and gravity), and economic index of laying hens reared in cage and cage-free systems. A total of 312 40-week-old Hy-line brown laying hens were distributed in a fully randomized design, split into two treatments (cage-free and cage) with 12 replicates in each system. We housed 144 birds in galvanized-wire cages (12 birds each) and 168 birds in a cage-free system in boxes with wood shaving bedding (14 birds each). The experiment lasted 112 days and divided into four 28-day periods. Regarding performance, feed intake (g) and feed conversion (g/g) of birds reared in the cage-free system were higher (p<0.0001) than the cage system, but no differences were observed (p>0.05) for the other performance parameters and also for egg quality. As for economic index, egg production in the cage-free system was higher (p<0.0001) than the cage system. In conclusion, birds reared in the cage-free system have higher feed consumption but worse feed conversion, increasing egg production cost compared to caged birds; however, there are no changes in egg production and physical quality.(AU)

Objetivou-se avaliar o desempenho, qualidade de ovos e índice econômico de poedeiras semipesadas criadas em sistemas cage-free e em gaiolas. Foram utilizadas 312 poedeiras da linhagem Hy Line Brown, com 40 semanas de idade, distribuídas em um delineamento inteiramente casualisado (DIC), em dois tratamentos (cage-free e gaiolas) com 12 repetições em cada sistema, sendo 144 aves alojadas em gaiolas de arame galvanizado com 12 aves em cada gaiola e 168 aves alojadas em sistema cage-free, em boxes sobre cama de maravalha com 14 aves em cada repetição. O experimento teve duração de 112 dias, divididos em quatro períodos de 28 dias. Nos parâmetros de desempenho, o consumo de ração (g/aves/dia) e a conversão alimentar (g/g) foi maior (P<0,0001) nas aves criadas no sistema cage-free comparado ao sistema de gaiolas, não sendo observado diferença (P>0,05) nos demais parâmetros de desempenho e também na qualidade de ovos. No índice econômico, a produção de ovos em sistema cage-free apresentou maior valor (P<0,0001) em relação ao sistema de gaiola. Conclui-se que as aves criadas em sistema cage-free apresentam maior consumo de ração, pior conversão alimentar ocasionando um maior custo nos ovos em relação às aves criadas em gaiolas, no entanto não há alteração na produção e qualidade dos ovos.(AU)

Emulsifiers in diets with energy reduction for laying hens

Emulsifiers in animal diets are an interesting and effective strategy for nutritionists to improve the digestion of dietary lipids and, consequently, provide better performance. This study aimed to evaluate the effect of the supplementation of diets with emulsifier based on mono-and diglycerides (120 g t-1of feed) associated with different energy levels (2,775; 2,725; 2,675 and 2,625 kcal of metabolizable energy kg-1of feed) on performance and egg quality of Hisex Brown laying hens. The laying hens weredistributed in 50 experimental plots with eight birds each. A completely randomized design with five treatments and ten replicates/treatments was used. The treatments in this study were: control diet (C) with 2,775 kcal of metabolizable energy (ME) kg-1of feed; C + E: diet C supplemented with an emulsifier (E) at 120 g t-1of feed; diet C with reduction of 50 kcal ME and supplemented with E (NC50 + E); diet C with reduction of 100 kcal ME and supplemented with E (NC100 + E); and diet C with reduction of 150 kcal ME and supplemented with E (NC150 + E). All diets had the same inclusion level of degummed soybean oil (2%). There was no influence of the treatments on the performance and quality of the eggs (p >0.05). The current study has shown that diets supplemented with emulsifiers based on mono-and diglycerides (120 g t-1) allows reducing the metabolizable energy level up to 150 kcal kg-1of feed, without impairment on performance and egg quality of Hisex Brown laying hens.(AU)

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.

Assessing Differences in the Quality Properties and Ultrastructure of Eggshell as Affected by Chicken Strain and Flock Age During Incubation Period

Three hundred hatching eggs from two layer breeder flocks (Hy-Line Brown and hy-Line W-36; 150 each) were obtained at three different periods of laying cycle (early, middle and late stages). The hatching eggs were randomly taken to assess the impact of chicken strain, age, and hatching time on some eggshell measurements and structures. Results indicate that egg weight, shell percentage and shell thickness were significantly affected by strain, breeder age, and incubation time. Increasing rate of calcium absorption and utilization by the embryos during the embryonic stage clearly reflects the decrease occurred in eggshell strength. The differences of eggshell breaking strength during incubation time periods were 0.41 and 0.55 kg/cm2, the differences due to the incubation time may be due to the higher demand for calcium utilization in the late incubation period (18 days), observed on the10th day of incubation. Brown eggs recorded significant higher calcium percentage in eggshell compared to the white ones. The brown breeder hens recorded significant higher total pores per egg compared to the white egg. Concerning eggshell ultrastructure, total thickness of the brown eggshell was significantly higher than those of the white eggshell by about 3.7%. All parameters, except for total thickness, were significantly affected by the interaction between strain and breeder age. Finally, we conclude that some traits including egg weight, shell percentage, shell thickness, calcium percentages in eggshell, and total pores per egg were significantly affected by strain, breeder age, and incubation time. Eggshell ultrastructure of brown egg was better compared to the white ones.(AU)

Investigation of Egg Weight, Ovarian Follicles Morphology and Growth Differentiation Factor 9 mRNA Expression in Potchefstroom Koekoek Chicken Breed

The growth differentiation factor 9 (GDF9) gene plays a vital role in the growth and maturation of ovarian follicles in laying hens. However, its messenger ribonucleic acid (mRNA) expression levels in preovulatory ovarian follicles of indigenous chickens remain poorly understood. The study aimed to identify the association between egg weight and egg quality traits, ovarian follicles morphology, and mRNA expression levels of the GDF9 gene in pre-ovulatory ovarian follicles of the South African Potchefstroom Koekoek chicken breed. The correlation results showed that egg weight (EW) had a positively high significant correlation (p<0.01) with egg width (EWD), yolk weight (YW), shell surface area (SSA), albumen weight (AW), albumen ratio (AR) and egg volume (EV), and a positive significant correlation (p<0.05) with egg length (EL). The Student's T-test results revealed that the numbers of large yellow follicles were significantly lower (p<0.05) than those of small yellow follicles. ANOVA findings showed that there was a significant difference (p<0.05) in the average weight of the large yellow follicles. The quantitative Reverse Transcription Polymerase Chain Reaction (RT-qPCR) findings indicated that there were significant differences (p<0.05) in the mRNA expression levels of the GDF9 gene in preovulatory ovarian follicles of the Potchefstroom Koekoek chicken breed. The mRNA expression was more abundant in F1 and F4 than in other ovarian follicles.(AU)

Qualidade de ovos comerciais oriundos de poedeiras tratadas com doxiciclina / Quality of commercial egg from laying hens treated with doxycycline / Calidad de huevos comerciales de gallinas ponedoras tratadas con doxiciclina

Doxiciclinaé um fármaco do grupo das tetraciclinas indicado para tratamento de diferentes doenças, em principal a coriza infecciosa. Entretanto, antimicrobianos do grupo das tetraciclinas tem capacidade de se ligarem e indisponibilizar minerais importantes para a formação dos ovos. O objetivo do projeto foi de avaliar a interferência da doxiciclina na qualidade de ovos comerciais. Realizou-se um estudo com 100 poedeiras Dekalb Brown®onde se avaliou a cor da gema, unidade Haugh, cor da casca, peso e espessura da casca. O delineamento adotado foi o inteiramente casualizadosem um esquema fatorial 2x2, resultando nos tratamentos: sem doxiciclina ao 5° dia; com doxiciclina ao 5° dia; sem doxiciclina ao 10° dia; com doxiciclina ao 10° dia. Coletou-se 4 ovos por repetição,totalizando 48 ovos analisado por tratamento em cada um dos períodos analisados. Não foram encontradas diferenças significativas entre os tratamentos para as variáveis de qualidade interna dos ovos (cor da gema e unidade Haugh). Para as variáveis de qualidade de casca, houve uma redução significativa dos níveis de amarelo com o uso de doxiciclina por 10 dias, além da redução do peso da casca e da espessura apical e equatorial da casca, principalmente no 10º dia e com o uso de doxiciclina. Conclui-se que o uso da doxiciclina não interfere na qualidade interna dos ovos, porém confere tonalidade acinzentada as cascas, e redução de peso e espessura das mesmas.(AU)

Doxycycline is a drug from the tetracycline group indicated for the treatment of different diseases, mainly infectious coryza. However, antimicrobials from the tetracycline group can bind and make minerals important for egg formation unavailable. The aim of this project is evaluated interference of doxycycline in quality of commercial egg. A study had carried out with 100 Dekalb Brown®laying hens where evaluated the yolk color, Haugh unit,color eggshell, weight and thickness eggshell. The delimitation had completely randomized in a 2x2 factorial scheme, resulting in treatments: without doxycycline at day 5; with doxycycline a day 5; without doxycycline at day 10; with doxycycline at day 10. Four eggs had gathered per replicate, totaling 48 eggs analyzed per treatment in each of the analyzed periods. No significant differences were found between treatments for internal egg quality variables (yolk color and Haugh unit). For the shell quality variables, there was a significant reduction in yellow levels with the use of doxycycline for 10 days, in addition to a reduction in shell weight and apical and equatorial shell thickness, mainly on the 10th day and with the use of doxycycline. It is concluded that the use of the doxycycline does not interfere in the internal quality of the eggs, but it gives a greyish tonality to the eggshells, and reduces their weight and thickness.(AU)

La doxiciclina es un fármaco del grupo de las tetraciclinas indicado para el tratamiento de diferentes enfermedades, principalmente el coriza infeccioso. Sin embargo, los antimicrobianos del grupo de las tetraciclinas tienen la capacidad de unirse y hacer que minerales importantes para la formación de huevos no estén disponibles. El objetivo de este proyecto es evaluar la interferencia de la doxiciclina en la calidad del huevo comercial. Se realizó un estudio con 100 gallinas ponedoras Dekalb Brown®donde se evaluó el color de la yema, unidad Haugh, color del cascarón, peso y grosor del cascarón. La delimitación tuvo completamente al azar en un esquema factorial 2x2,resultando tratamientos: sin doxiciclina en el día 5; con doxiciclina al día 5; sin doxiciclina el día 10; con doxiciclina el día 10. Se habían recolectado cuatro huevos por réplica, totalizando 48 huevos analizados por tratamiento en cada uno de los períodos analizados. No se encontraron diferencias significativas entre tratamientos para las variables de calidad interna del huevo (color de la yema y unidad Haugh). Para las variables de calidad de la cáscara, hubo una reducción significativa de los nivelesde amarillo con el uso de doxiciclina durante 10 días, además de una reducción del peso de la cáscara y del espesor apical y ecuatorial de la cáscara, principalmente al décimo día y con el uso de doxiciclina. Se concluye que el uso de la doxiciclina no interfiere en la calidad interna de los huevos, pero da una tonalidad grisácea a las cáscaras, y reduce su peso y grosor.(AU)

Evaluation of the interaction of citral, geraniol and thymol on the poultry red mite Dermanyssus gallinae (DE GEER, 1778) under in vitro conditions / Avaliação da interação de citral, geraniol e timol no ácaro-vermelho-das-aves Dermanyssus gallinae(DE GEER, 1778) em condições in vitro

The control of Dermanyssus gallinaein small productions of laying hens is carried out by using chemical methods. However, its indiscriminate use has generated resistance and environmental pollution problems. This problem has encouraged the use of natural substances to control mites. Thus, the objective of this work was to evaluate the acaricidal activity of the bioactivecitral (Ci), geraniol (Ge) and thymol (Thy) on D. gallinae under in vitro conditions using six concentrations (0.05, 1, 2, 3, 4 and 5g/mL). In addition, the interactions of the mixtures of the three bioactive were evaluated through binary (1:1) and tertiary (1:1:1) combinations. The interaction between of the combination of bioactive was performed by using CompuSyn software and calculating the combination index (CI). LC50, LC90, and LC99with 95% confidence limits were estimated by Probit analysis. The bioactive Ci, Ge and Thy showacaricidal activity on the poultry red mite. The combination of Ge:Thy and Ci:Ge showed very strong synergism with CI of 0.084 and 0.052, whereas Ci:Thy showed strong synergism with CI of 0.122 at a concentration of 0.05g/mL. Thetertiary combination in 1:1:1 showed a higher toxic effect and strong synergistic effects at low concentrations with 100% mortality at 1g/mL concentration with a CI of 0.147. The combination of natural bioactive could be an additional way to control D. gallinae without putting thewelfare of the birds at risk and would be an environmentally friendly measure.(AU)

O controle de Dermanyssus gallinaeem pequenas produções de poedeiras é realizado por métodos químicos.No entanto, seu uso indiscriminado tem gerado problemas de resistência e poluição ambiental. Este problema tem incentivado o uso de substâncias naturais para o controle de ácaros. Assim, o objetivo deste trabalho foi avaliar a atividade acaricida dos bioativos citral (Ci), geraniol (Ge) e timol (Thy) sobre D. gallinaeem condições in vitro utilizando seis concentrações (0,05, 1, 2, 3, 4 e 5g/mL). Além disso, as interações das misturas dos três bioativos foram avaliadas por meio decombinações binárias (1:1) e terciárias (1:1:1). O sinergismo da combinação dos bioativos foi realizado utilizando o software CompuSyn e calculando o índice de combinação (CI). LC50, LC90e LC99com limites de confiança de 95% foram estimados por análise Probit. Os bioativos Ci, Ge e Thy apresentam atividade acaricida sobre o ácaro-vermelho-da-aves. A combinação de Ge:Thy e Ci:Ge apresentou sinergismo muito forte com CI de 0,084 e 0,052, enquanto Ci:Thy apresentou forte sinergismo com CI de 0,122 na concentração de 0,05g/mL. A combinação terciária em 1:1:1 apresentou maior efeito tóxico e fortes efeitos sinérgicos em baixas concentrações com 100% de mortalidade em concentração de 1g/mL com CI de 0,147. A combinação de bioativos naturais poderia ser uma forma adicional de controle deD. gallinaesem colocar em risco o bem-estar das aves e seria uma medida ecologicamente correta.(AU)

Environment type and storage period on eggshell quality of laying hens at different ages / Tipos de ambiente e período de armazenamento sobre a qualidade de casca de ovos de poedeiras comerciais em diferentes idades

ABSTRACT: Eggshell quality is directly linked to the good acceptability of the product by consumers, whereas the industry is concerned with economic losses. Prolonged periods of laying, diseases, nutrition, bird age and genetics can influence egg quality. This study aimed to examine the influence of the environment, bird age and storage period on the physical characteristics of the shell of eggs from commercial laying hens. The experiment involved 288 eggs from Hy-line hens, which were distributed in a completely randomized design with a triple 3×2×4 factorial arrangement represented by three ages (31, 62 or 88 weeks), two storage temperatures (ambient or refrigerated), and four storage periods (one, 10, 20 or 30 days), totaling 24 treatments. Four replications were used with three eggs each. Eggshell strength, percentage and thickness were measured. Differences were observed, with the eggs stored at room temperature exhibiting lower shell strength. Laying eggs at an advanced age (88 weeks) resulted in decreased eggshell strength as compared with the other ages, whereas the eggs from young layers (31 weeks) had a thicker shell. The advancing age of the laying hens reduced eggshell quality, regardless of the storage environment. Nonetheless, the eggs stored in the refrigerator showed better eggshell quality and integrity than those stored at ambient temperature.

RESUMO: A qualidade da casca está diretamente ligada à boa aceitabilidade do produto pelos consumidores, enquanto a indústria se preocupa com as perdas econômicas. Períodos prolongados de postura, doenças, nutrição, idade da ave e genética podem influenciar a qualidade dos ovos. Objetivou-se avaliar a influência do ambiente, idade da ave e período de armazenamento nas características físicas da casca de ovos de poedeiras comerciais. Foram utilizados 288 ovos de poedeiras Hy-line, distribuídos em um delineamento inteiramente casualizado em fatorial triplo 3x2x4, sendo os fatores: três idades (31, 62 e 88 semanas), temperatura de armazenamento (ambiente e refrigerado), e quatro períodos de armazenamento (um, 10, 20 e 30 dias), totalizando 24 tratamentos, com quatro repetições de três ovos. Avaliou-se a resistência, percentual e espessura da casca. Foram observadas diferenças, uma vez que os ovos armazenados em temperatura ambiente apresentaram diminuição na resistência de casca. Ovos de poedeiras em idade avançada (88 semanas) apresentaram pior resistência de casca em relação às demais idades, enquanto ovos provenientes de poedeiras jovens (31 semanas) apresentaram maior espessura de casca. A idade avançada da poedeira reduziu a qualidade de casca dos ovos, independentemente do ambiente de armazenamento. Ainda, os ovos armazenados em geladeira apresentaram melhor qualidade e integridade da casca em comparação com os armazenados ao ambiente.

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)

Environment type and storage period on eggshell quality of laying hens at different ages / Tipos de ambiente e período de armazenamento sobre a qualidade de casca de ovos de poedeiras comerciais em diferentes idades

Eggshell quality is directly linked to the good acceptability of the product by consumers, whereas the industry is concerned with economic losses. Prolonged periods of laying, diseases, nutrition, bird age and genetics can influence egg quality. This study aimed to examine the influence of the environment, bird age and storage period on the physical characteristics of the shell of eggs from commercial laying hens. The experiment involved 288 eggs from Hy-line hens, which were distributed in a completely randomized design with a triple 3×2×4 factorial arrangement represented by three ages (31, 62 or 88 weeks), two storage temperatures (ambient or refrigerated), and four storage periods (one, 10, 20 or 30 days), totaling 24 treatments. Four replications were used with three eggs each. Eggshell strength, percentage and thickness were measured. Differences were observed, with the eggs stored at room temperature exhibiting lower shell strength. Laying eggs at an advanced age (88 weeks) resulted in decreased eggshell strength as compared with the other ages, whereas the eggs from young layers (31 weeks) had a thicker shell. The advancing age of the laying hens reduced eggshell quality, regardless of the storage environment. Nonetheless, the eggs stored in the refrigerator showed better eggshell quality and integrity than those stored at ambient temperature.

A qualidade da casca está diretamente ligada à boa aceitabilidade do produto pelos consumidores, enquanto a indústria se preocupa com as perdas econômicas. Períodos prolongados de postura, doenças, nutrição, idade da ave e genética podem influenciar a qualidade dos ovos. Objetivou-se avaliar a influência do ambiente, idade da ave e período de armazenamento nas características físicas da casca de ovos de poedeiras comerciais. Foram utilizados 288 ovos de poedeiras Hy-line, distribuídos em um delineamento inteiramente casualizado em fatorial triplo 3x2x4, sendo os fatores: três idades (31, 62 e 88 semanas), temperatura de armazenamento (ambiente e refrigerado), e quatro períodos de armazenamento (um, 10, 20 e 30 dias), totalizando 24 tratamentos, com quatro repetições de três ovos. Avaliou-se a resistência, percentual e espessura da casca. Foram observadas diferenças, uma vez que os ovos armazenados em temperatura ambiente apresentaram diminuição na resistência de casca. Ovos de poedeiras em idade avançada (88 semanas) apresentaram pior resistência de casca em relação às demais idades, enquanto ovos provenientes de poedeiras jovens (31 semanas) apresentaram maior espessura de casca. A idade avançada da poedeira reduziu a qualidade de casca dos ovos, independentemente do ambiente de armazenamento. Ainda, os ovos armazenados em geladeira apresentaram melhor qualidade e integridade da casca em comparação com os armazenados ao ambiente.

Environment type and storage period on eggshell quality of laying hens at different ages / Tipos de ambiente e período de armazenamento sobre a qualidade de casca de ovos de poedeiras comerciais em diferentes idades

Eggshell quality is directly linked to the good acceptability of the product by consumers, whereas the industry is concerned with economic losses. Prolonged periods of laying, diseases, nutrition, bird age and genetics can influence egg quality. This study aimed to examine the influence of the environment, bird age and storage period on the physical characteristics of the shell of eggs from commercial laying hens. The experiment involved 288 eggs from Hy-line hens, which were distributed in a completely randomized design with a triple 3×2×4 factorial arrangement represented by three ages (31, 62 or 88 weeks), two storage temperatures (ambient or refrigerated), and four storage periods (one, 10, 20 or 30 days), totaling 24 treatments. Four replications were used with three eggs each. Eggshell strength, percentage and thickness were measured. Differences were observed, with the eggs stored at room temperature exhibiting lower shell strength. Laying eggs at an advanced age (88 weeks) resulted in decreased eggshell strength as compared with the other ages, whereas the eggs from young layers (31 weeks) had a thicker shell. The advancing age of the laying hens reduced eggshell quality, regardless of the storage environment. Nonetheless, the eggs stored in the refrigerator showed better eggshell quality and integrity than those stored at ambient temperature.(AU)

A qualidade da casca está diretamente ligada à boa aceitabilidade do produto pelos consumidores, enquanto a indústria se preocupa com as perdas econômicas. Períodos prolongados de postura, doenças, nutrição, idade da ave e genética podem influenciar a qualidade dos ovos. Objetivou-se avaliar a influência do ambiente, idade da ave e período de armazenamento nas características físicas da casca de ovos de poedeiras comerciais. Foram utilizados 288 ovos de poedeiras Hy-line, distribuídos em um delineamento inteiramente casualizado em fatorial triplo 3x2x4, sendo os fatores: três idades (31, 62 e 88 semanas), temperatura de armazenamento (ambiente e refrigerado), e quatro períodos de armazenamento (um, 10, 20 e 30 dias), totalizando 24 tratamentos, com quatro repetições de três ovos. Avaliou-se a resistência, percentual e espessura da casca. Foram observadas diferenças, uma vez que os ovos armazenados em temperatura ambiente apresentaram diminuição na resistência de casca. Ovos de poedeiras em idade avançada (88 semanas) apresentaram pior resistência de casca em relação às demais idades, enquanto ovos provenientes de poedeiras jovens (31 semanas) apresentaram maior espessura de casca. A idade avançada da poedeira reduziu a qualidade de casca dos ovos, independentemente do ambiente de armazenamento. Ainda, os ovos armazenados em geladeira apresentaram melhor qualidade e integridade da casca em comparação com os armazenados ao ambiente.(AU)

Rastreability of bovine meat and bone meal using the stable isotope technique in egg production

ABSTRACT The present study aimed to verify whether the inclusion of other ingredients in the diet of laying hens could interfere with the traceability of bovine meat and bone meal (BMBM) in eggs through stable carbon and nitrogen isotope analysis. Two hundred and fifty-six white laying hens were used and randomly distributed into eight treatments composed of: CONTROL: control diet; GLUTEN: control diet + corn gluten; YEAST: control diet + yeast; GLUTEN + YEAST: control diet + corn gluten + yeast; BMBM: control diet + 4.5 % BMBM; BMBM + GLUTEN: control diet + corn gluten + 4.5 % BMBM; BMBM + YEAST: control diet + yeast + 4.5 % BMBM; BMBM + GLUTEN + YEAST: control diet + corn gluten + yeast + 4.5 % BMBM. The isotopic results were subjected to multivariate analysis of variance (MANOVA) and LDA multivariate linear discriminant analysis. At 28 days, the eggs of the birds given diets without the addition of BMBM differed from the CONTROL group. The yolks showed that all treatments were significantly different from the CONTROL, and at 56 days, all eggs and egg yolks were different from the CONTROL. At 28 days, albumen was significantly different for all CONTROL experimental treatments; however, at 56 days, the YEAST treatment showed no difference from the control. Thus, it was concluded that even with the addition of other ingredients, the isotope technique is still able to detect the BMBM in eggs.

Natural and synthetic pigments in sorghum-based diets for laying hens

The objective of this work was to evaluate the supplementation of yellow natural pigment levels based on Marigold Flower extract (2%) and yellow synthetic pigment (Carophyll Yellow 10%) in sorghum-based rations for commercial laying hens and their influence on bird performance and egg quality. A completely randomized design was adopted with 5 treatments, 6 replicates, and 5 laying hens in each repetition. The treatments evaluated were: Sorghum based diet without supplementation with pigmentant - Negative Control; 150 g t-1 of Yellow Natural Pigment feed; 300 g t-1 of yellow natural pigment feed; 450 g t-1 of yellow natural pigment feed; 25 g t-1 of yellow industrial pigment feed. The Tukey test was applied at 5% for the analysis of the variables of performance and quality of the eggs. The variables related to external and internal egg quality and poultry yield performance did not present significant results (p > 0.05). Only the variable color of the yolk obtained significance (p < 0.01), with an increase according to the number of pigments included in the diet. Sorghum can be used together supplementation of natural and synthetic pigments in the diet to improve yolk pigmentation. It is recommended to include 450g t-1 of natural marigold flower pigment feed (2%) in sorghum-based diets for better pigmentation of the yolk in place of 25 g t-1 of yellow synthetic pigmented, by improving the color of the yolk and not interfering in the productive performance of the laying hens and the quality of the eggs.(AU)