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.

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)

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.

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.

Multivariate analysis of sources of polyunsaturated fatty acids, selenium, and chromium on the productive performance of second-cycle laying hens

An experiment was conducted to evaluate the effect of the intake of a mixture of fish and sacha inchi oils (iOM), organic selenium (iSe), and organic chromium (iCr) on egg production (EP) and feed conversion ratio (FCR) of Isa Brown second-cycle laying hens (SCLH) for 16 weeks (91-106 weeks old). Egg production and FCR were evaluated using multivariate models that included conventional equations and artificial neural networks (ANN) to study multiple nutritional interactions as alternatives to univariate dose-response models. Based on the best models, iOM, iSe, and iCr levels were optimized, and a global sensitivity analysis was implemented to quantify their influence on EP and FCR. The modified logistic model was selected as the best strategy to represent EP. In the case of FCR, an ANN model with a feed-forward architecture and softmax transfer function was selected as the best alternative. One of the scenarios to simultaneously optimize EP (89.1%) and FCR (1.94 kg feed/kg egg) at 16 weeks of production was established with 3.3 g/hen·day of iOM, 0.132 mg/ hen·day of iSe, and 0.176 mg/hen·day of iCr. However, optimization considering only FCR results in much lower optimal iCr levels (between 0.083 and 0.105 mg/hen·day) with a slight decrease in EP (87.9%). The global sensitivity analysis showed that iSe is an essential factor associated with the increase in EP, and iCr is the most influential factor for the decrease in FCR. When both criteria were taken into account simultaneously from a desirability function, iSe was the most critical factor.(AU)

Use of Mathematical Models in the Analysis of Growth and Commercial Performance of Brown Layers

Small and medium-sized table egg producers have a large volume of data and information on daily production, which is not used in the decision-making process. It is important to define the best mathematical model for the prediction of both the growth and the egg production of brown layers to relate pullet growth traits with productivity in a commercial cycle. For the above purpose, growth and production data were obtained from 15 brown layer flocks, six mathematical models of growth and five of egg production were tested. Correlations were made between the parameters of growth and egg production, as well as between the parameters derived from the mathematical models. The prediction equations for the egg production indicators were estimated.As a result,the best model for predicting layer growth (Gompertz) and for egg production was obtained (Yang). The growth parameters with the greatest influence on egg production were the maximum growth rate (MGR) and the theta value (TV). Body weight at 8, 9, 10, 12, and 16 weeks of age had effects on egg production. As a conclusion maximizing the growth of the brown layer in key stages of its development has positive effects on egg production.(AU)

The Protective Role of Silymarin to Ameliorate the Adverse Effects of Ochratoxin-A in Laying Hens on Productive Performance, Blood Biochemistry, Hematological and Antioxidants Status

This study was planned to examine the effect of silymarin on diminishing adverse effects of ochratoxin-A (OTA) in laying hens. A total number of 300 Inshas, local layer hens of 28 weeks of age were randomly distributed into 4 groups with 5 replicates each (15 hens). The birds were fed on the following treatments, (Control): fed a hen diet without any supplementation; (SL): fed the control diet supplemented with SL (1000 mg/kg feed); (OTA-diet): was fed the control diet contaminated with 1 ppm of OTA/kg diet, and (OTA+SL): fed the OTA-diet plus SL (1ppm OTA+1000 mg SL/kg feed). Results showed that feeding OTA at 1 ppm reduced productive performance compared with those fed the control diet. In OTA treated groups the total erythrocytes count, leukocytes count, PCV and Hb were decreased when compared to the control and SL groups. Albumin, globulin and serum total proteins in OTA treated groups were significantly lower when compared to the control and SL groups. Serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were significantly increased in OTA fed groups in comparison with the control and SL groups. Creatinine and uric acid were increased in OTA treated groups but were almost normal in the SL group. The results showed that OTA had a severe effect on liver and kidney, but SL treated group had normal liver and kidneys showing its hepatoprotective effects.(AU)

Effect of Dietary Tetramethylpyrazine on Egg Production, Nutrient Retention and Cecal Bacterial Diversity in Aged Laying Hens

This study aimed to investigate the effect of tetramethylpyrazine (TMP) supplementation on egg production, nutrient retention and cecal microbiota diversity using 288 commercial Hy-Line brown hens as of wk 75 to 86. Four treatments consisted of TMP addition at 0 (control, basal diet), 100, 150 and 200 mg/kg of diet. The results showed that diets supplemented with TMP addition improved egg-laying rate as of wk 77 compared to the control, which led to an increase (p<0.001) of egg mass by 97-225 g/hen throughout the whole trial, and a linear increase (p=0.003) of egg mass to the incremental TMP doses was found. At wk 86, the apparent digestibilities of dry matter and crude protein were enhanced (p<0.05), exhibiting consistent linear increases (p≤0.033) with the TMP doses. However, TMP did not cause alpha and beta diversity of cecal microbiota. The results suggest that TMP can be an additive to improve egg production and nutrient digestibility of aged laying hens.(AU)

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.

Principal Lesions and Patterns of Mortality Observed in a Broiler Breeder Flock During the Laying Period

ABSTRACT In any broiler breeder flock, there is always some mortality that is considered to be normal during the life of the flock. The aim of this study is to summarize the prevalence and patterns of mortality during the production period. To evaluate the mortality, each dead hen was systematically and completely examined via necropsy. In addition to post mortem evaluation, weights (whole body, liver, spleen and heart) were recorded to correlate the birds physical condition with the mortality category or lesion. In general, the variation in mortality was not associated with the specific weight of the organs. However, for specific diseases like fatty liver, septicemia and ascites, there was a correlation with the organ weight of the liver, spleen and heart respectively. Ovaritis was observed to be the most prevalent lesion found in dead hens during the production period followed by ovarian regression (atrophy), peritonitis, internal lay and vent pecking. The two periods with the higher total percentage of morality were onset of lay (25-30 weeks) and end-stage of the production period (56-61 weeks). During the laying period, we mainly observed metabolic disorders followed by infectious lesions. Infectious lesions, including ovaritis and septicemia, were the predominant cause for mortality at the onset production. Vent and feather pecking were also primarily concentrated during the first weeks of the production period. Metabolic diseases were observed in higher prevalence during the latter half of the production period.

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.

Innate immunity in chicken lines developed by EMBRAPA Suínos e Aves: antimicrobial activity of macrophages and serum

The objective of this study was to compare the antimicrobial activity of macrophages and serum in laying hen (MM, CC, and CCc) and broiler chicken lineages (TT and LL). Macrophages were evaluated for phagocytic and antimicrobial activity. Microbicidal serum activity was evaluated by the resistance test for serum and the agar test. The results showed that phagocytic activity was higher in males of the MM strain, with 13% of macrophages presenting phagocytosis, while the other lineages studied, and even female MM, presented a rate of 6% of phagocytic cells. However, antimicrobial activity in macrophages from males of CCc lineage and females of TT lineage were higher, eliminating more than 30% of the Salmonella enterica inoculum, while in the other strains, the results were similar, with inoculum reduction below 30%. In the serum resistance assay, female laying lines presented higher antibacterial activity than female broiler lines. In the trials to evaluate the microbicide activity of the serum, females of both broiler and laying lineages presented higher performance when compared with males of the same lineage. Females of laying hen lines (MM and CC) present a greater antibacterium activity than males. These results can contribute to a better understanding of the immune response in broiler chicken and laying hen lineages, to aid development of lineages of birds more resistant to pathogens.

Levels of Polyamines in Feces of Laying Hens Fed with Agave Fructans (Agave Tequilana, Weber) in Association with the Quality and Production of Egg

ABSTRACT In this study two experiments were carried out, the effect of a diet supplemented with fructans of Agave tequilana Weber, was analyzed in Hy-line hens in regards to their egg quality and production as well as on the levels of the polyamines, putrescine, spermidine and spermine in their feces. In the first study 300 Hy-line W-36 hens per group, which were aged 36 weeks, were randomly separated as follows for each of the three treatments. One group of 100 hens was fed with a diet supplemented with 0.1% fructans. Another group of 100 hens was supplemented with 0.2% fructans and a group of 100 hens without any fructans was added as a control group. Feed consumption was lower in the supplemented groups compared to the control group (p 0.05). Egg yolk quality was measured using Haugh units. The quality of the shell was studied using an Egg Force reader (g pressure/mm2). Putrescine levels was measured in 10 animals in each group. In the second study, 1,155 laying hens, aged one day from the Hy-line W-35 genetic line were also randomly divided into three groups containing 385 hens in each one (A, B, C). Egg laying levels and weight was measured during 35 weeks. The egg laying percentage increased considerably in hens ingesting supplemented diets (p 0.05) and the egg weight was greater mainly in the supplementation with 0.1% fructans (p 0.05). Thus, it was shown that diet supplementation with fructans of agave improves egg quality and homeostasis and food consumption in the Hy-line hen.

Physical quality of eggs of four strains of poultry

The layer poultry is an important activity for food production with high biological value. Measuring egg quality has great relevance to ensure safety and quality products for consumers. Thus, the objective was to evaluate the egg physical quality of four laying hen’s strains. Were used 864 eggs from four laying hens’ lines (Hisex Brown®, Hy-Line Brown®, Isa Label®, and Lohmann Brown®). The experimental design was completely randomized composed of four treatments (strains) with nine replications with four eggs each. Egg weight, eggdiameter, egg length, specific gravity, yolk, albumen and shell weight and percentage, Haugh units, and shell thickness were evaluated. There was a significant difference for all parameters evaluated. The Hisex Brown®strain showed the best results for egg diameter, egg length, specific weight, albumen height, Haugh units, yolk weight, albumen%, shell weight, shell%, and shell thickness, while the Hy-Line Brown®produced bigger and heavier eggs, and Isa Label®presented the highest yolk%. The Hisex Brown®strain showed the better physical quality of eggs when compared to the other studied lines, the strain being indicated when the objective is to produce eggs with better internal and external quality.

Evaluation of actions of the official veterinary service to mitigate outbreaks of infectious laryngotracheitis and improve biosecurity on laying hen farms

ABSTRACT: Infectious laryngotracheitis (ILT), caused by an Alphaherpesvirus (Gallid herpesvirus-1; GaHV-1), has been noticed in the region of the Terras Altas da Mantiqueira, Minas Gerais. From 2010 to 2018, the Serviço Veterinário Oficial (SVO) of the Instituto Mineiro Agropecuário (IMA), implemented measures to prevent spread of the virus to other regions and control the disease in the area. Due to the close proximity and consequent epidemiological link among farms, the region was considered a unique epidemiological unit. To check the efficiency of the ILT control measures, we carried out: (1) a seroepidemiological survey, (2) questionnaires for evaluating biosecurity measures; and (3) an evaluation of the influence of farm population density on the occurrence of ILT. In 2016, 2017, and 2018, ILT was investigated using epidemiological and clinicopathological methods, along with GaHV-1 molecular detection. Serological survey was carried out on 24 farms in the quarantined region and on 13 farms from other regions of the state. In 2010 and 2018, questionnaires were applied to collect data and determine indicators of biosecurity practices in all farms of the quarantined area. The differences were then assessed (Wilcoxons p 0.05). The results indicated positive serology throughout the region, although only on four farms (16.6%) the chickens have clinical signs, macroscopic and histological lesions of ILT. The prevalence of viral infection increased from 2016 (27%) to 2017 (50%) and was higher in farms with a high stock density (p=0.033). No disease, virus or antibodies were detected in the farms outside of the quarantined area. Although the biosecurity indicators had improved on all farms in the quarantined area (p 0.05), the virus was active and circulating in the region. The contingency measures have contained the outbreak, but biosecurity practices are paramount in the control of new outbreaks. Official control will be maintained in the region, including surveillance of new cases and biosecurity procedures to mitigate the risk of the virus reaching other regions.

RESUMO: Laringotraqueíte infecciosa (LTI), causada por um alfaherpesvírus (herpesvírus Gallid-1; GaHV-1), foi observada na região das Terras Altas da Mantiqueira, Minas Gerais. De 2010 a 2018, o Serviço Veterinário Oficial (SVO) do Instituto Mineiro Agropecuário (IMA) implementou medidas para impedir a disseminação do vírus para outras regiões do estado e controlar a doença na região interditada. Devido à proximidade e consequente vínculo epidemiológico entre as granjas, a região foi considerada uma unidade epidemiológica única. Para verificar a eficiência das medidas de controle de LTI, foram realizados: (1) pesquisa soroepidemiológica, (2) questionários para avaliar medidas de biosseguridade; e (3) avaliação da influência da densidade populacional da granja na ocorrência de LTI. Em 2016, 2017 e 2018, a LTI foi investigada usando métodos epidemiológicos e clínico-patológicos, com a detecção molecular de GaHV-1. O levantamento sorológico foi realizado em 24 granjas da região interditada e em 13 granjas de outras regiões do estado. Em 2010 e 2018, foram aplicados questionários para coletar dados e determinar indicadores de medidas de biosseguridade em todas as granjas da área interditada. As diferenças foram avaliadas (p 0,05 de Wilcoxon). Os resultados indicaram sorologia positiva em toda a região, embora apenas em quatro granjas (16,6%) as galinhas apresentaram sinais clínicos, lesões macroscópicas e histológicas da LTI. A prevalência de infecção viral aumentou de 2016 (27%) para 2017 (50%) e foi maior em fazendas com alta densidade de alojamento (p=0,033). Presença da doença, vírus ou anticorpos foram detectados nas granjas fora da área interditada. Embora os indicadores de biosseguridade tenham melhorado em todas as fazendas da área interditada (p 0,05), o vírus está ativo e circulava na região. As medidas de contingência contiveram o surto, mas as práticas de biosseguridade são fundamentais para o controle de novos surtos. O controle oficial será mantido na região, incluindo a vigilância de novos casos e procedimentos de biosseguridade para mitigar o risco de transmissão do vírus para outras regiões.

Multivariate modeling strategies to predict nutritional requirements of essential amino acids in semiheavy second-cycle hens

An experiment with 23 diets was performed to evaluate the effect of digestible lysine (Lys), digestible methionine + cysteine (Met+Cys), and digestible threonine (Thr) on egg production of H&N Brown second-cycle laying hens (SCLH) for 20 weeks (92-111 weeks of age) in cages under environmental conditions. Body weight (BW), feed intake (FI), feed conversion ratio (FCR), egg weight (EW), number of hen-housed eggs, and livability were also evaluated during the experiment. Diets were formulated from a central composite design that combined five levels of Lys, Met+Cys, and Thr ranging from 727 to 1159, 662 to 1055, and 552 to 882 mg/kg, respectively. Egg production (EP) data were evaluated through three different modeling strategies: egg production models, multivariate polynomial models, and artificial neural networks (ANN). A cascade-forward neural network with logsigmoid transfer function was selected as the best model according to goodness-offit statistics in both identification and validation data. One of the best scenarios for EP of H&N Brown SCLH under specific outdoor conditions was established at Lys, Met+Cys, and Thr levels of 1138, 1031, and 717 mg/hen·day, respectively. The ANN model may be an appropriate tool to study and predict EP of H&N Brown SCLH based on the combination of three different levels of essential digestible amino acids. The strategies included in this work may contribute to improving poultry performance based on modeling techniques to study other production parameters in terms of different nutritional requirements and productive conditions.

Influence of Effective Microorganism Supplementation to the Drinking Water on Performance and Some Blood Parameters of Laying Hens Exposed to A High Ambient Temperature

In the present study, seventy-two 30-week-old laying hens (Brown Hisex) were separated into two groups (control and treatment) and fed with a standard layer diet. In the treatment group the amount of effective microorganism (EM) added to the drinking water is equal to1000 ppm EM dose. Throughout the 8-week study period, 16 h thermoneutral (20-22 ºC) and 8 h hot (35-37 ºC) environmental temperature regime was applied daily. The results indicated that EM supplementation affected performance and some egg quality characteristics of layers exposed high environmental temperature. Feed intake and conversion ratio, yolk index, albumen index, yolk colour b, Haugh unit were decreased by supplemental EM. Serum glucose, cholesterol, triglycerides, calcium, total oxidant- antioxidant concentration were not affected by EM. It is concluded that EM supplementation in laying hens could have potential to improve feed intake and feed conversion ratio under high environmental temperature. However, supplemental EM with drinking water decreased some egg quality parameters.(AU)

Influence of Effective Microorganism Supplementation to the Drinking Water on Performance and Some Blood Parameters of Laying Hens Exposed to A High Ambient Temperature

In the present study, seventy-two 30-week-old laying hens (Brown Hisex) were separated into two groups (control and treatment) and fed with a standard layer diet. In the treatment group the amount of effective microorganism (EM) added to the drinking water is equal to1000 ppm EM dose. Throughout the 8-week study period, 16 h thermoneutral (20-22 ºC) and 8 h hot (35-37 ºC) environmental temperature regime was applied daily. The results indicated that EM supplementation affected performance and some egg quality characteristics of layers exposed high environmental temperature. Feed intake and conversion ratio, yolk index, albumen index, yolk colour b, Haugh unit were decreased by supplemental EM. Serum glucose, cholesterol, triglycerides, calcium, total oxidant- antioxidant concentration were not affected by EM. It is concluded that EM supplementation in laying hens could have potential to improve feed intake and feed conversion ratio under high environmental temperature. However, supplemental EM with drinking water decreased some egg quality parameters.

Effects of chromium yeast supplementation on productive and metabolic responses of laying hens fed diets containing different energy levels

This study evaluated the effects of chromium yeast (Cr yeast) and two apparent metabolizable energy (AME) levels on productive performance, egg quality, and lipid and carbohydrate metabolism in laying hens. A total of 192 Bovans White laying hens at 47 weeks of age were randomly assigned to eight dietary treatments (six replicates each) in a 4 × 2 factorial arrangement: four levels of supplemental Cr (0, 0.2, 0.4, and 0.8 ppm as Cr yeast) and two AME levels (2,780 and 2,900 kcal AME kg−1). No significant effect of Cr yeast supplementation on feed intake, egg weight, egg production, intact eggs, egg mass, feed conversion ratio, or egg quality was observed. Egg quality parameters and Cr content in the yolk were not affected by dietary treatments. Plasma glucose and lipid levels were not influenced by either Cr yeast or AME levels used in this study. However, Cr yeast supplementation improved yolk percentage and hepatic glycogen content. The inclusion of Cr yeast at 0.2 and 0.4 ppm induced the highest hepatic glycogen content with the energy levels 2,900 and 2,780 kcal AME kg−1, respectively. Laying hens fed 2,900 kcal AME kg−1 showed the highest abdominal fat. The results observed in the present study support the hypothesis that the lack of positive effects of Cr yeast supplementation on production performance and egg quality may be related to good management practices, as the birds were not subjected to stressful conditions.

Influence of Low and High-density Diets with Yeast Supplementation on Feed Intake, Nutrient Digestibility, Egg Production and Egg Quality in Hy-line Brown Laying Hens

A total of 432 laying hens (40 weeks old) were used in a 10- weeks feeding trial. The birds were randomly assigned to 1 of 4 treatments with 18 replications (6 birds per replication) in a 2×2 factorial arrangement with low-density diet (LD), and high density (HD) diets supplemented with or without (0.1 %) of yeast. Laying hens feed intake during the 5th, 6th and 10th weeks has significantly increased (p<0.05) in LD diet and HD diet supplemented with (0.1 %) of yeast supplementation. However, egg production and broken rate was not affected with or without yeast and density diet. The quality of egg and shell color during the 5th, 6th, and 7th weeks has significantly reduced (p<0.05) by yeast supplementation with HD and LD diet. Eggshell strength was significantly improved at week 4, moreover albumin height was also significantly improved by yeast supplementation diets at week 5. During week 1 and 2 the yolk color was higher in LD diet and HD diet compared with yeast supplementation. However, eggshell strength was significantly improved on HD diets than LD diets during the 4th and 7th weeks. Eggshell color and albumen height were significantly decreased in laying hens fed HD or LD diets during week 5 and 6. The apparent total tract digestibility (ATTD) of dry matter (DM), nitrogen (N), and Energy was not affected (p<0.05) by laying hens fed with or without yeast and HD than LD diets. In summary, 0.1% of yeast supplementation proved a positive impact on feed intake and egg quality of layer chicken.(AU)