Hen Age Research Articles

Quality and chemical composition of eggs affected by rearing system and hen's age

The aim of this study was to evaluate the effect of rearing system and hen's age on quality and chemical composition of eggs. The tested rearing systems were: cage, floor and organic (30 birds Isa Brown hybrid per group). Fifteen eggs per group were collected for analyses in each of three phases of the productive cycle (32, 48 and 72 weeks hen's age). In these samples were investigated external (egg weight and egg shape index), internal (albumen height, Haugh unit and yolk colour) and chemical composition of eggs (dry matter, minerals, protein and lipids content). The general conclusion is that the egg weight and Roche values were increased, while egg shape index, albumen height and Haugh unit were decreased with hen's age. Organic eggs had higher albumen height and more Haugh units in the 48 and 64 weeks compared to the floor and cage eggs. Yolk colour of the floor and cage hens most dependent on the hen's age, on the other hand - yolk colour of organic hens most dependent on the grass availability at the outlet. Eggs from the organic rearing system had a lower dry matter, proteins and lipid content as compared to the cage system.

Exploratory study on characteristics of oyster shell and eggshell quality in Chile

This study aimed to characterise oyster shell and white egg shell quality in Chile. The work was based on samples of both oyster shell and eggs, which were sourced from 7 laying farms over a period of several weeks during the production stage. Oyster shells were characterised according to their calcium content and granulometric distribution, and were classified in three types of particles (mm): coarse (≥1.7), medium-sized (0.9-1.6) and fine (≤0.8). Eggs were characterised, according to hen age and farm, by determining their weight, eggshell resistance, and thickness. Currently, Chilean farms use oyster shells whose calcium content ranges from 32.5% to 34.8%, and their granulometric distribution is 51.7% coarse, 27.6% medium-sized and 18.1% fine particles. Thus, the predominant form of oyster shell traded by major companies in Chile is the coarse type of particles, followed by medium-sized and fine particles. Similar calcium contents were observed for oyster shell samples sourced from different farms. Similar weight of the eggs were found for all farms (60-64 g). Contrarily, farms presented different results for eggshell resistance (3,934-5,057 g) and eggshell thickness (0.322-0.376 mm). Eggshell resistance and thickness values were within the expected range for white hen eggs. Key words : calcium, eggs, granulometry, oyster shell.

Effect of Laying Hens Age on Some Egg Quality Traits with Emphasis on their Correlation

Effect of Laying Hens Age on Some Egg Quality Traits with Emphasis on their Correlation

The influence of hen age on fatty acid composition of commercial eggs

The influence of hen age on fatty acid composition of commercial eggs

Eggshell characteristics and cuticle deposition in three laying hen genotypes housed in enriched cages and on litter

The objective of the present study was to compare the eggshell characteristics and cuticle deposition of Lohmann Brown, Hy-Line Silver Brown, and Isa Brown layers kept in two different housing systems. The three laying hen genotypes were housed in enriched cages (100 hens, 750 cm<sup>2</sup>/hen, 10 hens/cage) and in littered pens (100 hens, 9 hens/m<sup>2</sup>, 10 hens/pen). The experiment was carried out in weeks 40–56 of hens age. Non-significant interactions of genotype and housing system for eggshell quality parameters and cuticle deposition were detected in this study. Egg weight was significantly affected by genotype (P ≤ 0.001) and housing system (P ≤ 0.043). The heaviest eggs were laid by Lohmann Brown, while the lightest eggs were produced by Hy-Line Silver Brown. Eggshell strength was not affected by genotype and housing system, however, genotype had a significant effect on eggshell thickness (P ≤ 0.033). Isa Brown eggs had thicker eggshells compared to Lohmann Brown and Hy-Line Silver Brown. However, a non-significant effect of housing system on eggshell thickness was observed. Eggshell percentage was significantly affected by both genotype and housing system. Genotype of laying hens had a significant effect on cuticle deposition; significantly higher cuticle deposition was observed in Lohmann Brown eggs (P ≤ 0.001). It could be concluded that genotype had a significant effect on eggshell quality parameters and cuticle deposition. However, the housing system effect was less important in these characteristics.

Analysis of hatching results in broiler chickens in relation to the genetic origin and age of hens

Analysis of hatching results in broiler chickens in relation to the genetic origin and age of hens

EFEK PENAMBAHAN JUS DAUN SIRIH (Piper bettle linn) SEBAGAI ADITIF PAKAN TERHADAP PERFORMA AYAM PETELUR

Development of poultry has been done in terms of breeding, feeding and management. However, the implementation still faces many challenges such as the problem of production decrease. One cause of the decline in production is a health disorder caused by pathogenic bacteria (Salmonella sp and Escherichia coli). One way to overcome the problem is the use of Piper bettle linn Juice as a feed additive. The purpose of this study is to determine the effect of Piper bettle linn Juice as a feed additive to the performance of laying hens. The method used is the biological test of laying hens age 69 weeks of Isa Brown Strain of 250 laying hens, using Completely Randomized Design (RAL) with 5 treatments and 5 replications. The results of the research showed that Piper bettle linn Juice gave no significant effect (P> 0,05) to feed consumption and mortality. Influence significantly (P<0,01) to Hen Day Production (HDP), egg weight and Feed Conversion Ratio (FCR).

Study on the role of gga-miRNA-200a in regulating cell differentiation and proliferation of chicken breast muscle by targeting Grb2

ABSTRACTGrowth factor receptor-bound protein 2 (Grb2) have been proved by a lot of studies playing a major role in cell proliferation and cell differentiation. However, the regulation of Grb2 expression by microRNAs (miRNAs) in chicken breast muscle still remains unknown. The expression profile of Grb2 was checked based on our previous RNA sequencing data and the Grb2 relative expression level in breast muscle of aged hens (55-week-old) was validated significantly higher than juvenile hens (20-week-old) using qRT-PCR. miRNAs that interact with Grb2 have been predicted in chicken and the relationship between the potential miRNA and Grb2 was verified using dual luciferase reporter assay in chicken DF1 cells. Dual-luciferase reporter assays results demonstrated that the expression of luciferase reporter gene linked with part sequence of the 3′UTR of chicken Grb2 gene was down-regulated by the overexpression of gga (Gallus Gallus)-miR-200a-3p in the DF1 cells, and the down-regulation behavior was abolished when the gga-miR-200a-3p binding site in 3′UTR of Grb2 was mutated, indicating that gga-miR-200a can suppress the expression level of its target gene Grb2. Therefore, we concluded that the significantly increased expression level of Grb2 in the breast muscle of aged chicken can (at least partly can) be explained by the decreased expression of miR-200a, which reduced the inhibitory effect on Grb2. Taken together, these findings suggest that gga-miR-200a can suppress the expression level of its target gene Grb2 and might be involved in the cell differentiation and proliferation of chicken breast muscle through binding with the 3’UTR of Grb2.

PRODUCTIVE PERFORMANCE OF HUBBARD CLASSIC BROILER BREEDER CHICKENS UNDER DIFFERENT HOUSING SYSTEMS

his investigation aimed to evaluate the effect of two housing types (closed and semi-closed), broiler breeder age and their interaction on broiler breeder performance during egg production (25-45 wks ofage), at a private local broiler breeder farm in Alexandria desert road. The results indicated that: Housing system significantly affected on body weight which was heavier in semi-closed compared to closed housing system. No significant difference in egg production, egg weight and feed consumption during egg production period of breeder under two housing system. Housing system significantly affected on mortality rate percentage of breeder during egg production period which was higher under closed housing type. Body weight, egg production, egg weight, feed consumption and mortality rate of female broiler breeders were significantly affected by breeder age. Generally, in most cases, the interaction between type of house and age of breeder hens for studied criteria were insignificant.

Age influence on quality of shell and penetration in bacterial laying lightweight eggs

ABSTRACT This study evaluated the influence of the bird’s age on the quality of the shell and percentage of bacterial penetration in commercial eggs. White-shelled commercial eggs were used, laid by light laying hens in their first laying cycle at 21, 39, 51, and 62 weeks of age. Shell quality evaluations comprised: egg weight, specific gravity, percentage and thickness of shell, number and size of pores. For evaluations regarding bacterial penetration, strains of several enterobacterias and one salmonella were used, all of which resistant to Nalidixic acid (100µg/ml). The method employed for evaluation of bacterial penetration was filling the eggs with growth medium. The data were subjected to variance analysis with 5% of probability using SAS (Education Analytical Software, 2013). Eveb though increase in the laying hen's age caused reduction of the quality of eggshells, it failed to affect the percentage of penetration of the bacterial samples evaluated.

RENDIMENTO DE INCUBAÇÃO EM FUNÇÃO DA IDADE DA MATRIZ

The factors involved in poultry egg incubation include breeder hen age, which may influence both the external and internal quality of eggs. In this context, this study sought to determine incubation yield among eggs from breeder hens at three ages. A total of 1,728 eggs were obtained from Cobb broiler breeders at three ages (26 weeks, 32 weeks, and 53 weeks) and incubated. At the end of the incubation process, eclosion, hatchability, the percentage of infertile eggs, the time of embryo mortality, and chick weight were all analyzed according to breeder hen age. Analysis of variance was applied to the results, and egg fertility was found to be associated with breeder age, since lower rates of eclosion were found in eggs from younger broiler breeders. Chick weight was also found to be influenced by breeder age, since eggs from older broiler breeders hatched into heavier chicks. However, neither mortality nor hatchability were found to be affected by breeder hen age.

FORM OF LAYING HENS EGGS IN THE FUNCTION OF DIFFERENT LAMPS USED IN PRODUCTION

ABSTRACT: Lighting, either in its intensity or in its luminous spectrum, affects the eggs quality. This study evaluated the effect of four lamps (sodium vapor lamp, mercury vapor lamp, fluorescent lamp and incandescent lamp) that have different luminous spectra in the form of commercial poultry eggs. For this, 60 laying hens of the same age were separated for 63 days in four aviaries with reduced and distorted scale. In each treatment, different lamps were installed which provided similar luminous intensities. At the end of the period, these eggs were taken as samples for the fluorescent, incandescent, mercury vapor and sodium vapor lamps. In this way, images were made of these eggs, using a camera installed on a fixed tripod on a flat table with black background. In a room with controlled lighting, ensuring the same distance and angle for all eggs. The Matlab® program was used to perform the image analysis, recording measurements of area, perimeter and minimum and maximum distances of the mass center of each egg. The measurements were grouped by treatment and the Tukey's test of averages was applied. The results showed that the eggs removed from the sodium vapor treatment presented a more elongated shape. It is concluded that the light spectrum of the lamps affects the shape of the eggs and this should be considered in the planning of lighting programs in aviaries.

Egg production and egg quality in free-range laying hens housed at different outdoor stocking densities

Free-range laying hen systems are increasing in number within Australia. Variation in outdoor stocking densities has led to development of a national information standard on free-range egg labeling, including setting a maximum density of 10,000 hens per hectare. However, there are few data on the impacts of differing outdoor densities on production and egg quality. ISA Brown hens in small (150 hens) flocks were housed in identical indoor pens, each with access (from 21 weeks) to different sized ranges simulating one of three outdoor stocking densities (2 replicates each: 2,000 hens/hectare (ha), 10,000 hens/ha, 20,000 hens/ha). Hen-day production was tracked from 21 through 35 weeks with eggs visually graded daily for external deformities. All eggs laid on one day were weighed each week. Eggs were collected from each pen at 25, 30, and 36 weeks and analyzed for egg quality. There were no effects of outdoor stocking density on average hen-day percentage production (P = 0.67), egg weight (P = 0.09), percentages of deformed eggs (P = 0.30), shell reflectivity (P = 0.74), shell breaking strength (P = 0.07), shell deformation (P = 0.83), or shell thickness (P = 0.24). Eggs from hens in the highest density had the highest percentage shell weight (P = 0.004) and eggs from the lowest density had the highest yolk color score (P < 0.001). The amount of cuticle present did not differ between densities (P = 0.95) but some aspects of shell colors (P ≤ 0.01) and location of protoporphyrin IX (P = 0.046) varied. Hen age affected the majority of measurements. Stocking density differences may be related to hen diet as previous radio-frequency identification tracking of individual hens in these flocks showed birds used the range for longer in the lowest density and the least in the highest density, including depleting the range of vegetation sooner in the smaller ranges. An additional study assessing the relationship between individual hen range use, nutrition, and egg quality is warranted.

GnRH-1, GnIH mRNA and Luteinizing Hormone in Domestic hens (Gallus gallus domesticus) Exposed to Different Wavelengths of light

The objective of this study was to establish the effects of red spectrum of light (650nm, treated n=12) and normal spectrum of light (450nm control=12) on GnRH-I and GnIH mRNA expression, amplitude and frequency of luteinizing hormone (LH) and egg production from 42 to 52 weeks of age in white leghorn hens. Blood samples were collected at weekly interval from both the groups. At the 47th week of age blood samples from both the groups were collected at every 3 h for 36h to study the pulsatile secretion of LH surges. GnRH and GnIH mRNA expression pattern was studied between control and treated birds. Egg production and pause days were calculated between the two groups. LH concentration in the plasma was increased significantly (P&lt;0.01) in hens exposed to red spectrum of light. Plasma LH concentration was higher (P&lt;0.01) in treated birds with more number of LH surges. The amplitude and frequencies of LH were advanced in birds exposed to red spectrum of light during 36 h of sampling at 3h intervals. GnRH-I mRNA concentration was significantly (P&lt;0.01) higher, whereas GnIH mRNA was significantly (P&lt;0.01) lower in birds exposed to red spectrum of light compared to controls. It is hypothesized that exposure of birds to red spectrum of light enhanced (P&lt;0.01) GnRH-I mRNA, along with LH required for ovulation and egg lay. During 77 days (42-52 weeks of age) of the experimental period, egg production was increased (p&lt;0.01) with lower incidence of pause days in the treated group. It is concluded that low GnIH mRNA and higher levels of GnRH-I mRNA, LH, lower number of pause days enabled the birds to lay more eggs by stimulating GnRH through red spectrum of light.

The Effect of Storage and Age of Hens on the Quality of Table Eggs

Abstract Quality of poultry products, especially eggs, is a very important issue for the consumers and for the processing industry. The aim of the present study was to examine the interaction between the storage time and age of laying hens and their effect on the quality of table eggs. Eggs from 34 and 59- wk-old Bovans Brown hens were sampled and stored in the refrigerator for 1, 2, and 3 weeks. Significant effect of hen age (P&lt;0.01) was found on egg weight, shell strength, albumen height and Haugh units (HU). Eggs from older hens had 2.58% higher mass compared to the eggs of young hens. Eggs from 59-weeks old hens had significantly lower shell strength (3.63 kg vs. 4.31 kg). Albumen height and HU were lower in eggs from the older hens compared to the young ones (5.7 mm vs. 7.11 mm for albumen height; 70.35 vs. 81.77 for HU). Significant negative effect of storage time was found on egg weight, albumen height, HU and yolk colour (P&lt;0.01). The results indicated that egg quality characteristics monitored in this study decrease by hen age and during storage. The interaction effects between storage time and age of hens were significant only for yolk colour (P&lt;0.05).

Age-Related Variations in Intestinal Microflora of Free-Range and Caged Hens.

Free range feeding pattern puts the chicken in a mixture of growth materials and enteric bacteria excreted by nature, while it is typically unique condition materials and enteric bacteria in commercial caged hens production. Thus, the gastrointestinal microflora in two feeding patterns could be various. However, it remains poorly understood how feeding patterns affect development and composition of layer hens’ intestinal microflora. In this study, the effect of feeding patterns on the bacteria community in layer hens’ gut was investigated using free range and caged feeding form. Samples of whole small intestines and cecal digesta were collected from young hens (8-weeks) and mature laying hens (30-weeks). Based on analysis using polymerase chain reaction-denaturing gradient gel electrophoresis and sequencing of bacterial 16S rDNA gene amplicons, the microflora of all intestinal contents were affected by both feeding patterns and age of hens. Firmicutes, Bacteroidetes, Actinobacteria, Proteobacteria, and Fusobacteria were the main components. Additionally, uncultured environmental samples were found too. There were large differences between young hens and adult laying hens, the latter had more Firmicutes and Bacteroidetes, and bacterial community is more abundant in 30-weeks laying hens of all six phyla than 8-weeks young hens of only two phyla. In addition, the differences were also observed between free range and caged hens. Free range hens had richer Actinobacteria, Bacteroidetes, and Proteobacteria. Most of strains found were detected more abundant in small intestines than in cecum. Also the selected Lactic acid bacteria from hens gut were applied in feed and they had beneficial effects on growth performance and jejunal villus growth of young broilers. This study suggested that feeding patterns have an importance effect on the microflora composition of hens, which may impact the host nutritional status and intestinal health.

The effect of essential oils on quality and mineral composition of eggshell

The effect of essential oils on quality and mineral composition of eggshell

Effect of hen age and storage time on egg weight loss and hatchability results in turkeys

Abstract The aim of this study was to determine the effect of egg water loss during storage and incubation on hatch rates in heavy-type broad-breasted white BUT Big 6 turkeys. Turkey hens started laying eggs at 30 weeks of age. In weeks 2, 8, 16 and 21 of the laying season, 1512 eggs were selected randomly and divided into 4 groups of 378 eggs each. The groups of eggs were stored for 7, 10, 13 or 17 days before incubation. At the beginning and end of the storage period and on days 9, 15, 21 and 24 of incubation, eggs were weighed to determine the percent water loss relative to the egg’s weight. Four incubation cycles of 378 eggs each were performed for each storage period. A total of 16 incubation cycles were carried out (4 weeks of the laying season × 4 egg storage periods) and the following parameters were determined (%): egg fertilization, dead embryos, unhatched eggs and hatchability results from fertilized eggs. The percentages of dead embryos and unhatched poults with physical defects and abnormal position were determined in hatchery waste from each incubation cycle. Egg water loss varied throughout storage and reached 0.57% of total egg weight after 7 days, 0.79% after 10 days, 0.87% after 13 days and 1.28% after 17 days (P≤0.05). After 7 days of storage, egg water loss during a 15-day and 21-day incubation period reached 5.76% and 8.72%, and lower values were noted after 17 days of storage (P≤0.05). Egg water loss of 1.28% during storage resulted in a high rate of early embryonic mortality (14.81%) and a low hatch rate (72.12%) (P≤0.05). High water loss in stored eggs contributed to a higher percentage of congested embryos. During storage, egg water loss reached 0.72% in week 2 of the laying season, 0.78% in week 8 and ≥1% in weeks 16 and 21 of the laying season (P≤0.05). Egg water loss during a 21-day incubation period was similar in weeks 2, 8 and 16 of the laying season, and lower in week 21 (P≤0.05). The hatchability of turkey eggs was lowest in weeks 16 and 21 of the laying season (P≤0.05). Low water loss during incubation contributed to a high rate of late embryonic mortality (13.2%). High water loss during egg storage is accompanied by lower water loss during incubation. Water loss should be monitored after storage and on days 15 and 21 of incubation to evaluate water metabolism in hatching eggs.

닭의 산란연령에 따른 자궁내막조직의 변화 및 난각 관련 유전자의 발현양상

계란의 난각은 닭의 자궁에서 형성되는 복잡하고 고도화된 다층 석회화 구조이다. 본 연구는 닭의 산란연령에 따른 자궁내막조직의 변화 양상과 난각 형성에 관여하는 주요 유전자들의 발현 양상을 고찰하였다. 난각 형성과 관련하여 난각 단백질과 관련한 OCX-32, OCX-36, OC-17, OC-116 유전자와 난각 이온과 관련한 CALB1, SPP1, SCNN1G, ATP2A2, CA2, CALM1 유전자를 분석대상으로 하였다. 자궁내막조직의 현미경적 관찰 결과, 연령이 증가함에 따라, 자궁 섬모상피세포의 탈락 및 세포의 위축과 섬유화 진행양상이 심화되었다. 그러나 연령 증가에 따른 혈중 이온성분의 농도차이는 없었다. 자궁내막 상피세포의 텔로미어 함량 분석 결과, 산란연령이 증가함에 따라 텔로미어 함유율이 감소됨을 확인하였다. 대부분의 난각 형성 관련 유전자의 발현량은 산란연령에 따라 유의한 변화를 나타내었다. 일부 난각 단백질 관련 유전자의 발현량은 산란연령이 증가함에 따라 증가양상을 보였으나, 이들 유전자들 간의 상호 관련성은 유의한 관계를 보이지 않았다. 난각 형성 이온 관련 유전자인 ATP2A2, SCNN1G, CA2, CALM1 유전자 간에는 상호 밀접한 관련이 있는 것으로 나타났다. 또한 난각 단백질 관련 OCX-32 및 OCX-36 유전자는 대부분의 이온 관련 유전자들과 높은 정의 상관을 보였다. 따라서 OCX-32, OCX-36, CALB-1, ATP2A2, SCNN1G, CA2 및 CALM1유전자들이 난각 형성에 상호 협력하거나 또는 독립적으로 작용한다. 결론적으로 산란연령이 증가함에 따라 자궁내막세포의 손상이 일어나지만, 그럼에도 불구하고 정상적인 난각을 형성할 수 있는 이유는 난각 단백질 및 난각 형성 이온 관련 일부 유전자들이 발현을 조절하여 난각 형성의 항상성 유지하기 때문인 것으로 사료된다. The eggshell is an intricate and highly ordered structure composed of multiple layers and a calcified matrix. The eggshell is formed at the uterine segment of the chicken oviduct. In this study, histological changes in the uterine endometrium and the expression of the eggshell-related genes were investigated according to hen age. We analyzed the expression of eggshell protein-related genes, such as OCX-32, OCX-36, OC-17, OC-116, and eggshell-ion-related genes, such as CABL-1, SPP1, SCNN1G, ATP2A2, CA2, and CALM1. In chicken uterine endometrium, histological deformation, fibrosis, atrophy and elimination of micro-villi were found with increasing hen age. The concentration of blood-ion components did not significantly change with age. The amount of telomeric DNA in uterine endometrial cells decreased with increasing hen age. The expression of most of the eggshell-related genes changed significantly with increasing hen age. The expression of some ovo-proteins, which play a role in eggshell formation, increased with increasing hen age; however, there were no significant correlations among eggshell protein genes. Eggshell ion-related genes, such as ATP2A2, SCNN1G, CA2, and CALM1, were closely related to each other. The OCX-32 and OCX-36 genes were closely related to some of the eggshell ion genes. Eggshell protein-related genes, such as the OCX-32, OCX-36 genes and ion-related genes such as CALB-1, ATP2A2, SCNN1G, CA2, CALM1, affected eggshell formation, mutually or independently. This study shows that, uterine although endometrial cell damage occurs with increasing hen age, normal eggshells can be formed in old hens. This suggests that eggshell protein-and eggshell ion-related genes also control the homeostasis of eggshell formation.

The effect of maternal canthaxanthin supplementation and hen age on breeder performance, early chick traits, and indices of innate immune function

Hen age and nutrition influence chick innate immunity. The immunomodulatory antioxidant carotenoid canthaxanthin is transferred from the hen diet to the egg. Antioxidants could protect the chick from bactericidal oxidative species produced by the immune system. Broiler breeder hen diets were supplemented with 0 (Control), 6 (Low), or 12 (High) mg/kg canthaxanthin. Chick early growth and ex vivo innate immunity were measured at 31 to 33 (Early), 45 to 47 (Mid), and 57 to 59 (Late) wk of hen age. Escherichia coli (E. coli) bactericidal capacity, phagocyte activation (number of phagocytes containing at least one E. coli), phagocytic capacity (number of phagocytes containing one or more E. coli), and oxidative burst at 1 and 4 d of age were determined. Egg and chick liver canthaxanthin and chick plasma total antioxidant capacity were measured. Differences were considered significant at P ≤ 0.05. Breeder productivity was greatest for the Low hens; diet did not affect egg yolk, albumen, or shell proportions. Egg canthaxanthin increased with maternal supplementation and plateaued after 28 days, but was not affected by hen age. Chick liver canthaxanthin increased with maternal supplementation, but decreased as hens aged. Hen diet did not affect broiler chick performance to 21 days of age. Maternal canthaxanthin at 6 mg/kg increased chick E. coli bactericidal capacity and d 1 oxidative burst; phagocytosis was unaffected. E. coli bactericidal capacity decreased as hens aged, but increased from 1 to 4 d, indicating maturation of chick innate immunity. Plasma total antioxidant capacity at d 1 increased with maternal canthaxanthin in chicks from Mid and Late hens. Canthaxanthin possesses immuno-modulatory and antioxidant properties, and hen age affected chick innate immune development. Single-comb White Leghorn hens were fed the same levels of canthaxanthin to determine the rate of incorporation into eggs. Egg canthaxanthin reached a plateau after 7 d. Canthaxanthin in the hen diet at 6 mg/kg resulted in the greatest positive effect on hen performance, with little effect on the chick.