Egg Production Research Articles

The Effects of Replacing Soybean Meal with Chlorella vulgaris in Laying Hen Diets on Performance and Physical Characteristics of Eggs.

Chlorella vulgaris (CV) is a microalga with considerable nutritional value, containing high levels of protein, carotenoids, and polyunsaturated fatty acids, which have the potential to positively influence the productive performance and egg quality of laying hens. CV emerges as a more sustainable ingredient than soybean meal (SBM) as it can be produced locally and with fewer inputs. In this regard, a study was conducted with 48 H&N Brown Nick strain laying hens, at 19 weeks of age, over a period of 16 weeks. The hens were divided into four treatments, with 12 replicates each. The treatments consisted of providing four different diets: a control diet based on corn and SBM without the inclusion of CV, and three other diets with partial substitution of SBM by 2.5, 5, and 10% of CV. The results showed that the inclusion of CV in the diets did not significantly affect feed intake, feed conversion ratio, or egg production (p > 0.05). In addition, moderate CV levels increased egg weight, while higher levels reduced it. Haugh units, yolk index, albumen index, egg surface area, specific density, and translucency were not affected (p > 0.05), while shell index and shell thickness were lower in the groups that received the CV (p < 0.0001). Yolk color improved significantly with increasing CV levels (p < 0.0001), with darker, more intensely colored yolks at higher CV concentrations. The results of this study suggest that the incorporation of CV in the diet of laying hens had a limited impact on performance parameters. In addition, CV supplementation can positively influence egg quality and yolk color, although careful consideration of optimal levels is necessary to avoid negative effects on other parameters.

Manothermosonication – A potential alternative to thermal pasteurisation of liquid whole egg: Comparison of physico-chemical attributes

Liquid egg products are typically exposed to a defined thermal load to achieve the required safety level, under which their functional properties can be adversely affected. In this study, manothermosonication (MTS) (132 μm, 300 kPa) was investigated as alternative preservation for liquid whole egg (LWE) compared to thermal pasteurisation (60 °C, 3.5 min), assessing results against untreated (fresh) LWE in terms of selected physico-chemical properties. Results showed that MTS resulted in improved LWE foaming properties, increasing foam capacity by a 3.2-fold factor compared to thermal treatment. Emulsion stability was also enhanced after MTS, exhibiting smaller droplet size, and a higher elasticity of gels was obtained. Regarding the protein properties, favourable protein changes (protein unfolding) were identified for MTS through direct (asymmetric flow field flow fractionation) and indirect (surface hydrophobicity and sulfhydryl group content) measurements. In addition, an increase in protein solubility of 11.4 % was observed in MTS compared to thermal treatment.

Premeiotic endoreplication is the mechanism of obligate parthenogenesis in rock lizards of the genus Darevskia.

Among vertebrates, obligate parthenogenesis occurs exclusively in squamate reptiles. Premeiotic endoreplication in a small subset of developing oocytes has been documented as the mechanism of production of unreduced eggs in minutely explored obligate parthenogenetic lineages, namely in teiids and geckos. The situation in the lacertid genus Darevskia has been discussed for decades. Certain observations suggested that the ploidy level is restored during egg formation through a fusion of egg and polar body nuclei in Darevskia unisexualis and D. armeniaca. In this study, we re-evaluated the fusion hypothesis by studying diplotene chromosomes in adult females of sexual species D. raddei nairensis and obligate parthenogens D. armeniaca, D. dahli and D. unisexualis. We revealed 19 bivalents in the sexual species and 38 bivalents in the diploid obligate parthenogens, which uncovers premeiotic endoreplication as the mechanism of the production of non-reduced eggs in parthenogenetic females. The earlier contradicting reports can likely be attributed to the difficulty in identifying mispairing of chromosomes in pachytene, and the fact that in parthenogenetic reptiles relying on premeiotic endoreplication only a small subset of developing oocytes undergo genome doubling and overcome the pachytene checkpoint. This study highlights co-option of premeiotic endoreplication for escape from sexual reproduction in all independent hybrid origins of obligate parthenogenesis in vertebrates studied to date.

A comprehensive review on freeze-induced deterioration of frozen egg yolks: Freezing behaviors, gelation mechanisms, and control techniques.

Over the years, the production of eggs has increased tremendously, with an estimated global egg production of 9.7 billion by 2050. Further processing of shell eggs to egg products has gained growing popularity. Liquid egg yolks, an innovative form of egg replacement, still suffer from short shelf-life issues, and freezing has been applied to maintain freshness. An undesirable phenomenon called "gelation" was found during the production of frozen egg yolks, which has attracted numerous scholars to study its mechanism and quality control methods. Therefore, we comprehensively reviewed the history of the studies on frozen egg yolks, including the production procedure, the fundamentals of freezing, the gelation mechanism, the factors affecting gelation behaviors, and the techniques to control the gelation behaviors of frozen egg yolks. Reporting the production procedure and freezing fundamentals of frozen egg yolks will give readers a better understanding of the science and technological aspects of frozen egg yolks. Furthermore, a comprehensive summary of the mechanism of egg yolk gel formation induced by freeze-thawing and relevant control techniques will provide insights to researchers and manufacturers in the field of frozen egg processing.

Environmental constraints can explain clutch size differences between urban and forest blue tits: Insights from an egg removal experiment.

Urban environments present novel ecological challenges to wild species. In birds, urban populations generally exhibit reduced clutch sizes compared to forest populations. However, whether smaller urban clutches are adaptive or a result of environmental constraints is unclear. To investigate these two hypotheses, we quantified the ability of urban and non-urban blue tits (Cyanistes caeruleus) to lay new eggs after an experimental manipulation aimed to increase egg production. We removed the first four eggs laid by urban and forest birds to test their ability to produce new eggs. If the urban environment imposes constraints on egg production, we predicted that urban birds would not lay new eggs. If the small clutches of urban birds are an adaptive response, we predicted they would lay new eggs to reach the optimal clutch size for the environment. Consistent with the environmental constraint hypothesis, our results suggest that urban females do not lay new eggs to the same extent as forest birds following egg removal. Forest birds laid approximately two new eggs after our experimental manipulation, while urban birds laid approximately 0.36 new eggs following egg removal. Our manipulation resulted in a brood reduction in the urban experimental nests, yet there was no difference in the number of fledged offspring between urban control and experimental nests. This suggests that females might be misjudging urban habitat quality and produce a clutch with more eggs than nestlings they can rear. Overall, our results suggest that environmental constraints could limit the number of eggs that urban females lay, generating urban versus non-urban differences in this trait.

Egg Production, Blood Profile, and Histopathology in Japanese Quail with Phytogenic Additives

Egg Production, Blood Profile, and Histopathology in Japanese Quail with Phytogenic Additives

Development status and prospects of egg products industry in China

Development status and prospects of egg products industry in China

PSII-23 Egg production and quality in older Lohmann LSL lite hens in response to rearing space allowance and provision of omega-3 fatty acids and yeast bioactives from placement through to 17 wk of age

PSII-23 Egg production and quality in older Lohmann LSL lite hens in response to rearing space allowance and provision of omega-3 fatty acids and yeast bioactives from placement through to 17 wk of age

Ant queens cannibalise infected brood to contain disease spread and recycle nutrients

Filial cannibalism, where parents eat their own offspring, is a taxonomically widespread behaviour with a multitude of potential adaptive explanations1. Of these, the impact of pathogens on the expression of filial cannibalism is, in particular, poorly understood. Cannibalising young with low survival probability may enable parents to reinvest valuable resources into future reproduction1. However, cannibalising offspring that harbour pathogens may be potentially harmful to parents, and such risk may therefore select against this behaviour. Although disease-induced cannibalism of eggs has been reported in fish2, the benefits of consuming infected brood to contain infections - as an explanation for the evolution of filial cannibalism - remain largely unexplored. Here, we demonstrate that solitarily founding ant queens cannibalise sick larvae in their nests before they become contagious, showing that filial cannibalism both contains an otherwise lethal infection without any long-term consequences on queen survival and also enables the reinvestment of recouped energy into additional egg production.

Financial impact of low pathogenic avian influenza virus subtype H9N2 on commercial broiler chicken and egg layer production systems in Pakistan

Low Pathogenic Avian Influenza (LPAI) subtype H9N2 is endemic in Pakistan and impacts poultry farming through disease related mortality, poor weight gain and reduced egg production. This study aims to estimate the farm-level financial impact of LPAI H9N2 infection on commercial broiler and layer production systems in Pakistan.A questionnaire based cross-sectional survey of 138 broiler farms and 136 layer farms in Pakistan was conducted in 2019. Primary data collected by cross-sectional survey along with expert opinion and published literature were used to parameterize five stochastic production and gross margin models for three broiler and two layer production systems: fully integrated production (FIP), partially integrated production (PIP) and independent farming production (IP) systems. Partial budget analysis were then carried out to estimate the financial impact of LPAI H9N2.Results indicate that in broiler production systems, starting with 35,000 day old chicks (DOC) per batch, the net cost of disease (million PKR/production cycle) was estimated at 4.10 (14,862 USD), 4.62 (16,747 USD) and 2.46 (8917 USD) for IP, PIP and FIP systems, respectively. The disease produced a negative gross margin (defined here as revenue minus replacement and variable costs) in IP (-53 PKR (-0.19 USD)/DOC bought) and PI (-25 PKR (-0.091 USD)/DOC bought) systems, while remained positive for FIP systems (87 PKR (0.32 USD)/DOC bought). For layer production systems, (mean flock size as 48,000 DOCs) the net cost (million PKR/production cycle) was 29.75 (107,095.21 USD) and 29.51 (106,223.45 USD) IP and PIP systems, respectively, and produced negative gross margin in both systems.The outcomes of the study highlight the vulnerability of independent and partially integrated production systems to the disease. These findings also offer a decision-making tool to the farmers and policy makers to evaluate avian influenza surveillance systems and control interventions in Pakistan.

Supplementation of curcumin promotes the intestinal structure, immune barrier function and cecal microbiota composition of laying hens in early laying period

The prelaying period is critical for laying hens, marked by significant physiological changes such as increased egg production, hormone secretion, and higher nutritional demands. These changes stress the intestine, which is vital for nutrient digestion, absorption, immune defense, and maintaining antioxidant and microbial balance. During this period, maintaining the intestinal health is essential for efficient nutrient absorption. Curcumin, a plant-derived extract, offers antioxidant, anti-inflammatory, antimicrobial, and immunomodulatory benefits, that can improve gut function. This study evaluated the effects of curcumin on the intestinal structure, immune barrier function, and cecal microbiota composition in laying hens during their early laying period. A total of 180 Snowy White chickens (154 days old) were divided into 5 experimental groups, receiving curcumin at 0 mg/kg, 100 mg/kg, 200 mg/kg, 300 mg/kg, and 400 mg/kg for 12 wk. The results showed that curcumin significantly improved the intestinal morphology (P < 0.05), increased mRNA expression of digestive enzymes (such as MGAM, SI, and ANPEP), and enhanced the digestive and absorptive functions. Further, curcumin improved the levels of antioxidant parameters (such as CAT, GSH-PX, T-AOC, and T-SOD) in the ileum, jejunum, and duodenum, and increased the expression of immunoglobulins (IgA, IgM, IgG) in the intestinal segments and serum (P < 0.05). Curcumin also improved the intestinal immune barrier function by increasing ZO-1 and Occludin expression. Furthermore, it altered the gut microbiota composition by increasing the relative abundance of beneficial bacterial phyla such as Bacteroidetes, Actinobacteria, Proteobacteria, and Fusobacteria (P < 0.05). At the genus level, curcumin supplementation enhanced the beneficial genera like Phocaeicola, Alistipes, Prevotella, Barnesiella, and Bifidobacterium (P < 0.05), thereby promoting the gut health and microbial diversity. In conclusion, curcumin supplementation during the early laying period of hens offers significant benefits by improving the intestinal health, immune function, and gut microbiota composition. Hence, curcumin serves as a promising dietary additive to support nutrient absorption and immune defense in laying hens during the early laying period of hens.

The effect of multicarbohydrase-phytase complex supplementation on the egg production performance, egg quality, and economics of laying hens

The effect of multicarbohydrase-phytase complex supplementation on the egg production performance, egg quality, and economics of laying hens

The effectiveness of using plant-based feed supplement made of Astragalus cicer in the diets of laying hens

Agricultural producers are increasingly using plant-based feed additives in the diets of livestock and poultry as a way to increase animal productivity and stabilize the protective functions of the body. The purpose of the research was to study the effectiveness of using Astragalus cicer feed supplement in the diets of laying hens of the Lohmann Brown-Light cross at the age of 25-51 weeks. The composition of the compound feed included a phytoadditive made from Astragalus cicer in the volume: I experimental group – 3.60 %, II experimental – 7.20 % by the weight of the compound feed. The duration of the scientific and production experiment was 183 days. The analysis of the content of biologically active substances in the Astragalus cicer phytoadditive has revealed a high content of dihydroquercetin – 336.25 mg/100g of absolutely dry substance.image As the result of the research, it was found that laying hens of the II experimental group, which received 7.20 % of Astragalus cicer phytoadditive in the compound feed, had more intensive metabolic processes in the body, which contributed to obtaining a greater effect from them. Laying hens of the II experimental group compared with the control and I experimental groups had 2.19 and 2.18 % higher values of nitrogen utilization out of taken feed, egg production was higher by 2.81 and 1.10 %, the cost of compound feed decreased by 10 pcs. eggs, that was by 4.76 and 2.38 %, respectively. The profitability level of egg production in the II experimental group was higher compared with the control and I experimental groups by 3.83 and 5.16%, respectively.

Tracking dustbathing behavior of cage-free laying hens with machine vision technologies

Dustbathing (DB) is a functionally important maintenance behavior in birds that clean plumage, realigns feather structures, removes feather lipids, which helps to remove parasites and prevents feathers from becoming too oily. Among different natural behaviors birds perform in cage-free (CF) housing, DB is one of the important behavior related to bird welfare. Earlier studies have identified DB behavior using manual method such as counting number of DB bouts, and duration of DB bouts from video recordings. The manual detection of DB behavior is time-consuming, sometimes prone to errors, and have limitations. Therefore, an automated precision monitoring method is needed to detect DB behavior in laying hens from an early age in CF housing environment. The objectives of this study were to (1) develop and test a deep learning model for detecting DB behavior and find out the optimal model; and (2) assess the performance of the optimal model in detecting DB behavior at different growing phases. In this study, deep learning models, i.e., YOLOv7-DB, YOLOv7x-DB, YOLOv8s-DB and YOLOv8x-DB, networks, were developed, trained, and compared in tracking DB behavior in 4 CF rooms each with 200 hens (W-36 Hy-Line). Results indicate that the YOLOv8x-DB model outperform all other models on detecting DB behavior with a precision of 93.4%, recall of 91.20%, and mean average precision (mAP@0.50) of 93.70%. All models performed with over 90% detection precision; however, model performance was affected by equipment like drinking lines, perches, and feeders. Based on the optimal model (YOLOv8x-DB), DB detection precision was highest during grower phase (precision of 96.80%, recall of 97.10%, mAP@0.50 of 98.60%, and mAP@0.50-0.95 of 79.10% followed by prelay, layers, developer, and peaking phases. This study provides a reference for poultry and egg producers that DB behavior can be detected automatically with precision of at least 89% or more using optimal model at any growing phase of laying hens.

Expression profiling and single nucleotide polymorphism of mitogen-activated protein kinase kinase kinase 8 MAP3K8 in white muscovy ducks (Cairina moschata)

A previous study on ovarian and hypothalami transcriptome analysis in white Muscovy duck revealed that MAP3K8 gene participated in MAPK signaling pathway that influence egg production. Additionally, MAP3K8 was predicted as a target gene of miRNA-509-3p that promotes the secretion of oestradiol which is an important hormone in egg ovulation. This suggested that MAP3K8 might have a functional role in the reproductive performance “egg production” of white Muscovy ducks. Herein, we focused on expression level of MAP3K8 in reproductive and non-reproductive tissues of highest (HP) and lowest (LP) egg producing white Muscovy ducks and identified the polymorphism in MAP3K8 and its association with three egg production traits; Age at first egg (AFE), number of eggs at 300 days (N300D) and 59 weeks (N59W). The results of expression level indicated that mRNA of MAP3K8 was significantly (p < 0.01) expressed in the oviduct than in the ovary and hypothalamus. Seven synonymous SNPs were detected, and association analysis showed that g.148303340 G>A and g.148290065 A>G were significantly (p < 0.05) associated with N300D and N59W. The results of this study might serve as molecular marker for marker-assisted selection of white Muscovy ducks for egg production.

The effect of feeding a mixture of shellfish meal and fish oil on egg production and egg storability of Lohmann Brown laying hens

The aim of the research was to determine the effect of feeding a mixture of shellfish (SF) and fish oil (FO) on egg production performance and storability of Lohmann Brown hen eggs. The study used a completely randomized design consisting of 4 treatments and 4 replications, and each replication consisted of 40 Lohman Brown hens with the same laying age (45 weeks of age). The four treatments were mixed levels of shellfish flour with fish oil in feed, namely 0%, 1%, 2%, and 3%, as treatments P0, P1, P2, and P3. Egg samples were taken at the end of the study, then stored and observed for 4 weeks. The results showed that egg pH and haugh units (HU) in the P2 and P3 hen groups significantly (P&lt;0.05) increased. Meanwhile, egg shell weight and egg yolk color did not show significant differences (P&gt;005). Feeding SFFO to P2 and P3 hen groups increased (P&lt;0.05) egg weight, hen-day-production and feed efficiency (feed consumption/egg weight). It can be concluded that SFFO can be used as an ingredient in laying hens with an inclusion level of 20-30g/kg and can be used in chicken feed during the finishing phase. SFFO may affect the storability of Lohmann Brown hen eggs.

Impact of the novel chlorinated polyfluorinated ether sulfonate, F-53B, on gill structure and reproductive toxicity in zebrafish

6:2 Chlorinated polyfluorinated ether sulfonate, commonly known as F-53B, is widely used as a mist suppressant in various industries and is frequently detected in the environment. Despite its prevalent presence, the adverse effects of F-53B are not well understood and require future investigation. This study utilized zebrafish embryos and adults to examine the toxic effects of F-53B. Our findings revealed that F-53B impaired gill structure and increased erythrocyte numbers in adult zebrafish. Notably, F-53B demonstrated a higher sensitivity for inducing mortality (LC50 at 96 h) in adult zebrafish compared to embryos. Additionally, F-53B disrupted the expression of critical steroidogenic genes and hindered sex hormone production, which negatively affecting egg production. In conclusion, this study underscores the detrimental impact of F-53B on gill structure and reproductive toxicity in zebrafish, providing valuable insights into its overall toxicity.

Integrating Genomics and Transcriptomics to Identify Candidate Genes for Egg Production in Taihe Black-Bone Silky Fowls (Gallus gallus domesticus Brisson).

The Taihe Black-Bone Silky Fowl (Gallus gallus domesticus Brisson) possesses significant value in terms of consumption, medicinal applications, and ornamental appeal, representing a precious genetic resource and traditional Chinese medicinal material. However, considerable variation exists within populations regarding egg-laying performance. This study integrates a whole-genome selection signal analysis (SSA) with a transcriptome analysis to identify genes associated with egg-laying traits in Taihe Black-Bone Silky Fowls. We identified 31 candidate genes under selection from the high-yield chicken (HC) and low-yield chicken (LC) groups. Additionally, through RNA-seq analysis, 257 common differentially expressed genes (DEGs) were identified from four comparative groups. Two overlapping genes-LPL and SETBP1-were found in both the selected gene and DEG lists. These selected genes and DEGs were enriched in pathways related to ovarian development, including the lysosome pathway, the ECM-receptor interaction pathway, the TGF-beta signaling pathway, the Wnt signaling pathway, the PPAR signaling pathway, and the glycerolipid metabolism pathway. These research findings contribute to the breeding of Taihe Black-Bone Silky Fowls with high egg production traits and provide a theoretical foundation for exploring the regulatory mechanisms of avian reproduction.

Molecular characterization of miR-31 for regulating egg production in female Schistosoma japonicum

Schistosomiasis is caused by Schistosoma infection and affects more than 200 million people worldwide. A large number of eggs produced by adult Schistosoma play central the role in host pathology and subsequent disease dissemination. However, the underlying mechanisms of egg production in Schistosoma still need to be further elucidated. Previously, we found that miR-31 was highly enriched in the female reproductive organs of Schistosoma japonicum (S. japonicum), which was shown to be associated with ovarian development. In the present study, we analyzed the potential targets of miR-31 including mRNA and long noncoding RNAs (lncRNAs) in S. japonicum by RNA seq combined with bioinformatics. Then, six putative targets of miR-31 including three mRNAs such as EWB00_000918, EWB00_004242, and EWB00_009323 and three lncRNAs such as LncSJG_010465, LncSJG_015374 and LncSJG_013128 were further analyzed their expressions in the parasites treated with miR-31 inhibitor by qPCR to confirm their potential regulations. Whole mount in suit hybridization (WISH) analysis of some miR-31 targets were carried out to determine their colocalizations with miR-31. Furthermore, we selected EWB00_009323, which is an eggshell synthetic protein and also a target of miR-31, to inhibit its functions by small interfering RNA. The results indicated that inhibition of EB00_009323 led to decreased oviposition and defective ovarian morphology. Overall, the potential targets of miR-31 including mRNA and lncRNAs were identified in female S. japonicum and the results indicated that miR-31 coordinates with its targets, at least EWB00_009323, play an important role in ovarian development and egg production.

Modelling the complete life cycle of an arctic copepod reveals complex trade-offs between concurrent life cycle strategies

Calanus hyperboreus is a large-bodied, biomass dominant species that performs a crucial ecosystem energy transfer by converting the spring phytoplankton bloom into lipid reserves that fuel the higher trophic levels of the Gulf of St. Lawrence (GSL) pelagic ecosystem, including the critically endangered North Atlantic right whale (Eubalena glacialis). Given that the GSL, the southernmost core habitat of C. hyperboreus, is undergoing rapid warming, developing a population model allows us to synthesize existing knowledge of the species, and to examine the species response to environmental conditions. To simulate the multi-year life cycle in the northwest GSL, model equations are implemented for ingestion, assimilation, respiration, egg production, stage development, mortality, and vertical migration behaviors including dormancy entry and exit. The 1-D particle-based model predicts the evolution of individual stage, structural mass, lipid, age, sex, abundance, and egg production, as well as the seasonal evolution of the population structure in the northwest GSL. Individual lipid-based thresholds inform the timing of ontogenetic vertical migration. Life cycle targets defined from a literature review are used to guide model parameterization and assess its performance. The simulated population structure, phenology, and size at stage are generally consistent with observations. Under 10 years of repeat year forcing, the model simulates a quasi-stable overwintering population composed of late stages CIV, CV and CVI. Observations suggest that stage CIV is the first overwintering stage in the GSL, and point to the occurrence of iteroparous females. Using the model, the relative success of diverse dormancy and reproductive phenotypes are explored. Second reproduction females reproduce earlier in winter than first reproduction females, with implications for the ability of the new generation to match the spring bloom and accumulate sufficient lipid to overwinter as stage CIV. Without iteroparity, the time window of reproduction contracts and the population is reduced, underscoring the role of a flexible multi-year life cycle in population success.