Eggshell Thickness Research Articles

Improving Egg Production, Quality and Eggshell Hygiene by Supplementation of Sage (Salvia officinalis) and Lavender (Lavandula angustifolia) Essential Oils

ABSTRACT Objective: This study was performed to evaluate the effects of sage (Salvia officinalis) and lavender (Lavandula angustifolia) essential oils (EO) supplementation into drinking water on egg production, quality and eggshell hygiene in laying hens. Material and Methods: A total of 300 Nick Brown laying hens between 30 and 38 of age were used in a completely randomized design in three treatments and ten replicates. The treatments consisted of: control group, sage EO, lavender EO supplementation group. EOs were supplemented into drinking water (0.3 mL/L). Results: A lower value of egg production, egg weight, egg mass and deteriorations in feed efficiency, eggshell breaking strength and thickness were observed in lavender EO group (P

Dosing of Bacterial Phytase (EC 3.1.3.26) in Laying Hens’ Diets

Despite the acknowledged advancements in the utilization of phytase dosing, limited research has been conducted on commercial laying hens. To assess the effectiveness of doses of exogenous phytase, a total of 320 laying hens aged between 44 and 64 weeks were utilized. These hens were divided into five treatments, which were then distributed using a completely randomized design with eight replicates, each containing eight birds. The treatments consisted of phytase supplementation levels of 0, 500, 1000, 1500, and 3000 FTU/kg. Quadratic regression equations were utilized to determine the maximum and minimum values for the levels of phytase supplementation. A significant difference was observed in the levels of phytase supplementation, where a quadratic model was fitted to various variables including egg weight (g), egg mass (g/bird/day), feed conversion per egg mass (g/g), yolk concentration (%), albumen concentration (%), shell thickness (μm), shell strength (kgf), specific gravity, and yolk color. Further, an increased supplementation improved the digestive tract of the hens, thereby providing a better villus–crypt ratio. Considering the advantageous effects of phytase dosing, it is recommended to supplement corn and soybean meal-based diets with 1500 FTU/kg of bacterial phytase for laying hens during the 44- to 64-week production period.

Effects and interactions of dietary lysine and apparent nitrogen corrected metabolizable energy on yellow-feathered broiler breeder hens

BackgroundDietary lysine and apparent nitrogen-corrected metabolizable energy (AMEn) are two key variables affecting the production of breeder hens. In this study, the effects and interactions of lysine and AMEn on yellow-feathered broiler breeder hens were investigated. A total of 720 30-week-old breeder hens were fed in a 5 (lysine: 0.56%, 0.68%, 0.80%, 0.92%, and 1.04%) × 2 (AMEn: 11.50 and 11.10 MJ/kg) factorial arrangement for 12 weeks. The productive performance, reproductive traits, biochemical variables of breeder hens, the amino acid concentration and quality of eggs, and the growth performance of offspring broilers were determined.Result(1) Dietary lysine had quadratic effects (P < 0.05) on laying rate, average daily egg mass and feed intake/egg mass of breeder hens; birds with 11.50 MJ/kg AMEn (high AMEn) had higher (P < 0.05) BW than those with 11.10 MJ/kg AMEn (low AMEn); (2) dietary lysine significantly affected on the relative ovarian weight (quadratic and linear), and numbers of large yellow follicles (LYF, quadratic); birds with high AMEn had longer fallopian tube and more LYF than those with low AMEn (P < 0.05); (3) dietary lysine had significant effects (linear and quadratic) on eggshell thickness and shell strength of eggs from breeder hens; birds with high AMEn had thinner eggshells and deeper yolk color than those with low AMEn (P < 0.05); (4) there were higher (P < 0.05) contents of protein and concentrations of all measured animo acids (AAs) in eggs from birds fed low AMEn; (5) supplementation with high AMEn to breeder hens significantly increased the hatchability of fertilized eggs; (6) neither dietary lysine level or AMEn affected growth performance of offspring broilers; (7) both dietary lysine level and AMEn significantly affected gonadotropin concentrations and biochemical variables of breeder hens.ConclusionsDietary lysine had significant influences on productive performance, reproductive traits, and egg quality of yellow-feathered breeder hens. Based on productive performance, the optimal levels of dietary lysine were 0.81% to 0.83%, while 0.71% to 72% lysine was enough to obtain the best quality of breeding eggs. High AMEn was more beneficial to breeder hens for reproductive traits and hatchability of the fertilized eggs, while it showed detrimental effects on eggshell thickness and AA concentrations of breeding eggs.

Exploration of Some Nutrient Absorption-Related Genes and Intestinal Histology in Japanese Quails (Coturnix japonica) Throughout Their Productive Lifespan.

Quail is an efficient poultry species known for many years, and its productivity is highly affected by gastrointestinal function, health, digestion and commensal bacteria. Specific histological parameters and nutrient absorption-related genes could be used to study intestinal functionality and efficiency. This study aimed to evaluate the mRNA abundance of nutrient absorption-related genes and intestinal histology changes in laying Japanese quail during productive lifespan. A total of 135 quails from a commercial flock at different egg production periods (early production [EP, 6 weeks of age], pick production [PP, 21 weeks of age] and post pick production [PPP, 40 weeks of age]) were randomly selected (n=45/group) and kept for 6 weeks. Production performance was evaluated during last 2 weeks of the experimental period, and tissue samples were taken from the duodenum, jejunum and ileum for histological analysis and mRNA abundance purposes at the end of the experiment. The mRNA abundance of the CALB1, SGLT1, SGLT5, EAAT3 and NaPi-IIb genes were compared among groups. Production period did not affect the eggshell thickness, goblet cell number and mRNA abundance of CALB1, EAAT3 and NaPi-IIb (p>0.05). The PPP quails had the highest egg weight and FCR compared to EP and PP quails (p<0.001). Egg production and egg mass of the EP and PP quails were higher than those of PPP quails (p<0.001). Moreover, EP quails had the highest villus height (VH)/crypt depth (CD) ratio in the duodenum and jejunum and the lowest VH:CD in the ileum compared with the PPP quails (p<0.01). The lowest SGLT1 mRNA abundance was noted in the PP quails, whereas EP quails had the highest SGLT5 mRNA abundance (p<0.05). In conclusion, although histology parameter changes were in-line with the lowest performance observed in the PPP quails, the current results failed to show a relationship between mRNA abundance changes and production performance attributes at different productive lifespans.

Dietary sodium sulfate supplementation improves eggshell quality, uterine ion transportation and glycosaminoglycan synthesis in laying hens.

This study evaluated the effects of dietary sodium sulfate (Na2SO4) supplementation on eggshell quality, uterine ion transportation, and glycosaminoglycan (GAG) synthesis. A total of 432 48-wk-old Hy-line Brown laying hens were randomly divided into 6 dietary treatments with 8 replicates of 9 birds each. The experimental laying hens were fed the corn-soybean meal diets (containing 0.15% NaCl) supplemented with 0.22%, 0.37%, 0.52%, 0.68%, 0.83%, or 0.99% Na2SO4 for 12 weeks. Results showed that the eggshell breaking strength and eggshell ratio significantly increased in the 0.68% Na2SO4 group at the end of wk 56 and wk 60 (P < 0.05). In addition, eggshell thickness and weight significantly increased in the 0.68% Na2SO4 group at the end of wk 60 (P < 0.05). Eggshell calcium (Ca) content in the 0.68% Na2SO4 group was higher than that of 0.22% and 0.99% groups (P < 0.001). The concentrations of K+ and Ca2+ in the uterine fluid were significantly greater in the 0.68% group than in the other groups (P < 0.05). Dietary Na2SO4 increased the gene expression of SLC8A1, SCNN1A, ATP1B1, and KCNMA1 quadratically in the uterus (P < 0.05), and higher values were observed in 0.68% group. Additionally, the GAG contents of the eggshell, and ATP-S, SULT, CS, and DS contents of the isthmus increased linearly with the increment of dietary Na2SO4 (P < 0.05). There was a remarkable reduction in mammillary knob width, mammillary thickness, and the percentage of the mammillary layer (P < 0.05), and an increment in mammillary knob density, effective thickness, and total thickness in the 0.68% group compared with the 0.22% and 0.99% groups (P < 0.05). Overall, there was no dose-related difference with the increment of dietary Na2SO4 levels. The addition of 0.68% Na2SO4 in the corn-soybean basal diet (0.15% Cl) regulated uterine ion transport, increased GAG contents of eggshell, and improved eggshell ultrastructure and quality.

Developing a More Sustainable Protein and Amino Acid Supply of Laying Hens in a Split Feeding System.

Two model experiments were conducted to investigate the different protein and amino acid supply of laying hens fed split feeding (SF) diets. In Experiment 1, one conventional (C) and one SF dietary treatment were established, and the diets were implemented for 12 weeks. The concentrations of crude protein, SID Lys, Met, Met + Cys Arg, Val, Thr, Leu, Ile, and Trp of the SF morning diet were the same as in the C diet. The crude protein content of the SF afternoon diet was lower (92%), while the SID values of Lys, Met, Met + Cys were identical compared to the C diet (100%). The SF treatment resulted in a reduced protein/N intake, better feed conversion ratio, higher eggshell thickness and apparent ileal digestibility of Asp, Leu, Lys, Gly, and Ser, and lower concentration of N forms (total, fecal, NH4+, uric acid, urinary) in the excreta compared to the C treatment. In Experiment 2, a control and a low protein (-2% crude protein but the same SID values of Lys, Met, Met + Cys, Thr, Val) SF treatment were compared for 6 weeks. The low protein SF treatment led to a decreased protein/N intake, higher laying rate, lower egg weight, higher ileal digestibility of Ala, Asp, Leu, and Ile, and similar N emission compared to the control SF treatment.

Common cuckoo eggs are more resistant to puncture by the host

The puncture resistance hypothesis suggests that thick-shelled eggs of parasitic birds can resist puncture-ejection by the host. However, few experiments have yet been conducted to test this hypothesis in terms of natural host behavior (e.g., pecking at foreign eggs). To explore whether the eggshells of common cuckoos (Cuculus canorus) are resistant to puncture-ejection by their common hosts, Oriental reed warblers (Acrocephalus orientalis), we designed experiments to investigate if and how breeding Oriental reed warblers peck at foreign eggs that includes common cuckoo, Oriental reed warbler and budgerigar (Melopsittacus undulatus) eggs. The results showed that, given the same frequency of egg pecking, the probability of eggshell breakage was 87.5% for eggs of the Oriental reed warbler and 0% for eggs of the common cuckoo, with a significant difference (P = 0.001, Fisher's exact test). Our study shows clearly that common cuckoos' eggshells are less susceptible to puncture-ejection than those of Oriental reed warblers and budgerigars. This indicates that the eggshells of common cuckoos can resist host Oriental reed warblers' puncture-ejection, supporting the puncture resistance hypothesis.

Macleaya cordata extract improves egg quality by altering gut health and microbiota in laying hens

This study investigated the effect of Macleaya cordata extract (MCE) on the performance, gut health, and microbiota of laying hens. A total of 192 thirty-wk-old Hyline brown laying hens were randomly divided into 4 treatment groups. The CON group received a basal diet, while the low (MCE250), medium (MCE350), and high (MCE450) dose groups were supplemented with 250, 350, and 450 mg/kg MCE, respectively. The egg weight and Haugh unit demonstrated a linear and quadratic increase with the MCE dose during the initial 4-wk period of the experiment (P < 0.05). Furthermore, the dietary supplementation of MCE led to a significant enhancement in eggshell thickness and Haugh unit at wk 8 and the data showed a statistically significant linear and quadratic increase (P < 0.05). Serum cytokine assay showed that dietary supplementation of MCE led to linear and quadratic increases in IL-4 and IL-10 level (P < 0.05). Dietary supplementation of 350 and 450 mg/kg MCE was observed to result in linear and quadratic increase in serum lysozyme levels (P < 0.05). The addition of MCE to the diet resulted in a linear and quadratic increase in the levels of sIgA in the jejunum and ileum (P < 0.05). In terms of gene expression, the addition of MCE to the diet resulted in linear and quadratic increases in the expression of IL-10, IgA, Serpinb14, Serpinb14B, and OIH (P < 0.05). The expression of jejunal genes pIgR and IL-4 was observed to increase in a linear and quadratic manner, respectively, following the dietary addition of 350 mg/kg MCE and IL-1β decreased in a linear manner (P < 0.05). Moreover, these favorable effects were maximized at medium dosage (350 mg/kg) of MCE addition, and intestinal microbial composition in the control and MCE350 groups was assessed. 350 mg/kg MCE increased the relative abundance of Bryobacter and Parasutterella and decreased the relative abundance of Erysipelatoclostridium in the cecum (P < 0.05). Spearman correlation analysis revealed that Bryobacter, Parasutterella, Skermanella, and Erysipelatoclostridium were associated with nonspecific immune functions (P < 0.05). In conclusion, 350 mg/kg MCE supplementation elevated the immune response, and upregulated the expression of genes related to protein production in eggs, thereby improving egg quality. These effects may be associated with changes in the microbiota, specifically Bryobacter, Parasutterella, and Erysipelatoclostridium.

Xylanase and phytase supplementation of Moringa oleifera diets: effects on the performance, egg quality and blood profile of laying hens

Context Moringa oleifera leaves present enormous potential as an alternative feedstuff for laying hens. The utilisation of the leaves can be improved by exogenous enzymes owing to the presence of non-starch polysaccharides and phytate. Aims This study evaluated the influence of Moringa oleifera leaf meal (MOL) in diets supplemented with xylanase and phytase on laying hen performance and egg quality at peak production. Methods In total, 288 Dekalb White laying hens (32 weeks old) were distributed in a completely randomised design, following a 2 × 4 factorial arrangement (with or without MOL × 4 enzyme supplementations). Each treatment comprised six repetitions, each containing six hens. The control diet was based on ground corn and soybean meal, and the treatment diets were supplemented with 5% MOL, followed by three enzyme additives (xylanase, phytase and a xylanase + phytase blend). Key results The enzyme supplementation in MOL diets positively influenced egg production (P = 0.012), egg weight (P = 0.021) and egg mass (P = 0.009). The birds offered xylanase-supplemented diets had higher feed intakes (P = 0.015) than did those fed other diets. Moringa oleifera increased the albumen height (P &lt; 0.001) and Haugh unit (P &lt; 0.001), whereas MOL and phytase improved eggshell thickness (P &lt; 0.001) and the candling score (P = 0.049), compared with treatments without phytase supplementation. MOL and enzyme supplementation improved yolk colour intensity (L, A and R parameters) and decreased plasma total cholesterol and LDL cholesterol concentrations. The inclusion of 5% MOL in diets did not impair laying performance. However, when MOL diets were supplemented with exogenous enzymes, there was an increase in egg weight. Conclusions MOL can be included at 5% in layer diets without affecting performance. When used in combination with xylanase and phytase, they improve performance, intensify yolk colour, and improve shell thickness, candling score, as well as serum biochemical profile. Implications These findings suggest that the combination of dietary MOL + xylanase + phytase can improve performance and egg quality in laying hens at peak production.

Replacement of Soybean Meal with Rice Distiller’s Dried Grains with Soluble in Layer Diet on Chicken Egg Quality

The experiment was conducted on 144 layers of BV- 300 strain from age of 59th week and completed at 70th week for the period of 12 weeks to study the replacement of soybean meal with rice distiller’s dried grains with soluble (rDDGS) in layer diet on egg quality parameters. The egg weight, shape index, egg surface area, albumin index, yolk index, yolk color score, percent eggshell weight and eggshell thickness parameters were studied. The layer birds were randomly distributed into 4 equal treatments T1 (Control), T2, T3 and T4 with 36-layer birds in each group having 6 replicates of 6 layers each. The control group T1 fed basal layer ration as per the recommendation of BV-300-layer strain and treatment groups T2, T3 and T4 offered 5, 10 and 15% rDDGS inclusion levels replacing soybean meal in diet and recorded for egg quality parameters. It was observed that, the inclusion of rDDGS at 0, 5, 10 and 15% in treatment groups T1, T2, T3 and T4 respectively, in layer diets were non-significantly influenced on shape index, egg surface area, albumin index, yolk index, yolk colour score, percent eggshell weight and eggshell thickness. The egg weights were significantly (P&lt;0.05) decreased in treatment group T4 receiving diet at 15% rDDGS as compared to control group T1 and treatment group T2. However, there was non-significant differences for egg weight in groups T1, T2 and T3. Thus, it was concluded that the rice distiller’s dried grains with soluble (rDDGS) can be included up to 10% in layer diet with replacing soybean meal without affecting the body weights, external and internal egg quality parameters like eggshell weight, shape index, egg surface area, albumin index, yolk index, yolk colour score, egg surface area and eggshell thickness.

Additive efficacy of natural versus synthetic feed additive on cellular immunity and egg quality in layers

Feed additives are the products used in animal diets for the purpose of improving the quality of feed and the quality of food from animal origin or to improve animal performance and health. The present study was planned to evaluate the beneficial effect of two edible dried mushrooms, probiotics, antioxidant and antibiotic on layer performance, cellular immunity, and antioxidant activities under hot climatic conditions. In this trial, three hundred W-98 commercial hens of 35th week of age were randomly assigned to six dietary treatments, replicated five times with 10 hens per replicate for 12 weeks. Dietary treatments were as follows; antibiotic (enramycin) 50g/ 50 kg, probiotics 50g/ 50 kg, antioxidant (ethoxyquine) 60 ppm, organic acid 50g / 50 kg; Oyster mushroom and button mushroom 1% of feed bag. The data revealed that initial, final body weight, egg production (%) and feed intake, egg specific gravity, egg shape index, egg yolk index and shell thickness and livability were non-significant (p&lt;0.05) in all treatments. Egg weight, feed to egg mass ration, Haugh unit and damaged eggs were significantly (p&gt;0.05) higher among different treatment groups. Total anti-oxidative capacity was significantly (p&gt;0.05) higher in ethoxyquine, followed by oyster mushroom, button mushroom, negative control (without any feed additives), probiotics and enramycin (positive control / antibiotic). Antioxidant parameters like super oxide dismutase was significantly (p&gt;0.05) higher in ethoxyquine followed by probiotics, oyster mushroom, button mushroom, negative control, and positive control treatments groups. Immunity parameters like catalase (interferon gamma) was non-significant (p&gt;0.05) in all treatment’s groups. IFN-γ (Interferon-gamma) was significantly (p&lt;0.05) higher in oyster mushroom and ethoxyquine followed by probiotics, button mushroom, negative control (without any feed additives) and positive control (with antibiotic). IL-10 (Interleukin-10) was significantly (p&lt;0.05) higher in button mushroom, oyster mushroom and probiotics followed by ethoxyquine, negative control (without any feed additives) and positive control (with antibiotic). On whole mushrooms are effective feed additives in poultry production IFN-γ (Interferon-gamma) was significantly (p&lt;0.05) higher in oyster mushroom and ethoxyquine followed by probiotics, button mushroom, negative control (without any feed additives) and positive control (with antibiotic). IL-10 (Interleukin-10) was significantly (p&lt;0.05) higher in button mushroom, oyster mushroom and probiotics followed by ethoxyquine, negative control (without any feed additives) and positive control (with antibiotic). On whole mushrooms are effective feed additives in poultry production

A novel intron variant in the prolactin gene associated with eggshell weight and thickness with putative alternative splicing patterns in chickens

A novel intron variant in the prolactin gene associated with eggshell weight and thickness with putative alternative splicing patterns in chickens

Dietary starch structure modulates nitrogen metabolism in laying hens via modifying glucose release rate

The objective of this study was to investigate the effects of starch structure (Amylopectin/Amylose, AP/AM) in a low-protein diet on production performance, nitrogen utilization efficiency, and cecal flora in laying hens. Four hundred eighty 45-wk-age Hy-Line Gray laying hens were randomly allocated to five dietary groups and subjected to a 12-wk feeding trial. The AP/AM ratios of the five experiment diets were 1.0, 1.5, 2.0, 3.0, and 4.0. The results indicated that compared to other groups, laying hens fed with AP/AM 4.0 diets showed significantly improved average egg weight and feed conversion ratio (P < 0.05). Furthermore, as the AP/AM ratio increased, there was a significant linear enhancement in intestinal amino acids apparent digestibility, apparent metabolizable energy, and villus area (P < 0.05). Compared to the high AP groups, high-AM diets significantly increased eggshell thickness, crude protein digestibility, and reduced energy supply from amino acid oxidation in ileum (P < 0.05). Additionally, moderate-AM diets enriched with short-chain fatty acid-producing bacteria in the cecum, such as Lactobacillus, Rikenellaceae_RC9_gut_group, and Christensenellaceae_R-7_group, which are associated with the promoting nitrogen utilization. These findings may offer useful information on optimizing starch structure for the design of food products and relevant therapies due to the potential effects on nutrient metabolism and gut homeostasis.

A 3D micro-computed tomography study comparing embryonic skeletal development in layer versus broiler strains of the domestic chicken

Our objective was to analyze the effect of selection for divergent traits in the domestic chicken on embryonic skeletal development, which could affect postnatal bird welfare. Development was compared between the Ross 308 broiler line (fast growth and muscle mass accrual) and Novoponte layers (high laying rate and egg quality). In Study 1 (Initial Conditions), we characterized egg composition prior to incubation and identified the onset of embryonic skeletal mineralization in the 2 strains. In Study 2 (Developmental Dynamics), we used 3D X-ray tomographic imaging (µCT) on incubation days ED11, ED13, ED15 and ED17 to track skeletal maturation trajectories as a pseudo-time series. Results showed that Ross 308 embryos, which are heavier than Novoponte embryos, possess higher levels of yolk nutrients including phosphorus and calcium, but lower eggshell mineral content, than Novoponte embryos. Skeletal mineralization started synchronously in both strains, on ED11. The higher mineral ion content in the larger yolk of Ross 308 eggs compared to Novoponte eggs may partly explain why skeletal mineralization in Ross 308 embryos advances faster: using µCT, we show that the mandible and tibiotarsi in Ross 308 embryos are larger at ED11 and ED13 compared with Novoponte embryos. However, Novoponte embryos catch up from this initial lag in mineralization by ED15. The timing of the Novoponte acceleration coincides with the functional activation of the chorioallantoic membrane in releasing calcium from the inner eggshell. This correlates with a decrease in eggshell thickness from ED11 to ED17 in Novoponte eggs, which was not observed during Ross 308 incubation. To conclude, while some temporal discrepancies exist in early skeletal development between the embryos of Ross 308 and Novoponte strains, overall prenatal skeletal maturation seems to be robustly regulated. Despite selection for antagonist production traits, layer and broiler prehatch skeletal morphology ultimately synchronizes. Practically, since the extent of skeletal maturity equalizes between strains towards the end of incubation, refinements of farming practices, postnatal environment, and diet should be considered for improving domestic fowl welfare.

Fermented blueberry pomace supplementation improves egg quality, liver synthesis, and ovary antioxidant capacity of laying hens

The present study aimed to investigate the effects of dietary fermented blueberry pomace (FBP) supplementation on production performance, egg quality and nutritional value, plasma biochemical parameters, follicle number, reproductive hormones, lipid metabolism, and antioxidant capacity of laying hens during the late laying period. A total of 320 (345-d-old) Yukou Jingfen No. 8 laying hens were randomly divided into 4 groups, with eight replicates per group and 10 hens per replicate. The birds were fed a basal diet (control group) and a basal diet supplemented with 0.25, 0.5, and 1.0% FBP. The trial lasted 56 d. The results showed that FBP (0.25-1.0%) supplementation increased the egg albumen height and Haugh unit compared with the control group on d 14, while 0.5 to 1.0% FBP increased the eggshell thickness compared with the 0.25% FBP group on d 28 of the trial (P < 0.05). The methionine content in egg white was higher (P < 0.05) in the 1.0% FBP group compared with the 0.25% FBP group. The CAT activity in the ovary was increased (P < 0.05) in the FBP groups compared with the control group, while plasma GSH-PX activity was higher (P < 0.05) in the 1.0% FBP group compared with the 0.25% FBP and 0.5% FBP groups. Dietary FBP supplementation up-regulated (P < 0.05) gene expressions related to lipid metabolism in the liver (ACC, FAS, SCD1, and SREBP1) and yolk precursor synthesis (ESR2 and VTG II). Moreover, CYP11A1 expression in the ovary was up-regulated (P < 0.05) in the FBP groups compared with the control group, as well as in the 0.25% FBP group compared with the 1.0% FBP group. In summary, dietary FBP supplementation improved egg quality and nutritional value, ovarian antioxidant capacity, and yolk precursor synthesis, while 1.0% FBP had better effects than 0.25 and 0.5% doses.

Study on the changing patterns of production performance of laying hens and their relationships with environmental factors in a large-scale henhouse

The production performance of laying hens is influenced by various environmental factors within the henhouse. The intricate interactions among these factors make the impact process highly complicated. The exact relationships between production performance and environmental variables are still not well understood. In this study, we measured the production performance of laying hens and various environmental variables across different parts of the henhouse, evaluated the weight of each environmental variable, and constructed a laying rate prediction model. Results displayed that body weight, laying rate, egg weight and eggshell thickness of hens decrease gradually from WCA to FA (P < 0.05). Serum levels of FSH and LH, as well as antibody level of H5 Re-13, gradually decrease from WCA to FA (P < 0.05). Moreover, the values for temperature (T), temperature-humidity index (THI), air velocity (AV), carbon dioxide (CO2), and particulate matter (PM2.5) gradually increase from WCA to FA (P < 0.05). Conversely, the relative humidity (RH) value gradually decreases from FA to WCA (P < 0.05). Additionally, the weights of the environmental variables, determined using a combination of the grey relational analysis (GRA) and analytic hierarchy process (AHP), were as follows in descending order: RH, THI, T, light intensity (LI), AV, PM2.5, NH3, and CO2. When the number of decision trees in the laying rate prediction model was set to 2,500, the results displayed a high level of agreement between the model's predictions and the observed outcomes. The model's performance evaluation yielded an R2 value of 0.89995 for the test set, suggesting strong predictive effects. In conclusion, the current study revealed significant differences in both the production performance of laying hens and the environmental variables across different parts of the henhouse. Furthermore, the study demonstrated that different environmental factors have distinct impacts on laying rate, with humidity and temperature identified as the primary factors. Finally, a multi-variable prediction model was constructed, exhibiting high accuracy in predicting laying rate.

Impact of different housing densities combined with Environmental enrichment on the production of Japanese quail

This study evaluated the zootechnical performance, egg quality, and behavior of Japanese quails in the laying phase housed in cages of different densities and with or without environmental enrichment. A total of 224 quail were used and distributed into two groups: one with a housing density of 122.7 cm2 bird-1 and one with a housing density of 157.8 cm2 bird-1, each with and without environmental enrichment. The results showed that environmental enrichment did not influence the zootechnical performance parameters of the quail. However, housing density independently affected performance, except for egg mass and bird viability. A lower density (157.8 cm2 bird-1) resulted in greater specific egg weight, albumen percentage, and shell thickness. The interaction between density and environmental enrichment revealed that eggs from quail housed at higher density without enrichment had a greater yolk percentage, while quails housed at lower density without enrichment had a greater shell percentage. The tonic immobility time of the quails was not affected by treatment with different densities or environmental enrichment agents. It can be concluded that a lower housing density, with seven quail per cage (157.8 cm2 bird-1), regardless of environmental enrichment, provides better zootechnical performance and egg quality.

Phytase super-dosing modulates bone parameters and the concentration of the calcium epithelial carrier calbindin-D28k in quails (Coturnix coturnix japonica) under thermal stress

Context Thermal stress causes significant changes in the bioavailability of minerals, especially calcium, in laying birds, resulting in reduced egg production, and compromising egg quality. Therefore, it is necessary to use additives that provide better nutrient availability and minimise the negative effects caused by high temperatures. Aims This study aimed to evaluate the effects of super-dosing the diet of laying quails submitted to different temperatures with phytase on their bone parameters and on the epithelial calcium transporter calbindin-D28K positivity. Methods Seven hundred and twenty (720) Japanese quails in the production phase were distributed in a completely randomised design, in a 5 × 3 factorial design, with five supplementation levels of phytase (0, 500, 1000, 1500, and 3000 FTU/kg), and three temperatures (24°C, 30°C and 36°C), totalling 15 treatments, and six replications of eight birds each. The study began at the 8th week of age and continued for two cycles of 21 days, totalling 42 days of experiment. Bone parameters of the tibias and calbindin-D28K positivity were measured by immunohistochemistry. The data were submitted to variance, Tukey, and regression analyses. Key results At 24°C, birds had higher averages for proximal, medial, and distal diaphyses than did birds at 30°C and 36°C, and a greater breaking strength of the tibias than did those at 36°C. There was an increasing linear effect on the medial diaphysis and Seedor index in the tibias with an increasing phytase supplementation level. Calcium (Ca) in the tibias was higher in birds kept at 30°C at a supplementation level of up to 1000 FTU of phytase, than in the birds at 24°C and 36°C, equalling at 1500 FTU, and lower at 3000 FTU. There was a quadratic effect for phosphorus (P) and the Ca:P ratio in the tibias of quails submitted to increasing concentrations of phytase. Quails kept at 30°C showed greater anti-calbindin-D28K positivity in the duodenum and jejunum, when compared to animals subjected to temperatures of 24°C and 36°C. Phytase doses of 500 and 1000 FTU increased calbindin-D28K positivity in the duodenum of quails kept at 30°C. At a supplementation level of 1500 FTU, phytase provided greater eggshell thickness and greater calbindin-D28K positivity in the uterus of quails kept at 36°C. Conclusions Therefore, it is recommended to use 1500 FTU of phytase for Japanese quail exposed to high temperatures. Implications These findings suggest that dietary phytase super-dosing can help alleviate thermal stress in Japanese quail.

Effect of organic and nano trace minerals at reduced levels in layer diets on egg quality characteristics and its trace mineral content

An experiment was conducted to assess the effect of organic and nano trace minerals (copper, zinc, manganese and iron) at reduced levels in layer diets on various egg quality characteristics and its trace mineral content. 240 Hy- Line W80 layer birds of 29 weeks old were randomly distributed to five treatment groups with four replicates having twelve birds each. Basal diet was supplemented with inorganic trace minerals to meet 100 per cent requirement to form control diet or with organic trace minerals at 75 and 50% of requirement or with nano trace minerals at 50 and 25% of requirement to form four test diets. Each diet was offered to four replicate groups for 84 days which was conveniently divided into three phases of 28 days each. Egg quality parameters, viz. egg weight, egg shape index, albumen index, yolk index, yolk color score, Haugh unit score, egg shell weight, albumen weight and yolk weight among the treatment groups were not affected by source and level of trace minerals. However, egg shell thickness was significantly higher in 25% nano trace mineral group on 28th day. The trace minerals (Zn and Fe) in the yolk were significantly lower at reduced trace mineral levels (50% organic or nano and 25% nano form) when compared to 100% (inorganic) and 75% levels (organic form). It was concluded that the substitution of inorganic trace minerals with organic or nano trace minerals at reduced levels (50 or 25%, respectively) in layer diets does not affect the egg quality parameters, but reduces Zn and Fe content in egg yolk.

Effect of dietary daidzein supplementation on reproductive performance, egg quality and bone mineralization in laying hens at first-cycle of production via reproductive-growth axis

Daidzein (Da), an isoflavone, resembles natural oestrogen in structure and activity. We investigated the effects of dietary Da on the reproductive performance, egg quality, and bone mineralisation of hens in the pre-peak laying period. A total of 432 laying hens (110 days) were randomly allocated to control (CON) or Da-supplemented diet (10, 25, and 50 mg/kg). Each treatment had six replicates of 18 birds/replicate, and the feeding trial lasted 8 weeks. Supplementation of dietary Da significantly improved laying rate, egg weight, egg mass, and feed-to-egg ratio (p < 0.05). Likewise, dietary Da significantly improved albumen quality (Haugh unit, thick albumen fraction, and albumen proportion) and eggshell quality (eggshell; strength, eggshell thickness, gloss, and colour) (p < 0.05). Dietary Da exerted a notable significant increase (p < 0.05) on magnum weight, follicle numbers, serum levels of growth hormones, thyroid hormones (T3 and T4), reproductive hormone (oestrogen, follicle-stimulating hormone, luteinizing hormone), and mRNA expression of related genes (ESR1, FSHR1, PRL1, GNHR1). Also, Da significantly increased serum levels of superoxide dismutase, catalase, glutathione and decreased malondialdehyde (p < 0.05). Furthermore, the Da groups showed enhanced tibia strength, length, phosphorus, and bone mineral content (p < 0.05). In summary, dietary Da enhanced early onset of lay and improved albumen, eggshell, and bone quality in laying hens during the pre-peak period. Positive outcomes may be due to the efficient metabolism of Da and the safety level of inclusion. The enhancement of reproductive hormones, related genes, and antioxidant enzymes may explain daidzein’s effects on laying hens. Highlights Daidzein improved egg production significantly. Albumen, eggshell and tibia quality were enhanced. Optimal inclusion level at 25 or 50 mg/kg was safe.