Eggshell Breaking Strength Research Articles

The Impact of Eggshell Thickness on the Qualitative Characteristics of Stored Eggs Produced by Three Breeds of Laying Hens of the Cage and Cage-Free Housed Systems

The study aimed to compare the physical-chemical attributes of table eggs from three laying hen breeds housed in the cage and cage-free conditions and to characterize the morphological characteristics of the eggshell interior. A morphological and elemental analysis performed by scanning electron microscope coupled with energy dispersive X-ray spectroscopy revealed no abnormalities in the structural integrity of eggshells. The thickness of the eggshell varied in the range from 356.2 to 366.4 µm, with no statistically significant differences between the values. Eggshell membrane thickness was between 20.0 and 59.9 µm, with eggs derived from cage-housed hens, i.e., H/LS/CCE and H/HN/CCE having thinner membrane layers. The results revealed no direct relationships between eggshell and membrane thickness and physical-chemical parameters’ change. However, the presence of thick and long spider-like microcracks on the eggshell surface of eggs from cage-free housed hens H/D/BWE was the main factor that presumably contributed to substantial weight loss during 36 days of egg storage. A noticeable decline in eggshell-breaking strength along with the enlargement of air cells was observed in eggs produced under an enriched cage system H/LS/CCE after 28 days. In contrast, the minor changes in air cell size occurred in eggs from cage-free housed laying hens H/D/BWE. Protein quality indicators such as albumen height and Haugh units were well correlated with each other, and the intensity of their changes during egg storage, to a greater extent, was found to be storage time-dependent. No significant depletion of egg albumen was revealed during the first 15 days of egg storage. According to the United States Department of Agriculture, the quality corresponded to grade A (reasonably firm). However, after 18 days of storage, Haugh unit values were lower than 60, corresponding to grade B (weak and watery). The most apparent reduction in the Haugh unit was observed in eggs produced by enriched cage H/HN/CCE and cage-free H/D/BWE hens. The egg quality was storage time-dependent, and their deterioration rate was primarily associated with the genetic background of laying hens and housing conditions.

A novel source of calcium: effects of calcium pidolate concentration on egg quality in aged laying quails (Coturnix coturnix Japonica)

AbstractCalcium content in the diet can affect egg quality and production in aged birds. Calcium pidolate is a new form of calcium supplementation in poultry diets, which favours the absorption of this mineral. The current study was conducted to evaluate the effect of dietary calcium pidolate concentration in the diets of aged laying Japanese quails. A total of 120 female quails (27 weeks old) were assigned to four treatment groups, each with six replicates of five quails per pen. In the 10-week trial, quail diets were supplemented with calcium pidolate at four concentrations (0, 0.25, 0.50 and 1.00 g/kg), providing 25.1, 25.4, 25.8 and 26.5 g/kg calcium, respectively. As a result of this study, body weight, feed intake and feed conversion ratio did not change with the concentration of calcium pidolate (P > 0.05). In contrast, albumen and yolk index decreased as calcium pidolate level increased (P < 0.05). Moreover, calcium pidolate at a concentration of 0.50 g/kg resulted in the greatest egg production, eggshell breaking strength and eggshell thickness (P < 0.05), while above these levels the factors studied were negatively affected. According to these results, the optimal concentration of calcium pidolate in the diets of aged laying quails was 0.50 g/kg.

Effects of rearing systems on the eggshell quality, bone parameters and expression of genes related to bone remodeling in aged laying hens.

Public concerns regarding animal welfare are changing the selection of rearing systems in laying hens. This study investigated the effects of rearing systems on eggshell quality, bone parameters and relative expression levels of genes related to bone remodeling in aged laying hens. A total of 2,952 55-day-old Jing Tint Six pullets were randomly assigned to place in the conventional caging system (CCS) or aviary system (AVS) and kept until 95 weeks of age. The AVS group delayed the decrease of eggshell quality and alleviated the symptoms of osteoporosis in the humerus rather than in the femur. Eggshell breaking strength, thickness, weight, weight ratio, stiffness and fracture toughness were decreased linearly with age (from 55 to 95 weeks of age, p < 0.05). The AVS group had higher eggshell breaking strength, stiffness and fracture toughness than the CCS group (p < 0.05). Higher total calcium and phosphorus per egg were presented in the AVS group at 95 weeks of age (p < 0.05). At 95 weeks of age, the AVS group had a humerus with higher weight, volume, length, midpoint perimeter, cortical index, fat-free dry weight, ash content, total calcium per bone, total phosphorus per bone, average bone mineral density, strength, stiffness and work to fracture compared to the CCS group (p < 0.05). Such differences did not appear in the femur. The relative expression levels of alkaline phosphatase (ALP) and osteocalcin (OCN) genes in the femur and hormone receptors (vitamin D receptor (VDR), estrogen receptor alpha (ERα) and fibroblast growth factor 23 (FGF23)) genes in the humerus were significantly upregulated (p < 0.05) in the AVS group. The level of tartrate-resistant acid phosphatase (TRAP) transcripts was also increased (p < 0.05) in the femur of the AVS group. Overall, compared with the CCS, the AVS alleviated the deterioration of eggshell and bone qualities of aged laying hens, which may be related to the changes in the expression of genes associated with bone remodeling.

The association of Curcuma and Scutellaria plant extracts improves laying hen thermal tolerance and egg oxidative stability and quality under heat stress conditions

Chronic exposure to high ambient temperatures is detrimental to laying hen performance and egg quality. Plant secondary metabolites may alleviate effects, partly due to their antioxidant activities. Herein, we investigated the effects of dietary supplementation with a phytonutrient solution (PHYTO) consisting of a plant extract combination of Scutellaria baicalensis and Curcuma longa on young layers (25–32 wk of age) raised under naturally elevated temperature conditions. Four hundred, 24-wk-old Lohmann hens were allocated in 50 cages and, after a week of adaptation, were offered a diet either containing 2 g/kg of PHYTO or not, for 8 wk. Hen BW was measured at the beginning and end of the trial, and egg production and feed intake were recorded weekly. At week 32, four eggs per cage were collected to determine egg quality characteristics as well as the rate of lipid and albumen oxidation in fresh eggs. At the end of the trial, two hens per cage were blood sampled for assessment of biochemical markers, one of which was euthanized for histopathological evaluation of the liver and intestine and assessment of intestinal histomorphometry. The herbal mixture supplementation significantly increased egg production rate at weeks 28 and 29 and for the overall production period, and feed efficiency at weeks 26–29. In addition, the degree of liver necrosis and microvascular thrombosis was lower (P < 0.05) whereas intestinal villosity was greater in duodenal and jejunal segments (P < 0.05) in the PHYTO compared to the control group. Supplementation also reduced (P < 0.05) blood concentrations of corticosterone, alanine aminotransferase activity, and TBARS, and a reduction in catalase activity was observed. Egg quality characteristics were not affected, except for eggshell thickness, egg diameter, and eggshell breaking strength that were superior in the PHYTO group (P < 0.05). PHYTO supplementation significantly improved egg lipid oxidation status of fresh eggs. In conclusion, supplementation with PHYTO improved laying hen productivity and egg quality, which was associated with an improvement in laying hen thermotolerance.

Improved offspring performance of broiler breeder hens fed amino acid complexed trace minerals

The present study aimed to evaluate the effects of partial substitution of inorganic trace minerals ( ITM ) by amino acid complexed minerals ( AACM ) on broiler breeder hens’ performance and offspring. A total of 640 Cobb 500 broiler breeder hens, 22 wk of age, were allocated to four dietary treatments: T1- (Control) contained ITM forms of Zn, Mn, Cu, Fe and Se at 100, 100, 10, 50 and 0.30 ppm, respectively; T2- (Partial replacement) of Control by AACM Zn, Mn, Cu, and Se at 60, 60, 3, and 0.15 ppm of ITM, and 40, 40, 7, and 0.15 ppm of AACM, respectively.; T3- (Partial replacement) of Control, same as T2 but with Fe at 10 and 40 ppm of ITM and AACM, respectively; T4- (On Top) supplementation of Zn, Mn, Cu, Se and Fe (T1+T3). Laying production was evaluated from 26 to 66 wk, whereas egg quality was evaluated at 35, 45, 55, and 65 wk of age. At each period, eggs were incubated and evaluated for hatchability parameters and chick quality. At 66 wk of age, eggs were incubated to obtain 800-day-old male chicks for the progeny performance trial. Total and settable egg production and incubation parameters were not affected by supplementation treatments (P > 0.05). Eggshell breaking strength significantly increased (P < 0.05) in the On Top supplementation group compared to the Control. The offspring from hens fed partially Zn, Mn, Cu, Se and Fe AACM had higher body weight gain ( BWG ) in the first week (P < 0.05) and maintained a smaller feed conversion ratio ( FCR ) from 1 to 35 d compared to the offspring of Control ITM group (P < 0.05). Maternal AACM supplementation increased offspring BWG and FCR from 1 to 7 d and 1 to 35 d, respectively.

Effects of manual washing with three alkaline sterilizing agent solutions on egg quality during storage

This study aimed to investigate the abundance of microorganisms and quality of eggs washed with different washings (tap water, 0.03% calcium hypochlorite solution, 0.25% hydrogen peroxide solution, or 1% sodium percarbonate solution) and unwashed for 28-day storage. The results showed that the washing significantly decreased the abundance of microorganisms in all cases. Washing with one of the three alkaline sterilizing agent solutions significantly inhibited the deterioration of egg quality (evidenced by lower weight loss, air cell depth, albumen pH, yolk pH, and total volatile base nitrogen, but higher Haugh unit and yolk index) during storage, while washing with tap water showed opposite effects. The texture profile analysis and high-resolution scanning electron microscopy observation showed that all washings had slight negative effects on eggshell quality (eggshell breaking strength and microstructure), and washing with the alkaline sterilizing agent solution had no additional effects. The results might be attractive to egg preservation industry.

The influence of hen size and diet nutrient density in early lay on hen performance, egg quality, and hen health in late lay

The effect of hen size and diet nutrient density during early lay on egg production (EP) at 24 and 69 wk of age (WOA) and late lay egg quality and hen health was evaluated. Based on bodyweight (BW) at 18 WOA ISA Brown hens were assigned as heavier (HW; n = 120) or lighter weight (LW; n =120). Sixty birds from each BW group were fed an early-lay diet of higher nutrient density (HND), or lower nutrient density (LND) between 18 and 24 WOA. From 25 WOA all hens received the same early-lay diet and then from 40 WOA the mid-lay diet. Hen average daily feed intake (ADFI), hen-day EP, egg weight (EW), egg mass (EM), and feed conversion ratio (FCR) were assessed at 24 and 69 WOA. Between 66 and 70 WOA eggshell and internal egg quality was evaluated and at 70 WOA BW, liver and bone health were assessed. At 24 WOA BW was highest in HW birds and birds receiving the HND diet (P < 0.01). Concurrently ADFI, and FCR were higher and hen-day EP was lower in HW compared to LW birds (P < 0.05). The HND diet resulted in lower ADFI and FCR at 24 WOA, but higher EW and EM compared to the LND diet (P < 0.01). At 69 WOA HW birds had higher ADFI, EW (P < 0.02) and heavier 70 WOA BW compared to LW hens. The lower FCR of the LW birds at 69 WOA was approaching significance (P = 0.054). Hen weight and diet density did not affect 69 WOA egg production. Between 18 and 69 WOA cumulative FI and EM were higher in HW hens (P < 0.01) than LW hens, as was cumulative FCR (P = 0.053). Hen weight and diet density did not alter 66–70 WOA internal egg quality, but the HND diet generated thicker eggshells and higher eggshell breaking strength (P < 0.05). Seventy WOA liver health, keel curvature and femur breaking strength did not differ. Overall LW hens had lower FCR than HW hens and the early-lay HND diet facilitated improved eggshell integrity during late lay compared to the LND diet.

Low Level of Dietary Organic Trace Minerals Improved Egg Quality and Modulated the Status of Eggshell Gland and Intestinal Microflora of Laying Hens During the Late Production Stage.

This study aimed to investigate the effects of dietary organic trace minerals on egg quality and intestinal microflora of laying hens during the late production stage. In total, 1,080 Jinghong-1 laying hens aged 57 weeks were randomly assigned to five treatment groups: CON, basal diet containing about 6, 29, 49, and 308 mg·kg−1 of Cu, Mn, Zn, and Fe; IT100, basal diet supplemented with 10, 80, 80, and 60 mg·kg−1 of Cu, Mn, Zn, and Fe (each as inorganic sulfates), respectively; OT20, basal diet supplemented with 2, 16, 16, and 12 mg·kg−1 of Cu, Mn, Zn, and Fe (each as organic trace minerals chelated with lysine and methionine in the ratio of 2:1 amino acid: organic trace minerals), respectively; OT30, basal diet supplemented with 3, 24, 24, and 18 mg·kg−1 of organic Cu, Mn, Zn, and Fe, respectively; and OT50, basal diet supplemented with 5, 40, 40, and 30 mg·kg−1 of organic Cu, Mn, Zn, and Fe, respectively. Overall, OT20, OT30, and OT50 had equal or higher potential to promote Cu, Mn, Zn, and Fe deposition in egg yolks compared with IT100. In addition, OT50 enhanced the eggshell breaking strength and the antioxidant status of the eggshell gland. Cecal microbiota, including Barnesiellaceae and Clostridia, were significantly decreased in IT100- and OT50-treated hens compared with the CON group. Clostridia UCG-014 was negatively correlated with eggshell weight and OCX-32. In conclusion, reduced supplementation of organic trace minerals can improve the eggshell quality and trace mineral deposition, possibly by modulating genes involved in the eggshell formation in the eggshell gland and by controling of the potentially harmful bacteria Barnesiellaceae and Clostridiales in the cecum. Inorganic trace minerals may be effectively replaced by low level of complex organic trace minerals in laying hens during the late production stage.

Correlation between Internal and External Egg Quality Indicators in the Early Phase of Hy-Line Brown Laying Hens

This study investigated correlations between egg quality indicators to identify external egg quality traits to predict internal egg quality using non-destructive and convenient measurements. Thirteen indicators, including Haugh unit, albumen height, eggshell breaking strength, eggshell thickness, eggshell color (CIE L^*, CIE a^*, CIE b^*), and reflectivity value, egg weight, egg length, egg width, shape index, and yolk color, were investigated. A total of 180 brown eggs were obtained from one 27-week-old flock of Hy-line brown-laying hens raised in a cage system. Correlations were evaluated using Pearson’s correlation coefficient (r). The results showed strong correlations between Haugh unit and albumen height, eggshell color CIE L^* and reflectivity, egg weight and width, egg weight and length, eggshell color CIE L^* and CIE a^*, eggshell color CIE a^* and reflectivity, and shape index and egg length (<i>P</i>&lt;0.001). Moderate correlations were observed between eggshell breaking strength and eggshell thickness, eggshell color CIE a^* and CIE b^*, and shape index and egg width (<i>P</i>&lt;0.001). Eggshell color CIE L^* was correlated with eggshell breaking strength (<i>P</i>&lt;0.01), and eggshell color CIE a^* was correlated with Haugh unit, albumen height (<i>P</i>&lt;0.01), and eggshell breaking strength (<i>P</i>&lt;0.001). The present study showed significant correlations between eggshell color and other quality indicators. Thus, this study suggests that eggshell colors based on reflectiveness and the CIE L^*a^*b^* value can be used to estimate the Haugh unit, albumen height, eggshell breaking strength, and thickness.

Dietary Energy and Protein Levels During the Prelay Period on Production Performance, Egg Quality, Expression of Genes in Hypothalamus-Pituitary-Ovary Axis, and Bone Parameters in Aged Laying Hens.

Nutrition during the pre-lay period takes effect on the production performance in the laying flock. This study evaluated the effects of dietary energy and protein levels in pre-lay diet on performance during the whole laying period and the egg quality, bone quality, and mRNA expression of hypothalamus-pituitary-gonadal (HPG) axis-related genes of hens at the end of the laying cycle. A total of 1,856 15-wk old Hy-Line brown pullets were randomly assigned to one of the four dietary treatments: using a 2 × 2 factorial arrangement with 2 energy levels (2,700 and 2,800 kcal/kg ME, respectively) and 2 protein levels (15 and 16.5% CP, respectively). Pullets were fed ad libitum from 15 to 20 wk and from 20 wk onward, fed with a similar laying diet till 72 wk of age. At 72 wk, the expression of genes in the hypothalamus, pituitary, ovarian, and follicles and bone quality was evaluated. At 72wk, there were no differences in production performance, BW, organ index, and ovarian parameters among the dietary treatments. High-CP diet increased the egg shape index and eggshell thickness (p < 0.05), but the eggshell breaking strength, Haugh unit, and albumen height did not differ among the treatments. Neither dietary energy nor protein level took an effect of bone quality. Low-energy diet increased the mRNA expression of gonadotropin-releasing hormone-1 (GnRH-1) in the hypothalamus (p < 0.05). The mRNA expression level of estrogen receptor-1 (ESR-1) in the hypothalamus and ovary was elevated by the 2,700 ME-15%CP diet (p < 0.05). The expression of cytochrome family 17 subfamily A polypeptide 1 (CYP17A1) in the large white follicle (LWF), small yellow follicles (SYF) and dominant follicle (DF) was decreased by the 2,800 kcal/kg diet (p < 0.05). These results indicate that the prelay diet had no influence on the production performance but had minimal effect on the eggshell characteristics and bone parameters. These results suggest that the energy and protein level of the prelay diet changes the expression of HPG axis-related genes of hens around the end of the laying cycle without changing the circulating sex hormone profile. The effect of prelay diet on the endocrinal adjustment at the end of the laying cycle needs to be investigated further.

Rasyona Ham ve Kavrulmuş Elekaltı Fasulye İlavesinin Yumurtlayan Bıldırcınlarda Performansa, Yumurta Kalitesine ve Serum Biyokimyasal Parametrelerine Etkisi

The aim of this study is to examine the effects of using under sieve beans, which is a waste product, as raw and roasted in laying quail diets on performance, egg quality, and serum metabolic profile. For this purpose, a total of 160 female Japanese quails at the age of 70 days were randomly distributed to 8 treatment groups consisting of 4 levels (0, 6, 12 and 18%) under sieve beans and 2 processing techniques (raw and roasted) with 5 replications. Compared to the control group, feed intake and feed conversion ratio were adversely affected by 12% under sieve bean level, and the negative effect was even more pronounced by 18% level. Egg mass and eggshell breaking strength were statistically affected using under sieve beans in the diet and the best results were obtained at the 6% level for these parameters. Eggshell thickness decreased significantly by 12% and 18% sieve bean levels. The serum glucose concentration of quails increased significantly with the use of 18% under sieve beans in the diet, and the serum phosphorus concentration increased significantly with the use of 6% under sieve beans. Egg production, egg mass and feed efficiency and total protein, albumin and phosphorus concentrations of serum were significantly improved by roasting of under sieve beans. The interactions between the under-sieve bean levels and the processing technique only affected the eggshell thickness and serum glucose concentration statistically. According to the results obtained from this study, it has been observed that under sieve beans can be used up to 6% in the diets of laying quails and the roasting process improves performance and serum parameters.

Farklı Seviyelerde Aspir (Carthamus tinctorius L.) Küspesi İçeren Bıldırcın Rasyonlarına Enzim İlavesinin Performans, Yumurta Kalitesi ve Serum Parametrelerine Etkisi

This study was carried out to determine the effects of 0 and 1000 mg/kg multi-enzyme addition to the diets containing different levels (0, 5, 10 and 20%) of safflower seed meal on performance, egg quality and serum parameters in laying Japanese quails. 160 female Japanese quail (Coturnix coturnix Japonica) at 8 weeks of age were used in the study. It was carried out for 84 days with 5 replications in a quail cage with 4 Japanese quails in each of 8 treatment groups consisting of enzyme addition to diets containing different levels of safflower seed meal. In laying quail, the effect of enzyme addition to the diets containing different levels of safflower meal on body weight, body weight change, egg production and feed conversion ratio at the end of the experiment was insignificant. While feed intake was not affected by the addition of enzyme to the diet, feed intake in the group containing 20% safflower meal was significantly higher than the group containing 5% safflower meal, and this group was similar to the other groups. Egg weight and eggshell breaking strength were not significantly affected by the treatments. While the effect of dietary safflower meal levels on egg mass and eggshell thickness was significant, the effect of enzyme addition on eggshell ratio was significant. The effects of treatments on albumen index, yolk index and Haugh unit were insignificant. While a* and b* values in egg yolk colour properties were not significantly affected by the treatments, a significant decrease was observed in L* value with the addition of enzyme to the diet. The effects of treatments on serum glucose, cholesterol, AST, ALT, calcium, and phosphorus concentrations were insignificant. According to the test results, it can be said that 20% safflower meal can be used in laying quail diets without the need for enzyme addition.

Effect of the addition of bee pollen to the diet on performance, eggshell quality and serum parameters in layer quails

This study was carried out to determine the effect of bee pollen addition to quail diets on performance, eggshell quality and serum biochemical properties. In the experiment, 120 quails aged 70 days were randomly distributed to 6 treatment groups with 4 replicates. The quails were fed for 10 weeks with 6 trial diets with 0, 2, 4, 6, 8 and 10 g/kg bee pollen added. The body weight change, egg production, egg weight, egg mass, feed conversion ratio, damaged eggs, eggshell weight, eggshell thickness and serum glucose, creatinine, albumin, globulin and total protein levels of quails were not affected by the addition of bee pollen to the diet (P&gt;0.05). The addition of 10 g/kg bee pollen to the diet significantly decreased feed intake compared to the control group (0 g/kg). Eggshell breaking strength was decreased by adding bee pollen to the diet and the lowest value was observed at the group fed the diet containing 6 g/kg bee pollen.Serum cholesterol concentration was minimized when 10 g/kg bee pollen was added to the diet(P&lt;0.05). In addition, serum calcium and phosphorus contents were increased compared to the control (0 g/kg) group and these parameters reached the maximum at the 10 g/kg bee pollen level (P&lt;0.01).According to the results of the experiment, the addition of bee pollen to the diet had a positive effect on serum cholesterol, calcium and phosphorus levels in layer quails, however, it had a negative effect on eggshell breaking strength.

Effect of hempseed meal on performance, egg quality and egg yolk fatty acids content in laying quails

In this study, the laying performance, external egg quality, egg yolk colour and fatty acids profile of quails (Coturnix coturnix japonica) fed on diets containing hemp seed meal (HSM) were determined. During 8 weeks trial, a total of 150, 10-weeks-old laying quails were used. Five diets were formulated to contain HSM at the level of 0 (control),5, 10, 15, and 20% that represented as 0 HSM, 5 HSM, 10 HSM, 15 HSM and 20 HSM, respectively.The performance parameters were not significantly (P&gt;0.05)influenced by the dietary HSM contents. Eggshell ratio, eggshell breaking strength, egg shape index, egg yolk index and egg yolk colour values were not significantly (P&gt;0.05) influenced by the dietary HSM, whereas eggshell thickness was significantly (P&lt;0.05) affected. The albumen index has been significantly (P&lt;0.05) increased by increasing in the HSM level in the diets. The HSM supplementation to the diets was effective on fatty acid composition and total saturated fatty acids, total mono unsaturated fatty acids and total polyunsaturated fatty acids content of the egg yolk depending on the addition level. In conclusion, HSM can be used to increase egg total monounsaturated fatty acids and especially omega-3 fatty acids without unfavourable effects on the performance and egg quality parameters.

Effect of limestone particle size on performance, eggshell quality, bone strength, and in vitro/in vivo solubility in laying hens: a meta-analysis approach

Numerous publications over the past 5 decades have investigated the effect of limestone particle size (LmPS) on production performance, bone mineralization, and limestone solubilization in laying hens. Coarse limestone particles have been shown to improve eggshell quality and bone mineralization. However, there is a large variability of responses in birds to this factor, indicating the need to better quantify the effect of modulating factors related to coarse particles that could explain this variability. The objective of this meta-analysis was to study the impact of LmPS on the digestive and metabolic fate of Ca to optimize its utilization by laying hens. Fifty-eight papers published between 1971 and 2019, including 71 experiments were included in this study. Four categories of dependent variables were identified: Ca solubility, production performance, eggshell quality, and bone strength. Independent variables tested were LmPS and age. Results showed that the in vitro solubilization of limestone linearly decreased (P < 0.001; R² = 0.91) while in vivo solubilization linearly increased with LmPS (P < 0.001; R² = 0.91). Coarse limestone particles were retained longer in the gizzard (P < 0.001; R² = 0.60), inducing higher solubilization by gastric juices than fine limestone. LmPS showed no effect on production performance while all eggshell quality parameters increased with LmPS (P < 0.001; R² > 0.91): increasing specific gravity by 0.8%, eggshell thickness by 1.1%, and eggshell breaking strength by 3% when increasing from 0.15 mm to 1.5 mm. LmPS had an effect on tibia breaking strength dependently of age (Age × LmPS, P < 0.001; R² = 0.89): coarse limestone particles increased tibia breaking strength with aging compared to fine limestone particles. The current study renders it possible to quantify the effects of age and LmPS on eggshell quality and tibia breaking strength. This work showed an interaction between eggshell quality and bone strength and showed that LmPS increases bone strength in older laying hens.

Myostatin Mutation in Japanese Quail Increased Egg Size but Reduced Eggshell Thickness and Strength.

Simple SummaryAvian eggs provide huge benefits to both science and society by providing an important model for developmental studies and a high-quality protein source for the human diet. Especially, the hard-shell layer existing at the outer part of eggs is a unique characteristic, which is exclusive in avian species compared to other egg-laying species. Among various avian models developed to investigate genetic factors for potential industrial application, myostatin (MSTN) mutations in quail and chickens were recently generated, resulting in improved meat yield. In addition to previously reported growth and egg production traits in MSTN mutant quail, eggshell quality of mutants was further investigated in this study. Although eggshell height, width, and weight were increased by the MSTN mutation, eggshell breaking strength (EBS) and eggshell thickness were decreased in mutant eggs compared to wild-type eggs. Although these data indicated that decreased eggshell thickness contributed to decreased EBS in mutant eggs, the cellular mechanism of thinner eggshell formation in uterus by MSTN mutation needs to be further investigated using MSTN mutant quail.Recently developed myostatin (MSTN) mutant quail and chickens demonstrated similar effects of MSTN on muscle and fat developments between avian and mammalian species. However, the effect of MSTN mutation on the quality of eggshells, an important avian specific characteristic, has not yet been investigated although egg production traits of mutant quail have been studied. In this study, several parameters for eggshell quality, including eggshell size, eggshell weight, eggshell breaking strength (EBS), and eggshell thickness, were all compared between MSTN mutant and wild-type (WT) eggs. MSTN mutant eggs had greater height and width along with heavier eggshell weight compared to WT eggs, which shows proportional improvement in egg size as affected by the MSTN mutation. However, EBS and eggshell thickness were decreased in mutant eggs compared to WT eggs. In addition, the palisade layer, the thickest and most important layer for the strength of an eggshell, was also decreased without a change in the number of vesicular holes. These data indicated that decreases in the thickness of the eggshell and the palisade layer would be a main factor contributing to a lower EBS in mutant eggs. MSTN mutant quail provide a useful model to better understand the function of MSTN on avian uterine cell development and eggshell biomineralization.

Bone and eggshell quality throughout an extended laying cycle in three strains of layers spanning 50 years of selection

Decades of intensive genetic selection in commercial layers has resulted in earlier maturation, while sustaining high production rates to 100 wks of age (woa). To support eggshell formation while maintaining a healthy skeletal frame, substantial adaptations of calcium metabolism in the hen are necessary. Thus, skeletal growth, bone density, and egg quality were compared in 3 strains of layers, with the Lohmann LSL-lite as the current commercial strain, the heritage Shaver white leghorn as the mid-2000s strain, and the white-leghorn derived Smoky Joes as the non-selected 1960s strain. Tibia and Femur (n = 4/strain) were collected at 12, 17, 20, 25, 45, 60, 75, and 100 woa. Bones were measured and weighed, with bone mineral density assessed within medullary (mBMD) and cortical (cBMD) regions of the tibia using micro-Computed Tomography. Egg analyses including weight, eggshell thickness (EST) and eggshell breaking strength (EBS), were conducted throughout lay. Blood samples were collected to measure plasma calcium immediately prior to lay (18 woa) and periodically throughout the laying cycle. Femur and tibia weight, or size, did not increase beyond 12 woa, indicating that all hens reached maximum skeletal size by this time. An interaction (P = 0.005) was observed between strain and tibia mBMD, as all three strains demonstrated an accumulation of medullary bone from 12 to 100 woa. Regarding egg weight, while Lohmann hen eggs displayed the highest quality at 26 woa, an elevation in egg weight in Lohmann and Shaver hens (P < 0.001) resulted in a decline in EST and EBS over time (P < 0.01). Yet, at 100 woa, no strain differed in EST or EBS, despite larger variations in cumulative egg numbers (P < 0.001). Plasma calcium levels were significantly elevated between the immature state and peak of lay but remained unchanged throughout lay in all strains. In conclusion, our results show that although genetic selection of layer hens resulted in tremendous improvement in productivity, no detrimental effects on cBMD or mBMD were observed throughout an extended laying period up to 100 woa.

Role of conventional and split feeding of various limestone particle size ratios on the performance and egg quality of Hy-Line® W-36 hens in the late production phase

As progress is made towards extending the production cycle of the modern laying hen beyond 60 weeks of age, it is vital to develop effective nutritional strategies to sustain egg production and maintain eggshell quality. A 20-week study was conducted to evaluate the effects of feeding various ratios of fine (FL) and coarse (CL) limestone continuously (conventional) or only in the afternoon (split) on egg production and egg quality. The experiment was designed as randomized complete blocks with split plots over hen age. A 2 × 4 factorial arrangement of two feed distribution regimens (conventional and split) and four ratios of fine and coarse limestone (35:65, 25:75,15:85, and 0:100 FL:CL, respectively) were studied. Eight feeding regimens were tested with 4 feeding regimens that received the same diet in the morning and afternoon and the other 4 feeding regimens that received a diet without limestone in the morning but 4 diets with all the added limestone in the afternoon. An interaction was observed between feeding regimens and age of birds for mean eggshell breaking strength (P = 0.044), indicating that the split feeding regimen maintains eggshell breaking strength compared to conventional feeding regimen. There was an interaction (P < 0.001) between limestone particle ratio and age for feed intake indicating that higher amount of feed is consumed when fine limestone is not added to the diet. The main effect of limestone ratio was observed for tibial breaking strength (TBS) (P = 0.026), where the birds fed 35FL:65CL or 25FL:75CL ratio diets had a greater TBS than 15FL:85CL and 0FL:100CL. Split feeding alone was not able to improve the eggshell breaking strength. Therefore, future research should focus on a combined strategy of improved genetics, nutrition, feeding regimen, and management strategy to maintain the eggshell quality in the late production phase.

The impact of different boron levels in diet on performance and eggshell quality of Japanese quails (Coturnix japonica)

This study was carried out to investigate the effects of different levels of boron supplementation on the performance and eggshell quality of 162 breeding quails at 7 weeks of age. For this purpose, 9 different diets with addition of 0, 20, 30, 40, 60, 80, 120, 160 and 240 mg/kg B were used. The experiment was designed at 9 different levels of B, as 3 replicates, on 27 subgroups in total. Each cage compartment was accepted as replicate and 4 female and 2 male quails were placed in each cage. Water and feed are provided as ad-libutum to the quails that are housed in battery-type cages and the lighting was applied continuously. The final body weight (FBW) of the quails, body weight gain (BWG), feed intake (FI), egg production (EP%), egg mass (EM), feed conversion ratio (FCR), egg weight (EW), egg specific gravity (ESG), egg surface area (ESA), eggshell weight (ESW%), eggshell breaking strength (ESBS) values were measured. The effect of the addition of different levels of B to the rations on BW, BWG, FI, EP %, EM and FCR was not statically significant, while effects on EW (p < 0.01), ESG (p < 0.01), ESA (p < 0.05), ESR % (p < 0.01) and ESBS (p < 0.01) was found to be significant. As a result, the 20 mg/kg B addition to the rations was sufficient for a good eggshell quality and performance, and it was observed that higher doses had a negative effect on performance and shell quality in general.

Effect of Production System and Age on Egg Quality Parameters: A Case of Niğde Province Çamardı District, Turkey

This study compared egg quality parameters in layers under free-range system with prefabricated pens and backyard while emphasizing hen age. A total of 300 eggs collected from prefabricated pens and backyard farming families in the Çamardı District of Niğde Province were used as study materials. The assessed external and internal egg quality characteristics included egg weight, shape index, shell thickness, shell breaking strength, albumen index, Haugh unit, yolk index, and yolk colour. The effect of production system on albumen index, Haugh unit, and yolk colour score was found statistically significant. There was a significant effect of age on shape index, shell thickness, shell breaking strength, albumen index, Haugh Unit, yolk index, and yolk colour score. The effect of interaction between age and production system was statistically significant for shape index, shell thickness, yolk index, Haugh Unit, and yolk colour score. It was determined that the egg`s meat and blood spots percentages from the free-range and backyard systems were 10.6% and 15.3%, respectively. It was concluded that while eggs produced from free-range system are superior in terms of egg weight, shape index, and Haugh unit those obtained from backyard hens are higher in eggshell thickness, eggshell breaking strength, and egg yolk colour.