Recent insights into egg quality and larval vitality of the European EEL anguilla anguilla

To date, the eel industry still depends on wild-caught juveniles that are grown to marketable size. There is an urgent need to close the eel life cycle in captivity to make aquaculture independent of the natural population. With this artificial reproduction protocol, yolk-sac larvae can be produced but egg quality may be impaired. Low survival rates and high deformity rates are frequently observed during the first week after hatching. Over the past four years, we have conducted studies with the aim to optimize the artificial reproduction protocol, thereby focussing on increasing egg and larval quality. Weekly carp or salmon pituitary extract (PE) treatment was successfully replaced with recombinant gonadotropins (rGTHs) to mature female eels and produce larvae. 17α,20β-dihydroxy-4-pregnen-3-one (DHP) was replaced with upstream precursor progesterone (P) to induce the endogenous production of DHP by the female eel. DHP and P were found equally potent in inducing oocyte maturation and ovulation. The effects of antibiotics on larval survival and the occurrence of deformities were investigated. Antibiotic treatment increased survival and decreased the occurrence of deformities indicating bacterial infection as an important cause. A deformity determination key for young eel larvae has been developed that provides a framework of reference for larval deformities which will be instrumental with gaining insights on the reasons behind each larval deformity. These improvements of the artificial reproduction protocol and hatchery practices will contribute to the production of robust eel larvae that survive, grow and metamorphose into juveniles that will later be able to reproduce in captivity.

Mulberry branch fiber improved lipid metabolism and egg yolk fatty acid composition of laying hens via the enterohepatic axis

BACKGROUND

The utilization of mulberry branch fiber (MF), the largest by-product of the sericulture industry, is an important issue. Supplementation with MF as a dietary fiber for poultry may serve as a useful application. However, little is known about the effects of MF on liver lipid metabolism and egg yolk fatty acid composition of laying hens and their underlying mechanisms. In this study, we performed a multi-omics investigation to explore the variations in liver lipid metabolism, egg yolk fatty acid composition, gut microbiota, and the associations among them induced by dietary MF in laying hens.

RESULTS

Dietary MF had no harmful effects on the laying performance or egg quality in laying hens. The enzyme activities associated with lipid metabolism in the liver were altered by the addition of 5% MF, resulting in reduced liver fat accumulation. Furthermore, dietary 5% MF induced the variation in the fatty acid profiles of egg yolk, and increased the polyunsaturated fatty acid (PUFA) content. We observed a significant reduction in the diversity of both gut bacteria and changes in their compositions after the addition of MF. Dietary MF significantly increased the abundance of genes involved in fatty acid biodegradation, and short-chain fatty acids biosynthesis in the gut microbiota of laying hens. The significant correlations were observed between the liver lipid metabolism enzyme activities of hepatic lipase, lipoprotein lipase, and total esterase with gut microbiota, including negative correlations with gut microbiota diversity, and multiple correlations with gut bacteria and viruses. Moreover, various correlations between the contents of PUFAs and monounsaturated fatty acids in egg yolk with the gut microbiota were obtained. Based on partial-least-squares path modeling integrated with the multi-omics datasets, we deduced the direct effects of liver enzyme activities and gut bacterial compositions on liver fat content and the roles of liver enzyme activities and gut bacterial diversity on egg yolk fatty acid composition.

CONCLUSIONS

The results indicate that dietary MF is beneficial to laying hens as it reduces the liver fat and improves egg yolk fatty acid composition through the enterohepatic axis. Video Abstract.

Effect of the storage temperature on the quality of eggs inoculated with Salmonella Enteritidis onto shell

This study explored the temperature-dependent effect on the growth characteristics of Salmonella Enteritidis (SE) on eggshell toward identifying an appropriate storage temperature for unwashed eggs in an actual distribution environment. Among the test storage temperatures (10 °C, 25 °C, and 35 °C), 25 °C was determined to be an appropriate storage temperature, with no effect of changing temperature on the control of SE on eggshell. Regarding the effect of the temperature on egg quality, the quality indicators of egg such as Haugh unit, yolk index, albumin index, and albumin pH were significantly maintained. These results indicated that unwashed eggs should be distributed at 25 °C for SE control, and the storage temperature should be below 10 °C from at least day 4 onward after the start of distribution to maintain egg quality. This study will assist for safety management of unwashed egg in an actual distribution environment.

Cold atmospheric pressure air plasma jet disinfection of table eggs: Inactivation of Salmonella enterica, cuticle integrity and egg quality

Eggshell cuticles are first lines of defense against egg-associated pathogens, such as Salmonella enterica serovar Enteritidis (SE). Infections from eggs contaminated with this strain remain a significant risk. In addition, changes in the cuticle are closely related to changes in egg safety. The emerging non-thermal atmospheric pressure plasma technology enables a high rate of microbial inactivation at near-ambient temperatures, making it ideal for food safety applications. This study examines the effects of a cold atmospheric pressure air plasma jet (CAAP-J) on eggshell cuticle and egg quality whilst inactivating SE. Shell eggs inoculated with SE (7 log10 cfu/egg) were used as the samples to test the decontamination performance of the device. The tests were conducted using an industrial CAAP-J with different power levels (600-800 W), exposure times (60-120 s), at a fixeddistance of 20 mm from the plasma jet and an air flow rate of 3600 L/h. It was found that the best results were obtained after 120 s at maximum plasma power (800 W). Subsequent to the implementation of this plasma procedure, it was determined that no viable cells could be detected. After CAAP-J treatment, the temperature remains below 50.5 °C, thereby minimizing the risk of altering egg quality. All specific measurements (egg white pH, yolk pH, yolk color, HU, and eggshell breaking strength) have shown that CAAP-J treatment has no negative effect on egg quality. No changes in eggshell cuticle quality after CAAP-J treatment was confirmed through scanning electron microscope (SEM).

Dietary flaxseed cake influences on performance, quality, and sensory attributes of eggs, serum, and egg trace minerals of laying hens

Nowadays, there is a global shortage in feed supply for animal nutrition; however, there are a considerable amount of agro-industrial co- and by-products that may offer a reasonable solution. Flaxseed cake (FSC) is a by-product of flaxseed for oil extraction rich in n-3 α-linolenic acid (ALA). Thus, the dietary inclusion of FSC on laying performance, egg quality, and serum and egg trace elements (Se, Zn, and Fe) was evaluated using Hisex White hens. The hens were distributed to three equal experimental treatments and provided diets including 0%, 5%, or 10% FSC from 48 to 58 weeks of age. Findings clarified that up to 10% FSC in the laying hen diet had no detrimental effect on laying rate, egg mass, and feed utilization. It was found that FSC resulted in a valuable source of protein, energy, macro- (Ca and P), micro- (Se, Zn and Fe) elements, and essential amino acids, with arginine being the highest. Dietary FSC did not negatively influence the egg quality traits, as well as egg sensory attributes. Including 5% or 10% FSC in diet did not significantly affect serum total protein and renal function in terms of creatinine, uric acid, and uric acid-to-creatinine ratio. Different FSC levels did not influence the chemical composition of eggs and trace elements in serum and eggs. It could be concluded that FSC is a valuable feedstuff that can provide a good source of energy, protein, amino acids, and macro- and micro-elements for hens' nutrition. The inclusion of up to 10% of FSC in hens diet did not adversely influence egg laying performance, egg quality of both fresh and stored eggs, sensory attributes, and nutritional composition, as well as Se, Zn, and Fe in serum and eggs due to balanced nutrient profile of FSC.

Impact of the mites Dermanyssus gallinae and Tyrophagus putrescentiae on production and health of laying hens

Mites are considered a threat to the commercial poultry industry due to their direct and indirect pathogenic effects. Dermanyssus gallinae is among the mite species that endanger production, as it is hematophagous and poses a serious sanitary risk. Recently, Tyrophagus putrescentiae has also drawn attention as a potential pest in the poultry industry, and its attacks have been related to clinical symptoms such as cutaneous eruptions and bird restlessness. Considering the potential economic, sanitary, and productive losses both species represent to the laying-hen industry, the aim of the present study was to evaluate the influence of D. gallinae and T. putrescentiae on the health and productivity of commercial laying hens by carrying out infestation experiments and by monitoring laying hens for a period of 60 days. Tyrophagus putrescentiae and D. gallinae affected egg quality and zootechnical parameters in laying hens. Hens infested by T. putrescentiae had behavioral changes, weight loss, stress symptoms, and decreased egg laying and quality, as well as diarrhea, gradual feather loss, and itching. Hens infested by D. gallinae also had weight loss, behavioral changes, and stress symptoms, leading to decreased laying and egg quality. The present study proposes an experimental model to understand the impacts caused by T. putrescentiae and D. gallinae on commercial laying production and egg quality parameters.

Effects of dietary supplementation with Radix Isatidis polysaccharide on egg quality, immune function, and intestinal health in hens

This study aimed to investigate the effects of supplementing laying hen diets with Radix Isatidis Polysaccharide (RIPS) on egg quality, immune function, and intestinal health. The research was conducted using 288 Hyland Brown hens, which were randomly assigned to four dietary treatments: control (without RIPS), low dose (200 g/t), medium dose (500 g/t), and high dose (1000 g/t) of RIPS. Each dietary treatment was administered to eight replicates of nine hens for nine weeks. The results revealed that RIPS inclusion in diets significantly improved egg quality parameters such as egg shape index, yolk color, haugh unit, and protein height (P < 0.05). Additionally, RIPS supplementation enhanced immune function as evidenced by an alteration in serum biochemical parameters, an increase in the spleen index, and a decrease in the liver index. Further, an evaluation of intestinal health showed that RIPS fortified the intestinal barrier, thus increasing the population of beneficial intestinal bacteria and reducing the abundance of harmful ones. Such mechanisms promoted intestinal health, digestion, and nutrient absorption, ultimately leading to enhanced egg quality. In conclusion, supplementing laying hen diets with RIPS has been demonstrated to improve egg quality by boosting immunity and optimizing intestinal digestion and absorption.

Dietary pyrroloquinoline quinone improvement of the antioxidant capacity of laying hens and eggs are linked to the alteration of Nrf2/HO-1 pathway and gut microbiota

Pyrroloquinoline quinone disodium (PQQ·Na2) has been considered a human food supplement for human health promotion with its antioxidant properties. To determine whether PQQ·Na2 had similar functions to improve the antioxidant ability of layers and eggs, 180 laying hens were fed with 0 or 0.4 mg/kg PQQ·Na2 diets. Supplementation with PQQ·Na2 increased the albumen height, Haugh unit of the eggs. PQQ·Na2 also led to a higher glutathione peroxidase (GSH-Px) concentration in plasma and a lower malondialdehyde (MDA) content in the liver and egg yolk. Similarly, liver gene and protein expression of nuclear factor erythroid 2-related 2 (Nrf2) and heme oxygenase 1 (HO-1) were up-regulated by PQQ·Na2. Moreover, PQQ·Na2 increased the abundance of Firmicutes, Microbacterium, Erysipelatoclostridium, Mailhella, Lachnospiraceae_UCG-010, and Herbaspirillum in gut. Overall, these results suggested PQQ·Na2 increased the antioxidant ability of layers and eggs which might be in connection with the activation of the Nrf2/HO-1 pathway and optimized gut microflora.

Effects of algal supplementation in feed to broiler breeders on transfer of nutrients and antibodies to chicks and quality of hatchlings

Breeder nutrition is an important factor for chick quality since the chick embryo relies on nutrients available in the egg for growth and development. In addition, the egg is providing the chick with important antibodies that are vital during the first weeks of life. Brown algae contains several bioactive compounds, and dietary supplementation with algal extracts have shown improved gut health and immune responses in both pigs and poultry. The aim of this study was to investigate if feeding the brown algae Saccharina latissima, intact or as an extract, to broiler breeders can affect breeder hens' antibody responses to vaccination, egg quality and transfer of antibodies and nutrients to the egg and thereby improve the quality of newly hatched chicks. Forty-five hens and nine roosters of the parent lines of the fast-growing broiler Ross 308 were included in the experiment where hens were 31 weeks at the start. The hens were housed individually and fed one of three dietary treatments for seven weeks; (a) control, (b) addition of 0.6% algal meal or (c) addition of 0.08% algal extract. The hens were given a booster vaccination against infectious bronchitis virus (IBV) 21 days after the start of experiment. During experimental days 32-42, hens were naturally mated every 5th day and hatching eggs were collected. A total of 255 chicks were hatched, and chick quality was assessed. Moreover, on chick day three, blood was collected from 48 focal chickens and total immunoglobulin Y levels and specific titres to IBV in serum were determined. The results showed that feeding the brown algae Saccharina latissima, intact or as an extract to broiler breeders did not affect egg production, egg quality, antibody responses to vaccination or transfer of antibodies from hen to chick. However, feeding intact algae significantly increased the levels of iodine and decreased the level of selenium in the eggs and resulted in a lower proportion of chicks with maximum quality score. Interestingly, algal feeding, both intact and as an extract, increased the abdominal fat pad in broiler breeders by about 17% without affecting BW. In conclusion, supplementation of broiler breeder diets with algal extract from Saccharina latissima, but not intact algal meal is a promising dietary strategy to increase the abdominal fat pad without causing any adverse effects on nutrient level in eggs or chick quality.

Genome-wide association study exploring the genetic architecture of eggshell speckles in laying hens

BACKGROUND

Eggshell speckle phenotype is an important trait in poultry production because they affect eggshell quality. However, the genetic architecture of speckled eggshells remains unclear. In this study, we determined the heritability of eggshell speckles and conducted a genome-wide association study (GWAS) on purebred Rhode Island Red (RIR) hens at 28 weeks to detect potential genomic loci and candidate genes associated with eggshell speckles.

RESULTS

The heritability of eggshell speckles was 0.35 at 28 weeks, and the speckle level is not related to other eggshell quality traits in terms of phenotypic correlation. We detected 311 SNPs (6 significantly, and 305 suggestively associated) and 39 candidate genes associated with eggshell speckles. Based on the pathway analysis, the 39 candidate genes were mainly involved in alpha-linolenic acid metabolism, linoleic acid metabolism, ether lipid metabolism, GnRH signaling pathway, vascular smooth muscle contraction, and MAPK signaling pathway. Ultimately, ten genes, LOC423226, SPTBN5, EHD4, LOC77155, TYRO3, ITPKA, DLL4, PLA2G4B, PLA2G4EL5, and PLA2G4EL6 were considered the most promising genes associated with eggshell speckles that were implicated in immunoregulation, calcium transport, and phospholipid metabolism, while its function in laying hens requires further studies.

CONCLUSIONS

This study provides new insights into understanding the genetic basis of eggshell speckles and has practical application value for the genetic improvement of eggshell quality.

Feeding laying hens with lactobacilli improves internal egg quality and animal health

Feeding animals with lactobacilli strains is a biotechnological strategy to improve production, food quality, and animal health. Thus, this study aimed to select new lactic acid bacteria (LAB) able to improve laying hens health and egg production. Forty Bovans White layers (two days old) were randomly divided into four experimental groups that receive an oral gavage with saline solution (control group) or with one of the three lactobacilli selected (KEG3, TBB10, and KMG127) by their antagonistic activity against the foodborne pathogen Bacillus cereus GGD_EGG01. 16 S rRNA sequencing identified KEG3 as Lentilactobacillus sp., and TBB10 and KMG127 as Lactiplantibacillus sp. The data showed that feeding birds with LAB increased weight uniformity and improved the internal quality of the eggs (high yolk index and Haugh unit) compared with the control group (p < 0.05). Beta-diversity analysis showed that LAB supplementation modifies the cecal microbiota of laying hens. The prokaryotic families Bacteroidaceae, Ruminococcaceae, Rikenellaceae, and Lactobacillaceae were most important to the total dissimilarity of the cecal microbial community (calculated by SIMPER test). At end of in vivo experiments, it was possible to conclude that the feed of laying hens with Lentilactobacillus sp. TBB10 and Lentilactobacillus sp. KEG3 can be an important biotechnological tool for improving food quality and animal health.

Acceleration of gonadal maturity of female striped catfish, Pangasianodon hypophthalmus (Pisces, Pangasiidae) by irradiation to low-power soft-laser

This study was aimed to investigate the effects of red photodiode soft-laser irradiation on gonadal maturity and egg quality of female striped catfish, Pangasianodon hypophthalmus. Four female striped catfish (weighing 700-800 g) at stage I of gonadal maturation (for all treatments) were exposed four times (once a week) to different doses (0.2, 0.4, 0.6, and 0.8 J/cm2) of red photodiode soft-laser in the reproductive acupoint. Doses of 500 IU and 0.5 mL per kg body weight of human chorionic gonadotropin (hCG) and Ovaprim™, respectively were injected intramuscularly at week 4 (positive control), and no treatment (negative control). Finally, gonadal maturation stage (GMS), gonadosomatic index (GSI), hepatosomatic index (HSI), fecundity, and egg diameter were measured at week 5. The results showed that red photodiode soft-laser irradiation of 0.4 J/cm2 dose accelerated GMS IV at early week 3 (100 %) and increases GSI (3.42 %), HSI (1.26 %), fecundity (67,665 eggs/body weight), and egg diameter (1.01 mm) compared to the other treatments. Treatments of 0.2, 0.6, and 0.8 J/cm2 doses, and positive and negative controls only reached GMS III (75 %), III (25 %), I (100 %), II (25 %), and I (100 %), respectively. GSI values were 2.20 %, 1.47 %, 0.93 %, 0.44 %, and 0.42 %, respectively and HSI values were 1.07 %, 0.85 %, 0.7 7%, 0.66 %, and 0.53 %, respectively. Females irradiated with doses of 0.2 and 0.6 J/cm2 had fecundities of 38,822 and 29,530 eggs/body weight, respectively, and egg diameters of 0.88 and 0.29 mm, respectively. These results suggest that a red photodiode soft-laser irradiation accelerates gonadal maturity and improves egg quality in female striped catfish.

Artificial reproduction of the indoor-cultured brackish form of maraena whitefish (Coregonus maraena) under recirculated aquaculture system (RAS) conditions

Maraena whitefish (Coregonus maraena) is a promising coldwater aquaculture species, especially in terms of meat quality. This versatile whitefish species, which inhabits both fresh and brackish waters, including the Baltic Sea, offers promising prospects for aquaculture breeding and cultivation. However, the main problem is the lack of availability of spawners of this species. Therefore, in this study, an attempt was made to raise the spawning stock under controlled conditions and then artificially reproduce the fish to obtain high-quality gametes and then larvae. The conducted research showed that successful culture of maraena whitefish spawners is possible under recirculating aquaculture system (RAS) conditions. The application of proper nutrition and manipulation of environmental conditions allowed the breeding of sexually mature whitefish spawners in less than two years in captivity (meat weight 476 g). Through stimulation of environmental conditions (temperature and photoperiod), it was possible to stimulate the final maturation of gametes of the F1 generation of cultured fish. The use of Ovaprim hormonal stimulation induced 100% of females to ovulate within 10 days of injection, compared to 60% of females in the control group. Additionally, the other examined parameters, such as the pseudogonado-somatic index (PGSI: 11.46% vs. 6.80%), fertilization rate (94.2% vs. 60.1%), embryo survival rate (92.6% vs. 41.1%) and embryo survival rate to the eyed-egg-stage (90.0% vs. 28.0), were significantly higher in the hormonally induced group, finally two times and three times, respectively. The mortality rate of spawners, after spawning and within three months of artificial spawning, was extremely low. The results obtained from the study demonstrate the feasibility of culturing the spawning stock of maraena whitefish in captivity and successfully inducing artificial spawning.

The efficacy of polyphenols as an antioxidant agent: An updated review

Global production of the two major poultry products, meat and eggs, has increased quickly. This, in turn, indicates both the relatively low cost and the customers' desire for these secure and high-quality products. Natural feed additives have become increasingly popular to preserve and enhance the health and productivity of poultry and livestock. We consume a lot of polyphenols, which are a kind of micronutrient. These are phytochemicals with positive effects on cardiovascular, cognitive, anti-inflammatory, detoxifying, anti-tumor, anti-pathogen, a catalyst for growth, and immunomodulating functions, among extra health advantages. Furthermore, high quantities of polyphenols have unknown and occasionally unfavorable impacts on the digestive tract health, nutrient assimilation, the activity of digestive enzymes, vitamin and mineral assimilation, the performance of the laying hens, and the quality of the eggs. This review clarifies the numerous sources, categories, biological functions, potential limitations on usage, and effects of polyphenols on poultry performance, egg composition, exterior and interior quality traits.

Comparative evaluation of different moulting methods on productive performance, egg quality, and antibody response of leghorn hens

The aim of the study was to compare three moulting procedures and their effect on productive performance, egg quality, and antibody response of leghorn hens. For this, a total of 324 laying hens were distributed into three treatment groups having 12 replicates of 9 birds each according to completely randomized design. Treatments consisted of three moulting procedures based on feed and light restriction. The targeted weight at the end of moulting was 1450-1470 g. As soon as the moulting procedure is complete, the comparative analysis of post-moult productive performance (feed intake, egg production, egg weight, egg mass, feed per dozen eggs, feed per kg egg mass, livability), egg quality characteristics (egg weight, egg length and width, shape index, surface area, volume, albumen height, weight, Haugh unit score, yolk width, height, index, egg shell pore number, shell weight, thickness, breaking strength), and antibody response against Newcastle disease and avian influenza (H-9) were evaluated. Birds subjected to moulting procedure 3 (8 days fasting and gradual decrease in light) showed improvement in productive performance, egg geometry and quality traits, and antibody response against Newcastle disease virus. Birds experienced moulting procedure 1 (11 days fasting) had improved feed intake, egg production, and livability. However, birds moulted with procedure 2 (6 days fasting) revealed intermediate result in all the studied parameters. In conclusion, moulting through feed and light restriction with 8 days fasting and gradual reduction in light has potential to improve performance of leghorn hens.

Effect of rosemary (Rosmarinus officinalis) leaf meal supplementation on production performance and egg quality of laying hens

This experiment was conducted to investigate the supplemental effect of rosemary leaf meal (RLM) on egg production and egg quality in Lohmann-Brown laying hens. For each treatment, six replicates were performed with four 24-week-old laying hens for a total of 96 chickens. Dried rosemary leaf meal (RLM) was present in the commercial laying hen ration at 0, 1.7, 3.5 and 5.2%, respectively. The interactions between dietary treatments, egg storage temperatures (4 °C, 21.5 °C), and egg storage durations (7, 14, 21, 28, and 35 days) were examined in factorial designs using a fully randomized design. The data were analyzed using the Statistical Analysis System (SAS, 2014, Ver. 9.3) and Tukey's multiple range tests to separate the means. The inclusion of dried RLM at a level of 5.2% (p < 0.05) significantly improved the hens' daily egg production (78.9%). Feed conversion ratio (2.25) and egg weight (56.7 g) compared to control treatment. Similarly, at 3.5% and 5.2% RLM supplementation, eggshell weight (5.876 g) and eggshell strength increased significantly (p < 0.05) (compared to control, a weight of 3.76 kg/cm2 and a shell thickness (0.37 mm) was observed. In addition, the groups fed 5.2% RLM had significantly higher albumin weight (34.9 g/L), albumin height (6.9 mm), and yolk weight (15.6 g/L). l), yolk height (15.9 mm), yolk color (5.3 points), and Hough unit (83.9 points) than the control groups. Regarding the external characteristics of stored eggs, a group of hens fed at rates of 3.5 and 5.2% RLM showed significantly greater (p < 0.05) egg weight with increases in storage temperature and duration as a control group. There was a significant interaction effect between stored eggs collected from the supplemented groups in terms of egg weight, weight loss, shell weight, shell strength, and shell thickness stored at specific temperatures and storage durations. There was a decrease in albumen level and Haugh unit (HU) with an increase in storage temperature and duration over treatment (P < 0.05). Therefore, better external quality was observed in eggs collected from a group of chickens fed 4.5 and 5.2% RLM after 35 days of storage compared to a control group. Mean albumen height, albumen weight, HU, yolk height, and yolk color of eggs stored in the refrigerator (4 °C) were an exception for yolk weight, which was higher compared to room temperature (21.5 °C). Significantly low (P < 0.05) albumen height (6.61 to 2.96 cm), Hough unit (82.49 to 47.64 points), and yolk height (14.66 to 12.35 mm) were observed at 35 days storage recorded in the control group. In conclusion, supplementation with RLM at 3.5% and 5.2% improved the performance and quality of both fresh and stored eggs.

A study on egg quality and hatching traits of indigenous and exotic chickens reared in Silte zone, Southern Ethiopia

The objective of this study was to evaluate egg quality and hatchability of indigenous and exotic chickens in the midland, lowland, and highland agroecological zones of the Silte zone. One district was selected from each agroecological zone, and a total of 399 households (133 from each district) were randomly chosen from six purposefully selected Kebles to collect data on egg hatchability. For external and internal egg quality evaluation, 300 eggs (150 from indigenous and 150 from exotic chickens from each agroecology) were collected. The study found that Sasso chickens had better egg quality in terms of egg weight, yolk width, yolk height, albumen height, yolk index, and Haugh unit compared to indigenous chickens in both the highland and lowland areas. In the highland area, Sasso chickens had higher values for egg weight, yolk width, yolk height, albumen height, yolk index, and Haugh unit compared to the lowland area. This suggests that Sasso chickens performed better in terms of egg quality in both the highland and lowland areas compared to indigenous chickens. The hatchability percentages of Sasso and Koekoek chickens were 70.8 ± 14.1 and 69.7 ± 12.7, respectively, in the midland area. This suggests that Sasso and Koekoek chickens performed well in terms of hatchability, followed by indigenous chicken eggs. However, approximately 68% of respondents did not use exotic chicken eggs for hatching. The study suggests that practicing hatching of exotic chicken eggs could be beneficial in increasing the productivity of indigenous chickens.

Lipid profiles and production performance responses of laying hens to dietary Moringa oleifera leaf meal: systematic review and meta-analysis

The inclusion of Moringa oleifera leaf meal (MLM) in chicken diets especially in developing countries is on the increase due to scarcity of traditional feedstuffs. Therefore, this investigation aimed to explore the effects of MLM on lipid profiles and production characteristics of laying hens. Twenty-three publications retrieved from Web of Science, PubMed, Scopus and Google Scholar search engines were used for the analysis. Data from the 23 studies were analysed using random-effects model in OpenMEE software. Results were presented as standardised mean difference (SMD) at a 95% confidence interval. The results show significant improvement in feed conversion ratio (SMD =  - 0.49; p < .001), egg mass (SMD = 0.35; p = .003), Haugh unit (SMD = 0.39; p < .001), eggshell thickness (SMD = 0.63; p < .001) and eggshell weight (SMD = 0.45; p < .001) at a reduced feed intake. On the other hand, egg weight, hen-day egg production and blood high-density lipoprotein cholesterol were not statistically different from controls. Results reveal that dietary MLM enhanced blood cholesterol, low-density lipoprotein (LDL) cholesterol, triglycerides and yolk cholesterol concentrations in laying hens. There is presence of significant heterogeneity and meta-regression revealed that study country, number of hen, housing system, hen age, inclusion level and layer strains were predictors of the treatment effect. In conclusion, the results of this meta-analysis suggest that inclusion of MLM in the diet of laying hens improved feed conversion ratio, aspects of egg quality and blood/yolk cholesterol concentrations in laying hens at a reduced feed intake.

Quality of fish eggs and production of androgenetic and gynogenetic doubled haploids (DHs)

Induced development of haploid embryos (H) with only paternal (androgenesis) or maternal (gynogenesis) chromosomes requires irradiation of eggs before fertilization or activation of eggs with irradiated spermatozoa, respectively. To provide doubled haploids (DHs), androgenetic and gynogenetic haploid zygotes need to be subjected to the thermal or high hydrostatic pressure (HHP) shock to suppress the first mitotic cleavage and to double paternal or maternal haploid set of chromosomes. Androgenesis and mitotic gynogenesis (mito-gynogenesis) result in the generation of fully homozygous individuals in a single generation. DHs have been utilized in selective breeding programs, in studies concerning the phenotypic consequences of recessive alleles and to evaluate the impact of sex chromosomes on the early ontogeny. Moreover, the use of DHs for the NGS approach radically improves de novo the assembly of the genomes. However, reduced survival of the doubled haploids limits the wide application of androgenotes and gynogenotes. The high mortality of DHs may be only partly explained by the expression of recessive traits. Observed inter-clutch variation in the survival of DHs developing in eggs originating from different females make it necessary to take a closer look at the quality of the eggs used during induced androgenesis and gynogenesis. Moreover, the developmental competence of eggs that are subjected to irradiation before fertilization in order to deactivate maternal chromosomes when undergoing induced androgenesis and exposed to the physical shock after fertilization that leads to the duplication of the zygotes in both mito-gynogenesis and androgenesis may be also altered as irradiation and sublethal values of temperatures and hydrostatic pressure are considered as harmful for the cell organelles and biomolecules. Here, recently provided results concerning the morphological, biochemical, genomic, and transcriptomic characteristics of fish eggs showing high and low competence for androgenesis and mito-gynogenesis are reviewed.

Effects of Zinc, Manganese, and Taurine on Egg Shell Microstructure in Commercial Laying Hens After Peak Production

Much strive has been made to improve egg shell quality in laying hens. This study was conducted to evaluate the effects of two microminerals, zinc and manganese, besides taurine semi-essential amino acid on eggshell quality after peak production of Hy-line laying hens. A total of 720 laying hens were assigned to 18 treatments in a completely randomized design (3 × 3 × 2 factorial) at week 71. Experimental period included 8-week adaptation and using 18 dietary treatments for about 6 weeks. Dietary treatments included Zn (0, 80, and 160 mg/kg), Mn (0, 90, and 180 mg/kg), and taurine (0 and 1960 mg/kg). Supplementation of 90 mg Mn and 1960 mg taurine in laying hens' diet after peak of production improved egg shell quality without any negative effect on the internal quality of the egg. Egg specific gravity significantly increased in response to Zn, Mn, and taurine in comparison with control treatment (P < 0.05). Applying 1960 mg taurine/kg diet significantly improved calcite crystal's structure and eggshell strength in comparison with control treatment (P < 0.05). It was concluded that adding Mn and taurine can positively affect eggshell quality of laying hens post peak period.

The use of purple carrot powder in the diet of laying quails improved some egg quality characteristics, including antioxidant capacity

The goal of the current experiment was to investigate the effect of dietary concentrations of purple carrot powder (PCP) on performance, egg production, egg quality, and the antioxidant capacity of the yolk in laying quails. A total of one hundred and fifty 22-week-old Japanese laying quails were allotted to 5 dietary treatments each with 6 replicates of 5 quails. Quails were allocated to five dietary treatments (0, 0.1, 0.2, 0.3, and 0.4%) with PCP addition at an increasing level from 0 to 4000 mg/kg diet respectively, which were fed ad-libitum throughout the duration of the experiment. No differences were detected between dietary treatments for any of the performance parameters or egg production. Eggshell weight and eggshell thickness (P < 0.05) were linearly affected by PCP dietary, reaching maximum levels at 0.4% of PCP supplementation, while the percentage of damaged egg and egg-breaking strength remained similar for all experimental groups (P < 0.05). Quails receiving PCP diets showed a yellowness (b*) (P < 0.05) egg yolk color than those fed the control diet, without affecting the rest of the color parameters and egg internal quality. Increasing PCP levels in diets reduced linearly yolk TBARS (P < 0.01) and increased linearly DPPH (P < 0.01). The addition of PCP, a safe and readily available agricultural by-product, as a component of the diet of laying quail was effective without adversely affecting quail production. Moreover, the inclusion of PCP in the diet might benefit laying quails' eggs by improving some quality traits and enhancing the yolk's antioxidant capacity, which could improve their shelf-life and acceptability.

Assessment of variations in productive performance of two different plumage color varieties of Japanese quail and their reciprocal crosses

This study aimed to detect the phenotypic differences between the brown (BB) and white (WW) feathered quails and their reciprocal crosses (BW and WB) over two successive generations. The WW and cross quails, especially the BW, had the heaviest body weights, throughout the studied period, with significant variations between the two studied generations (P<0.05). Moreover, the WW and BW possessed the largest egg production during the F1, while in the F2, the BB had superiority among the studied quails with a prominent superiority of the F2 over the F1 (P<0.05). However, the F1 had higher egg weights than F2 with superiority of WW quails compared to the others (P<0.05). Also, the WW quails had the lowest lipid contents of the eggs. These phenotypic variations among the studied quails might be preliminarily explained by the results of the analyzed microsatellite markers despite the few markers used. The high variability among the BW and WB quails might be due to the larger number of alleles (N_A and N_e) and the lower values of F_IS with low heterozygosity levels (H_O and H_e). Moreover, the BW and BB were the closest, while WB and WW were the farthest because of the high and low genetic identities and the high and low genetic distance between them, respectively. So the obtained results might introduce an initial scientific basis for evaluating and employing the genetic properties of BB, WW, BW, and WB quails in further genetic improvement program, and more microsatellite markers are recommended.

Effect of adding lavender oil to laying quail diets on performance, egg quality, oxidative status, and fatty acid profile

This study aims to investigate the effects of lavender essential oil on performance, egg quality parameters in quails, malondialdehyde (MDA) in fresh and stored (28 days at ₊4°C) eggs, and individual and total fatty acids. To this end, 100 female quails (Coturnix coturnix Japonica) which were 5 weeks old with an average weight of 224 g were used. The study lasted 45 days, including 10 days of introduction and 35 days of study. Quails were fed ad libitum with four different treatments. Four groups were formed as control groups (0g lavender essential oil/kg feed), Lav125 (125mg lavender essential oil/kg feed), Lav250 (250mg lavender essential oil/kg feed), and Lav500 (500mg lavender essential oil/kg feed). There were five subgroups under each group and five quails in each subgroup. Feed consumption and egg weight parameters increased in Lav500 group compared to the control group (p<0.05). The highest egg yield compared to the control group was determined in Lav500 group (p>0.05), and the highest egg mass compared to the control group was determined in Lav125 group. The highest feed conversion ratio compared to the control group was in Lav250 group (p>0.05). In addition, egg white height and Haugh Unit (HU) compared to the control group were the highest in Lav500 group (p<0.05). The MDA concentration decreased in Lav125 and Lav250 group in fresh and in Lav500 group in stored eggs (at +4C for 28 days) compared to the control group (p<0.05). Omega 3 fatty acids in fresh and stored eggs were higher in lavender groups compared to the control group (p<0.05). However, the concentration of omega 9 (oleic acid) fatty acid decreased in the lavender groups compared to the control group (p<0.05). As a result, it was found that adding lavender essential oil to the diet leads to an increase in body weight, egg yield, egg mass, egg weight, egg white height, HU, omega 3 fatty acids, and a decrease in MDA concentration.

rotundum) leaves on laying performance, egg quality characteristics, and oxidative stability in laying hens

This study aimed to examine the effect of dietary supplementation of dried wild leek (Allium scorodoprasum L. subsp. rotundum) leaves on laying performance, egg traits, antioxidant status, and oxidative stability in laying hens. For this purpose, a total of 96 Lohmann White laying hens aged 22 weeks allocated into four treatment groups each containing 24 hens. Hens were fed a diet supplemented with 0 (control), 1 (WL1), 2 (WL2), and 3 (WL3) g/kg dried wild leek (DWL) leaves. During the 10-week trial, egg weight was increased and feed efficiency was improved with 2 and 3 g/kg DWL leaves. No significant differences were observed among groups for egg production, feed intake, internal and external egg quality characteristics, and egg yolk cholesterol concentration. Levels of malondialdehyde and total antioxidant-oxidant status of egg yolk were not affected from DWL supplementation. However, 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity was increased and oxidative stress index was decreased in egg yolk. Superoxide dismutase enzyme activity was increased in the group of WL3, and total antioxidant status levels were increased in the groups of WL2 and WL3 in serum. DWL supplementation reduced serum cholesterol concentration significantly. No marked changes were observed in other blood parameters. In conclusion, DWL is considered to be high antioxidant supplement due to having high antioxidant capacity and important bioactive compounds. Dietary supplementation of DWL leaves at 3 g/kg could be a viable and beneficial feed additive to improve egg weight and feed efficiency, increase DPPH radical scavenging activity in egg yolk and antioxidant status of hen. Therefore, the usage of DWL leaves in the laying hen diets will be beneficial for egg producers and poultry nutritionists to produce functional eggs having low cholesterol and high antioxidants.

Reuse of vegetable wastes in animal feed: the influence of red beet powder supplementation on performance, egg quality, and antioxidant capacity of layer quails

The survey was carried out to establish the impact of red beet powder (RBP) on performance parameters and egg quality in laying quails. One twenty hundred (120) female laying quails aged 22 weeks were randomly assigned into five groups of 4 females each, and six replicates. Treatments diets were formed by adding 0, 0.2, 0.4, 0.6, and 0.8% RBP to the basal diet. The dietary inclusion of RBP did not affect performance parameters and egg production (P > 0.05) except feed conversion ratio, which was quadratically affected (P < 0.05). The feed conversion ratio was improved in the 0.4% group with concerning control. The inclusion of RBP did not modify the yolk color (L*, a*, b*) or egg quality (P > 0.05). However, the yolk index showed the highest value (P < 0.05) in quails fed 0.2% RBP. Free radical scavenging capacity (DPPH) of the yolk decreased (P < 0.05) when RBP levels increased above 0.6%. In contrast, the 0.6% RBP group had the highest level of thiobarbituric acid reactive substances (TBARS). Data from the present study provide valuable information to include RBP as an ingredient without affecting performance and egg production. It is an interesting option within the framework of the circular economy and of reusing vegetable products to use this ingredient in animal feed.

Genetic parameters for production, quality, and colors from eggs in Brazilian lineages of chickens

Genetic parameters were estimated for egg production, egg quality, and eggshell colors in eight lineages of Brazilian laying hens. Age at first egg (AFE), total egg production up to the 45th week (PROD), egg weight (EW), albumen height (AH), yolk color (YC), the Haugh units (HU), eggshell strength (ESS), eggshell thickness (EST), yolk weight (YW), eggshell weight (ESW), and eggshell color (L*, a*, and b*) were measured in 2030 eggs obtained from 645 laying hens. Variance components were estimated from a mixed animal model, which included the fixed effects of contemporary groups, cage location, and hen line, and the additive genetic, permanent environmental, and residual as random effects. In general, heritabilities were low to moderate (h² = 0.11 to 0.48). Genetic correlations among eggshell quality traits were moderate to high (0.36 and 0.69). High genetic correlations were obtained between the eggshell color traits [r_g = -0.90 (L* and a*); r_g = -0.64 (L* and b*); and r_g = 0.65 (a* and b*)]. Results suggest that EW is strongly correlated with ESW, but the genetic correlations between EW and ESS and between EW and EST were low. Genetic correlations between L* and eggshell quality traits were low to moderate, suggesting that L* has little or no relation with external egg quality. However, genetic correlations between a* and b* values and eggshell quality traits were high. The genetic correlations between eggshell color and eggshell quality traits were low, suggesting that the eggshell color does not influence external egg quality. Genetic correlations between PROD and egg quality traits were negative and varied between -0.42 and -0.05. This antagonistic relationship emphasizes the importance of adopting breeding schemes that allow the simultaneous genetic progress of these traits by considering their genetic correlation and economic relevance, such as the selection index.

RNA binding proteins are potential novel biomarkers of egg quality in yellow catfish

BACKGROUND

Egg quality is a major concern in fish reproduction and development. An effective evaluation of egg quality prior to fertilization is helpful in improving the fertilization rate and survival rate of the larva. In this study, we aim to identify quality instructors from the combination study of fertilization rate, hatching rate, embryo malformation rate and gene expression profile.

RESULTS

Eggs from 25 female fish were fertilized with sperm from the same fish. The egg quality was determined by the fertilization rates, hatching rate and embryo malformation rate and divided into three categories, low-quality (< 35%), medium-quality (35 to 75%), and high-quality (> 75%). Due to the distinct difference in fertilization, hatching and embryo malformation rate between low-quality eggs and high-quality eggs, these two groups were considered for the identification of quality markers. Then RNA-seq was performed for the originally preserved eggs from the low-quality group and high-quality group. We profiled the differentially expressed genes and identified a group of RNA-binding proteins (RBPs) as potential regulators. Gene function analysis indicated that most of these genes were enriched in RNA-regulated pathways including RNA processing. The RBPs were more related to egg quality from the PLS-DA analysis. Finally, gene expression was validated by qRT-PCR.

CONCLUSIONS

We found a cluster of RBP genes including igf2bp3, zar1, elavl1, rbm25b and related regulatory factors including yy1, sirt1, anp32e, btg4 as novel biomarkers of egg quality.

Effects of weathered polyethylene microplastic ingestion on sexual maturation, fecundity and egg quality in maturing broodstock Atlantic cod Gadus morhua

Microplastics (MPs) have become a global issue as they are omnipresent in the ocean. Fish ingesting MPs through feed could be affected in their physiological function, e.g., disrupted enzyme production and function, reduction of feeding and reproductive failure. This study assessed the effects of feed containing naturally weathered MPs from the Oslofjord (Norway) on the reproductive physiology of Atlantic cod (Gadus morhua). Farmed cod broodstock were fed either control (C-diet) or feeds containing 1% microplastic (MP-diet) starting nine months prior to spawning, from June until May. No major differences were found between diet groups in overall biometrics or gonad histology. Sex steroid levels (testosterone, 11-ketotestosterone and 17β-estradiol) resulted in expected profiles increasing over time without any significant differences between treatments. Gene expression levels of the steroidogenic enzyme 20β-hydroxysteroid dehydrogenase (20β-hsd) and vitellogenin1 (vtg1) showed significant differences between dietary treatments with lower expression in the control group. This can be a direct effect of MPs, but endocrine disrupting effects of potentially leachable plastic additives cannot be completely ruled out. Thus, these enzymes could be indicators of exposure to contaminants that disrupt sexual maturation by affecting the production of primarily maturation-inducing steroid. Although the concentration of MPs employed in this study may not be high enough to elicit any observable short-term biological effects, the observed gene expression suggests that long-term consequences should be considered caused by an expected increase of MPs in marine environments.

Effect of increasing valine level in the diet on performance, egg quality, and serum components in laying quails

This research was conducted to determine the effect of increasing dietary valine level on performance parameters, egg quality criteria, and blood and serum components. In the study, 120 female Japanese quails at the age of 10 weeks (241.4 ± 8.6 g) did randomly allocate to six experimental groups contained five subgroups. Treatment diets were prepared to contain 0.93% (control), 1.00%, 1.10%, 1.20%, 1.30%, or 1.40% valine. The egg mass decreased linearly with the increasing level of valine in the diet, while egg weight decreased in both linear and quadratic manner (P < 0.05). Increased levels of dietary valine increased eggshell breaking strength in cubic manner (P < 0.05). The administration of the valine to the diet caused a linear decrease in the albumin index and Haugh unit (P < 0.05). Other egg quality parameters were not affected (P > 0.05). Serum glucose and triglyceride concentrations of laying quails were reduced by the increasing dietary valine levels; the effect on serum glucose was linear, while both linear and quadratic effects were significant on triglyceride concentration (P < 0.05). White blood cell, lymphocyte, and neutrophil counts increased with the increasing dietary levels of valine (P < 0.05). Both linear and quadratic effects were significant on white blood cells and lymphocytes, while the effect on neutrophil counts was linear. However, erythrocyte and haematocrit (P < 0.05) decreased quadratically with increment in the dietary levels of valine. In conclusion, the increased valine levels in the diet adversely affected the egg weight, egg mass, and Haugh unit. but it reduced the serum triglyceride and glucose. Results may suggest that dietary valine at 0.93% level is sufficient for egg production and egg quality in laying quails, but positive effects of increased dietary valine levels on white blood cells may worth to investigate further.

Dietary supplementation with chia polyphenols alleviates oxidative stress and improves egg nutritional quality in Japanese quails under heat stress

Heat stress in poultry is a major concern, especially in regions with hot summers and scarce cooling infrastructure. Dietary supplementation with antioxidants, such as polyphenols, has risen as a strategy to mitigate the physiological consequences of heat stress. A by-product of the extraction of oil from chia seeds, which is discarded if not used, could be a possible source of polyphenols. The aim of the present study was to evaluate the effects of dietary supplementation with polyphenols from defatted chia seed cake on the general performance, and oxidative status of Japanese quail exposed to heat stress. Furthermore, productive performance, egg quality and yolk fatty acid composition were also assessed. A total of 36 females (96 days of age) were randomly assigned to different diets: BASAL (control), LDCP (low dose of chia polyphenols), or HDCP (high dose of chia polyphenols). Half the animals in each diet group were exposed to 34 °C for 9 h a day (Heat Stress; HS), while the other half remained at the standard 24 °C (No Heat Stress; NHS). After 23 days of experimental conditions, animals under HS showed higher body temperatures and time spent panting, but lower egg laying rate. Moreover, HS modulated the activity of catalase and glutathione peroxidase enzymes, increasing lipid peroxidation in serum and liver; and increased saturated fatty acids in egg yolk. Supplementation with chia polyphenols helped to mitigate the HS effects, especially on glutathione peroxidase activity, decreasing lipid peroxidation. In addition, supplementation with HDCP showed the highest proportion of polyunsaturated fatty acids in liver and egg yolk. In conclusion, the use of defatted chia seed cake could represent a sustainable strategy to mitigate heat stress effects on Japanese quail, due to its capacity to decrease oxidative stress and improve the nutritional quality of egg, while decreasing the amount of waste generated by the food industry.

Evaluating the quality of indigenous chicken eggs in Gena Bossa district of Dawro zone, South Ethiopia

This study was carried out in the Gena Bossa district to evaluate the quality of indigenous chicken eggs in different agro-ecology and education levels of chicken producers. A total of 108 fresh eggs were collected from randomly selected 36 households for the determination of egg quality parameters and three eggs from each household, 36 eggs from each Agro-ecology, and 27 eggs from each education level of farmers collected. Eggs collected from highland agro-ecologies had the highest egg weight (43.94 ± 0.42g), shell thickness (0.54 ± 0.01mm), albumen weight (23.31 ± 0.40g), and shell weight (5.25 ± 0.73g). Lowl and eggs had the highest yolk color score (8.65 ± 0.14). Eggs collected from primary second cycle educated farmers had the highest egg weight (44.41 ± 0.48g), albumen height (5.17 ± 0.17mm), Haugh unit score (75.34 ± 1.41%), yolk height (15.58 ± 0.33), albumen weight (23.65 ± 0.46g), and shell weight (5.33 ± 0.08g). Except for shell thickness (0.54 ± 0.11mm) all egg quality parameters were lowest for eggs collected from illiterate farmers. Egg weight was most appropriate in primary first cycle and primary second cycle interactions with respective highland and midland agro-ecologies. However, shell strength was most appropriate in the interactions of highland agro-ecology with illiterate education level. The combinations of primary second cycle with highland agro-ecology was most appropriate than other interactions for albumen weight. Depending on this conclusion, it will be better to investigate further studies on factors affecting internal and external qualities of the eggs in the study area.

Ameliorative effects of dietary selenium against cadmium toxicity on production performance and egg quality in laying hens

In order to reveal the influences of supplemented dietary selenium (Se) on the suppressive effect of cadmium (Cd) toxicity on performance and egg properties of laying hens, the effects of co-treatment Se and Cd on the performance, egg quality, levels of amino acids and the antioxidant capacity of egg and serum were investigated. A total of 128 31-week-old laying hens were randomly distributed in four treatments, which were fed with the basic diet (0.2 mg/kg Se and 0.08 mg/kg Cd), and the basic diet with Se (1.1 mg/kg Se and 0.08 mg/kg Cd), Cd (0.2 mg/kg Se and 92.1 mg/kg Cd) and Se+Cd for 13 weeks, respectively. Hens supplemented with Cd led to an impairment on production performance and egg quality with decreased egg production (EP), egg mass (EM), feed intake (FI), eggshell color, eggshell thickness, yolk color, albumen height and haugh unit and increased the feed conversion ratio (FCR) (p < 0.05). Cd treatment decreased the contents of cysteine (Cys), histidine (His), lithium (Li), aluminum (Al), chromium (Cr), manganese (Mn), nickel (Ni), zinc (Zn), arsenic (As), Se, strontium (Sr), stannum (Sn), mercury (Hg) and thallium (Tl) and increased the contents of isoleucine (Ile) and Cd (p < 0.05). Cd destroyed the egg yolk and serum redox states with the increased concentration of malondialdehyde (MDA) and the decreased activities of superoxide dismutase (SOD) and glutathione peroxidase (GPx) (p < 0.05). The expression levels of ovarian apoptotic genes (protein 53, Caspase9, Cytochrome c and Bcl-2 associated X protein) increased, and B-cell lymphoma 2 (Bcl-2) expression decreased in the Cd group (p < 0.05). Feeding Se significantly alleviated Cd-induced toxicity on performance and egg quality. Se+Cd treatment restored the balance between oxidation and antioxidant systems and modulated the elements' homeostasis and alleviated the changes in apoptotic-related genes expression levels. Se could alleviate the Cd toxicity to laying hens and their eggs but could not counteract all negative effects of Cd.

Meta-analysis of Zinc Supplementation on Laying Performance, Egg Quality Characteristics, and Blood Zinc Concentrations in Laying Hens

There are inconsistent results on the influence of zinc (Zn) supplementation levels on productive indices of laying hens. This study, therefore, uses meta-analysis to synthesis evidence on the effect of inclusion of Zn in chicken diets on performance, egg quality, and blood Zn status of laying hens. Eleven studies were identified and used to analyze the effect of diets with or without Zn supplementation on feed intake, feed conversion ratio (FCR), hen day egg production (HDEP), egg weight (EW), egg mass (EM), Haugh unit (HU) scores, eggshell thickness (EST), eggshell weight (ESW), and blood Zn concentrations in laying hens. Data extracted from the 11 studies included in the meta-analysis were pooled using a random-effects model and expressed as standardized mean differences (SMDs) at a 95% confidence interval (CI). Results indicate that dietary Zn supplementation reduced FCR (SMD =  - 0.50 g feed/g egg; 95% CI: - 0.68 to - 0.31) and increased HDEP (SMD = 0.33%; 95% CI: 0.18 to 0.48), EW (SMD = 0.14 g; 95% CI: 0.03 to 0.25) and EM (SMD = 0.58 g/hen/day; 95% CI: 0.22 to 0.95), HU (SMD = 0.64; 95% CI: 0.42 to 0.85), EST (SMD = 0.84 mm; 95% CI: 0.45 to 1.23), and plasma Zn concentration (SMD = 4.20 mg/dl; 95% CI: 2.99 to 5.40) compared with the controls. In contrast, feed intake and ESW were not significantly different from controls. Restricted subgroup analysis indicated that chosen moderators (age of hen, inclusion level, chicken breed/strain, and supplementation duration) influenced the results of this meta-analysis. There was evidence of significant heterogeneity, and meta-regression indicated that moderators explained most of the sources of heterogeneity. We conclude that dietary zinc supplementation had positive effect on feed conversion ratio, laying performance, aspects of egg quality traits, and blood zinc concentrations in laying hens. The findings from this meta-analysis will help in policy advancements and sustainable use of zinc in the egg production industry.

Effect of dietary flaxseed meal supplemented with dried tomato and grape pomace on performance traits and antioxidant status of laying hens

This study was carried out to determine the effect of dietary flaxseed meal (FSM) supplemented with dried tomato pomace (DTP) and dried grape pomace (DGP) on performance, egg quality, biochemical parameters traits and antioxidant status of laying hens. Birds (1825 ± 87 g of body weight) were divided into 12 dietary groups with six replicates per group (eight birds per replicate), under a completely randomized design with factorial arrangement 2 × 3 × 2 consisted of two levels of DTP (0 and 15%), three FSM levels (0, 4 and 8%) and two levels of DGP (0 and 5%). As a result of this study, there were no significant differences in egg production and weight as well in feed conversion ratio (FCR) among treatments (p > 0.05). Feeding of DGP reduced significantly feed intake and egg mass when compared to control group (p < 0.05). There was no effect (p > 0.05) of dietary treatment on shell thickness and strength, shape index, Haugh unit and egg specific gravity. Hens consuming 15% DTP and 5% DGP revealed a significantly higher yolk color compared to the other dietary treatments (p < 0.05). Moreover, there was no difference among dietary treatments in terms of serum low-density lipoprotein cholesterol (LDL) and high-density lipoprotein cholesterol (HDL) cholesterol, atherogenic index, triglycerides, total cholesterol levels (p > 0.05). Serum antioxidant parameters as glutathione peroxidase (GSH-Px) activity, malondialdehyde (MDA), total superoxide dismutase (TSOD) and total antioxidant capacity (T-AOC) were not influenced by treatments (p > 0.05). Based on findings, FSM and DTP supplements did not significantly impact most of hens' performance indicators and egg quality parameters, whereas significant improvements were observed by feeding of 15% DTP and 5% DGP on egg traits, in particular on egg-yolk color that plays a key-role in consumer's choice. However, the supplementation of FSM and DTP or DGP even in laying hen diet is still controversial and further research is needed.

Quantitative proteome profiling reveals molecular hallmarks of egg quality in Atlantic halibut: impairments of transcription and protein folding impede protein and energy homeostasis during early development

Background

Tandem mass tag spectrometry (TMT labeling-LC-MS/MS) was utilized to examine the global proteomes of Atlantic halibut eggs at the 1-cell-stage post fertilization. Comparisons were made between eggs judged to be of good quality (GQ) versus poor quality (BQ) as evidenced by their subsequent rates of survival for 12 days. Altered abundance of selected proteins in BQ eggs was confirmed by parallel reaction monitoring spectrometry (PRM-LC-MS/MS). Correspondence of protein levels to expression of related gene transcripts was examined via qPCR. Potential mitochondrial differences between GQ and BQ eggs were assessed by transmission electron microscopy (TEM) and measurements of mitochondrial DNA (mtDNA) levels.

Results

A total of 115 proteins were found to be differentially abundant between GQ and BQ eggs. Frequency distributions of these proteins indicated higher protein folding activity in GQ eggs compared to higher transcription and protein degradation activities in BQ eggs. BQ eggs were also significantly enriched with proteins related to mitochondrial structure and biogenesis. Quantitative differences in abundance of several proteins with parallel differences in their transcript levels were confirmed in egg samples obtained over three consecutive reproductive seasons. The observed disparities in global proteome profiles suggest impairment of protein and energy homeostasis related to unfolded protein response and mitochondrial stress in BQ eggs. TEM revealed BQ eggs to contain significantly higher numbers of mitochondria, but differences in corresponding genomic mtDNA (mt-nd5 and mt-atp6) levels were not significant. Mitochondria from BQ eggs were significantly smaller with a more irregular shape and a higher number of cristae than those from GQ eggs.

Conclusion

The results of this study indicate that BQ Atlantic halibut eggs are impaired at both transcription and translation levels leading to endoplasmic reticulum and mitochondrial disorders. Observation of these irregularities over three consecutive reproductive seasons in BQ eggs from females of diverse background, age and reproductive experience indicates that they are a hallmark of poor egg quality. Additional research is needed to discover when in oogenesis and under what circumstances these defects may arise. The prevalence of this suite of markers in BQ eggs of diverse vertebrate species also begs investigation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-022-08859-0.

Effect of weight and storage time of broiler breeders' eggs on morphology and biochemical features of eggs, embryogenesis, hatchability, and chick quality

The transfer of hatchability results obtained under experimental conditions to the commercial ground with a positive financial effect proves the value and usefulness of these data. On the other hand, finding results on commercial processes of broiler breeders' egg incubation in the literature is challenging. The presented study aimed to determine the effects of egg weight and storage time on the physical, biochemical characteristics of hatching eggs, embryogenesis and hatchability in Ross 308 broiler breeders. On the laying day, the eggs were divided into four weight groups: S - small eggs (57-61 g), M - medium eggs (62-66 g), L - large eggs (67-71 g), and XL - extra-large eggs (72-76 g). The eggs were then stored for 3, 7, 14, and 21 days under controlled conditions. As the egg storage time increased, a decrease in the yolk quality (lower index) was observed. The highest Haugh units were found in eggs from the S and M groups. The cholesterol content of the M, L, and XL groups was lower on days 7, 14, and 21 as compared to that of eggs only stored for 3 days. Egg weight loss during incubation decreased with an increase in the egg weight. An extension of the egg storage time caused an increase in the loss of egg weight. On the 14th and 18th days of hatching, an increase in the eggshell temperature was noted with an increase in the weight of the egg. The eggs stored for 7 days were characterised by the highest shell temperature on each day. The highest hatchability percentage was recorded for the M group. The hatchability rate decreased with the prolongation of the storage time, while the number of crippled chicks after hatching increased. The results confirmed that the increased weight of the eggs and prolonged storage time (14 and 21 days) increased the weight and decreased the length of the newly hatched chicks, respectively. Chicks from the heaviest eggs and those stored for 14 and 21 days showed poor results on the Pasgar score® test. The observations indicate the need to adopt various (of those available) methods to assess the quality of newly hatched chicks in hatcheries in order to produce high-quality broiler chickens. The results also indicate that prolonged egg storing beyond 14 days may affect the thyroid hormone economy during the hatching of chicks, especially in the XL group.

Effect of dietary supplementation of zinc proteinate on performance, egg quality, blood biochemical parameters, and egg zinc content in White Leghorn layers

A study was conducted to investigate the effects of zinc proteinate (Zn-P) on laying performance, egg quality, antioxidant indices, and egg zinc content in laying hens from 38 to 49 weeks of age. A total of 150 White Leghorn layers were randomly assigned to five treatments, each with six replicates with five birds per replication. Dietary treatments included a corn-soybean meal-based basal diet with no zinc addition and basal diet supplemented with Zn-P at 40, 80, 120, or 160 mg/kg of feed for 12 weeks. The analyzed zinc concentrations of the five diets were 29.5, 70.8, 110.2, 147.5, and 187.5 mg Zn/kg, respectively. Dietary Zn-P supplementation had no effect on feed intake and egg production. However, raising the zinc level improved egg weight (P < 0.01) and egg mass (P < 0.05) and lowered the feed conversion ratio (P < 0.05) during the later (46-49 weeks) period. The Zn-P supplementation also significantly (P < 0.05) increased Haugh units, egg shell strength, and shell thickness and had no influence on other egg quality parameters. Increasing zinc levels in the diet resulted in increase in egg zinc contents and serum zinc level. The serum triglyceride and LDL-cholesterol levels significantly decreased (P < 0.05) in Zn-P-supplemented groups. Supplementation of Zn-P significantly (P < 0.05) increased serum Cu-Zn-SOD activity and reduced MDA concentration. It could be concluded that dietary supplementation of higher levels of Zn-P, more than 80 mg/kg diet, significantly improved the egg zinc content, some egg quality traits, antioxidant activity, and serum zinc levels.

Effect of Fermented Corn By-products on Production Performance, Blood Biochemistry, and Egg Quality Indices of Laying Hens

Residual wastes can be fermented by using probiotics to formulate a well-balanced diet for poultry. The current study was conducted to investigate the effect of fermented feed (FF) formulated by the supplementation of probiotics into corn by-products, on the production performance of laying hens. A total of 468 49-week-old Hy-Line Brown chickens were randomly allocated into four treatments with three replicates, control group (basal diet), group Ⅰ (4% FF, w/w), group Ⅱ (8% FF, w/w), and antibiotic group (flavomycin, 50mg/kg). Laying hens were housed in three-tier cages (28 × 48 cm x 48 cm) and the temperature was maintained at 21ºC. The birds were fed 4.56 kg of feed to each group twice a day. Compared to the control group, the egg production and feed intake (FI) in the FF groups increased significantly. Egg weight (EW) in group Ⅰ was higher than that of group Ⅱ and antibiotic (p<0.01) while that in group Ⅱ was lower than control (p<0.05). The feed to egg ratio of FF groups compared to control was decreased (p<0.05). Eggshell strength (ESS) and egg shape index (ESI) in group Ⅱ were decreased significantly as compared to the control group (p<0.05). Yolk color (YC) albumen height (AH) and Haugh unit (HU) in FF groups were improved compared to the control group and antibiotic group (p<0.01). Yolk triglyceride (TG) level was significantly reduced in group II, compared to group I. These results indicated that the FF has no adverse effects and has beneficial effects on production performance and egg quality parameters of laying hens.

Pathogenicity comparison between QX-type and Mass-type infectious bronchitis virus to different segments of the oviducts in laying phase

Background

The QX-type infectious bronchitis virus (IBV) has become the predominant genotype worldwide in recent years and has caused serious economic losses to the chicken industry. The most significant feature of QX IBV is that its infection in the early growing stage can cause abnormal oviduct development, resulting in a high proportion of ‘false layers’ in poultry flocks of laying hens and breeders. However, few studies have evaluated whether infections of QX-type IBV in laying stages can also cause severe pathological changes in the oviduct.

Methods

In this study, 300-day-old specific-pathogen-free chickens were infected either with the QX-type strain QXL or Massachusetts (Mass)-type strain M41 to compare their pathogenicity on different segments of the oviduct.

Results

Both the QXL and M41 strains successfully replicated in all segments of the oviduct; however, the QXL strain was more highly distributed in mucosal layer and caused severe lesions in the lamina propria, including interstitial dilation, inflammatory cell infiltration, and distinct expansion of tubular glands. Moreover, the QXL strain induced high expression of proinflammatory cytokines and cytotoxic molecules in the majority of segments in the oviduct. Further research found that the QXL strain may affected the formation of shell membranes and eggshells by inhibiting the expression of type I collagen and CaBP-D28k.

Conclusions

Our results indicate that the QX-type IBV is more pathogenic than Mass-type IBV to oviduct in laying phase. Collectively, these findings provide detailed information on the pathological changes in different segments of the oviduct in laying phase, which could offer a better understanding about the pathogenicity of IBV.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12985-022-01788-0.

Reducing ammonia emission by aluminum sulfate addition in litter and its influence on productive, reproductive, and physiological parameters of dual-purpose breeding hens

This research investigated the impact of aluminum sulfate (AS) as amendment to different types of litter (new, reused, and mixed litters) for reducing ammonia emission and improving productive performance of local dual-purpose breeding hens. A total of 450 hens and 60 cocks from the Inshas strain were randomly assigned to six groups (five replicates each of 15 hens + 2 cocks) raised in pen floor furnished with a wheat straw litter. The groups included: (1) new, (2) reused, (3) mixed (50% new + 50% reused) litter; the other groups (4, 5 and 6) were respectively housed on the same litter as groups 1, 2 and 3 but with the addition of 495 g of AS/m² litter. The feed conversion ratio was better for layers raised on new litter with or without AS than other groups. Different kinds of litter had different moisture (p < 0.05) and pH (p < 0.05) values. Birds raised on litter types treated with AS significantly (p < 0.05) decreased intestinal pH and decreased total bacterial count compared to the same litter types without AS at the end of the experiment. Birds raised on new litter supplemented with AS had the highest plasma T3, total protein, globulin, Hgb, and PCV% and the lowest levels of uric acid and cholesterol at the end of the experimental period. Therefore, litter amendment with AS, also the mixed or reused one, could be recommended to reduce ammonia and, in turn, increasing plasma T3 and decreasing total bacterial count, leading to increasing bird's performance.

Effect of micro-algae Schizochytrium sp. supplementation in plant diet on reproduction of female rainbow trout (Oncorhynchus mykiss): maternal programming impact of progeny

Background

The broodstock diet, and in particular the lipid and fatty acid composition of the diet, is known to play a key role in reproductive efficiency and survival of the progeny in fish. A major problem when replacing both fish meal and fish oil by plant sources is the lack of n-3 long chain polyunsaturated fatty acids, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). To address this problem, we studied the effect of the plant-based diet supplemented with Schizochytrium sp. microalgae, source of DHA, compared to a conventional commercial diet rich in fish meal and fish oil on reproductive performance and egg quality and the consequences on progeny, in female rainbow trout broodstock.

Results

The results demonstrated that DHA-rich microalgae supplementation in a plant-based diet allowed for the maintenance of reproductive performance and egg quality comparable to a conventional commercial feed rich in fish meal and fish oil and led to an increased significant fry survival after resorption. Moreover, when females were fed a plant-based diet supplemented with micro-algae, the 4-month-old progenies showed a significant higher growth when they were challenged with a similar diet as broodstock during 1 month. We provide evidence for metabolic programming in which the maternal dietary induced significant protracted effects on lipid metabolism of progeny.

Conclusions

The present study demonstrates that supplementation of a plant-based diet with DHA-rich microalgae can be an effective alternative to fish meal and fish oil in rainbow trout broodstock aquafeed.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40104-022-00680-9.

Quality assessment of chukar partridge (A. chukar) eggs during different conditions (time, turning and position) of storage

The present study was conducted with the aim of investigating the effect of storage length, turning frequency and egg position on internal quality traits of chukar eggs obtained from 56-week-old chukar partridges under the same nutrition and management conditions. A total of 720 eggs were collected and assigned to 36 subgroups according to storage length (7, 14, 21, and 28 d), turning frequency (0, 1, and 24 per day) and egg position (pointed end up, blunt end up and horizontal). As a result of the study, almost all the internal quality traits of chukar eggs were negatively affected by lengthening of storage period especially 21 days and longer (p < 0.001). Internal egg quality traits weren't statistically affected by turning frequency except yolk index (p < 0.01). An improvement was observed in Haugh unit, albumen index and heigh of eggs stored with pointed end up (p < 0.001). Some significant interactions occurred among all internal egg quality traits which were mostly dependent on the eggs stored horizontally, extended storage time more than 21 days and egg turning during storage. The results and interactions showed that internal quality traits would be preserved well for the eggs stored less than 21 days with the position of pointed end up independent of turning. If the storage period was to exceed 21 days, the eggs should be positioned horizontally and turning should be applied to preserve the quality of chukar eggs.

Organic acid and probiotic derived from grass silage improved egg quality in Pegagan laying duck: a research note

The aim of this study was to evaluate the effect of supplementation of organic acid and probiotic derived from grass silage on the egg quality of duck. Seventy-two Pegagan laying ducks (average age: 24 weeks) were randomly allocated to six treatment groups: basal diet, basal diet + organic acid, basal diet + probiotic, basal diet + tetracycline, basal diet + probiotic + organic acid, and basal diet + organic acid + tetracycline. The result showed that the feeding diets containing probiotics and organic acid significantly (P < 0.05) reduced yolk fat and yolk cholesterol and increased eggshell weight, egg index, yolk color score, Haugh unit, and protein content. However, egg weight, albumen weight, yolk weight, albumen index, yolk index, and water content were not significantly (P > 0.05) different. It is concluded that dietary supplementation of organic acid and probiotic derived from grass silage improved egg quality in terms of yolk color score, fat, and cholesterol content.

Impact of relative humidity on the laying performance, egg quality, and physiological stress responses of laying hens exposed to high ambient temperature

The present study investigated the effects of relative humidity (RH) on the laying performance, egg quality, and stress indicators of laying hens raised at high ambient temperatures. A total of 180 Hy-Line Brown laying hens (68-wk-old) were randomly allotted to one of the following three RH conditions for 12 h a day (9:00 a.m.-9:00 p.m.) over four weeks: low RH (LRH; 25% RH), moderate RH (MRH; 50% RH), and high RH (HRH; 75% RH); ambient temperature was 30 °C under all treatments. None of the RH treatments affected hen-day egg production, egg weight, or egg mass (P > 0.05). However, feed intake was lower in the HRH group than in the LRH group (P < 0.05). Plasma corticosterone (CORT) concentration on day 21, yolk CORT concentration on day 3, and albumen CORT concentration on day 7 following RH exposure were higher in the HRH group than in the LRH group (P < 0.05). Moreover, plasma HDL-cholesterol concentration on day 14 was higher in the HRH group than in the LRH group (P < 0.05). On days 3 and 14, the Haugh unit decreased (P < 0.05) in the LRH group compared with that in the MRH and HRH groups. The HRH-exposed laying hens showed the lowest (P < 0.05) eggshell thickness on day 14. The absolute weights of eggshell, yolk, and albumen decreased in the HRH group compared with those in the MRH and LRH groups. Overall, high RH lowered feed intake and egg quality except for the Haugh unit, and induced stress response as manifested by elevated plasma, yolk, and albumen CORT concentrations. To our best knowledge, the present study is the first to demonstrate the role of RH in triggering temperature stress responses in laying hens.

Effects of dietary palm kernel meal and β-xylanase on productive performance, fatty liver incidence, and excreta characteristics in laying hens

The objective of the present experiment was to investigate the effect of dietary palm kernel meal (PKM) and β-xylanase supplementation on productive performance, egg quality, fatty liver incidence, and excreta characteristics in laying hens. A total of 320 Hy-Line Brown laying hens (33 weeks of age) were allotted to 1 of 4 treatments with 8 replicates in a feeding trial. Each replicate consisted of 10 consecutive cages with 1 hen per cage. The corn-soybean meal-based control diet was prepared. Additional diet was prepared by including 10% of PKM in the control diet with a partial replacement of corn, soybean meal, and animal fat. In addition, 0.025% β-xylanase was supplemented at the expense of celite to those 2 diets to produce 4 treatment diets in a 2 × 2 factorial arrangement. All hens were provided the diet and water ad libitum for 8 weeks. Results indicated no significant interactions between inclusion of dietary PKM and β-xylanase for all measurements; therefore, the main effects were mainly discussed. Hens fed diets containing 10% PKM had greater (p < 0.05) feed intake and yolk color than those fed diets containing no PKM. However, dietary PKM did not influence fatty liver incidence and excreta characteristics. Dietary β-xylanase supplementation had no effects on all measurements, regardless of inclusion of PKM. In conclusion, PKM can be a potential feed ingredient for laying hens at the inclusion of 10% in the diet. It appears that dietary β-xylanase used in the current experiment has little effect on layer productivity, regardless of inclusion of 10% PKM in the diet.

Mix of cassava pulp, napier grass, and enzymes can be used as low cost alternative feed ingredient for laying hens

Two experiments were carried out to evaluate the effect of mixed cassava pulp and napier grass (MCN) supplemented with multi-component enzymes on the hen performance and egg quality as well as nutrient digestibility. In experiment 1, forty laying hens (Isa Brown) of 34 weeks in age were randomly allotted to 5 groups: control and 5, 10, 15, and 20% MCN for 10 days (one bird per cage, eight cage replicates). The results indicated that dry matter, and organic matter digestibilities, or nitrogen retention (P > 0.05) showed no significant alteration when used MCN up to 20%. In experiment 2, one hundred and eighty Isa Brown laying hens of 67 weeks in age were randomly assigned to 5 groups (control and 4 MCN: 5, 10, 15, and 20%) and raised for 8 weeks. It revealed that the inclusion rate of MCN up to 20% did not affect the productive performance, plasma cholesterol concentration, cecal microbial populations, or ammonia production (P > 0.05). In addition, egg yolk cholesterol was found to be lower in laying hens fed 20% MCN compared to 5% MCN (P < 0.05), but no significant differences compared to the control. In conclusion, it is indicated that MCN can be used as a partial part of an energy source in laying hen diets with no adverse effects on productive performance, nutrient digestibility or egg quality.

Effect of stocking density and age on physiological performance and dynamic gut bacterial and fungal communities in Langya hens

Background

The characterization of colonization and dynamic changes related to gut microorganisms might be vital, as it presents an opportunity to quantify the co-variation between stocking densities and gut microbiome of dynamic distribution. The objective of this study was to determine the stocking density on physiological performance and dynamic distribution of gut microbiome (including bacterial and fungal communities) of Langya laying hens in the two development stages.

Methods

A randomized design with 2 × 3 factorial controls consisting of two development stages (24, 43 weeks-old) with three different stocking densities was performed. Three different stocking densities were allocated to a total of 300 11-week-old Langya laying hens (450 cm²/bird, 675 cm²/bird, 900 cm²/bird). Three housing densities were accomplished by raising different chickens per cage with the same floor size. The dependent variables of stocking densities at each sampling point were; growth performance, organs index, egg quality and the changes of dynamic gut bacterial and fungal communities in the cecum.

Results

Results showed that the stocking density didn’t affect liver index, eggshell thickness, breaking shell strength and egg shape index. Hens from the highest stocking density had the lowest body weight, fallopian tube index, egg weight and yolk colour score. Except for the yolk colour score, the measurement changes caused by age followed the opposite pattern as stocking density. We observed a substantial rise in taxa linked with health threats when stocking density was increased, including Talaromyces, Oscillospiraceae_UCG-002, Oscillospira, and Dielma. The opposite was observed with Bacteroides, Bifidobacterium, Lachnoclostridium, Eisenbergiella, and Kurtzmaniella. Also, most taxa were linked to polymicrobial infection in clinical cases, especially species whose percentage declined as the hens aged, such as Terrisporobacter, Faecalicoccus, Dialister, Cylindrocarpon etc. Whereas Sellimonas, Mitsuokella, Eurotium, Wardomyces and Cephalotheca had the opposite trend.

Conclusion

We speculated that excessive high density drove the abundance of bacteria and fungi connected with health problems. Where the gut microecology gradually reach a mature and balance status with age. Overall, this study demonstrates gut microbiome ecological processes in Langya layers at various stocking densities and finds possible connections between stocking density, microbiome and production performance. Our study will contribute to new insights associating suitable density patterns and production performance in laying hens by harnessing such a relative microbiome.

Effect of Supplementation of Zinc-Methionine on Egg Production, Semen Quality, Reproductive Hormones, and Hatchability in Broiler Breeders

A biological study was conducted to explore the effect of zinc-methionine (Zn-Met) supplementation on productive, reproductive, and immunological response in broiler breeders. Adult healthy 45-week breeder males (192) and females (288) were used in a completely randomized design. Birds were randomly divided into four treatments consisting of six replicates and fed basal diet (control, 40 mg/kg), basal diet supplemented with Zn-Met 20 (T1), 40 (T2), and 60 mg/kg (T3). There was no effect (P > 0.05) on body weight and feed consumption among the breeders due to the supplementation of organic Zn. The T3 group had significantly (P < 0.05) higher semen volume, sperm motility, concentration, and live sperm count. The seminal plasma calcium and alkaline phosphatase activity were higher (P < 0.05), and total cholesterol and aspartate transaminase levels were low in the T3 group. Birds fed with additional supplementation of Zn (60 mg/kg) had improved both cellular and humoral immunity. Throughout the experimental period, the hen day egg production was comparable (P > 0.05) among the experimental groups. Organic Zn-supplemented group showed significant difference in both the internal and external egg qualities-albumen, yolk index, and shell thickness. The higher dose of organic Zn-fed groups had a significant difference in estrogen and progesterone concentration, and the highest testosterone concentration was observed in the T2 group. Supplementary organic Zn had a significant effect on the concentration of Zn and Cu in the seminal plasma. Serum Zn and Cu concentration was significantly increased due to the supplementation of organic zinc in both male and female breeders. The fertility and hatchability percentage were higher (P < 0.05) in the T2 group. It could be concluded that the additional supplementation of organic Zn (zinc-methionine) at 40 mg/kg to the basal diet improved the reproductive performance in broiler breeders.

Productive performance, fertility and hatchability, blood indices and gut microbial load in laying quails as affected by two types of probiotic bacteria

This study investigated two kinds of probiotic bacteria (Bacillus toyonensis, B1 and Bifidobacterium bifidum, B2) on laying Japanese quail’s performance, egg quality, fertility and hatchability, blood biochemical characteristics and microbiological parameters. A total of 270 mature quails (180 females and 90 males) were distributed into ten groups in a completely randomized design at eight weeks of age. The experimental groups were as follows: T1: basal diet only (control); T2-T5, basal diet plus 0.05, 0.075, 0.10 and 0.125% B1, respectively; T6: basal diet plus 0.10% B2; T7-T10: basal diet plus 0.05, 0.075, 0.10 and 0.125% B1 plus 0.05% B2, respectively. Results revealed that egg number (EN) and egg weight (EW) were gradually increased (P < 0.01) as the levels of both probiotic types increased. The feed conversion ratio (FCR) was significantly (P < 0.05) better within the total experimental period (8–20 weeks) due to B1 alone or/with B2 supplementation. Values of yolk percentage (Y%) were statistically (P < 0.01) higher only at 8–20 weeks of age and T10 recorded the highest value. By increasing the level of probiotics, fertility and hatchability percentages (F% and H%) were gradually increased (P < 0.01 and P < 0.05). Creatinine (CR) level was statistically reduced in birds fed T4 diet. Also, urea-N and aspartate aminotransferase (AST) levels were reduced in treated birds. The opposite was found regarding alkaline phosphatase (ALP). Conclusively, using B1 and B2 enhanced the productive performance, some egg quality traits, fertility and hatchability, digestive enzyme activities, and reduced the harmful bacteria in the gut of laying Japanese quail. Our findings could recommend to apply T4 (basal diet + 0.10 % B1), T6 (basal diet + 0.10% B2) and T9 (basal diet + 0.10% B1 + 0.05% B2) levels for the best results.

Organic zinc and manganese and 25-hydroxycholecalciferol improves eggshell thickness in late-phase laying hens

The aim of this study was to evaluate the effects of organic micromineral zinc (Zn) and manganese (Mn) and 25-hydroxycholecalciferol supplementation in late-phase laying hens' diets on performance, egg quality, lipid stability of fresh and stored eggs, and bone quality. The treatments were a basal diet and diets supplemented with 32 mg Zn-Met/kg diet; 26 mg Mn-Met/kg diet; 32 mg Zn-Met/kg diet and 26 mg Mn-Met/kg diet; 1500 IU 25-hydroxycholecalciferol/kg diet; 32 mg Zn-Met/kg diet; 26 mg Mn-Met/kg diet; and 1500 IU 25-hydroxycholecalciferol/kg diet. On performance, the birds supplemented with organic manganese had the lowest feed intake. Regarding egg quality, the birds supplemented with Zn-Met and Mn-Met, with 25-hydroxycholecalciferol alone, and with Zn-Met, Mn-Met and 25-hydroxycholecalciferol presented a greater eggshell thickness than those receiving the basal diet. Lipid stability of the yolk varied only according to storage time. No effect of supplementation was observed on bone quality. Supplementation with Zn-Met and Mn-Met, or associated with 25-hydroxycholecalciferol, or 25-hydroxycholecalciferol alone, improved eggshell thickness in aged white layers. However, the associated or isolated supplementation with these nutrients did not influence performance, lipid stability of fresh and stored egg yolk or bone quality.