Young Eggs Research Articles

Polymeric Coatings with Electrolyzed Acidic Water: A Novel Approach to Extending Egg Shelf Life and Quality.

Electrolyzed acidic water (EAW) contains hypochlorous acid as its active compound, which is a potent antimicrobial. It was encapsulated in polymeric coatings and applied to the surface of eggs. The antimicrobial activity and the ability to extend the shelf life of eggs at ambient temperature for 45 days were evaluated, by physical, microbiological, and sensory analyses. The analysis also included the evaluation of mechanical, thermal, and crystallinity properties and the interaction between the coating components and the eggshell. The results showed that eggs from young, middle-aged, and adult hens, encapsulated and coated with EAW, hydroxypropyl methylcellulose, polyvinyl alcohol, and chitosan, gained resistance and a glossy appearance. The thickness of the coating was 2.9 µm for young and adult hens' eggs and 2.60 µm for those of old hens, as observed by SEM. Shelf life was extended to 45 days under refrigeration and more than 30 days at ambient temperature. Coated eggs were acceptable for 85% of the panelists compared to 57% acceptance of non-coated eggs. The encapsulation and coating with EAW as an antimicrobial agent improved the surface protection of commercial eggs, reduced albumen liquefaction, and maintained quality by acting as a barrier against air, thereby preserving sensory characteristics.

β-Triketones from Leptospermum scoparium (mānuka) oil show potential as scabicides.

Scabies is a debilitating and neglected infectious disease with limited effective treatment options and affecting millions of people worldwide, mainly in poor and overcrowded settings. Essential oils from Australasian Myrtaceae are known to have parasiticidal properties, often attributed to the presence of β-triketones, which are known inhibitors of the tyrosine catabolism pathway through inhibition of hydroxyphenylpyruvate dioxygenase (HPPD). In this study, essential oils from mānuka (Leptospermum scoparium) were evaluated in vitro for miticidal and ovicidal activities and their active β-triketone constituents (flavesone, leptospermone, and isoleptospermone) were identified. Mite survival and egg hatching bioassays were performed to assess the scabicidal (miticidal and ovicidal) properties of Australasian Myrtaceae essential oils (mānuka, tea tree, and kunzea), mānuka oil fractions and three β-triketones (leptospermone, isoleptospermone, flavesone). Scabicidal constituents of mānuka oil were determined and quantified by 1H NMR spectroscopy and gas chromatography. To investigate HPPD as a potential target of β-triketones in scabies, tyrosine and fumarate levels were measured in mites following exposure to flavesone, and in silico docking of β-triketones in homology models of scabies HPPD structures was performed. Mānuka oil had superior scabicidal activity compared to conventional treatments, ivermectin and permethrin, as well as kunzea and tea tree oils. The analysis of the chemical composition of mānuka oil revealed a high abundance of sesquiterpenes (42 %), and three β-triketones, flavesone (4.7 %), leptospermone (17.2 %), and isoleptospermone (5.1 %). Miticidal and ovicidal activity was strongly correlated with the presence of these β-triketones, but not the sesquiterpenes. The β-triketones had similar miticidal activity (LC50 58.6-61.7 mM at 4 h; LT50 1.3-1.4 h at 150 mM) to each other and to mānuka oil, and showed high ovicidal activity in young and mature eggs, with leptospermone being the most potent (LC50 33.6-75.9 mM). Significantly altered tyrosine and fumarate levels in mites after exposure to flavesone compared to untreated mites indicate a possible interference of flavesone with the tyrosine catabolism pathway. Molecular docking experiments indicate that this activity is likely underpinned by their inhibition of the Sarcoptes scabiei hydroxyphenylpyruvate dioxygenase (SsHPPD). Our results demonstrated that mānuka oil and the β-triketones flavesone, leptospermone, and isoleptospermone can effectively kill scabies mites and eggs at early and late developmental stages, likely through their inhibition of tyrosine catabolism. This work has revealed SsHPPD as a potential new target for the development of novel topical scabies drugs that target all life-stages of the parasite.

Developmental stage and level of submersion in water impact the viability of lone star and winter tick eggs.

Female ticks deposit large egg clusters that range in size from hundreds to thousands. These egg clusters are restricted to a deposition site as they are stationary, usually under leaf litter and other debris. In some habitats, these sites can be exposed to periodic flooding. When the clusters of tick eggs are disturbed, they may float to the surface or remain underneath organic debris entirely submerged underwater. Here, we examined the viability of egg clusters from winter ticks, Dermacentor albipictus, and lone star ticks, Amblyomma americanum, when partially or fully submerged in water and in relation to the developmental stages of the eggs under lab conditions. In general, egg clusters that were older and partially submerged had a higher viability than fully submerged, younger eggs. Of the two species, A. americanum was more resistant to water exposure. These studies highlight that egg clusters for certain tick species can remain viable when exposed to water for at least two weeks. These resultsalso suggest that distribution by flooding of egg clusters could occur for some species and water submersion will differentially impact tick egg survival based on the specific developmental stage of exposure and species.

Pengaruh Level Minyak Kelapa Murni dalam Pengencer Air Kelapa Muda Terhadap Kualitas Spermatozoa Babi Landrace

This study aimed to examine the addition of various levels of virgin coconut oil (VCO) in young coconut water-egg yolk (YCW-EY) diluent on the quality of landrace boar spermatozoa. Semen was collected once a week using the massage method from landrace boars that have reached sexual maturity with healthy conditions. This study was experimental with a completely randomized design consisting of five treatments and five replicates. The treatments consisted of young coconut water (YCW 80%) and egg yolk (EY 20%) added with virgin coconut oil (VCO) with levels: 0% (P0), 2% (P1), 4% (P2), 6% (P3) and 8% (P4). The diluted semen was stored in a cool box at 15-20ºC and evaluated every 8 hours for motility, viability, abnormality and survival of spermatozoa up to a minimum motility of 40%. The results of this study showed that semen diluted using YCW-EY in treatment P4 (VCO 8%) had higher quality (P<0.05) compared to other treatments, namely motility reached (43.00±7.59%), viability (49.20±7.59%), abnormality (4.56±2.36%) and survival (25.42±2.78 hours). It was concluded that the addition of 8% VCO to YCW-EY diluent was effective in maintaining the quality of landrace boar spermatozoa.

Prevalence of the FMR1 Gene Premutation in Young Women with a Diminished Ovarian Reserve Included in an IVF Program: Implications for Clinical Practice.

The relationship between premature ovarian insufficiency (FXPOI) and premutation in the FMR1 gene is well established. In recent years, though, a potential relationship between the latter and a low ovarian reserve has been suggested. To explore it, we conducted a retrospective study in an IVF program at a university tertiary referral center in Barcelona (Spain). Data were obtained retrospectively from a total of 385 women referred for FMR1 gene testing at our institution from January 2018 to December 2021. We compared the prevalence of FMR1 gene premutation between 93 of them, younger than 35 years, with a diminished ovarian reserve (DOR), characterized by levels of anti-Mullerian hormone < 1.1 ng/mL and antral follicle count < 5; and 132 egg donors screened by protocol that served as the controls. We found a higher prevalence of FMR1 premutation in the DOR group (seven patients (7.69%)) than in the control group (one patient (1.32%)), Fisher-exact test p-value = 0.012). We concluded that compared with the general population represented by young egg donors, the prevalence of FMR1 gene premutation is higher in young patients with a diminished ovarian reserve. Although these findings warrant further prospective validation in a larger cohort of patients within DOR, they suggest that, in clinical practice, FMR1 premutation should be determined in infertile young patients with DOR in order to give them adequate genetic counselling.

Effects of age and eggshell thickness on the hatching results of stored broiler breeder eggs.

The present study was conducted to determine the effects of breeder age and eggshell thickness on the hatching results of broiler breeders. A total of 3000 eggs were collected from three flocks at different ages, viz., 27 (young), 48 (middle-aged) and 65 (old) weeks. Eggs were individually weighed and eggshell thicknesses were determined using an ultrasound gauge. The eggs of each age group were classified as thin-, medium- or thick-shelled and stored for 7 days at 18°C and 60% relative humidity prior to incubation. Total egg weight loss during storage and incubation was higher in middle-aged (48 weeks old) flock eggs (11.46%) than in young (10.14%) and old (10.37%) flock eggs. Hatchability was significantly lower in the eggs of the old flock than of the other flocks. The highest hatchability (70.6%) was observed in the young flock. Eggs with thick shells better tolerated the detrimental effects of storage and more eggs remained fertile than amongst the medium- and thin-shelled eggs. The overall hatchability of the old flock was 38.0%, whilst hatchability of set eggs in the thick-shelled group of old flock eggs was 58.3%.

Rapid egg cooling rate after oviposition influences the embryonic development, hatchability, and hatch time of young and old broiler hatching eggs

This study investigated the effect of the egg cooling profile after oviposition on blastoderm development, embryonic mortality, hatchability, and hatch time of broiler hatching eggs from young and old breeder flocks. Hatching eggs were obtained from commercial Ross 308 broiler breeders at 28 wk (young) and 64 wk (old) of age. A total of 3,150 eggs laid within a 15-min period were collected and randomly assigned to 2 temperature-controlled chambers in both flocks. The eggshell temperature (EST) was cooled to 24°C either within 6 h (control) or 45 min (rapid). After the EST reached 16°C in the chambers in all groups, eggs were transported to the commercial hatchery. Eggs were stored for 6 d at 16°C and 75% relative humidity. The development of the blastoderm in sampled eggs (25 embryos in each batch) was determined immediately after egg collection and before transport to the hatchery (after cooling) on a farm in each flock. At each flock age, there were 5 replicate trays of 150 eggs per egg cooling treatment set in a single commercial incubator. The results showed that the embryonic developmental stage was retarded by rapid cooling and by the younger flock. A flock age×cooling rate interaction was observed for fertile hatchability and early and late embryonic mortality (P < 0.001). In the young flock eggs, the fertile hatchability was significantly lower in the rapid than in the control cooling treatment (88.7 vs. 92.8%) due to higher early and late embryonic mortality, whereas rapid cooling reduced early embryonic mortality (P < 0.01) and numerically increased the fertile hatchability (88.7 vs. 87.2%) in the old flock eggs. Hatch time was affected by the cooling treatment. The average hatch time was delayed by 3 h by rapid cooling (486.2 vs. 489.2 h) after oviposition compared with the control. This study showed that cooling the EST to 24°C within 45 min (rapid cooling) compared to 6 h (control) after laying retarded the blastoderm developmental stage and hatch time of eggs from both young and old broiler breeder flocks. This was apparently detrimental for the young flock as indicated by the higher early and late embryonic mortality but beneficial for the old flock due to the lower early embryonic mortality. The differences in hatchability between young and old flock eggs resulting from a rapid cooling rate might depend on the differences in embryonic development at oviposition.

P-252 A roadmap to normal human embryo development – a timelapse study of embryos resulting in the live birth

Abstract Study question What are the morphokinetic parameters of preimplantation development in normal human embryos? Summary answer We provide a timeline of early developmental events and the incidence of embryo morphological features compatible with childbirth. What is known already Timelapse embryo monitoring provides unique insight into early human development. Implementation of this technique in clinical practice allows for assessing developmental dynamics for improved embryo selection. Several markers and ranking algorithms have been proposed to predict blastulation or implantation outcomes, but only a few studies assessed time-lapse data with live birth as the primary endpoint. Therefore, the comprehensive morphokinetic profile of embryos that gave rise to live birth has not been defined. Study design, size, duration Retrospective observational analysis of 300 time-lapse records of IVF embryos known to develop into healthy newborns. Out of total 73 quantitative/qualitative signs annotated, we focused on 9 developmental events and 14 morphological features and evaluated their timing, duration, and incidence. The influence of potential confounding factors (i.e., egg age, donor egg, donor sperm, sperm quality, and sex of the child) was evaluated by advanced statistical methods. Participants/materials, setting, methods Embryo monitoring was performed by a GERI-timelapse incubator. Image acquisition of individual embryo development lasted 5-6 days, starting 10 minutes after ICSI, which was used as reference time point. Transmitted light images were automatically captured in 5-minute intervals and 7-11 focal planes. The embryo selection for transfer was based solely on its morphology. The annotation data represent the consensus of minimum 3 experienced embryologists. Generalized linear models were used to explore relationships between dataset variables. Main results and the role of chance The average age of female participants was 27.5 years; 71.67% of embryos were derived from young donor eggs without fertility disorders. The severe andrological factor was present in 8% of male patients; donor sperm was used in 23% of cases; 16% of embryos were derived from dysmorphic oocytes. Both sexes were equally represented among analyzed embryos. Our analysis showed that early development was characterized by remarkably short first mitosis (2.68 ± 0.73h) and the interval between the second and third division (t4-t3 = 0.65 ± 0.66h), whereas the third cleavage was less synchronous (t8-t5 = 5.46 ± 4.9h) No association between quantitative signs and confounding factors was found. Interestingly, 2-cell stage embryos often contained multiple nuclei in at least one blastomere (51%), but multinucleation was reduced at the 4-cell stage (8%). Multipolar divisions were absent during zygotic division and rare (2.3%) during the second cleavage. Preterm and partial compaction was observed in 26.6% and 34% of embryos, respectively. Importantly, we noticed that 11.6% of embryos in our dataset deviated from conventional scenario of cleavage dynamics. These “atypical” embryos were characterized by a significantly higher incidence of multipolar divisions during the second cleavage compared to “typical,” regularly dividing embryos. Additionally, the odds of partial compaction increase 10 times in “atypical” embryos. Limitations, reasons for caution The presented analysis only involved embryos confirmed to result in a live birth after transfer. The comparison with data from embryos that did not produce pregnancy was not performed because it would be impossible to discriminate between the role of the embryo and endometrial factors in implantation failure. Wider implications of the findings Human embryos may develop into healthy children despite irregular cell division. A high incidence of partial compaction in “atypical” embryos suggests a self-correction mechanism rescuing their developmental potential. A larger-scale analysis of features compatible with live birth is needed to improve embryo selection criteria for evidence-based decision-making. Trial registration number not applicable

P-073 Comparison of human preimplantation embryo development after sperm selection for ICSI using the microfluidic ZyMōt device versus density gradient centrifugation

Abstract Study question Does microfluidic sperm selection using ZyMōt device has a significant effect on blastocyst development, ploidy, and improves pregnancy outcomes when compared with density-gradient centrifugation. Summary answer The study demonstrated that sperm selection using a microfluidic device had no impact on euploid blastocyst rates or clinical pregnancy outcomes. What is known already Selecting competent spermatozoa with the highest genomic integrity for ICSI is a key to achieving normal embryo development and a healthy live birth. Several sperm preparation techniques have long been scrutinized with varied success. The novel microfluidic ZyMōt device appears promising for improving the quality of sperm used in Assisted Reproductive Technologies. Preliminary tests have shown that ZyMōt may increase sperm motility and considerably decrease DNA fragmentation, which could potentially enhance euploid blastocyst development rates. However, the impact of this sperm selection method on clinical outcomes has not been fully investigated. Study design, size, duration This is a retrospective cohort study performed in a single academic IVF centre (IRB # 16367). Data were collected from 1286 ICSI cycles in 2020-2021 (730 with ZyMōt and 556 with DGC), including 867 cycles with PGT-A outcomes. Morphological grading of 6640 blastocysts cultured in a time lapse imaging incubator (Embryoscope™) and ploidy of 4783 blastocysts using high resolution NGS (Illumina platform and Blue Gnome) were compared between the two study groups. Participants/materials, setting, methods All male partners were normo-spermic according to standard semen analysis. ICSI results for a total of 7277 mature oocytes injected with spermatozoa processed with ZyMōt device and 5977 oocytes injected with spermatozoa processed by gradient-density centrifugation were compared. For the analysis of 1478 euploid embryo transfer outcomes, all cases included a single blastocyst transferred in a frozen-thaw cycle. Associated patient characteristics, including age and fertility diagnosis were collected. Main results and the role of chance A significantly higher fertilization rate was observed with ZyMōt compared to the gradient prepared sperm (83.4% vs 81.0%, P = 0.0004, respectively). The blastocyst rates (61.3%, vs 60.4%, P = 0.34) as well as the proportion of high-quality blastocysts were similar in both groups (P = 0.20). Euploidy rates were not different between all female age groups, including young egg donors (≤ 30y of age) to patients with advanced maternal age (&amp;gt;40 y of age). Microfluidic sperm selection did not improve clinical pregnancy rates after euploid embryo transfer (42.9% vs 41.4%; P = 0.58). Limitations, reasons for caution Although this is the largest study to date evaluating application of the ZyMōt device, the retrospective nature and cohort design limited the interpretation of our results. The patient population did not include male factor cases and sperm DFI data was not available. Embryo transfer outcomes were limited to clinical pregnancies. Wider implications of the findings The ZyMōt device offers a convenient alternative to standard sperm processing by density gradient method. Further studies are needed to fully determined the impact of ZyMōt on embryo quality and clinical outcomes in different age and diagnosis groups of patients; particularly for those with high DFI and poor IVF/ICSI outcomes. Trial registration number not applicable

The RagA GTPase protects young egg chambers in Drosophila

The preservation of female fertility under unfavorable conditions is essential for animal reproduction. Inhibition of the target of rapamycin complex 1 (TORC1) is indispensable for Drosophila young egg chamber maintenance under nutrient starvation. Here, we show that knockdown of RagA results in young egg chamber death independent of TORC1 hyperactivity. RagA RNAi ovaries have autolysosomal acidification and degradation defects, which make the young egg chambers sensitive to autophagosome augmentation. Meanwhile, RagA RNAi ovaries have nuclear-localized Mitf, which promotes autophagic degradation and protects young egg chambers under stress. Interestingly, GDP-bound RagA rescues autolysosome defects, while GTP-bound RagA rescues Mitf nuclear localization in RagA RNAi young egg chambers. Moreover, Rag GTPase activity, rather than TORC1 activity, controls Mitf cellular localization in the Drosophila germ line. Our work suggests that RagA separately controls autolysosomal acidification and Mitf activity in the Drosophila young egg chambers.

Feeding Behaviour of the Mite Blattisocius mali on Eggs of the Fruit Flies Drosophila melanogaster and D. hydei

Many predatory mites use insects for dispersal; however, their possible negative effects on insect hosts during transportation and on insect offspring while preying in the hosts’ habitats are still poorly understood. A recent study has revealed that the predatory mite Blattisocius mali can not only spread by means of drosophilid fruit flies but also feed on their bodies during dispersal. The aim of this study was to examine the capability of B. mali to prey upon the eggs of their fruit fly hosts and determine the effect of the egg’s age on the voracity of this predator. Drosophila melanogaster oviposited on agar media for 1 h and D. hydei for 8 or 16 h. During 10-h experiments with fifteen fly eggs per cage, a single female predator totally consumed on average 3.62 ± 0.673 “1-h” D. melanogaster eggs and 3.00 ± 0.612 “8-h” eggs of D. hydei, while it partially consumed 2.75 ± 0.586 and 3.00 ± 0.612 eggs of each fly species. In the experiments involving D. hydei, the predator totally destroyed a similar number of “8-h” and “16-h” eggs, but it partially consumed significantly more younger eggs than older eggs. Ethological observations showed that mites returned to some partially fed eggs, usually from the side where the first puncture was made, and only then did they consume them whole.

Actin limits egg aneuploidies associated with female reproductive aging.

Aging-related centromeric cohesion loss underlies premature separation of sister chromatids and egg aneuploidy in reproductively older females. Here, we show that F-actin maintains chromatid association after cohesion deterioration in aged eggs. F-actin disruption in aged mouse eggs exacerbated untimely dissociation of sister chromatids, while its removal in young eggs induced extensive chromatid separation events generally only seen in advanced reproductive ages. In young eggs containing experimentally reduced cohesion, F-actin removal accelerated premature splitting and scattering of sister chromatids in a microtubule dynamics-dependent manner, suggesting that actin counteracts chromatid-pulling spindle forces. Consistently, F-actin stabilization restricted scattering of unpaired chromatids generated by complete degradation of centromeric cohesion proteins. We conclude that actin mitigates egg aneuploidies arising from age-related cohesion depletion by limiting microtubule-driven separation and dispersion of sister chromatids. This is supported by our finding that spindle-associated F-actin structures are disrupted in eggs of reproductively older females.

The Effect of Using Papaya and Watermelon Juice as a Non-Synthetic Buffer on the Quality of Kacang Goat's (Capra Hircus) Liquid Semen During Cold Storage at 5oC

This study examines the role of non-synthetic buffers from watermelon and papaya juice added to coconut water diluent on the liquid semen quality of Kacang goats during cold storage at 5oC for three months. An experimental method was used in which semen from a 2.5-year-old male was collected twice a week using an artificial vagina. The primary ingredients include young coconut water, Viridis, watermelon, papaya, NaHCO3, and Egg Yolk (KT). Furthermore, the observed variables were individual motility, viability, and abnormality. This study used a Randomized Block Design (RAK)) with 3 treatments and 10 replications, namely P0: Coconut Water + NaHCO3 + 10% KT, P1: Coconut Water + Watermelon Juice + 10% KT, and P2: Coconut Water + Papaya Juice + 10% KT. The data were analyzed using Variety Analysis. The results showed the treatment had a significant effect (P&lt;0.01) on individual motility at all storage times, with the best motility up to 120 storage minutes with 61.00±3.16% at P1. Furthermore, the treatment had a significant effect (P&lt;0.01) on viability at all storage times. The best treatment was P0 (72.24±5.28%), and the lowest was P2 (1.40±0.84%), with a shelf life of 120 minutes. The treatment had no effect (P&gt;0.01) on abnormality at all storage times. It can be concluded that the use of watermelon and papaya juice as non-synthetic buffers in coconut water diluent on Kacang goat semen affects motility and viability but has no effect on abnormality.

'Gift with a price tag': Nigerian egg donors' knowledge, experiences and motivations.

Research around the world has indicated that the demand for egg donation has grown considerably among young females. This study qualitatively examines the knowledge, experiences, and motivations of young egg donors at a Nigerian health facility. In-depth interviews were conducted in Igbo and English with consenting thirty-one egg donors attending a fertil-ity clinic in Anambra State, south-eastern Nigeria. Data were collected and analysed to generate themes with the aid of NVivo 10 software. Three themes were identified from the participants' motivations and include (a) monetary (93.6%), (b) altruistic (3.2%), and (c) both monetary and altruistic reasons (3.2%). Findings highlighted that the differences were based on a variety of reasons in Nigeria. All the participants were literate and single, and the majority received payment. The majority (77.4%) of those who received payment mentioned that the payment was not worth the donation program. The participants preferred to be anonymous because they had not discussed their donation with their family members, and the non-acceptance of egg donation program by the Nigerian society. Given that the market for egg donation has become a common method of infertility management in Nigeria, our findings have important implications for practices, policy actions, and future research.

Low-expenditures diets in the feeding of poultry

The purpose of the research was to increase the egg productivity of poultry using low-expenditures compound feed with lupin. In order to achieve this purpose two scientific and farm experiments were conducted on young poultry and laying hens of the cross Haisex Brown. The research was carried out under the conditions of the enterprise AO “Agrofirma “Vostok” in the Volgograd region. The replacing of 50, 75 and 100 % of full-fat soya bean with lupin as part of compound feed for poultry of the 1st, 2nd and 3rd experimental groups compared with the control group positively affected the live weight of young animals, which increased to 29,2 g, while the expenditures of compound feed per 1 kg of gain decreased to 0,1 kg. In laying hens during the experiment period the number of laid eggs increased to 3,1 %, the egg weight to 1,2 % and feed expenditures decreased by 10 pcs eggs up to 3,03 %. In young poultry and laying hens the digestibility of nutrients and the use of nitrogen, calcium and phosphorus were higher in the experimental groups compared to the control group, respectively: crude protein by 0,43–1,28 and 0,29–0,78 abs.%, crude fiber by 0,39–0,62 and 0,35–0,59 abs.%, crude fat by 0,22–0,69 and 0,41–0,68 abs.%. The use of nitrogen from the accepted was higher by 0,31–1,04 and 0,13–1,83 abs.%, calcium by 0,41–1,36 and 1,65–2,75 abs.%, phosphorus by 0,63–1,43 and 0,77–1,85 abs.%. It was revealed during the experiments on young poultry and laying hens that replacing of full-fat soy bean in the diet with lupin influence on the digestibility of nutrients, the use of nitrogen, calcium and phosphorus, and also has a positive effect on feed expenditures, live weight of young poultry and egg productivity of laying hens.

Comparison of the Parasitization of Chelonus inanitus L. (Hymenoptera: Braconidae) in Two Spodoptera Pests and Evaluation of the Procedure for Its Production.

Simple SummarySuccessful integrated pest management of horticultural crops requires the evaluation of natural enemies used in biological control. To improve the mass rearing of Chelonus inanitus (L.) in the factitious host Ephestia kuehniella Zeller, we investigated the influence of host age and number of females parasitizing simultaneously on quality parameters evaluated in the commercial production of biological control agents, such as overall rearing success, duration of life cycle and body size. Under semi-field conditions, we investigated how the competition among females impacted the parasitism success on important pests Spodoptera exigua (Hübner) and S. littoralis (Boisduval). For the parasitoid mass rearing optimization, mature eggs seem to be more convenient because they increased the female percentage in the offspring and shortened the parasitoid life cycle. Furthermore, a high number of females parasitizing simultaneously reduced the emergence of non-parasitized hosts. Under more realistic conditions, the parasitoid effectively controlled both pests, but S. exigua may be a more convenient host because the parasitoid offspring was much larger. With this research, we provide a foundation that aims to better manage these cosmopolitan, highly polyphagous pests that exhibit long-distance migratory potential, alongside the potential use of this natural enemy.Chelonus inanitus (L.) is an egg-larval parasitoid of noctuids Spodoptera exigua (Hübner) and S. littoralis (Boisduval), whose mass rearing or real potential has not been targeted yet. To improve the rearing in the factitious host Ephestia kuehniella Zeller, we investigated the influence of host age and number of females parasitizing simultaneously on the overall rearing success, the influence of host age on the life cycle, and the influence of host species on the parasitoid body size. The proportion of emerging C. inanitus was higher from young host eggs, but more females emerged from mature eggs. Under high parasitoid competition, we observed a reduction in non-parasitized hosts without reducing parasitoid emergence. The parasitoid life cycle was longer in females, but the mismatch between sexes was smaller in mature eggs. The parasitoid size was smaller in the factitious host than in the natural hosts. Under semi-field conditions, we investigated the competition among parasitoid females on the overall parasitism success. The reproductive parasitism was more successful in S. exigua than in S. littoralis, and the maximum emergence was reached with three and four females, respectively. The control of S. littoralis may be attributed to the high developmental mortality, a non-reproductive parasitism that is often underestimated.

Features of embryonic development of meat quails

The influence of breed and storage period of hatching eggs on the duration and results of incubation and the development of quail was studied. It has been noted that in breeding quail farms, the collection period for hatching eggs can be as long as 2-3 weeks. Storage time has a negative effect on incubation time, embryo development, egg hatchability and hatchability of young chicks, which consequently reduces the economic efficiency of the poultry farm. The study was carried out on the eggs of the Pharaoh and Texas White quail breeds. It was found that storage of quail eggs for more than 7 days reduces the hatchability of eggs by 8.3-38.2% and the hatchability of young quail eggs by 15.7-41.4%. Reduced fertilization of eggs correlated with the loss of egg weight during storage (r = 0.974-0.995, p &lt; 0.05). Extending the shelf life of quail eggs to 14-21 days increased the average incubation hour of the Pharaoh breed by 6.3-12.1 hours, and the Texas white breed by 2.5-9.7 hours, had a significant effect during the embryogenesis period on the live weight of day-old quails of both breeds, utilization of yolk sac nutrients and development of the heart, liver and gizzard (η2= 0.541-0.902, p &lt;0.05-0.01). Hatchery eggs of the meat quail breeds Pharaoh and Texan White should be stored for no more than 7 days before incubation. The results of this study can be used in breeding, industrial and farm quail farms for planning sampling times, the number of eggs laid for incubation and places for planting day-old chicks, the number of future layers, the amount of feed needed; in the educational process of agrarian educational institutions.

Egg Cannibalism Varies With Sex, Reproductive Status, and Egg and Nymph Ages in Arma custos (Hemiptera: Asopinae)

Background: Egg cannibalism is common in nature. In China, Arma custos (Hemiptera: Asopinae) has been widely used as a natural enemy to control agricultural and forestry pests. A previous study showed that adult A. custos devour their eggs. However, no research has investigated the interaction between A. custos cannibalism and egg development. Clarifying the mechanisms involved in egg cannibalism by A. custos improves our understanding of the evolutionary relationships to enable more efficient mass rearing and biological control systems.Results: Virgin females showed a lower egg cannibalism inclination than gravid females. Both virgin and mated females showed a higher egg cannibalism inclination than virgin and mated males. The first and second instar nymphs did not devour eggs. The third, fourth, and fifth instar nymphs devoured eggs. Younger eggs were more readily eaten than older eggs. Neither A. custos nymphs nor female adults consumed all the available eggs, allowing an emergence ratio of &amp;gt;70%.Conclusion:Arma custos females exhibit a higher tendency for egg cannibalism than males. Egg cannibalism varies not only with the developmental stage of the eggs and nymphs but also with sex and reproductive status of A. custos females. These findings help us to better understand the evolutionary relationships in egg cannibalism by A. custos and contribute to the efficient mass rearing and realization of A. custos in biological control systems.

SERUM 24,25-DIHYDROXYVITAMIN D3 IS AN ACCURATE INDICATOR OF FOLLICULAR VITAMIN D STATUS AND OOCYTE AGING IN IVF PATIENTS

There is increasing evidence supporting the role of vitamin D in telomere biology and thus the potential need for normal vitamin D status to develop a competent oocyte. The unreliable results obtained with immunoassay-based methods have supported the use of liquid chromatography-tandem mass spectrometry (LC-MS/MS) and other vitamin D metabolites measurement. We previously reported that 24,25-dihydroxyvitamin D3 (24,25(OH)2D3), the main catabolite of 25-hydroxyvitamin D3 (25OHD3), is a more accurate and stable indicator of systemic and ovarian vitamin D status in young egg donors. Consequently, we aimed to explore if 24,25(OH)2D3 is a suitable indicator of systemic and follicular vitamin D status in a population of women undergoing IVF PGT-A cycles. Then, we aimed to evaluate the correlation between telomere length in cumulus cells (CCTL) and vitamin D metabolites concentrations in serum (S) and follicular fluid (FF) in this IVF patient population. 27 women between 37 and 40-years old undergoing IVF PGT-A cycle were included in this prospective proof of concept study. On the pick-up day, S and pooled FF from mature follicles were evaluated for 24,25(OH)2D3 and 25OHD3 levels via LC-MS/MS. Cumulus cells (CC) were obtained after oocyte stripping for CCTL measurement. Genomic DNA from CC was isolated and average delta cycle threshold (ΔCt) was determined using a SYBR green quantitative real-time PCR protocol with Taqman probes for relative telomere length (TL) normalized by multicopy Alu. Difference in means between S and FF vitamin D metabolites and correlation between 24,25(OH)2D3 and ΔCtCC, were evaluated by t-test and Pearson correlation test. 25OHD3 and 24,25(OH)2D3 mean concentrations were, respectively, 43.15 ± 10.28 ng/ml and 14.30 ± 4.95 in S, and 33.67 ± 6.87 ng/ml and 11.67 ± 3.53 ng/ml in FF. Both metabolites highly correlated between them in S (r=0.78, p=1.5e-06) and in FF (r=0.73, p=1.8e-05). When analyzing each metabolite separately, 24,25(OH)2D3 showed the strongest association between S and FF levels (r=0.96, p=1.9e-15) followed by 25OHD3 (r=0.92, p=2.2e-11). ΔCtCC mean value was 7.54 ± 1.04, and we found a significant negative correlation with 24,25(OH)2D3 levels in S (r=-0.51, p=0.0068) and FF (r=-0.42, p=0.0307). Since ΔCt values are inversely proportional to the amount of nucleic acids amplified, a higher ΔCt value indicates a shorter telomere. Our results show serum 24,25(OH)2D3 is a better indicator of ovarian vitamin D status than serum 25OHD3. Further, the observed significant inverse correlation between this metabolite and CCTL, indicates that, the higher the vitamin D concentrations in S and FF, the longer the telomeres in the cumulus cells in this homogenous population of women undergoing IVF PGT-A cycle.

P–563 Assessing ovarian age: Could we use leukocyte telomere length as a surrogate marker of cumulus cells telomere content?

Abstract Study question Is leukocyte telomere length (LTL) correlated with cumulus cells telomere length (CCTL) in an age-heterogeneous women population? Summary answer LTL showed a positive correlation with CCTL in the studied population. Hence, its potential value as indicator of ovarian age would deserve further evaluation. What is known already Progressive telomere shortening has been related to ovarian aging and genomic instability during early development. A positive correlation between short telomere length of the first polar body and aneuploidy rate has been reported. CCTL has shown to be a biomarker of oocyte and embryo quality, but its assessment is impractical. LTL has been proposed as a surrogate of TL of follicular cells, but telomere lengthening through folliculogenesis could be controlled by different mechanisms. Thus, we aimed to determine if LTL in an age-heterogeneous population is correlated with CCTL and therefore considered an accurate surrogate for telomere length in the ovary. Study design, size, duration In this prospective non-interventional cohort study, 35 egg donors and 17 women undergoing Preimplantation Genetic Testing for Aneuploidy (PGT-A) treatment were included during sixteen months. Following controlled ovarian stimulation determined by treating physicians, oocyte retrieval was performed 36 hours after final maturation induction. Cumulus cells (CC) for telomere length (TL) measurement were obtained after the pick-up and oocyte stripping. A blood sample was collected through peripheral venous access for LTL measurement. Participants/materials, setting, methods Genomic DNA of CC and leukocytes from the 52 subjects was isolated. Average delta cycle threshold (ΔCt) was determined using a SYBR green quantitative real-time PCR protocol for relative TL. For normalization of measurements, a Taqman assay for the multicopy gene Alu was performed. ΔCtL and ΔCtCC were compared by a paired t-test analysis and the fold change was calculated. Additionally, the association between them and patient age was analyzed by a Pearson correlation test. Main results and the role of chance Mean participant’s age was 29.94 ± 7.55 years and mean values for ΔCtL and ΔCtCC were 7.99 ± 0.53 and 7.46 ± 0.75, respectively. A positive significant correlation was found between age and ΔCt (ΔCtL: R2=0.71, p-value=5.18e–09; ΔCtCC: R2=0.47, p-value=0.00049). Since ΔCt values are inversely proportional to the amount of nucleic acids amplified and, therefore, to the telomere length, this correlation means that TL in both cell types decreases as women age. Additionally, ΔCtL was significantly higher than ΔCtCC (ΔCt fold change: 0.93, p-value=9e–07), meaning that CC showed significantly longer telomeres than leukocytes, thus supporting our previous published results in young egg donors. When analyzing the ΔCtL and ΔCtCC in these age-heterogeneous sample, a positive moderate and significant correlation was observed (R2=0.42, p-value=0.002). Thus, LTL could be suggested as a potential indicator of CCTL and therefore as a candidate for a biological marker of ovarian aging. Limitations, reasons for caution The sample size of this study was moderate and perhaps increasing the number of subjects might give additional strength to our findings. In addition, although relative telomere length allowed for adequate comparison between subjects, this method did not allow for absolute TL measurement. Wider implications of the findings: While reproductive implications of LTL measurement need to be further studied, our results support the potential usefulness of LTL measurement as an indicator of CCTL and ovarian aging when analyzing an age-heterogeneous population. Further, our findings suggest that CC could possess different mechanisms to cope against telomere length shortening. Trial registration number Not applicable