Hatchability Of Fertile Eggs Research Articles

Effects of MDA-19 on Zebrafish Larval Behavior: Perspectives From Neurodevelopment, Oxidative Stress, and Metabolomics.

As global regulations on synthetic cannabinoids tighten, illicit vendors increasingly turn to new structures of synthetic cannabinoids to evade legal scrutiny. MDA-19, a novel synthetic cannabinoid, exhibited significant agonistic effects on type 2 cannabinoid receptors invivo and showed emerging trends of abuse in illicit markets. However, research on the toxicological effects of MDA-19 remains scarce. In this study, we examined the effects of MDA-19 on neurodevelopment, behavior, oxidative stress, and metabolomics by exposing zebrafish embryos to MDA-19 solutions with concentrations of 1, 10, and 20 mg/L over 5 days. Results revealed that exposure to 10 and 20 mg/L of MDA-19 accelerated hatching in zebrafish embryos but led to reduced body length without affecting mortality or malformation. Furthermore, exposure to all concentrations of MDA-19 resulted in diminished swimming ability and reduced activity time in zebrafish. Transgenic zebrafish (hb9-GFP) exposed to MDA-19 exhibited impaired development of spinal motor neurons. Notably, exposure to 20 mg/L MDA-19 increased the levels of reactive oxygen species (ROS) in zebrafish and elevated the activity of antioxidant enzymes such as superoxide dismutase (SOD) and catalase (CAT), while the levels of the lipid oxidation product malondialdehyde (MDA) remained unaffected. Nontargeted metabolomics analyses showed that MDA-19 interfered with multiple metabolic pathways affecting energy metabolism, such as alanine, aspartate, and glutamate metabolism; the citric acid cycle (TCA cycle), pantothenate, and coenzyme A biosynthesis; and purine metabolism. In conclusion, the present study provided the essential evidence for the neurotoxic effects of MDA-19, which was associated with impaired neurodevelopment, dysregulation of oxidative stress homeostasis, and altered energy metabolism.

Sound and vibration control crocodile hatching

Abstract The birth of a baby or the hatching of an egg are moments when the risk of predation is particularly high. In oviparous species where clutches contain many eggs, one strategy for limiting predation is based on mechanisms that synchronise hatching, which reduces the individual risk of being targeted and may allow hatchlings to emerge under parental protection. These mechanisms involve communication signals between eggs and between eggs and parents. While previous studies in various species have shown the importance of sound and vibration signals in these exchanges, how embryos integrate this information remains poorly understood. Here we show that crocodile embryos respond differently to calls emitted by siblings (hatching calls) and to vibrations mimicking parental intervention (rubbing and scratching the shell) or the presence of a predator, suggesting that these two stimuli carry different information. Through playback experiments, we confirm that hatching calls elicit vocal responses and synchronous hatching in mature embryos, while embryos hatch earlier when they perceive vibrations. Our study underlines that the control of hatching by external factors can rely on differential apprehension of multiple sensory inputs by embryos.

Stimulation of inactivated Metschnikowia bicuspidata promotes the growth, and immunity of Eriocheir sinensis larvae

The Chinese mitten crab (Eriocheir sinensis) is an economically essential crustacean specie in China. The outbreak of disease caused by Metschnikowia bicuspidata has resulted in high mortality and huge economic loss in the E. sinensis aquaculture industry. Immune priming can protect invertebrates against pathogens in the second exposure, which has been reported in adult E. sinensis and provides a novel approach for disease control. This study evaluated the effects of treatment with formalin-killed M. bicuspidata on the growth, development, and immunity of E. sinensis embryos and larvae. Stimulation of E. sinensis embryos with inactivated M. bicuspidata (Mb group) did not significantly affect the mass and size of embryos. While the carapace width, abdominal length, and tail length of larvae in the Mb group were significantly longer than those of control group in most stages. At 120 h and 144 h after embryo hatching, the metamorphosis rate of larvae in the Mb group was 24.59-fold (p < 0.05) and 16.07-fold (p < 0.001) higher than that in the control group. Moreover, after the larvae suffered alive M. bicuspidata challenge, the mortality in the Mb group significantly decreased (0.48-fold, p < 0.05) compared with that in the control group, and the mRNA expression levels of genes related to immunity (MAPK, Toll2, and STAT), growth (ATGL, Chi, Chymotrypsin, and mTOR), and development (Ubx) were significantly increased in the Mb group. These results suggested that stimulation of E. sinensis embryos with inactivated M. bicuspidata significantly promoted the growth and development of larvae and endowed them with stronger resistant capacity to M. bicuspidate. This finding may provide a novel and safe approach for preventing disease and improving larvae quality in E. sinensis aquaculture.

Ferroptosis involvement in the neurotoxicity of flunitrazepam in zebrafish

The occurrence of psychoactive drugs such as benzodiazepines (BZDs) has been frequently observed in water environments, however, there is still limited understanding regarding their potential impact on neurological health and underlying mechanisms. This study evaluates the neurotoxicity of the typical BZD drug flunitrazepam (FLZ, 0.2 and 5 μg/L) in zebrafish embryos and adults, and investigates the relationship between ferroptosis and FLZ-induced neurotoxicity. The results indicate that acute exposure to FLZ significantly inhibits zebrafish embryo hatching and promotes death, induces larval deformities, and leads to abnormal neurobehavioral responses in larvae, likely due to ferroptosis induction. Results from a 30-day subacute exposure to FLZ show that it decreases motor function and induces cognitive impairment in adult zebrafish. Immunofluorescence of brain tissues revealed a reduction in neurons in the telencephalon and an increase in microglia in the mesencephalon of the zebrafish exposed to FLZ. The ultrastructure of brain mitochondria showed serious damage. Besides, FLZ exposure increased iron levels, reduced GSH/GSSG and increased LPO in brain tissue, which is related to the abnormal expression of genes associated with ferroptosis. In the rescue experiments with co-exposure to deferoxamine (DFO), the motor-related parameters and biochemical indexes related to ferroptosis were restored, suggesting that FLZ can induce ferroptosis. The molecular docking results indicated that FLZ had a higher affinity with transferrin. This study elucidates the close relationship between ferroptosis and FLZ-induced neurotoxicity, which is significant for understanding the physiological damage caused by psychoactive substances and assessing environmental risks.

Effects of Thermal Manipulation During the Second Half of Incubation on Embryo Physiology, Hatching Parameters, and Quality of Broiler Chickens in Tropical Climate of Togo

Chickens are sensitive to environmental challenges caused by temperature. The current study aimed to determine the effects of heat manipulation during embryonic development on the physiological responses of Goliath chickens. A total of 2000 hatching eggs from 48-week-old breeders were weighed, numbered, and randomly distributed equally into 4 incubators. Each incubator received 500 eggs (4 replicates of 125 eggs each). Eggs in two of the incubators were rotated hourly at a 45° angle and maintained at 37.8°C and 60% relative humidity (T0 groups). Between embryonic days (ED) 10 and 18 of incubation, the eggs from the other two incubators were heated to 38.5°C for 6 hours per day (T1 groups). The eggs were reweighed and candled, and viable eggs were moved to the hatching baskets at ED 18 of incubation. Hatching eggs were examined individually for hatching events every three hours during the final three days of incubation. On day 21, blood samples were collected from 12 chicks per group for hormonal and biochemical analyses. The evaluated blood parameters included Triiodothyronine (T3), T4 (thyroxine), cortisol, uric acid, lactate dehydrogenase, and total protein. At hatch, chicks were weighed and their quality (survival after hatching and performance standards) was evaluated. Data were collected on embryonic development, hatching window, hatching events, biochemical parameters, and hormonal concentrations. Results indicated that hatchability, chick’s weight, Tri-iodothyronine, and corticosterone were higher in the T1 group, compared to the control group. At hatch on day 21, the pipping muscle of chicks in the treated group (T1) was significantly heavier than that of the control group, while the embryonic mortality rate was significantly higher in the T0 group. In conclusion, applying heat treatment for 6 hours at 38.5°C from ED10-ED18 of embryogenesis increased significantly the hatching rate, the pipping muscle, and the chick’s weight in this study. Keywords: Embryonic development, Physiology, Slow-growing broiler, Thermal manipulation, Tropical climate

Interactions between broiler parent stock age and egg pre-incubation duration: effects on embryo development, hatchability, day-old chick weight, and yolk sac weight

Egg storage is a common practice in commercial hatcheries, but prolonged storage can negatively impact hatchability, causing a significant problem for the poultry industry. Repeated pre-incubation could mitigate the decline depending on the age of the parent stock. The study investigated the interactions between parent stock age (30, 45, and 58 weeks) and repeated pre-incubation on the hatchability and embryo development of 15-day stored eggs from Ross 308 parent stock. Three different pre-incubation durations were employed during storage: no pre-incubation and twice at the 5th and 10th days of egg storage for either 4 or 8 h. For each parent stock age, 3 600 eggs collected on the same day from the same parent stock were used for hatchability assessment. The duration of pre-incubation was determined as the eggshell temperature increased from 28 °C to a maximum of 35 °C and then cooled to 28 °C; the persistency at 35 °C was either 1 or 4 h for the total pre-incubation period. The hatchability of both set and fertile eggs and early, middle, and late embryonic mortality depended on the parent stock’s age (P < 0.001). Pre-incubation alone did not have any impact on hatchability. Conversely, a significant interaction was observed between parent stock age and pre-incubation duration on the hatchability of fertile eggs (P = 0.001). At 30 weeks of parent stock age, both durations of pre-incubation positively influenced the hatchability. At 45 weeks of parent stock age, pre-incubation length had no effect on hatchability. At 58 weeks of parent stock age, a longer pre-incubation period, 2 × 8 h, was associated with decreased hatchability. Early embryonic mortality was not influenced by pre-incubation. However, a significant interaction was observed (P = 0.003). At 30 weeks of parent stock age, both short and long lengths of pre-incubation were associated with a decrease in early embryonic mortality. However, at 45 and 58 weeks, pre-incubation did not significantly affect early embryonic mortality. Additionally, longer pre-incubation periods significantly increased middle mortality compared to untreated eggs (P = 0.035). The median of embryo development for untreated eggs was the same across all ages (stage 10). In the older parent stock (45 and 58 weeks), repeated pre-incubation increased variability in embryo development, while in the younger parent stock, repeated pre-incubation decreased variability in embryo development. In conclusion, the duration and the frequency of pre-incubation should be specified based on the age of the parent stock.

Hybridization and growth characteristics of interspecific crosses between Crassostrea hongkongensis and Crassostrea iredalei

Interspecific hybridization of oysters is a highly efficient breeding strategy that can produce commercially viable phenotypes. Crassostrea hongkongensis, the primary cultivar in southern China, faces increasing summer mortality risks and slow growth rates, which elevate commercial risks for farmers. C. iredalei, a commercially cultivated species in Southeast Asia, has been expanding its ecological niche northward in recent years, providing opportunities for interspecific hybridization with C. hongkongensis. This study conducted a 2 × 2 factorial cross between C. hongkongensis and C. iredalei (II: C. iredalei ♀ × C. iredalei ♂, HH: C. hongkongensis ♀ × C. hongkongensis ♂; IH: C. iredalei ♀ × C. hongkongensis ♂, HI: C. hongkongensis ♀ × C. iredalei ♂) and set up 6 salinity treatments (14, 17, 20, 23, 26 and 29 ppt) to explore the optimal salinity for embryo hatching. The results showed that the hybridization was successful, despite bidirectional fertilization and pronounced asymmetry in fertilization success. The optimal hatching salinity for C. iredalei and C. hongkongensis was 23 ppt and 17–20 ppt, respectively, while the optimal salinity for reciprocal hybrids was 20 ppt. Notably, the hatching rate of IH was lower than that of the control group at the optimal salinity. During the pelagic larval stage, hybrid larvae exhibited significant hybrid inferiority, with slower growth rates and higher mortality rates compared to intraspecific hybridization. It is worth noting that IH failed to overcome genetic incompatibility, resulting in complete mortality during the pelagic larval stage and failure to enter the growth stage. At the 360th day of the growth period, HI hybrids grown in Sanbaimen Sea exhibited significant hybrid vigor in shell height (15.65 %), and in Daya Bay Marine Biology Research Station, Chinese Academy of Sciences (MBRS), they showed significant single-parent hybrid advantages in shell height (28.44 %) and cumulative survival rate (58.11 %) compared to C. hongkongensis. In terms of gonadal development, HI hybrids were able to produce functional and viable gametes, although with some delay compared to their parents. The hybrid offspring inherited the phenotypic traits of their parents, with a grayish-yellow flesh color intermediate between the two oyster species. HI is a valuable genetic resource for oyster breeding, and its growth potential should be further explored to meet commercialization demands.

Development of germline progenitors in larval queen honeybee ovaries.

Honeybees (Apis mellifera) are a keystone species for managed pollination and the production of hive products. Eusociality in honeybees leads to much of the reproduction in a hive driven by the queen. Queen bees have two large active ovaries that can produce large numbers of eggs if conditions are appropriate. These ovaries are also active throughout the long lives of these insects, up to 5 years in some cases. Recent studies have indicated that the germline precursors of the adult honeybee queen ovary are organized into 8-cell clusters, joined together by a polyfusome; a cytoplasmic bridge. To understand the origin of these clusters, and trace the development of the honeybee queen ovary, we examined the cell types and regionalization of the developing larval and pupal queen ovaries. We used established (nanos and castor), and novel (odd skipped) gene expression markers to determine regions of the developing ovary. Primordial germline cells develop in the honeybee embryo and are organized into ovary structures before the embryo hatches. The ovary is regionalized by larval stage 3 into terminal filaments and germaria. At this stage, clusters of germline cells in the germaria are joined by fusomes and are dividing synchronously. The origin of the 8-cell clusters in the adult germarium is therefore during larval stages. On emergence, the queen ovary has terminal filaments and germaria but has not yet developed any vitellaria, which are produced after the queen embarks on a nuptial flight. The lack of germaria, and the storing of germline progenitors as clusters, may be adaptions for queen bees to endure the metabolic demands of a nuptial flight, as well as rapidly lay large numbers of eggs to establish a hive.

Corrigendum to: Artificial incubation and hatching of embryos of the red swamp crayfish &lt;i&gt;Procambarus clarkii&lt;/i&gt; (Decapoda: Cambaridae)

Corrigendum to: Artificial incubation and hatching of embryos of the red swamp crayfish &lt;i&gt;Procambarus clarkii&lt;/i&gt; (Decapoda: Cambaridae)

Observation on embryonic development of Gymnodiptychus dybowskii (Kessler, 1874) in Manas River, Xinjiang, China

To protect the germplasm resources of Gymnodiptychus dybowskii (Kessler, 1874), a species endemic to Xinjiang, the key stages of embryonic development of G. dybowskii were studied. From May to July 2021, the artificial breeding of G. dybowskii was carried out at the fish breeding station of the Kenswart Water Conservancy Project. The embryos and early larvae were obtained using temperature promotion, water stimulation, hormone induction, and dry insemination techniques. their development process was observed, and morphological characteristics of each developmental stage were recorded. The results showed that the mature oocyte was round, heavy, and light yellow, with an egg diameter of (2.32 ± 0.21) mm. The fertilized egg was slightly viscous, and the viscosity disappeared after water absorption. Under the temperature of 15.6-17.7 ℃ (16.23 ± 0.52) ℃, the embryonic development of G. dybowskii lasted for 142 h and 33 min and went through 7 stages of fertilization, cleavage, blastula, gastrula, neurula embryo, organ formation, and membrane hatching, with a total of 26 periods. The membrane broke after 2376.724 ℃·h. The embryonic development of G. dybowskii follows the rule of freshwater bony fish, but it differs from other Schizothorax species in the muscular effect period and membrane emergence mode. In addition, differences in hatching water temperature among different geographic populations lead to differences in embryo development duration and accumulated temperature, which further proves that G. dybowskii is highly adaptive to the ecological environment of its habitat water, and these characteristics together constitute its survival and reproduction strategy in the natural environment. In this study, through the artificial breeding experiment of G. dybowskii, the characteristics of its embryonic development were explored, which laid the foundation for the cultivation of unique fish seedlings, enriched the early life history data of G. dybowskii, and further provided basic data for its resource protection.

Impact of different mating ratios of broiler breeder on reproductive performance during post moult phase.

Studies comparing mating ratio after forced molting are important for improving the efficiency of broiler breeder flocks. This study examined the effect of mating ratios on Egg production, chick weight, fertility, hatchability and embryonic mortality rate in Arbor Acres Plus broiler breeders post-moult phase. A total of 195 birds (62 weeks old), consisting of 15 cocks and 180 hens were randomly allocated with uniform body weight in a Completely Randomized Design into three groups based on the mating ratio (cock to hen). The groups included ratios of 1:10, 1:12, and 1:14, with each group replicated 5 times. Eggs were collected twice a day, and stored for 7 days at room temperature before placing them in the incubator. Results showed that mating ratios 1:10 and 1:12 had a positive effect on fertility rate and total hatchability compared to the 1:14 ratio. However, mating ratios did not affect laying rate, egg weight, egg mass, chick weight, hatchability of fertile eggs, and embryonic mortality rate. In conclusion, to reduce the cost of raising and caring cocks, a mating ratio of one cock to every twelve hens can be used for broiler breeders after forced molting to obtain the best fertility and hatching results.

Developmental Toxicity and Apoptosis in Zebrafish: The Impact of Lithium Hexafluorophosphate (LiPF6) from Lithium-Ion Battery Electrolytes.

With the growing dependence on lithium-ion batteries, there is an urgent need to understand the potential developmental toxicity of LiPF6, a key component of these batteries. Although lithium's toxicity is well-established, the biological toxicity of LiPF6 has been minimally explored. This study leverages the zebrafish model to investigate the developmental impact of LiPF6 exposure. We observed morphological abnormalities, reduced spontaneous movement, and decreased hatching and swim bladder inflation rates in zebrafish embryos, effects that intensified with higher LiPF6 concentrations. Whole-mount in situ hybridization demonstrated that the specific expression of the swim bladder outer mesothelium marker anxa5b was suppressed in the swim bladder region under LiPF6 exposure. Transcriptomic analysis disclosed an upregulation of apoptosis-related gene sets. Acridine orange staining further supported significant induction of apoptosis. These findings underscore the environmental and health risks of LiPF6 exposure and highlight the necessity for improved waste management strategies for lithium-ion batteries.

Transgenerational effects of the levonorgestrel-based birth control pill in zebrafish offspring

The consumption of hormone-derived medicines, such as levonorgestrel (LNG), is increasing worldwide, and its discharge into the environment reaches non-target organisms. In our previous study, we exposed the parental generation of zebrafish to environmentally relevant concentrations of LNG during the developmental phase. Subsequently, they had grown in a tank with clean water until adulthood. Now, we allowed this parental generation to reproduce to obtain F1 progeny unexposed to LGN, in order to analyze the transgenerational effects of parental LNG exposure on the survival and hatching of unexposed F1 embryos and the stress and behavior of F1 larvae. Here, we found decreased survival rates with higher LNG concentrations, providing a transgenerational effect. This highlights the environmental impact of exposure to LNG, causing damage at the individual and population level and affecting the next generation at the beginning of development, impacting qualities in the survival of the species.

Evaluation of d 18 in ovo administration of soursop (Annona muricata) leaf extract into the air space on hatch performance and physiology of Noiler chicks

Efficient poultry production can be accomplished using combined technologies. A combination of in ovo and ethno-veterinary technologies can deliver significant benefits, including reduced labour and production costs. This study evaluated the effect of in ovo administration of soursop leaf extract (SLE) on the hatching performance and physiology of Noiler chicks. A total of 550 eggs were incubated, and 460 fertile eggs were randomly distributed into 4 groups with 3 replicates on the 18th d of incubation. The eggs were then injected with 0.75 µg SLE, 1.5 µg SLE, and saline solution (negative control) at a rate of 0.2 ml in the air space. The noninjected group served as the positive control. At the end of the hatching period, the various groups were evaluated for embryo mortality, hatchability, hatch duration, organ weight, serum biochemistry, and chick quality. The results showed no significant differences (P > 0.05) in embryonic mortality, hatchability, organ weight, total protein, albumin, globulin, aspartate aminotransferase, alanine aminotransferase, and glucose among the treatment groups. However, chick weight, chick quality, and serum triglyceride levels were significantly (P < 0.05) higher in the extract-injected group. Additionally, incubation and hatch times were significantly lower (P < 0.05) in the SLE group compared to the other groups. In ovo administration of soursop leaf extract resulted in reduced incubation duration, hatch time, and embryo mortality. In conclusion, the in ovo injection of SLE improved hatch performance and chick quality.

Hazardous effects of plastic microfibres from facial masks to aquatic animal health: Insights from zebrafish model

Facial masks are a source of plastic microfibres (PMFs) in the aquatic environment, an emerging risk factor for aquatic organisms. However, little is known concerning its impact during the early developmental stages of fish. Thus, the current study aimed to evaluate the potential interaction and developmental toxicity of PMFs derived from leachate of surgical masks (SC-Msk) and N-95 facial masks (N95-Msk) using a multi-biomarker approach in developing zebrafish (Danio rerio). PMFs from both facial masks were obtained and characterized by multiple techniques. Zebrafish embryos were exposed to environmentally relevant concentrations of PMFs from both facial masks (1000, 10,000, and 100,000 particle L−1), and the toxicity was analysed in terms of mortality, hatching rate, neurotoxicity, cardiotoxicity, morphological changes, reactive oxygen species (ROS) levels, cell viability, and behavioural impairments. The results showed that both facial masks can release PMFs, but the N95-Msk produced a higher concentration of PMFs than SC-Msk. Both PMFs can interact with zebrafish chorion and don't cause effects on embryo mortality and hatching; however, zebrafish embryos showed cardiotoxic effects, and larvae showed increased agitation, average speed, and distance travelled, indicating the behavioural impairments induced by PMFs derived from facial masks. Overall, results showed the risk of PMFs to the health of freshwater fish, indicating the need for greater attention to the disposal and ecotoxicological effects of facial masks on aquatic organisms.

P-193 Does the day of laser-assisted hatching affects the clinical outcomes of single vitrified blastocyst transfer cycles? A propensity score–matched study

Abstract Study question What is the impact of different days of laser-assisted hatching on the clinical outcomes of single vitrified blastocyst transfer cycles? Summary answer Clinical pregnancy of single vitrified blastocyst were similar, irrespective of day of laser-assisted hatching. What is known already Assisted hatching aims to create a weakness in the ZP to aid embryo hatching and implantation. Day 5 assisted hatching is typically performed shortly before the embryo transfer while day 3 assisted hatching is performed before blastocyst culture expansion and vitrification. Despite over 25 years of use, there is still no standardized protocol for AH, and published data on its efficacy are controversial and inconclusive. While efforts have been made to study the link between AH techniques and pregnancy outcomes, there is limited consensus for optimizing AH protocols like the day of performance. Study design, size, duration This was a retrospective study based on data collected between January 2022 and October 2023. Propensity score matching (PSM) was performed in a 1:1 matching ratio. 123 patients of day 3 laser assisted hatching group (D3 LAH group) were successfully matched to 123 cycles of day 5 laser assisted hatching group (D5 LAH group). The D5 LAH group was from March 2023 to October 2023, and the D3 LAH from January 2022 to February 2023. Participants/materials, setting, methods Single vitrified day 5 embryo transfer, embryos survived after warming, and patient agreed to receive LAH were include in this study. We excluded donation cycles, missing data, severe female factors. Primary outcome is clinical pregnancy. Comparisons between groups were performed with chi-square test, Fisher’s exact test, Mann–Whitney U test, and Student’s t-test where appropriate, with a P value &amp;lt;0.05 considered statistically significant. A multivariable analysis in the GEE model was adjusted for the confounding factors. Main results and the role of chance After propensity score matching, there was no significant difference in patient characteristics between the groups, creating similar cohorts. For example, the frequency of primary infertility was significantly different between groups initially (61% vs 46.7% in D5 LAH vs D3 LAH respectively, P = 0.004). Following propensity score matching the rate of primary infertility was similar in both groups (with SMD=0.08). Standardized mean difference (SMD) &amp;lt; 0.1 suggests adequate variable balance after propensity matching. Clinical pregnancy rate were similar between two groups: 66/123 (53.7%) D3 LAH cycles and 75/123 (61%) D5 LAH cycles. When generalized estimating equation were performed: only TE grade, but not the day of laser assisted hatching, was noted to be an independent predictor of clinical pregnancy (OR = 0.068; 95% CI: 0.005-0.977; p = 0.048). Poor TE grade had a weak negative relationship with clinical pregnancy of single blastocyst cycles. Limitations, reasons for caution The main limitation of the study is its retrospective design and small sample size. Wider implications of the findings Clinical outcomes are comparable between day 3 laser assisted hatching and day 5 laser assisted hatching, although clinical pregnancy can be slightly improved with higher TE grade. Trial registration number not applicable

Research Note: Effects of different light-emitting diode lights during egg incubation on hatching performance and embryo development in White King pigeons

The light provide during incubation can influence hatching characteristics (hatching time, hatchability, etc.) and embryo development in chickens, geese, and turkeys. However, relevant studies on this factor in pigeons are lacking. This study investigated the effects of in ovo photostimulation during embryogenesis on hatching performance, squab quality, and embryo development in pigeons. 400 eggs from paired- bred pigeons were randomly distributed into 4 incubation lighting treatments, with 2 replicates per treatment. The treatments included dark as a control (NL), 12-h light, and 12-h dark photoperiods of white light (WL), red light (RL), and green light (GL) (100 lx at egg level) during the first 15 d of incubation. A total of 1,600 eggs in 4 batches from White King pigeons were used. The results showed that hatching time of the WL group was significantly shorter than that of the dark light group (P < 0.05). The hatchability of fertile eggs in the WL group was significantly higher (P < 0.05), whereas the hatchability of fertile eggs in the RL group was significantly lower (P < 0.05) than that of in the control group. Light stimulation had no effect on time to 90% hatching or average hatching time (P > 0.05). In addition, the hatch window was not extended by light stimulation (P > 0.05). The group incubated under GL showed an increase in embryo weight and relative leg muscle on embryonic d 14 and the hatching day compared to the dark incubation (P < 0.05). Green light stimulated the heart and liver development during the early and middle stages of embryogenesis. It was concluded that white light stimulation during embryogenesis accelerated the hatching process, whereas monochromatic green light had a positive effect on embryo development. Our findings provide important guidance for developing light protocols for pigeon egg incubation.

Ultra-high static magnetic fields altered the embryonic division and development in Caenorhabditis elegans via multipolar spindles

IntroductionUltra-high static magnetic fields (SMFs) have unique advantages in improving medical and academic research. However, the research on the early embryo exposure of ultra-high SMFs is minimal, extensive exploration is indispensable in living organisms. ObjectivesThe present study was aimed to study the effects of ultra-high SMFs on the early embryonic division and development of Caenorhabditis elegans (C. elegans). MethodsEarly adult parents containing fertilized eggs in vivo were exposed to SMFs at intensities ranging from 4 T to 27 T. The number of mitotic cells in the reproductive glands of the P0 worms, early embryonic cell spindle localization, embryo hatching and the reproductive as well as developmental indicators of F1 and F2 nematodes were examined as endpoints. ResultsOur results indicated that ultra-high SMFs has no obvious effect on the germ cell cycle, while 14 T and 27 T SMFs significantly increased the proportion of multi-polar spindle formation in early embryonic cells, and reduced the developmental rate and lifespan of C. elegans exposed at the embryonic stage. Spindle abnormalities of early embryonic cells, as well as the down-regulation of genes related to asymmetric embryonic division and the abnormal expression of the non-muscle myosin NMY-2 in the division grooves played a critical role in the slowing down of embryonic development induced by ultra-high SMFs. ConclusionsThis study provided novel information and a new sight for evaluating the biosafety assessment by exposure to ultra-high SMFs at the early embryonic stage in vivo.

Description of a Novel Procedure to Aid in Emergence of Larval La Palma Glass Frogs (Hyalinobatrachium valerioi) to Improve Survival Rate with Implications for Captive Management and Conservation

New, more efficient ways to accomplish objectives are key to improving the ability of zoological and conservation organizations to protect the animals they study and care for. Here, we describe an ovocesarean procedure, a novel task to assist the hatching of larval anurans in cases when allowing for hatching to occur naturally presents a risk to the survival of the progeny. This study focuses on two clutches of La Palma Glass Frogs (Hyalinobatrachium valerioi) where the eggs were not laid over a water body for the tadpoles to drop into upon emergence from the egg. A simple, three-step procedure that can be performed in just a few minutes resulted in a 95% success rate in emergence and led to increased survivability in the tadpoles that were assisted. Procedures that assist hatching of embryos and neonates are discussed in many circles of animal care but have not been described in detail to provide assistance to those that are not in a situation where they can learn it from a professional. This description of the ovocesarean procedure assigns a definitive, technical term to assisted hatching and can easily be extrapolated to other oviparous animals. Although the focal species here is of a Least Concern conservation status, this procedure can be key in improving reproductive success in other, more threatened species of anurans.

Effects of Hatching Eggs Storage at Room Temperature on Hatching Performance and Day Old Chick Quality of Arab Chickens

This study evaluated the effect of hatching egg storage at room temperature on hatching performance and day old chick quality of Arab chickens. Two hundreds hatching eggs were obtained at the same day from 55-weeks-old Arab chicken flocks. Hatching eggs were then randomly distributed into four treatments, including 1 day storage (1DS), 4 days storage (4DS), 7 days storage (7DS), and 10 days storage (10DS). Each of those treatment using five replicates and each of replicate consisted of 10 hatching eggs. Temperature and relative humidity in the storage room were 27.9 ± 0.55 °C and 55.4 ± 4.84%, respectively. At the end of each storage duration, hatching eggs were incubated at temperature and relative humidity of 37.8 ± 0.08 °C and 58.94 ± 5.66%, respectively, for 516 hours. Result showed that egg storage duration for up to 10 days did not affect (P &gt; 0.05) fertility. However, 4DS treatment had a higher (P &lt; 0.05) hatchability of set eggs and hatchability of fertile eggs. Embryonic mortality was also lower (P &lt; 0.05) in 4DS than the other treatments. Egg storage duration had no effect (P &gt; 0.05) on chick length, hatch yield, and Pasgar score. Whereas, chick weight in 1DS and D4S was higher (P &lt; 0.05) than 7DS and 10DS. Furthermore, saleable chicks in 4DS also higher (P &lt; 0.05) than the other treatments. It could be concluded that hatching egg storage at room temperature for 4 days provides optimum hatching performance and day old chick quality of Arab chickens.