Zygotes Research Articles

Synergistic induction of fertilization-independent embryogenesis in rice egg cells by paternal-genome-expressed transcription factors.

In flowering plants, rapid activation of the zygotic genome occurs after fertilization1-3, but there is limited knowledge of the molecular pathways underlying embryo initiation4. In rice, a key role is played by the transcription factor BABY BOOM 1 (OsBBM1), initially expressed from the paternal genome1. Ectopic OsBBM1 expression in the egg cell can override the fertilization requirement, giving rise to parthenogenetic progeny5. Here we show that the WOX-family transcription factor DWARF TILLER1 (OsDWT1)/WUSCHEL-LIKE HOMEODOMAIN 9 (OsWOX9A)6, another gene paternally expressed in zygotes, is a strong enhancer of embryo initiation by OsBBM1. Co-expression of OsWOX9A and OsBBM1 in egg cells results in 86-91% parthenogenesis, representing 4- to 15-fold increases over OsBBM1 alone. These results suggest that embryo initiation is promoted by the synergistic action of paternal-genome-expressed transcription factors in the fertilized egg cell. These findings can be utilized for the efficient production of haploids, as well as clonal hybrid seeds in crop plants7,8.

Proteomic and N-Glycosylation Analysis of Fertile Egg White during Storage and Incubation in Chickens

Proteomic and N-Glycosylation Analysis of Fertile Egg White during Storage and Incubation in Chickens

Impact of early postbiotic supplementation on broilers’ responses to subclinical necrotic enteritis

Necrotic enteritis (NE), an enteric disease caused by Clostridium perfringens, results in damage to the intestinal epithelial lining disrupting its function, nutrient absorption, and utilization. This study evaluated the effects of in ovo and post-hatch applications of a Saccharomyces cerevisiae-based postbiotic on performance and nutrient transporter genes of broilers during a NE challenge. At embryonic d 18, Ross 708 fertile eggs were injected with 0.2 mL of either water or postbiotic. A total of 288 male hatchlings were assigned to one of the following treatment groups: 1) NC (in ovo water injection, no challenge); 2) PIW (postbiotic in ovo and in drinking water, no challenge); 3) NC+ (NC with NE challenge); and 4) PIW+ (PIW with NE challenge). On d 14, all birds in the NE-challenged groups were orally gavaged with 3,000 Eimeria maxima sporulated oocysts followed by two doses of ∼1×108 CFU/mL/bird of C. perfringens on d 19 and d 20. Hatchability, weekly performance, intestinal lesion scores, and mRNA abundance of nutrient transporters in the jejunum and ileum were assessed. Data were analyzed by 2-way ANOVA in JMP and significance between treatments identified by LSD test (P ≤ 0.05). A significant postbiotic treatment and NE challenge interaction was observed in performance during d 21-28 with a greater ADG in PIW compared to NC and PIW+. Lesion scores in the jejunum and ileum were significantly reduced in PIW+ compared to NC+. On d 7, mRNA abundance of SGLT1 was significantly greater in PIW compared to the NC group. On d 14, birds in PIW had greater levels of GLUT2 and EAAT3 than NC group. No significant interaction effects were observed on d 21. PIW+ had significantly greater EAAT3 mRNA levels compared to PIW in jejunum and PIW and NC+ in ileum on d 28. In conclusion, in ovo and water supplementation of this postbiotic presents a potential to improve the performance, ameliorate pathology detriments associated with NE, and positively regulate the mRNA levels of key nutrient transporters during NE challenge.

Effect of Incorporating Soursop (Annona muricata) Leaves Powder on Reproductive Performance of Japanese Quail (Coturnix coturnix japonica)

Introduction: Soursop leaves are rich in various molecules, including total phenols, terpenes, and steroids, which possess a range of pharmacological properties that can be utilized in animal production to enhance both growth and reproduction of animals. The present study aimed to evaluate the effect of incorporating soursop (Annona muricata; A. muricata) leaves powder into feed on the reproductive performance of Japanese quail. Materials and methods: A total of 80 Japanese quails (64 females and 16 males) aged two weeks were randomly divided into four experimental groups, labeled T0, T1, T2, and T3, and received feed additives with 0 mg/kg body weight (bw), 250 mg/kg bw, 500 mg/kg bw, and 750 mg/kg bw of powdered soursop leaves, respectively. Additionally, water was provided ad libitum, and the quails' weights were measured every 7 days for a period of 75 days. At the end of the period, 12 female quails from each group were sacrificed after 24 hours fasting period. Blood was collected for hematological (Leukocyte, Erythrocyte, and Platelet indices) and serum biochemical (total serum cholesterol, total proteins, albumin, and globulin, Aspartate aminotransferase, Alanine aminotransferase, Urea, and Creatinine) analysis. The males were also sacrificed to evaluate the spermatozoa characteristics (mobility, concentration, and viability). Results: No statistical significant changes in growth characteristics or hematological parameters were observed. However, biochemical parameters increased significantly with the inclusion of Soursop (A. muricate) in quail feed, including increased total cholesterol, total protein, and globulin levels, and decreased malondialdehyde levels. This effect was most significant at dosage of 500 mg/kg bw. Serum levels of urea, Alanine aminotransferase, and Aspartate aminotransferase were not significantly affected by A. muricata whatever the concentration considered. A significant increase in fast progressive spermatozoa, along with a decrease in immotile spermatozoa, was observed with A. muricate at dosage of 500 mg/kg bw compared to the control. Sperm viability also increased significantly, particularly in live at dosage of 500 mg/kg bw. Significant increase was observed in fertility parameters, including increased fertility rate, hatchability rate of fertile eggs, total hatchability rate, and chick weight, along with decreased embryonic mortality at 500 mg/kg bw treatment compared to the control. Conclusion: In conclusion, the findings indicated that incorporating A. muricata leaf powder at 500 mg/kg bw into quail feed positively influences reproductive cells and boosts fertility growth promoters.

Mathematical Modeling of Mating Probability and Fertile Egg Production in Helminth Parasites.

In this work, we obtained a general formulation for the mating probability and fertile egg production in helminth parasites, focusing on the reproductive behavior of polygamous parasites and its implications for transmission dynamics. By exploring various reproductive variables in parasites with density-dependent fecundity, such as helminth parasites, we departed from the traditional assumptions of Poisson and negative binomial distributions to adopt an arbitrary distribution model. Our analysis considered critical factors such as mating probability, fertile egg production, and the distribution of female and male parasites among hosts, whether they are distributed together or separately. We show that the distribution of parasites within hosts significantly influences transmission dynamics, with implications for parasite persistence and, therefore, with implications in parasite control. Using statistical models and empirical data from Monte Carlo simulations, we provide insights into the complex interplay of reproductive variables in helminth parasites, enhancing our understanding of parasite dynamics and the transmission of parasitic diseases.

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.

Embryonic heat conditioning increases lipolytic gene expression in broiler chicks at day 4 post-hatch.

Exposure to elevated temperatures during incubation is known to induce epigenetic changes that are associated with immunological and stress-response differences at a later age. Reports on its effects on the adipose tissue are still scarce. In this experiment, we investigated the effect of embryonic heat conditioning (EHC) on growth, adipose tissue mRNA and global DNA methylation in broiler chicks at day 4 post-hatch. Fertile eggs were divided into two groups: control and EHC. Eggs in the control group were incubated at 37.8°C and 80% relative humidity from day 0 to day 18.5 (E0 to E18.5). The EHC eggs were subjected to an intermittent increase in temperature to 39.5°C and 80% relative humidity from E7 to E16 for 12h (07:30-19:30) per day. On day 4 post-hatch, control and EHC chicks were subjected to 36°C using three time points: 0 (no heat challenge serving as the control), and 2 and 12h relative to start of the heat challenge. Fifteen chicks were sampled from each group for every timepoint. Body weight was recorded before euthanasia and subcutaneous adipose tissue was collected. Body weights were similar in control and EHC groups. Diacylglycerol O-acyltransferase 2 (DGAT2) mRNA was lower in the EHC group at time 0 relative to control. Hormone-sensitive lipase (HSL) mRNA was greater in the EHC than control group at the 0h timepoint. Heat challenge affected adipose tissue DNA methylation, with methylation highest at 12h into the heat challenge. These findings highlight the dynamic molecular responses of chicks to heat stress during early post-hatch development and suggest that EHC may affect heat stress responses and adipose tissue development through mechanisms involving lipid remodeling and DNA methylation.

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.

APPLICATION OF CRISPR TO INCREASE MEAT YIELD IN CHICKEN

Meat production is one of the major purposes of the poultry industry. Meat is full of protein and accomplishes the protein requirement of the diet. This study was carried out to attempt to use CRISPR-mediated genome editing of chicken to increase meat yield. For this purpose, CRISPR was used to edit the gene sequence and then it was allowed to infect the PGC’s (Primordial germ cells). The successfully edited PGC’s having blocked exon 3 of MSTN gene were then injected into the blood bloodstream of 2.6 days of fertilized egg cells. The eggs were incubated up to hatch. The wild type was taken as control and the Mutated ones as T1. The CRD was used with three replications to find the significance of variation in To and T1. The weight of chicks for T0 (wild type) and T1 (Mutated) was significantly different. The average weight of three replications of each treatment was compared through a bar graph. it was found that the CRISPR-mediated edited chicks were more weighted than that of their wild types. The CRISP-mediated inhibition of MSTN has a significant effect on muscle growth in chickens. The more such genes may be targeted to get more meat yield.

The Effects of Rearing Systems on Incubation, Egg Production and Quality Traits in Pharaoh Quails

This study was conducted to determine the effect of rearing quails in different rearing systems on egg production, egg quality characteristics, and incubation results. The 360 quails were distributed equally to 3 different rearing groups (cage, enriched cage, and floor) in a male:female mixed at the age of 3 weeks. The eggs were individually weighed and recorded one by one daily (5487 eggs) for 3 months. To determine egg quality and incubation characteristics, 750 eggs were broken, and 3284 eggs were incubated, respectively. The results showed that female quail in the floor group have lower body weight at 6 weeks old (177.19 g), and they reached sexual maturity (age of first egg laying) later (65.36 day, P&lt;0.01), The lowest egg production (61.14%) occurred in the floor group during the 3-month egg production period (P&lt;0.05). The lowest average egg weight (9.07 g) was determined in the floor group (P&lt;0.05). It was determined that the eggs of quails raised in the enriched group had a rounder shape index because they have larger widths (P&lt;0.01). While the highest average yolk height (11.24 mm) was determined in the enriched cage group (P&lt;0.01), the highest averages of albumen length (72.41 mm) and lowest averages of yolk index (48.43%) were determined in the cage group (P&lt;0.01). The lowest average values (113.17) in Haugh unit were detected in the floor group (P&lt;0.05). The highest fertility rate (98.44%) was in Floor♂:Cage♀, the highest hatchability of fertile egg rate (94.67%) was obtained from Enriched♂:Cage♀, and the highest hatchability (89.10%) was obtained from Floor♂:Cage♀ pairing (P&lt;0.05). The lowest fertility rate (88.00%) was obtained from the Enriched♂:Floor♀, the lowest hatchability of fertile egg rate (86.01%) was obtained from the Enriched♂:Enriched♀, and the lowest hatchability (75.62%) was obtained from the Enriched♂: Enriched♀ groups. As a result, it has been revealed that the effect of various rearing systems is different on egg production, egg quality traits, and hatching results in quails. Thus, it has been shown that different programs at the rearing period to be applied to the male and female quails can achieve better incubation results and reproductive success.

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.

Influence of breeders age on initial embryonic development (from 0 to 72 hours) of Japanese quails during incubation

The initial stages of early embryonic development were analyzed as a function of the incubation period and age of Japanese quail breeders. A total of 203 Japanese quails housed in 29 conventional laying cages with 5 females and 2 males at 31, 39, 48, and 59 weeks of age were used, and the fertile eggs from these breeders were selected and incubated. The eggs were opened, and the embryos were isolated, fixed in a glutaraldehyde solution, analyzed and classified according to the stage of development. For after laying and the incubation periods of 24, 48, and 72 hours, the embryos presented, on average, Hamburger-Hamilton stages XI, HH 6.1, HH 12.7, and HH 18.5, respectively, with no effect of breeder age. It was also observed that, between 31 and 59 weeks of age in Japanese quail breeders, the eggs become longer and wider, with greater weight, volume, and area. Therefore, it is concluded that the age of the Japanese quail mother influences the weight, length, width, volume, and area of the eggs but does not influence the embryonic development up to 72 hours.

The embryotoxic and teratogenic effects of metamizole sodium.

Drug use during pregnancy is an important issue that must be investigated due to its adverse effects on maternal and foetal health. This study aimed to determine the embryotoxic and teratogenic effects of in-ovo administered metamizole (dipyrone), which can be used when needed during pregnancy and has potent analgesic, antipyretic, anti-inflammatory, and long bone (tibia and femur) effects. This study used 240 fertile eggs from Atak S breed chickens, divided into eight equal groups: control, vehicle control, and 15.62, 31.25, 62.5, 125, 250 and 500 mg/kg metamizole. The eggs were hatched on the 21st day of incubation, and the chicks' body weights and mortality rates were determined. The right and left femur and tibia bones were resected from the chicks. Anatomical reference points were determined after removing the soft tissues of the bones, and necessary morphometric measures were taken from these points with a 0.01 mm precision using digital callipers. The 100% lethal dose (LD100) was identified in the highest examined dose (500 mg/kg) in the Chicken Embryotoxicity Screening Test (CHEST)-I stage. The CHEST-II stage determined the 50% lethal dose (LD50). High-dose metamizole affected skeletal development, significantly decreasing tibia and femur lengths and corpus thicknesses and increasing mortality.

Characterization and antimicrobial resistance analysis of Salmonella enterica serovar Enteritidis recovered from broiler flocks and fertile eggs in Egypt

Characterization and antimicrobial resistance analysis of Salmonella enterica serovar Enteritidis recovered from broiler flocks and fertile eggs in Egypt

Monitoring egg fertility, embryonic morbidity, and mortality in an oviparous elasmobranch using ultrasonography.

Ultrasonography is widely used to monitor pregnancy in viviparous species, but it is underutilized as a tool to characterize embryonic development in oviparous species. Currently, a multi-institutional effort is underway to re-wild the endangered zebra shark (Stegostoma tigrinum) to locations where this species was previously extirpated by leveraging the reproductive efforts of aquarium sharks as a source of brood stock. Zebra sharks are oviparous and fecund, but a large percentage of their yolked eggs do not result in hatchlings. Therefore, ultrasonography represents a potential tool for distinguishing fertile eggs with developing embryos from degrading eggs, and to diagnose changes in early embryonic development predictive of poor outcomes. The objectives of the current study were to use ultrasonography to assess egg fertility, monitor early embryonic development, and identify morphological indicators that may be predictive of early embryonic mortality. Freshly laid eggs from four female zebra sharks were collected and inventoried daily at Aquarium of the Pacific. Eggs were incubated undisturbed for 2 to 4 weeks and subsequently examined weekly via ultrasound to assess fertility and monitor embryo development. Among 120 fertile eggs, embryos were identified as early as 8 days post-oviposition, with average (±SD) time to first observation at 30 ± 7 days. Morphological and behavioral abnormalities were observed for most embryos (n = 84, 70%) as early as 16 days and up to 95 days post-oviposition. Common abnormalities included: bent or curled tails, vesicle(s) at the base of the yolk stalk, and slow or weak movement. Only one embryo survived to hatch during the study and was genetically-confirmed parthenogenetic, suggesting hatching success for parthenotes is low (<1%). Ultrasonography was demonstrated to be an effective and non-invasive method to determine egg fertility, identify embryos with developmental abnormalities, and monitor embryo growth.

Contragestation or hidden abortion

The term contraception refers to a set of methods that act with an abortifacient mechanism by altering the physiology of the transport and implantation of the fertilized egg or by causing the elimination of the recently nested embryo. Euphemistically, they are also referred to as interception because they intercept the fertilized egg cell or are even unduly confused with contraceptives.

Detection and molecular characterization of chicken parvovirus and chicken megrivirus in layer breeders affected by intestinal dilatation syndrome

ABSTRACT Intestinal dilatation syndrome (IDS) is a segmental enteropathy characterized by dilatation of the junction of the ileum and jejunum (Meckel’s diverticulum). IDS severely affects the poultry industry by causing a chronic and irreversible drop in egg laying, reducing feed conversion efficiency, and increasing the mortality rate. The clinical and pathological features of IDS in white laying hens were described, and viral molecular and metagenomic research was conducted. The 50 – to 60-day-old chickens presented pale mucosa, apathy, depression, ruffled feathers, and diarrhoea, accompanied by a 20% loss in fertile egg production, 20% culling of birds, and 5% mortality. The main findings at necropsy were marked intestinal dilatation with intestinal stasis, a narrow distal jejunum in the region of Meckel's diverticulum, and undigested food. Microscopic analysis revealed marked atrophic lymphoplasmacytic and heterophilic enteritis with hyperplastic crypts, ulceration, and heterophilic and lymphoplasmacytic perineuritis. The molecular assays consistently detected the presence of chicken parvovirus in the three segments of the intestine, pancreas, and proventriculus, as well as chicken megrivirus in the intestinal contents. Marked atrophic enteritis with perineuritis and intestinal stasis were associated with clinical manifestations of poor intestinal absorption and secondary bacterial infection. Our data provide useful information about IDS and highlight the importance of further studies to determine the specific role of each detected virus in this syndrome. RESEARCH HIGHLIGHTS IDS presented pathognomonic dilatation of the jejunum up to Meckel's diverticulum. IDS caused weight loss, decreased egg production, and increased culling and mortality. Chicken parvovirus (ChPV) was consistently detected through PCR assays. Chicken megrivirus (ChMV) was consistently detected through viral metagenomics.

Developmental 6:2 FTCA exposure impairs renal development in chicken embryos via IGF signaling

6:2 fluorotelomer carboxylic acid (6:2 FTCA) is a perfluorooctanoic acid (PFOA) substitute, which is supposedly less accumulative and toxic than PFOA. However, 6:2 FTCA is structurally similar to PFOA, and there had already been reports about its toxicities comparable to PFOA. The aim of the current study is to assess potential effects of developmental exposure to 6:2 FTCA on the development of kidney in chicken embryo and to investigate underlying mechanism. Fertile chicken eggs were exposed to 1.25 mg/kg, 2.5 mg/kg or 5 mg/kg doses of 6:2 FTCA, or 2 mg/kg PFOA, then incubated to hatch. Serum and kidney of hatchling chickens were collected. Blood urea nitrogen (BUN) and creatinine (Cre) levels were measured with commercially available kits. Morphology of kidney was assessed with histopathology. To further reveal molecular mechanism of observed endpoints, IGF signaling molecules were assessed in the kidney samples with qRT-PCR, results indicated that IGFBP3 is a potentially crucial molecule. Lentiviruses overexpressing or silencing IGFBP3 were designed and applied to enhance/suppress the expression of IGFBP3 in developing chicken embryo for further verification of its role in the observed effects. Disrupted nephron formation, in the manifestation of decreased glomeruli number/area and increased serum BUN/Cre levels, was observed in the animals developmentally exposed to 6:2 FTCA. Correspondingly, IGF signaling molecules (IGF1, IGF1R and IGFBP3) were affected by 6:2 FTCA exposure. Meanwhile, overexpression of IGFBP3 effectively alleviated such changes, while silencing of IGFBP3 mimicked observed effects. In conclusion, developmental exposure to 6:2 FTCA is associated with disrupted chicken embryo renal development, in which IGFBP3 seems to be a remarkable contributor, suggesting potential health risks for human and other species. Further risk assessments and mechanistic works are necessary.

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.

Evaluating the interaction response of broiler chickens to in ovo feeding of Citrus aurantiifolia seed extract and its powder supplementation

This study aimed to evaluate the effect of in ovo injection and post-hatch supplementation of Citrus aurantiifolia seed on hatchability, growth performance, antioxidant capacity, immune organs weight, and intestinal morphology of Cobb 500 broilers chickens. On day 18 of incubation, 450 fertile eggs were randomly allocated into three sets: non-injected group, 0.5 µg/ml Citrus aurantiifolia seed extract (CASE) group and 0.75 µg/ml CASE group. After hatch, each set was allocated into two groups (5 replicates of 10 birds/replicate each) and was fed on a standard diet with or without Citrus aurantiifolia seed powder (CASP) supplementation (5 g/kg). The groups were divided as follows: IoCA0-C, IoCA0-CA, IoCA5-C, IoCA5-CA, IoCA75-C and IoCA75-CA where IoCA0-C was: non-injected group fed standard diet (negative control group), IoCA0-CA: non-injected and fed CASP supplemented diet (positive control group), IoCA5-C: 0.5 µg/ml of CASE-injected and fed standard diet, IoCA75-C: 0.75 µg/ml of CASE-injected and fed standard diet, IoCA5-CA: 0.5 µg/ml of CASE-injected and fed CASP supplemented diet and IoCA75-CA: 0.75 µg/ml of CASE-injected and fed CASP supplemented diet. The results revealed that the interaction between CASE in ovo injection at 0.5 µg/ml and dietary CASP supplementation at 5 g/kg in the diet increased body weight and weight gain (p < 0.001). The interaction between CASE in ovo injection and dietary CASP supplementation decreased the serum malondialdehyde concentration, the relative weight of the thymus and improved duodenum and ileum villus height (p < 0.05). In conclusion, in ovo injection and dietary supplementation of Citrus aurantiifolia seed powder can improve growth performance and the intestinal morphology of broiler chickens.