Embryonic Weight Research Articles

Exploring developmental MeHg impact on extraembryonic and cardiac vessels and its effect on cardiomyocyte contractility.

The toxicity of methylmercury (MeHg) during embryonic development is a relevant issue that remains unclear and deserves investigation. In this sense, there is evidence that links the intake of contaminated food with cardiovascular pathologies in human adults and children. Thus, this study aimed to verify the impact of MeHg on the structure and integrity of extraembryonic and cardiac blood vessels and the contractile function of cardiomyocytes, also evaluating embryonic weight and the cardiosomatic index (CSI). Thus, chicken embryos, used as an experimental model, were exposed to a single dose of 0.1μg MeHg/50 μl saline at E1.5 and analyzed at E10. After exposure, an increase in the number of extraembryonic blood vessels and the veins of the cardiac tissue was observed. These increases were accompanied by a reduction in the content of VEGF and VCAM proteins related to vessel growth and adhesiveness. Together, these results were related to reduced nitrite (NOx) levels. Furthermore, MeHg reduces the number of sarcomeres and increases the content of cardiac troponin I (cTnI), a protein that regulates contraction. In general, exposure to MeHg affected the integrity of extraembryonic and cardiac vessels and the contractile function of cardiomyocytes, which had a systemic impact evidenced by the reduction in embryonic weight gain and CSI.

Embryonic growth and effect of embryonic age on quantitative and functional characteristics of duck primary hepatocytes

Primary hepatocytes (PH) have been widely used in metabolic and disease-resistance mechanism research. However, hepatocyte isolation (HI) remains challenging in ducks. This study aimed to explore embryonic growth and the effect of embryonic age (EA) on the quantitative and functional characteristics of PH in ducks. For embryonic growth, the size and weight of the embryo and liver were determined from 6 to 28 EA (E6-E28, similar below). As EA increased, the corresponding size and weight grew significantly. Specifically, embryonic length varied from 12.5 mm to 133.0 mm, and liver width varied from 2.0 mm to 26.2 mm. Embryonic weight ranged from 0.259 g to 53.58 g, and liver weight ranged from 0.007 g to 1.765 g. Liver index initially decreased and then increased with a ratio ranging from 1.06 to 3.29%. For quantitative and functional characteristics, they were determined from E6 to E22, as there were no obvious liver features before E6 and few cells obtained after E22. The number of cells isolated in liver increased from E6 to E16 and then sharply decreased from E16 to E22. The viability remained relatively stable from E6 to E10 and then decreased from E12 to E22. The comprehensive intensity of hepatic glycogen was stronger at E8 and E14. Albumin expression increased markedly from E6 to E18 by qPCR, and the overall albumin expression was stronger at E8 and E14 by immunofluorescence assay. Hepatocyte purity exceeded 90% except for E20 and E22. During culture, cell clusters appeared after 24-h culture, which were identified as nonhepatocytes. The growth curve showed an initial increase in cell quantity followed by a decrease, another increase, and then remaining stable. In conclusion, EA had a significant effect on the quantitative and functional characteristics of PH, and the suitable EA for HI were E8 and E14. Considering better operability and quantity, E14 was the optimal EA, laying a solid foundation for further hepatocyte purification, nutrient metabolism, and disease-resistance mechanism explorations in ducks.

Cochlear pathology in preeclamptic rats: protective effects of vitamin D and magnesium sulfate.

This study investigated the possible degeneration in cochlear morphology induced by preeclampsia (PE) and the therapeutic/preventive effect of vitamin D (Vit D) and magnesium sulfate (MgSO4) used separately and together on feto-maternal outcomes. We created PE in rats using a reduced uterine perfusion pressure (RUPP) animal model and recorded blood pressure (BP), embryonic survival (ES), and embryonic weight (EW) and evaluated cochlear morphology by electron microscopy. The PE group had elevated BP, a decreased number and weight of live pups, and significant degeneration in the cochlea compared to the sham group. In the PEV group, we observed significant beneficial effects of Vit D supplementation at 14.5 and 19.5 dpc in terms of BP (p < 0.05), EW (p < 0.001), and cochlear degeneration compared to the PE group. In the PEM group, BP (p < 0.05) and cochlear degeneration nearly reached the level found in the sham group. However, although the EW was statistically different in the PE group, it did not reach sham group levels. We also observed that BP returned to sham level (p < 0.01) and noticed significant increases in the EW (p < 0.0001) and ES (p = 0.017) in the PEMV group compared to the PE group. According to the scanning electron microscope results, combined administration of VitD and MgSO4 is more effective than separate administration in improving cochlear degeneration induced by PE. The administration of Vit D and MgSO4 during pregnancy has beneficial effects on PE pathology and may play a significant role in preventing PE-related complications, including cochlear degeneration.

Effect of thermal manipulation on embryonic development, hatching process, and chick quality under heat-stress conditions

Thermal stress is a risk that threatens poultry welfare and productivity. Thermal manipulation during egg incubation is considered a prevention strategy used to mitigate the detrimental effects of high ambient temperatures on birds. This study aimed to investigate the impact of thermal manipulation, applied to chicken breeder's eggs during the incubation period, on embryonic development, hatching characteristics, and chick quality, as well as posthatch thermotolerance and performance. A total of 1,200 fertile eggs were randomly and equally assigned into 2 groups of 3 replicates (200 eggs/replicate), using a randomized experimental design followed by t test. The first group eggs (G1) were subjected to a commercial setter temperature of 37.5°C with 55% relative humidity (RH) throughout the incubation period (1-18 d) and served as a control, while the second group eggs (G2) were treated the same commercial setter conditions until the 11th day of the incubation, then the eggs were exposed to a higher temperature of 39.5°C with 60% RH for 4 h daily from the 12th to the 18th day of incubation. All eggs in both groups were exposed to the same temperature condition of 37.2°C with 70% RH from the 19th to the 22nd days of the incubation (hatching period). Three hundred hatched female chicks per each treatment group were transferred into a closed-system house and distributed randomly into 20 floor pens (15 birds per pen). At the 8th week of age, birds were exposed to a daily heat challenge by raising the temperature to 35°C for 6 h until the 18th week of the chick's age. According to the results, thermal manipulation at 12 to 18 d of egg incubation positively (P ≤ 0.05) affected several studied traits. It improved some embryonic development traits, such as embryonic weight and tibia length, as well as some hatching parameters, such as hatching time and pipped eggs. It also improved hatched chick quality traits, including the chick's weight, length, and activity. In addition, it enhanced the posthatch chick's thermotolerance and body weight. Hatched chicks of G2 had significantly (P ≤ 0.05) higher total protein, albumin, IgM, glucose, calcium, total antioxidant, and T3 than G1 chicks. They also had significantly (P=0.001) higher body weight (23%) at the 18th week of age than G1, as well as a lower feed conversion ratio (20.71%) than G1 chicks at 8 to 18 wk of age. Therefore, it is recommended to apply thermal manipulation during egg incubation, particularly at 12 to 18 d, for its positive effects on the pre- and posthatch performance.

Embryonic statistical analyses reveal 2 growth phenotypes in mouse models of Down syndrome

Down syndrome is associated with several comorbidities, including intellectual disability, growth restriction, and congenital heart defects. The prevalence of Down syndrome-associated comorbidities is highly variable, and intellectual disability, although fully penetrant, ranges from mild to severe. Understanding the basis of this interindividual variability might identify predictive biomarkers of in utero and postnatal outcomes that could be used as endpoints to test the efficacy of future therapeutic interventions. The main objective of this study was to examine if antenatal interindividual variability exists in mouse models of Down syndrome and whether applying statistical approaches to clinically relevant measurements (ie, the weights of the embryo, placenta, and brain) could define cutoffs that discriminate between subgroups of trisomic embryos. Three commonly used mouse models of Down syndrome (Dp(16)1/Yey, Ts65Dn, and Ts1Cje) and a new model (Ts66Yah) were used in this study. Trisomic and euploid littermate embryos were used from each model with total numbers of 102 for Ts66Yah, 118 for Dp(16)1/Yey, 92 for Ts65Dn, and 126 for Ts1Cje. Placental, embryonic, and brain weights and volumes at embryonic day 18.5 were compared between genotypes in each model. K-mean clustering analysis was applied to embryonic and brain weights to identify severity classes in trisomic embryos, and brain and placental volumetric measurements were compared between genotypes and classes for each strain. In addition, Ts66Yah embryos were examined for malformations because embryonic phenotypes have never been examined in this model. Reduced body and brain weights were present in Ts66Yah, Dp(16)1/Yey, and Ts65Dn embyos. Cluster analysis identified 2 severity classes in trisomic embryos-mild and severe-in all 4 models that were distinguishable using a putative embryonic weight cutoff of <0.5 standard deviation below the mean. Ts66Yah trisomic embryos develop congenital anomalies that are also found in humans with Down syndrome, including congenital heart defects and renal pelvis dilation. Statistical approaches applied to clinically relevant measurements revealed 2 classes of phenotypic severity in trisomic mouse models of Down syndrome. Analysis of severely affected trisomic animals may facilitate the identification of biomarkers and endpoints that can be used to prenatally predict outcomes and the efficacy of treatments.

Effects of In-Ovo Injection of sialic acid on Chick's embryonic development and physiological traits

This study was conducted at the College of Agriculture – University of Anbar, Iraq. From 16 January to 5 February 2022, this study aimed to investigate the effect of injected egg hatching at different sialic acid times in growth and embryonic development. Four hundred eggs of hatching types (Ross 308) were injected with different sialic acid concentrations at 0 days (before placing in the incubator), 7 and 14 days of incubation. Eggs were divided into four groups (100 eggs each) as follows: T1: The control group was placed in the incubator without injection. T2: Injected with a dose of 100 μg sialic acid at the age of zero. T3: Injected with 100 μg sialic acid dose at 7 days. T4: Injected with 100 μg sialic acid dose at 14 days of incubation. Statistical analysis was performed (CRD) (P=0.05); results show: Increase in the e length of the embryo, the diameter of the vascular region and the number of pairs of somites at 3 days of incubation for T1. Increase in the percentage of embryonic weight, decrease in the percentage of Albumin and the percentage of shell at 7 days of incubation for T2 and T3. Increase in percentage of embryonic weight and amniotic sac and liquid, decrease in the percentage of Albumin and yolk, at 14 days of include sialic acid for T2. Increase the percentage of embryonic weight, and decrease the percentage of yolk at 14 days incubation for T2. They have concluded that In-Ovo injection of the hatching eggs with sialic acid contributed to increased physiological traits and embryonic development. Keywords: In-Ovo, Sialic Acid, Erythropoietin, Oxygen, Anemia, and Anoxia.

Thermal manipulation modifies embryonic growth, hepatic free amino acid concentrations, and hatching performance in layer-type chicks

Thermal manipulation (TM) of incubation temperature has been demonstrated to alter metabolism and post-hatch thermotolerance in broiler strains (meat-type chickens). Fewer reports were focused on layer-type chickens and there was no report on amino acid metabolism during TM in layer-type embryos. In this study, we investigated the effects of TM on embryonic development, hepatic amino acid metabolism, and hatching performance in layer-type chickens. Fertilized eggs were incubated under control thermoneutral temperature (CT, 37.6°C) and TM with high temperature (TMH, 39°C, 8 h/day) or low temperature (TML, 20°C, 1 h/day) from embryonic day (ED) 8 to ED 15. The embryonic weight and relative embryonic weight (yolk-free embryonic weight to the initial egg weight) significantly declined in the TML group at ED 13 (P < 0.01) and ED 16 (P < 0.0001), and were significantly increased (P < 0.001) in the TMH group at ED 16, in comparison with the embryos in the CT group. The concentrations of all hepatic free amino acids were significantly increased (P < 0.01) with embryonic development. Interestingly, TMH and TML caused similar effects on hepatic amino acid metabolism, in which most of the essential and non-essential amino acids were significantly declined (P < 0.05) under TM treatments at ED 13 but not affected at ED 16. Until hatching, TML, but not TMH, caused a significant (P < 0.05) delay (31-38 min/day from ED 8) in incubation duration. The hatchability in the TML group was lower than the other two groups, which indicated that 20°C as cold stimulation was not suitable for layer embryos. The body weight, yolk weight, yolk-free body mass, and chick quality were not affected by TM treatments. However, the relative weight of the liver, but not the heart, was significantly reduced (P < 0.05) at hatching by TML treatment. In conclusion, TML, but not TMH, caused to delay in embryogenesis and affected the internal organ of chicks at hatch. Similar changes in amino acid metabolism under TMH and TML indicated that thermal stress induced by both high and low extreme ambient temperatures influences embryonic amino acid metabolism in a similar fashion in layer-type embryos.

The influence of litter birth weight phenotype on embryonic and placental development at day 30 of gestation in multiparous purebred Large White sows

The aim of this study was to understand the intrauterine biological processes associated with the low litter birth weight phenotype in pigs. Analyses were conducted on reproductive data from a purebred Large White maternal line to identify sows (>2 parities) with repeatable high or low litter birth weight phenotype (HLBWP or LLBWP). A total of 40 sows were selected (n = 20 HLBWP and n = 20 LLBWP) and bred with semen from purebred Large White boars of proven fertility. Sows were euthanized on day 28–30 of gestation (day 29.5 ± 0.6) and samples of placenta and embryos collected. Total number of embryos (TNE), embryonic weight (EW), embryonic viability, and crown-rump (CRL) measurements were recorded, along with the ovulation rate (OR) and allantochorionic fluid volume (AFV). No significant difference was detected (P > 0.05) in OR, TNE, and number of viable embryos on day 30 of gestation between the two groups. There was no significant difference in EW (LLBWP: 0.80 ± 0.05 g; HLBWP: 0.88 ± 0.04 g, P = 0.18) or CRL (LLBWP: 21.5 ± 0.7 mm; HLBWP: 21.9 ± 0.68 mm, P = 0.46). Placental development represented by the average AFV was significantly lower in the LLBWP compared to HLBWP (LLBWP: 131 ± 9.82 mL; HLBWP: 149 ± 9.39 mL, P = 0.03). In conclusion, placental development may be the main factor causing lower BW of entire litters in LLBWP sows.

Effects of Sibling Eggs Contact on Incubation Length and Hatching Synchrony in Red-Legged Partridge (Alectoris rufa)

Hatching synchrony is a desirable trait in the artificial incubation of eggs because it permits the simultaneous extraction of all the chicks from the hatcher, thus minimizing extraction queues. This study aimed at evaluating the effects on egg performance, incubation length, and hatching synchrony of different sibling contact regimes during the incubation in red-legged partridge (Alectoris rufa) eggs. To achieve these objectives, 196 eggs were arranged in four treatments according to the sibling eggs contact regime: (a) eggs without contact during the whole incubation process; (b) eggs in contact during the incubation phase (from day 1 to 20 of incubation); (c) eggs in contact during the hatching phase (from day 20 of incubation to hatching); (d) eggs in permanent contact throughout the incubation process (from day 1 of incubation to hatching). Development stage at embryonic mortality, hatchability, and egg weight loss during incubation were not affected, but incubation length was shortened and hatching synchrony was increased in eggs in contact during the hatching phase. The main conclusion was that keeping red-legged partridge eggs in close contact during the hatching stage in the artificial incubation does not affect hatchability but allows hatching synchrony to be maximized, facilitating the handling of 1 day old chicks.

146 Specific Gravity as an Objective Assessment of Embryonic Viability to Improve Implantation Rates of Bovine Embryos

Abstract Assessment of embryo quality and viability has traditionally been based on morphological evaluation. However, morphological evaluation, though somewhat reliable, is subjective in nature and varies greatly depending upon the skill and experience of the evaluator. Although research has been conducted with the goal of identifying more accurate and objective methods of evaluation, the issue of repeatability and consistency in predicting the likelihood of a successful pregnancy remains. Previous research has proposed the ability to utilize specific gravity to predict developmental energy reserves based on embryonic weight, theoretically identifying those embryos with an increased chance of success following standard embryonic transfer. The objective of this study was to determine if specific gravity could accurately identify those embryos that were most likely to succeed in generating positive pregnancies. Bovine embryos (n = 20) were dropped through media in a specific gravity chamber. Utilizing an embryo tracking software program, researchers recorded the time elapsed as the embryos descended 1 cm through the media. Embryos were then transferred into recipient cattle, and pregnancy was detected via ultrasound approximately 40 days post transfer. Of the 20 embryos transferred, 12 resulted in positive pregnancies. Descent times of these positive pregnancies ranged from 25.96 to 90.27 seconds, with an average descent time of 59.72 seconds. An analysis of the relationship between descent time and pregnancy outcome showed no significant difference (P &amp;gt; 0.05). Although there was no significance in the findings of this study, additional trials will be performed to thoroughly evaluate the potential of this technology as an objective measurement of embryonic viability.

Maternal Exposure to Oxidized Soybean Oil Impairs Placental Development by Modulating Nutrient Transporters in a Rat Model.

As an exogenous food contaminant, dietary oxidized lipid impairs growth and development, and triggers chronic diseases in humans or animals. This study explores the effects of soybean oil with different oxidative degree on the placental injury of gestational rats. Thirty-two female adult rats are randomly assigned to four groups. The control group is fed the purified diet with fresh soybean oil (FSO), and the treatment groups are fed purified diets with lipid content replaced by oxidized soybean oil (OSO) at 200, 400, and 800 mEqO2 kg-1 from conception until delivery. On day 20 of gestation, OSO decreased placental and embryonic weights as the oxidative degree increased linearly and quadratically. The expression of Bax showed a linear increase, and Bcl-2 decreased as the oxidative degree increased. The expression of Fosl1 and Esx1 is linearly and quadratically decreased in OSO-treated groups than FSO group. OSO decreased the level of IL-10 but increased expression of IL-1β in placenta and plasma. OSO remarkably upregulates levels of Fatp1 and Glut1 and decreases expression of Snat2 and Glut3. OSO aggravates placental injury by modulating nutrient transporters and apoptosis-related genes, impedes placental growth and development, and ultimately leads to the decrease of fetal weight.

Effects of In-Ovo injection of Biotin on chick’s embryonic development and physiological traits

This study was conducted at the local hatchery in Ramadi, Anbar Iraq from 1st to 23th Dec. 2018, to 26 Feb 2019. The objectives of this study were to investigate the effect of injected eggs hatching in times and different concentrations of Biotin in growth and embryonic development, hatchability. Six hundred eggs of hatching types (Ross 308) and injected with different concentrations of biotin at age of 0 days (before placing in the hatchery) and 18 days of incubation. Eggs were divided into five groups (120 eggs for each) as follows: 1.T0: Control group placed in the hatchery without injection. 2.T1: Injected with a dose of 100 μg biotin at age of zero. 3. T2: Injected with dose 75 μg biotin at age zero. 4.T3: Injected with a dose of 100 μg biotin at age 18 days of incubation. 5.T4: Injected with a dose of 4175 μg biotin at age of 18 days of incubation. Statistical analysis was performed (CRD) (P=0.065) results show: Increase length of the embryo, diameter of vascular region and number of pairs of somites at 3 days of incubation for T2. Increase percentage of embryonic weight, decrease the percentage of albumin and the percentage of at 7 days of incubation for T1 and T2. Increase in percentage of embryonic weight and amniotic sac and liquid, decrease in the percentage of albumin and yolk, at 14 days of incubation for T2. Increase percentage of embryonic weight, decrease the percentage of yolk at the age of 17 days incubation for T2. Increase hatchability of total eggs and fertile eggs. Decrease embryonic mortality and different stages of embryonic development. Concluded that In-Ovo injection of the hatching eggs with biotin contributed to increase physiological traits and embryonic development.

Impact of the electric shock on the embryonic development and physiological traits in chicks embryo

The objective of this study was to investigate the impact of stimulating the embryo during the dormancy in the incubation period. 450 eggs (Ross 308) were allocated in four treatments each with three replicates. The treatments were as follows: T1 control (without shock), T2 Shocked (40) Millivolts (mV), T3 Shocked (50) (mV), T4 Shocked (75) (mV). A different voltage device was used to shock the egg, after marking the eggs with a line of iron filings to ensure electrical conductivity, eggs were shocked at different times three times a day. The results showed that the percentage of embryonic weight increased significantly and the percentage of albumin decreased significantly and the percentage of shells for experimental treatments during the seven days of incubation compared to the control treatment. The significant increase in the percentage of embryonic weight and amniotic sac and liquid and a significant decrease in the percentage of albumin and yolk compared to the control treatment at 14 and 17 days of incubation for experimental treatment. Significant increase in neurophysiological traits of neurons, brain weight for T2, T3 and especially T4 concluded that electrical stimulation had a positive effect on the embryo.

Effects of Commercial Antioxidants Applied in Ovo on Chorioallantoic Membrane and Putative Plasma Vitellogenin of Philippine Mallard (Anas platyrynchos L.)

Two experiments were conducted to evaluate the effects of different antioxidants and its overdose (4x) in ovo. Experiment 1 were grouped as vitamin C, MegaAntioxidant® and Proflavanol C®, while experiment 2 were grouped as 100, 200 and 400ppm of MegaAntioxidant® having positive and negative control for both. The 200 fertile eggs in each experiment were injected with 100ul/egg of treatment solution and placebo (positive control), except negative control. Embryonic weight and body measurements were taken weekly (7-21 d). The anti-angiogenesis using CAM at day 4 was accomplished. Determination of putative vitellogenin (VTG) was done at 28th day using SDS-PAGE. Both experiments showed comparable embryonic weight, body length, and head diameter indicating no deleterious effects of different antioxidants and MegaAntioxidants® at high doses. Absence of red blemishes of liver was observed in three different antioxidants. The CAM resulted to lesser blood vessel formation significantly at 200 and 400 ppm MegaAntioxidant®. Further, the 175 kDa putative VTG, was present in vitamin C, Proflavanol C®, positive control and negative control, except MegaAntioxidant®. The results imply that MegaAntioxidant® having 32 different antioxidants could have protected the liver, spared VTG synthesis and had anti-angiogenic property at 200 and 400ppm doses.

PRE - AND POST HATCH GROWTH OF NIGERIAN INDIGENOUS GUINEA FOWL AS INFLUENCED BY EGG SIZE AND HATCH WEIGHT.

Two experiments were conducted to investigate the effects of egg size on embryonic growth during incubation and of egg size and hatch weight on growth to 12 weeks of age in the Nigerian indigenous Guinea fowl. Weight loss in eggs incubated was about 5.42% while weight gain was 1.02g with the fastest increase in the last trimester of incubation. At hatching, the keets were 72.42% of the weight of the eggs. Egg weight was positively significantly (P&lt;0.05) correlated with embryonic weight and is reliable for estimating the small, medium and large size. Egg weight was embryonic weight. Body weight up to 12 weeks of age differed when eggs were classified into significantly (P&lt;0.05) and positively correlated to body weight up to 4 weeks of age and egg weight was found to be reliable for estimating body weight up to 4 weeks only. Hatch weight was also significantly (P&lt;0.05) and positively correlated with subsequent body weight to 8 weeks of age.&#x0D;

Hyperglycemia results in significant pathophysiological changes of placental spiral artery remodeling and angiogenesis, further contributing to congenital defects.

Introduction: Hyperglycemic conditions achieved during pregnancy have been shown to have detrimental effects to fetal development and increase the prevalence of childhood comorbidities. However, the mechanisms in which diabetic pregnancies affect placental development and subsequently contribute to adverse health effects on the mother and offspring remain unclear. Research design and methods: Streptozotocin was used to induce gestational diabetes in mice. In this model, hyperglycemia was established at embryonic day 3.5 (E3.5). Pregnancy mass was collected at E10.5, E12.5, E14.5, and E16.5 for different assessments. Results: Both placental and embryonic weights were found to be significantly elevated at E16.5. At E14.5, a significantly larger junctional zone with increased number of glycogen trophoblasts was found in the placentas from hyperglycemic pregnancies (HG group) compared to the placentas from normoglycemic pregnancies (NG group). Importantly, the HG placenta exhibited decreased trophoblast giant cell (TGC) association and TUNEL+ cells, and increased expression of α-SMA on the spiral artery, suggesting arterial remodeling was impacted. Moreover, the interhemal membrane of the labyrinth layer, was found to be thicker in the HG placentas. Furthermore, hyperglycemia resulted in more offspring congenital defects, which were associated with a thicker interhemal membrane. Conclusions: Together, these results suggest that gestational diabetes perturbs proper placental development and function, specifically spiral artery remodeling and angiogenesis, thereby negatively impacting embryonic development.

Comparative developmental trajectory of four strains of chicken embryo during incubation and their post-hatch growth

This study evaluated egg traits, embryonic growth, and early growth rate in four strains of chicken. A total of 1200 hatching eggs, 300 each from four strains of chicken were used for this study. The strains included Nigerian indigenous chicken (NIC), Arbor acre, Hubbard, and Marshall broiler strains. Embryonic weights, yolk and albumen utilization were monitored throughout the incubation period. The chicks were randomly distributed into four rearing pens for a 28-day assessment of growth rate. Blood samples were collected at hatch (day-old), week 1, 2, 3 and 4 posthatch for thyroxine (T ) level determination. This study showed that the embryos 4 percentage weight gains were similar in the NIC and the broiler strains at embryonic (ED) 18. There was no difference (P&gt;0.05) in the rate of albumen utilization among the strains. At hatching, there was no difference ((P&gt;0.05) in the metabolic rate among the strains of chicken as shown by the levels of plasma T until later in the 4 growth phase. The day-old chick weight and the weights in subsequent weeks posthatch were smaller in the NIC than the broiler strains possibly as a result of low hatching weight and growth rate of the NIC in the first two weeks post-hatch. The early growth difference could not be explained by physiological parameters such as T . However, the differences in post-hatch physiological and metabolic parameters 4 may be due partly to genetic differences. It was concluded that embryonic development in the broiler strain was not superior to that of the NIC.

The effect of positioning eggs on hatchability and embryonic mortality of the Japanese quails (Coturnix Japonica)

In the last ten years, the little known about Japanese quail (Coturnix Japonica) commonly known as “Bater”, has been introduced in the progressing poultry industry of Pakistan. Study was planned to investigate the effect of various positions and condition of quail eggs on embryonic mortality, hatchability and chick weight. Total (n=150) fertile eggs of Japanese quails were grouped into A (vertical position with pointed end upward), B (vertical position with pointed end downward) and C (horizontal position) with average weight 10.87, 10.52 and 10.24 grams respectively. Statistically data was analyzed by determining the mean and standard deviation for each parameter. The group-A eggs weight was significantly higher (P<0.05) than other groups. The rate of early embryonic mortality was 8%, 12%, and 14% in dehydrated, infected and weak embryo respectively while 6% in late embryonic mortality in group-A. By the considering these parameters in group-B revealed 6%, 10%, 16% in early while 8% in late mortality. Similarly the eggs of group-C have 10%, 4%, 10% in case of early and 12% was recorded in late embryonic mortality. Hence overall embryonic mortality was low in group C (36%) compared with group A (40%) and B (40%). The hatchability rate was recorded high in group C (64%) than A (60%) and B (60%). Overall the horizontal position showed positive effects on chick weight and hatchability rate. Keywords: Egg; Embryonic mortality; Hatchability; Japanese quail; Positioning http://dx.doi.org/10.19045/bspab.2019.80091

EMBRYONIC MORTALITY AND BROILER CHICK QUALITY (Gallus gallus) FROM GLASS-SHELLED EGGS

Abstract The glass-shelled egg has various points on the surface with light gray coloration, which becomes more visible with the passage of egg storage period. The objective of this work was to evaluate the stage of embryonic mortality, egg weight during the incubation period, hatch window, and quality of chicks at hatch from glass-shelled egg. The research was divided into two parts. In the first part, 80 eggs from 45 weeks old hens were incubated, being half normal eggs and half glass-shelled eggs, while in the second part, 80 eggs from 70 weeks old hens from the same flock as the previous one were incubated. Again, half were normal shelled and half were glass-shelled eggs. No differences were observed for embryonic mortality, egg weight, hatch quality (hatch weight, uniformity, and navel quality), and hatch window between normal and glass-shelled eggs from hens of 45 and 70 weeks of age. However, there was higher contamination in glass-shelled egg from 70-week-old breeder hens. The results show that the presence of glass-shelled egg does not seem to interfere with the quality of the chick at hatch in the breed, ages, and studied conditions, but causes higher contamination in glass-shelled egg from 70-week-old breeder hens.

54 Altrenogest supplementation during early pregnancy improves swine embryonic development

Progesterone (P4) is of paramount importance in the establishment and maintenance of pregnancy for mammals. Progesterone stimulates the endometrial secretion of several molecules involved in conceptus growth and development during the peri-implantation period. Indeed, several studies involving ruminants have reported that exogenous P4 supplementation is related to increased early embryo development, higher levels of interferon tau, and improved pregnancy rate. However, there is a lack of information about P4 supplementation during early pregnancy regarding swine embryonic development. Additionally, some of the few studies involving pigs have shown an impaired pregnancy rate when supplementation was performed before Day 6 of pregnancy. Thus, the objective of this study was to evaluate the effects of progesterone/progestin supplementation from Day 6 of pregnancy on total number of embryos (TE), pregnancy rate (PR), embryo development, and maternal serum 17β-oestradiol concentration (17β-E). A total of 31 crossbred, 2 to 6 parity sows were used. All sows were inseminated every 24h through the first oestrus following a 21-day lactation, and ovulation was detected by transrectal real-time ultrasound to determine Day 0 of pregnancy. On Day 6 of pregnancy, animals were randomly allocated to one of the following groups: CON (n=11), non-supplemented sows; RU (n=11), sows supplemented daily with 20mg of Altrenogest-Regumate® from Day 6 to 12 of pregnancy; and PG (n=9), sows supplemented with 2.15 mg/kg of long-acting P4 IM on Day 6 of pregnancy. Sows were treated with altrenogest p.o. as a top dressing over a small portion of feed. Blood samples were collected from 12 sows (4 per group) on Day 12 of pregnancy to measure the level of plasma 17β-E by radioimmunoassay. Sows were slaughtered on Day 28 of pregnancy. The uterus from each sow was collected and embryos were counted to determine TE. Embryos were individually separated from their placentas, weighed, and crown-to-rump length was determined. Data were analysed by the SAS program. All variables were analysed by PROC-MIXED t-test. Statistical difference was considered when P&amp;lt;0.05. The PR did not differ among groups (91, 90, and 88%, for CON, RU, and PG, respectively; P&amp;gt;0.05). No difference was observed among groups for TE and 17β-E level (P&amp;gt;0.05). However, embryonic weight and crown-to-rump length differed among the 3 groups (P&amp;lt;0.001). The RU-treated sows had heavier and bigger embryos when compared with the other groups. In contrast, PG-treated sows had the lowest averages for the same variables (weight: 1.39±0.01, 1.46±0.02, and 1.22±0.01; crown-to-rump: 21.07±0.08, 21.61±0.11, and 20.66±0.11; for CON, RU, and PG, respectively). In conclusion, altrenogest supplementation from Day 6 to 12 of pregnancy increases size and weight of porcine embryos, whereas 2.15mg kg−1 of long-acting P4 on Day 6 of pregnancy decreased these variables when compared with non-supplemented sows. Research was supported by FAPESP Grant 2017/00290-0.