Background: The livestock industry is a growing field where assisted reproductive technologies like in vitro embryo production (IVEP) enhance production efficiency. However, in vitro embryos show lower developmental competence due to stress and suboptimal culture conditions. Supplementing culture media with growth factor, such as insulin-like growth factor-1 (IGF-1) can improve embryo development. This study investigates the effect of IGF-1 on the developmental competence of oocytes and early embryonic development. 
 
Methods: In this study, cattle oocytes were aspirated from 3-8 mm ovarian follicles, washed and matured in maturation media supplemented with different concentrations of IGF-1 (0, 10, 25, 50, 100 ng/ml) for 24 hours at 38.5oC 5% CO2. Frozen-thawed sperm were used for in vitro fertilization of matured oocytes in fertilization media supplemented with IGF-1. Presumptive zygotes were cultured in IGF-1-supplemented mCR2aa media and embryos were monitored for 8 days until the blastocyst stage. The experiment was replicated six times and data were statistically analyzed by one-way ANOVA followed by Duncan Multiple Range Test using SPSS. Results are presented as means&plusmn;standard error with graphs generated by GraphPad Prism. 
 
Result: IGF-1 @ 50 ng/ml significantly enhanced embryo development, with highest cleavage rates at 2-cell (85.35% &plusmn;2.24) and 4-cell (86.10% &plusmn;1.90) stages and improved morula (32.53% &plusmn;5.11) and blastocyst formation (15.81%&plusmn;1.07) and IGF-1 @ 100 ng/ml showed moderate benefits, while at lower concentrations i.e. 0 ng/ml, 10 ng/ml and 25 ng/ml had minimal effects. Overall, @ 50 ng/ml IGF-1 was the most effective in promoting oocyte maturation and early embryonic development.

Insulin-like Growth Factor-1 Supplementation and Early Embryonic Developmental Competence of Immature Cattle Oocytes

<div>Background: Since both fetal and postnatal development is determined by early embryonic development and the molecular mechanism and organogenesis process of early mouse embryos have been thoroughly studied. However, the specific development process of early embryos in Mongolian sheep remains poorly understood.&nbsp; 
 
Methods: The 16-day and 25-day embryo samples of Inner Mongolia Hulunbuir short-tailed sheep were evaluated by transcriptome sequencing technique and the genes with significant differences were screened and the gene function was enriched by gene ontology (GO) database and Kyoto Encyclopedia of Gene and Genome (KEGG) database. 
 
Result: A total of 4348 differentially expressed genes (DEGs) were analyzed by sequencing and especially significant DEGs included the genes such as COL6A2, COL4A4, LAMA4, ITGA8, FN1 involved in ECM-receptor interaction, focal adhesion, PI3K-Akt signaling and protein digestion and absorption pathways; YAP1, FZD4, TGFB1, WNT2, BMP5, BMP2, WNT11 involved in Hippo signaling pathway. In pathway analysis, those pathways mainly related to cell interaction and organogenesis were highlighted at the E16 stage. They are critical for transcriptional control in early embryonic development, especially during organ building. The genes that make organs and body structures more complex and detailed and those related to the development of brain, liver and immune system are enriched for the E25 stage. Therefore, this study provides important supplementary and exploratory reference data for the further research on early embryonic development in sheep.</div>

The Transcriptional Landscape of the Early Embryonic Developmental Biology in Hulunbuir Short-Tailed Sheep

<div style="text-align: justify;">Background: The ovarian follicle is the fundamental functional tissue unit that consists of mammalian ovary. In humans, it has been known that females are born with a maximum number of follicles or oocytes that are not only non-renewable, but also undergoing degeneration with time with a sharply decreased oocyte quality after the age of 35.&nbsp; Methods: Here, we demonstrate that successful isolation of primary, early secondary and late secondary follicles from the ovaries of CD-1 outbred female mice and in vitro culture system to successfully induce the development of MII oocytes.&nbsp; Result: The 9 days of in vitro culture of early secondary follicles showed significant higher rates in growth and maturation displaying higher numbers of antral follicles and MII oocytes developed from early secondary follicles compared to those cultured for 11 days. However, there was no visible difference induced by the size of initial follicles in the rates of growth and maturation. MII oocytes derived from in vitro culture of early secondary follicles following in vitro fertilization developed into two-cell embryos. These observations demonstrate that developmentally competent MII oocytes can be obtained by in vitro culture of preantral follicles derived from the ovaries of CD-1 mice and reveal a crucial role for CD-1 mice as a novel model for research on human ovarian follicles. Furthermore, this study proposes an in vitro culture system using preantral follicle as a therapeutic strategy for fertility preservation of humans for assisted reproductive medicine.&nbsp;</div>

<div style="text-align: justify;">In vitro Culture of Early Secondary Preantral Follicles to Obtain MII Oocyte Developmental Competence from CD-1 Outbred Mice</div>

Background: Kosali cattle are a native breed from Chhattisgarh, India, primarily raised in rural areas on agricultural residues. However, there is limited information about the prenatal development of their thymus. Therefore, current study was conducted to understand the prenatal morphohistogenesis of thymus in Kosali breed of cattle. 
 
Methods: The present investigation involves 24 Kosali foetuses for the prenatal gross morphometric development of the thymus and categorized on the basis of crown-rump length (CRL) into four groups: Group I (CRL &lt;20 cm), Group II (20-40 cm), Group III&nbsp; (40-60 cm) and Group IV (&gt;60 cm). A midventral cervical incision from the larynx to the thoracic inlet was made to expose the thymus for in situ examination of its topography and morphology. Thymus samples were collected and processed for Hematoxylin and Eosin, Van Gieson&rsquo;s, Verhoeff&rsquo;s and Gomori&rsquo;s staining for histological changes. 
 
Result: In Group I, the thymus had paired cervical parts and one unpaired thoracic part, with the right limb extending to the middle thyroid cartilage and the left to the cricoid cartilage. By Groups II to IV, the left limb shifted laterally. The thymus color changed from cream to pink and while lobes became more distinct, their number decreased and size increased. The capsule thickened and became more vascular. The stroma contained interlobar and interlobular septa that thinned over groups and the number of lobules per field decreased significantly, indicating involution of the thymus and functional adaptations with age. These observations suggest that the thymus undergoes progressive involution with age. The structural and vascular changes seem to reflect the functional adaptations that occur during development. 
&nbsp;

Prenatal Morphohistogenesis of Thymus in Kosali Breed of Cattle: A Developmental Study of Histological Changes during Embryonic Development

<div>Background: Embryonic mortality is one of the major factors leading to reproductive failure, decreased fertility and delayed pregnancy in cattle. 
 
Method: The study was aimed for investigating the incidence of embryonic mortality(EM), differentiate embryonic development and mortality based on color Doppler ultrasonographic characteristics. Different characteristics correlated were corpus luteum(CL) vascularity, embryonic development&nbsp;and EM features, monitored on day 21 post-insemination.&nbsp; 
 
Result: The overall incidence of EM was recorded to be 25%, with 15% and 10% mortality occurred between days 21-28 and 28-35 of gestation. Color Doppler analysis stated that, the CL in pregnant cows had a higher percentage of luteal tissue with positive Doppler signals on initial examination (day 21) differing significantly (P&lt;0.01) from non-pregnant and consistently increased till the end of the examination. However, cows with EM had a significantly lower CL vascularity than pregnant (P&lt;0.05) but significantly higher (P&lt;0.05) than non-pregnant cows on day 21. Embryos from pregnant cows (detected by 28 days) increased in size along the days of examination. However, cows diagnosed with EM showed signs (day 28), which included reduced intra-uterine allantoic fluid, absence of embryo proper with an embryonic heartbeat, hyperechoic free-floating embryonic debris in the uterus and distorted allanto-chorionic membrane. In conclusion, the present study firmly supports color Doppler ultrasonography in diagnosis of pregnant cows based on CL vascularity, visualizing the different characteristics signs of EM, and detecting non-pregnant animals undergoing EM as early as day 21.</div>

​Color Doppler Ultrasonographic Characteristics of Embryonic Development and Mortality in Dairy Cows

<div style="text-align: justify;">At present, broilers reach slaughter weight at a physiologically younger age and the embryonic developmental period as well as the first week after hatching represents a larger proportion (45%) of the whole life span. Thus, pre-hatch as well as the transitional post-hatch period must be achieved efficiently. It is known that body weight is increased three to four fold during the first week and considerable changes in gut, and muscle weight and morphology are observed. The post-hatch period is critical for the digestive tract because the system is switching itself from off to on. The first day after hatch is critical for the development of body systems in the chicken and certain types of manipulation must occur during the first days after hatch in order to achieve long-term effects. Meat-type broilers are capable of achieving 70 g/day until 40 days. This achievement requires emphasis on early phase nutrition (i.e. pre-starter diets). The use of pre-starter diets assumes that starter diets are somewhat inefficient in providing balanced nutrients. Early nutritional strategies offer the promise of sustaining progress in production efficiency and welfare of commercial poultry. In order to achieve broiler potential several unconventional changes must be made: supplying nutrients to the developing embryo before hatch, supplying feed within hatchery, developing highly digestible pre-starter diets. Integrate all of the above to create a continuous feeding process from several days prior to hatch, during hatch and till farm placement where first feed is provided.</div>

Early post hatch feeding in chicks and practical constrains-A review

Selecting viable fully grown germinal and matured oocytes were positively effect on further embryonic development and live birth.&nbsp;The use of feed and hormonal supplementation and biotechnologies to enhance&nbsp;oocyte&nbsp;competence was evaluated. In addition, the oocytes were selected based on ovarian follicular stage, follicles and oocytes morphology, follicular fluid characters and gene expression. Changes were obtained in oocyte maturation, fertilization and further embryo cleavage and development over selecting viable oocytes. The larger follicle diameter, the translucent follicle and the higher blood supply the higher developmental competence of resulting oocytes. The higher surrounding cumulus cells and homogeneity of cytoplasm the higher developmental competence of oocytes. In addition, oocytes obtained during luteal stage compared to those obtained during follicular phase were highly or comparably developed to embryos. Furthermore, follicular fluid characters and gene expression might predict the embryonic developmental competence of oocytes in addition to their viable staining with brilliant cresyl blue. In conclusion, the characters of ovarian follicles, oocytes, follicular fluid and gene expression have significant implications on further oocyte developmental competence in different mammalian species.

The Potential Impacts of Selecting Viable Oocytes on Further Embryonic Development in Mammals: A Review

Background: The developmental competency of in vitro matured oocytes to the blastocyst stage is a big concern in laboratory conditions. This study aims in finding the best combination of growth factors for enhancement of cleavage as well as early embryonic developmental rates in cattle. 
 
Methods: Fresh cattle ovaries were obtained from the nearest slaughterhouse in 0.15 M freshly prepared saline (35-38&deg;C) supplemented with penicillin (400 IU/ml). A total of 924 COCs were aspirated from ovaries and transferred to maturation media for incubation (5% CO2) at 38.5&deg;C with maximum humidity for 24 h. After maturation, the matured oocytes were co-incubated with the capacitated sperms for in vitro fertilization in the FBO medium for 16 h. After fertilization, the cumulus cells were removed from the presumptive zygotes and incubated in the mCR2aa medium for 45-48 h. The cleavage rates of the zygotes were observed and further cultured in the blastocyst medium for 7-10 days. After every 24 h, 80% of culture media was replaced with fresh media. Three different combinations of growth factors (PDGF+IGF, EGF+FGF and T3+T4) used in this study.&nbsp; 
 
Result: Supplementation of growth factors in culture media increased cleavage rate and blastocyst rate significantly (p&lt;0.05). PDGF+IGF @ 10 ng/ml+75 ng/ml, EGF+FGF @ 20 ng/ml+10 ng/ml and T3+T4 @ 100 ng/ml+100 ng/ml showed the best results in terms of cleavage rates and blastocyst development.

Effect of Different Growth Factors on in vitro Developmental Competence and Quality of Cattle Oocytes

<div>Background: In Sri Potti Sriramulu Nellore district of Andhra Pradesh long duration varieties of pigeonpea (160-180 days) is grown during rabi under rainfed conditions. Late or advancement of north east monsoon, prolonged breaks and early cessation of rainfall may have devastating effects on pigeonpea yield in rainfed areas of Sri Potti Sriramulu Nellore district, Andhra Pradesh even if the mean annual rainfall is normal. In this context, there is a need for introduction of suitable super early varieties of pigeonpea which are ideal even under changing climatic situations, with suitable crop geometry to enhance the yields of pigeonpea.&nbsp; 
 
Method: A field experiment was conducted during rabi, 2018-19 and 2019-20 at Agricultural Research Station, Podalakur, Sri Potti Sriramulu Nellore andhra Pradesh, to find out the suitable super early variety of pigeonpea and their response to different crop geometries. The present field experiment was laid out in a split plot design with 4 varieties of pigeonpea (V1: ICPL 20338; V2: ICPL 20325; V3: ICPL 11255; V4: LRG 52) as main plot treatments and 3 crop geometries (S1: 30 cm x 15 cm; S2: 45 cm x 15 cm); S3: 60 cm x 15 cm) as subplot treatments and replicated thrice. 
 
Results: Super early variety ICPL- 20325 recorded the highest mean grain yield (1098 kg ha-1) among the four varieties of pigeonpea tested. Among the three crop geometries tested significantly the highest grain yield (930 kg ha-1) was recorded at 45 cm x 15 cm. Super early varieties ICPL- 20325 (1256 kg ha-1), ICPL- 11255 (930 kg ha-1) and ICPL- 20338 (817 kg ha-1) recorded higher mean grain yield at crop geometry of 45 cm x&nbsp;15 cm. LRG-52 (996 kg ha-1) variety recorded higher grain yield at crop geometry of 60 cm x 15 cm.</div>

Response of Super Early Varieties of Pigeonpea to Crop Geometry under Rainfed Conditions

<div>Background: In view of developing early maturing groundnut that fit in high intensity multiple cropping system the present study was taken up to introgress early maturing traits in the well-established high yielding varieties. 
 
Methods: VRI 8, CO 7, ICGV 07222 and VRI 6 were takenas the variety to be improved and as a source for early maturity and male parent in the study viz., VRI 3, Chico, ICGV 91114 and ICGV 93468 were used. A crossing program was designed using these parent materials and selected crosses were forwarded to the next F2 generation and their backcross populations were also generated. The data recorded were subjected to Generation mean analysis and association analysis. 
 
Result: With consideration of early maturity and high pod yield the genotypes F2 of CO 7 &times; Chico and ICGV 07222 &times; Chico and B2 of ICGV 07222 &times; Chico recorded high mean values for the traits. The presence of duplicate epistasis was observed for, days to accumulation of 25 flowers (DTF) and days to maturity. This indicates that, inter-mating the selected segregating generations could result in the accumulation of favourable genes. The trait pod yield per plant exhibited positively significant correlation with days to accumulation of 25 flowers, days to maturity in all the crosses and the trait days to accumulation of 25 flowers is positively correlated to days to maturity. Thus, the trait-days to accumulation of 25 flowers is the major selection factor for early maturity in groundnut.</div>