Yellow Follicles Research Articles

Stimulatory effects of fish oil and vitamin E on ovarian function of laying hen

In recent years, there has been an increase in the consumption of omega-6 fatty acids (FAs) over omega-3. Moreover, the antioxidant nature of oil supplemented diet in human and animal studies is not clear. In this work, the n-3 effects on hen ovarian cells, ovarian dynamics, serum FA profiles and expression level of apoptosis genes in the presence or absence of vitamin E were studied. Sixty-eight laying hens were randomly divided into four groups and the groups were fed the following diets: basal diet +1.5% sunflower oil (control; C); basal diet +1.5% sunflower oil +1.1 U alpha-tocopherol/hen/day (E); basal diet +1.5% fish oil +1.1 U alpha-tocopherol/hen/day (n-3 + E); and basal diet +1.5% fish oil (n-3). In E, n-3 + E and n-3, small yellow follicle numbers were higher than control (p < .05). Large yellow follicle numbers as well as total numbers of follicles of n-3 + E and n-3 were higher (p < .05) than control and E. The rate of ovulation was significantly (p < .05) higher in n-3 (96%) compared to the control (89%). The proportion of intact primordial follicles in n-3 and n-3 + E was significantly more than control and E (p < .01). The expression of Bak (Bcl2 antagonist/killer) was significantly (p < .05) higher in control than the other groups. There was significant reduction in expression of Cas9 in n-3 and E compared to the control and n-3 + E (p < .05). While omega-3 and vitamin E can protect ovarian cells from apoptotic death, omega-3 source could have promoting roles on follicular development and ovulation rate, being independent of dietary vitamin E.HighlightsDespite the perceived importance of supplementing antioxidant with fatty acids, our results indicated that alone low level of n-3 has a great influence on ovary performance.

Effects of rearing systems on reproductive hormones secretion and their receptors gene expression in Xianju chickens under summer conditions.

Previous study in our lab showed that indigenous Xianju chickens from free-range system (FRS) under summer conditions had lower egg production than those from conventional cage rearing system (CRS). The objective of this study was to preliminarily determine the FRS-dependent mechanism of depressing laying performance according to determining the effect of rearing systems on reproductive hormones secretion and their receptors mRNA expression in Xianju chickens reared under summer conditions. A total of 360 indigenous Xianju chickens were randomly allocated to CRS and FRS groups, each of which included 5 replicates of 36 hens. The experiment lasted between 21 and 29 wk of age. We found that the ovarian weight, numbers of small yellow follicles, and large white follicles in the FRS group were lower than those in the CRS group (P < 0.05). Changing from CRS to FRS increased serum concentrations of prolactin and decreased serum-luteinizing hormone and progesterone levels (P < 0.05). Gene expressions in the preovulatory follicles from FRS hens were upregulated for prolactin receptor and downregulated for luteinizing hormone receptor and progesterone receptor, compared to those from CRS hens (P < 0.05). It can be concluded that changing from CRS to FRS in the current experimental conditions depressed egg production traits in Xianju chickens by inducing a synergistic activity of reproductive hormones and the gene expressions of their receptors.

Comparison of single- and multi-strain probiotics effects on broiler breeder performance, egg production, egg quality and hatchability

ABSTRACT1. This study was conducted to investigate the effect of multi-strain probiotic (containing Lactobacillus acidophilus 2.5 × 107 cfu/g, Lactobacillus casei 2.5 × 107 cfu/g, Bifidobacterium thermophilum 2.5 × 107 cfu/g and Enterococcus faecium 2.5 × 107 cfu/g) and single-strain probiotic (Pediococcus acidilactici 1 × 1010 cfu/g) on broiler breeder performance and gastrointestinal health.2. A completely randomised trial was conducted using 300 broiler breeder hens (Ross 308) aged 51 weeks old which were randomly allocated to 1 of 5 dietary treatments with 6 replicates per treatment in a 10 week trial. Treatments included (1) the basal diet a negative control, (2) basal diet supplemented with 0.1 g/kg multi-strain probiotic (MS), (3) basal diet supplemented with 0.1 g/kg single-strain probiotic (SS), (4) basal diet supplemented with 0.1 g/kg of both of probiotics (MS+ SS) and (5) positive control basal diet supplemented with 0.5 g/kg oxytetracycline antibiotic (OX).3. Body weight, egg production, yolk weight, eggshell thickness and weight, Haugh unit, fertility and hatchability were determined. Results showed that dietary treatments had no significant effect on total hen house or total hatching egg production, egg weight, yolk colour index, shell weight, mortality, body weight, fertility, hatchability, oviduct and stroma weight or number of large and small yellow follicles (P > 0.05). None of the jejunum morphological parameters, apparent ileal digestibility of protein and ileal Lactobacillus population were influenced by supplemental probiotics (P > 0.05), although ileum Escherichia coli count was reduced by inclusion of dietary probiotics (P < 0.05).4. It was concluded that although both probiotic treatments reduced coliforms, they did not improve broiler breeder performance or gastrointestinal tract (GIT) function.

A transcriptomic comparison of theca and granulosa cells in chicken and cattle follicles reveals ESR2 as a potential regulator of CYP19A1 expression in the theca cells of chicken follicles

Previous studies have shown that theca and granulosa cell layers in follicles do not play the same roles in mammals and birds, especially regarding the synthesis of estrogen. The functions of these two cell types have been well characterized in cattle, but they remain unclear in chickens. To clarify this issue, a comparison of small yellow follicles (SYFs) in chickens and cattle at different follicular development stages was done by weighted gene co-expression network analysis (WGCNA). The modules obtained from WGCNA were used for further identification of the key genes associated with CYP19A1 expression. Module preservation analysis showed high similarity between cow_D (the follicular phase before the LH surge) and chicken_SYF (small yellow follicle between 6 and 8 mm in diameter) datasets, and 10 top hub genes highly associated with CYP19A1 expression in chicken SYFs were identified in each module. A comparison of the transcriptomes of theca and granulosa cells (TCs and GCs) between chicken SYFs and cattle follicles at the differentiation stage, as well as the aforementioned hub genes, revealed that ESR2 is a potential regulator of CYP19A1 expression in the theca cells of chicken SYFs. Furthermore, 197 cell-specific (179 in theca and 18 in granulosa) and 235 cell-biased expressed genes (196 in theca and 39 in granulosa) in chicken small yellow follicles were also identified by transcriptomic comparison of theca and granulosa cells.

Functional genomics study of acute heat stress response in the small yellow follicles of layer-type chickens

This study investigated global gene and protein expression in the small yellow follicle (SYF; 6–8 mm in diameter) tissues of chickens in response to acute heat stress. Twelve 30-week-old layer-type hens were divided into four groups: control hens were maintained at 25 °C while treatment hens were subjected to acute heat stress at 36 °C for 4 h without recovery, with 2-h recovery, and with 6-h recovery. SYFs were collected at each time point for mRNA and protein analyses. A total of 176 genes and 93 distinct proteins with differential expressions were identified, mainly associated with the molecular functions of catalytic activity and binding. The upregulated expression of heat shock proteins and peroxiredoxin family after acute heat stress is suggestive of responsive machineries to protect cells from apoptosis and oxidative insults. In conclusion, both the transcripts and proteins associated with apoptosis, stress response, and antioxidative defense were upregulated in the SYFs of layer-type hens to alleviate the detrimental effects by acute heat stress. However, the genomic regulations of specific cell type in response to acute heat stress of SYFs require further investigation.

Effects of dietary methionine on productivity, reproductive performance, antioxidant capacity, ovalbumin and antioxidant-related gene expression in laying duck breeders.

The study investigated whether dietary methionine (Met) affects egg weight and antioxidant status through regulating gene expression of ovalbumin (OVAL), nuclear factor erythroid 2 like 2 (Nrf2) and haem oxygenase 1 (HO-1) in laying duck breeders. Longyan duck breeders (n 540, 19 weeks) were randomly assigned to six treatments with six replicates of fifteen birds each. Breeders were fed diets with six Met levels (2·00, 2·75, 3·50, 4·25, 5·00 and 5·75 g/kg) for 24 weeks. The egg weight (g), egg mass (g/d), feed conversion ratio, hatchability, 1-d duckling weight, albumen weight, albumen proportion and OVAL mRNA level improved with dietary Met levels, whereas yolk proportion decreased (P<0·05). The weight of total large yellow follicles increased linearly (P<0·001) and quadratically (P<0·05) with dietary Met concentration, and their weight relative to ovarian weight showed a linear (P<0·05) effect. Dietary Met level had a linear (P<0·05) and quadratic (P<0·001) effect on the gene expression of glutathione peroxidase (GPX1), HO-1 and Nrf2, and quadratically (P<0·05) increased contents of GPX and total antioxidant capacity (T-AOC) in liver of duck breeders. In addition, maternal dietary Met enhanced gene expression of GPX1, HO-1 and Nrf2, increased contents of GPX and T-AOC and reduced carbonylated protein in the brains of hatchlings. Overall, dietary Met concentration affected egg weight and albumen weight in laying duck breeders, which was partly due to gene expression of OVAL in oviduct magnum. A diet containing 4·0 g Met/kg would achieve optimal hepatic GPX1 and Nrf2 expression, maximise the activity of GPX and minimise lipid peroxidation.

Cytological features of pig oocytes in the process of spontaneous maturation

Aim. The study was aimed at determining the cytological changes, related to the germinal vesicle (GV) of porcine oocyte during the follicular maturation. Methods. The ovaries were classifi ed according to the estrous cycle phase, judging by the status of yellow bodies and follicles. The oocytes were isolated from each animal using dominating and atresiated follicles separately. The oocytes were used to prepare whole mounts by a specially designed express-method, which is thermal fi xation (about 95 °С) and their further transfer into the medium for clarifi cation. The whole procedure of preparing the mount from one oocyte or their group lasted for about 10 min. The microscopic studies were conducted using the phase contrast. A total of 831 oocytes were studied. Results. It was established that sow oocytes had eccentric location of GV which may be found in oocytes from early antral follicles. This condition is kept until the beginning of meiosis restoration and GV destruction. The nucleolus is also located eccentrically. Another relevant cytological change was gradual condensation of chromatin around the nucleolus, starting from separate clots on its surface and further formation of circular structures. Conclusions. Contrary to laboratory rodents, GV in porcine oocytes has eccentric localization, which is set even in early antral follicles and remains until the beginning of meiosis restoration. The process of chromatin transformation was found to be its gradual condensation around the nucleolus which may be defi ned as a nucleolus complex.

Genetic Architecture and Candidate Genes Identified for Follicle Number in Chicken

Follicular development has a major impact on reproductive performance. Most previous researchers focused on molecular mechanisms of follicular development. The genetic architecture underlying the number of follicle, however, has yet not to be thoroughly defined in chicken. Here we report a genome-wide association study for the genetic architecture determining the numbers of follicles in a large F2 resource population. The results showed heritability were low to moderate (0.05–0.28) for number of pre-ovulatory follicles (POF), small yellow follicles (SYF) and atresia follicles (AF). The highly significant SNPs associated with SYF were mainly located on GGA17 and GGA28. Only four significant SNPs were identified for POF on GGA1. The variance partitioned across chromosomes and chromosome lengths had a linear relationship for SYF (R2 = 0.58). The enriched genes created by the closest correspondent significant SNPs were found to be involved in biological pathways related to cell proliferation, cell cycle and cell survival. Two promising candidate genes, AMH and RGS3, were suggested to be prognostic biomarkers for SYF. In conclusion, this study offers the first evidence of genetic variance and positional candidate genes which influence the number of SYF in chicken. These identified informative SNPs may facilitate selection for an improved reproductive performance of laying hens.

Transcriptome Analysis on Single Small Yellow Follicles Reveals That Wnt4 Is Involved in Chicken Follicle Selection.

Ovarian follicle selection is an important process impacting the laying performance and fecundity of hens, and is regulated by follicle-stimulating hormone (FSH) through binding to its receptor [follicle-stimulating hormone receptor (FSHR)]. In laying hens, the small yellow follicle (6–8 mm in diameter) with the highest expression of FSHR will be recruited into the preovulatory hierarchy during ovarian follicle development. The study of molecular mechanism of chicken follicle selection is helpful for the identification of genes underlying egg-laying traits in chicken and other poultry species. Herein, the transcriptomes of chicken small yellow follicles differing in the mRNA expression of FSHR were compared, and a total of 17,993 genes were identified in 3 pairs of small yellow follicles. The Wnt signaling pathway was significantly enriched in the follicles with the greatest fold change in FSHR expression. In this pathway, the expression level of Wnt4 mRNA was significantly upregulated with a log2(fold change) of 2.12. We further investigated the expression, function, and regulation of Wnt4 during chicken follicle selection and found that Wnt4 mRNA reached its peak in small yellow follicles; Wnt4 stimulated the proliferation of follicular granulosa cells (GCs), increased the expression of StAR and CYP11A1 mRNA in prehierarchical and hierarchical follicles, increased the expression of FSHR mRNA, and decreased the expression of anti-Müllerian hormone and OCLN mRNA. Treatment with FSH significantly increased Wnt4 expression in GCs. Moreover, Wnt4 facilitated the effects of FSH on the production of progesterone (P4) and the mRNA expression of steroidogenic enzyme genes in the GCs of hierarchical follicles, but inhibited the effects of FSH in the GCs of prehierarchical follicles. Collectively, these data suggest that Wnt4 plays an important role in chicken follicle selection by stimulating GC proliferation and steroidogenesis. This study provides a theoretical basis for improving the egg-laying performance of chicken and a reference for the elucidation of the molecular mechanism of follicular selection in mammals.

Proteomic Analysis of Thermal Regulation of Small Yellow Follicles in Broiler-Type Taiwan Country Chickens.

Heat stress hampers egg production and lowers fertility in layers. This study investigated global protein abundance in the small yellow follicles (SYFs, 6–8 mm diameter) of a broiler-type strain of Taiwan country chickens (TCCs) under acute heat stress. Twelve 30-week-old TCC hens were allocated to a control group maintained at 25°C, and to three acute heat-stressed groups subjected to 38°C for 2 h without recovery, with 2-h recovery, or with 6-h recovery. Two-dimensional difference gel electrophoresis analysis identified 119 significantly differentially expressed proteins after acute heat exposure. Gene ontology analysis revealed that most of these proteins are involved in molecular binding (34%), catalytic activity (23%), and structural molecule activity (11%), and participate in metabolic processes (20%), cellular processes (20%), and cellular component organization or biogenesis (11%). Proteins associated with stress response and survival (HSP25, HSP47, HSP70, HSC70, HSPA9), cytoskeleton remodeling, mitochondrial metabolic process of ATP production, antioxidative defense (peroxiredoxin-6), cargo lipid export and delivery (vitellogenin, apolipoprotein B and A1), and toxin/metabolite clearance and delivery (albumin) were upregulated after acute heat stress in the SYFs of TCCs. No overt cell death and atresia were observed in SYFs after acute heat stress. Collectively, these responses may represent a protective mechanism to maintain follicle cell integrity and survival, thereby ensuring a sufficient pool of SYFs for selection into the ovulation hierarchy for successful egg production.

Pengaruh penggunaan tepung limbah udang fermentasi terhadap karakteristik organ reproduksi pada puyuh petelur (Coturnix coturnix japonica)

The aim of the present study was to evaluate the effect of fermented shrimp waste meal on the characteristics of reproductive organs such as live weight, oviduct weight and length, ovarian weight, total yellow follicles, total white follicles, oviduct percentage and reproductive organ percentage. This experiment was conducted on Faculty of Animal Science and Agriculture, Diponegoro University. A total of 250, 6-week-old Japanese quail (consist of 250 females) were randomly assigned to one of 5 dietary treatments. 1st group (T0) was fed by diet without shrimp waste (control), 2nd group (T1) was fed by diet with 7,5% non-fermented shrimp waste, 3rd group (T3) was fed by diet with 5% fermented shrimp waste (FSW), 4th group (T3) was fed by diet with 7,5% FSW and 5th group was fed by diet with 10% FSW. 2 quails from each replicates were taken as samples. The members of a given sample were killed by severing the neck then separated the reproductive organs from the body. Measured the live weight, oviduct weight and length, ovarian weight, total yellow follicles, total white follicles, oviduct percentage and reproductive organ percentage. All data were examined using analysis of variance (ANOVA). The results showed that the effect of fermented shrimp waste meal on reproductive organs characteristics such as live weight, oviduct weight and length, ovarian weight, total yellow follicles, total white follicles, oviduct percentage and reproductive organ percentage were not significant. The use of fermented shrimp waste up to 10% didn’t obstruct the growth and development of quail reproductive organs.

Expression of aquaporin 4 in the chicken ovary in relation to follicle development.

In the mammalian ovary, aquaporins (AQPs) are thought to be involved in the regulation of fluid transport within the follicular wall and antrum formation. Data concerning the AQPs in the avian ovary is very limited. Therefore, the present study was designed to examine whether the AQP4 is present in the chicken ovary, and if so, what is its distribution in the ovarian compartment of the laying hen. Localization of AQP4 in the ovarian follicles at different stage of development was also investigated. After decapitation of hens the stroma with primordial follicles and white (1-4mm), yellowish (4-8mm), small yellow and the three largest yellow pre-ovulatory follicles F3-F1 (F3<F2<F1; 20-36mm) were isolated from the ovary. The granulosa and theca layers were separated from the pre-ovulatory follicles. The AQP4 mRNA and protein were detected in all examined ovarian compartments by the real-time PCR and Western blot analyses, respectively. The relative expression of AQP4 was depended on follicular size and the layer of follicular wall. It was the lowest in the granulosa layer of pre-ovulatory follicles and the highest in the ovarian stroma as well as white and yellowish follicles. Along with approaching of the largest follicle to ovulation the gradual decrease in AQP4 protein level in the granulosa layer was observed. Immunoreactivity for AQP4 was present in the granulosa and theca cells (theca interna≥theca externa>granulosa). The obtained results suggest that AQP4 may take part in the regulation of water transport required for follicle development in the chicken ovary.

Effects of dietary octacosanol supplementation on laying performance, egg quality, serum hormone levels, and expression of genes related to the reproductive axis in laying hens

This experiment was conducted to evaluate the effects of dietary octacosanol supplementation on laying performance, egg quality, serum hormone levels, and gene expression related to reproductive axis in laying hens to confirm the reproduction-promoting function of octacosanol. In total, 360 Hy-Line Brown (67-wk-old) laying hens were randomly assigned to one of three treatments with 0, 5, and 10 mg octacosanol (extracted from rice bran, purity >92%)/kg feed. The feeding trial lasted for 10 weeks. The results showed that the dietary addition of 5 and 10 mg/kg octacosanol improved feed efficiency by 4.9% and 3.4% (P < 0.01), increased the albumen height by 20.5% and 13.3% (P < 0.01), the Haugh unit score by 12.9% and 8.7% (P < 0.01), and the eggshell strength by 39.5% and 24.5% (P < 0.01), respectively, compared with the control diet. Dietary octacosanol addition significantly affected serum triiodothyronine, estradiol, follicle-stimulating hormone levels (P < 0.05), and progesterone and luteinizing hormone level (P < 0.01). Compared with the control, dietary addition of octacosanol at 5 mg/kg promoted the follicle-stimulating hormone receptor (FSHR) mRNA expression in different-sized follicles, and significantly increased the FSHR mRNA expression of granulosa cells from the F2 and F3 follicles (P < 0.05). Dietary supplementation with both 5 and 10 mg/kg octacosanol promoted the mRNA expression of luteinizing hormone receptor and prolactin receptor in different-sized follicles, and significantly up-regulated the expression levels in F1 granulosa cells (P < 0.05). The ovarian weight was significantly increased with the dietary addition of 5 mg/kg octacosanol (P < 0.05). The numbers of small yellow follicles and large white follicles were increased with the addition of dietary 5 and 10 mg/kg octacosanol (P < 0.01). This study provides evidence that octacosanol has the capacity to improve reproductive performance, indicating that it is a potentially effective feed additive in egg production.

Estimation of dietary arginine requirements for Longyan laying ducks

This study aimed to establish the arginine requirements of Longyan ducks from 17 to 31 wk of age based on egg production, egg quality, plasma, and ovarian indices, as well as the expression of vitellogenesis-related genes. In total, 660 Longyan ducks with similar body weight at 15 wk of age were assigned randomly to 5 treatments, each with 6 replicates of 22 birds, and fed a corn-corn gluten meal basal diet (0.66% arginine) supplemented with either 0, 0.20%, 0.40%, 0.60%, or 0.80% arginine. Dietary arginine did not affect egg production by laying ducks, but it increased (linear, P < 0.01) the egg weight at 22 to 31 and 17 to 31 wk of age. Dietary arginine increased the yolk color score (linearly, P < 0.05) and the yolk percentage (quadratic, P < 0.05), where the maximum values were obtained with 1.26% arginine. Dietary arginine affected the total shell percentage and shell thickness, with the highest values using 1.46% arginine (P < 0.01). The weight and number of small yellow follicles (SYFs) increased (quadratic, P < 0.05) with the dietary arginine level and there was a quadratic response (P < 0.05) in terms of the SYFs weight/ovarian weight; the highest values were obtained in ducks fed 1.26% arginine. The plasma arginine concentration exhibited a quadratic (P < 0.05) response to dietary arginine. The plasma progesterone concentration decreased (linear, P < 0.05) as dietary arginine increased. The mRNA abundance of the very low density lipoprotein receptor-b increased in the second large yellow follicle membranes (quadratic, P < 0.05) with the dietary arginine level, where the highest value occurred with 1.26% arginine. According to the regression model, the dietary arginine requirements for Longyan laying ducks aged 17 to 31 wk are 1.06%, 1.13%, 1.22%, and 1.11% to obtain the maximum yolk percentage, SYFs number, SYFs weight, and SYFs weight/ovarian weight, respectively.

Effects of massive ovulation on oxidation state and function of the ovaries in laying hens

Modern laying hens show fast reduction in egg production rate after 60 weeks of age, which is associated with the decline in ovarian function. The aim of this study was to examine the influence of massive ovulation on the oxidation state and ovarian function in hens. In total, 48 Jing Hong hens aged 17 weeks were randomly divided into high ovulation (HO) and low ovulation (LO) groups. The LO hens were exposed to 6 h of light per day (6 L:18 D) up to 32 weeks to delay the initiation of egg production and then were switched to 16 L:8 D. The HO hens were reared at 16 L:8 D from 19 weeks. The treatment effects were analyzed by the independent samples t-test using SAS 9.0 software (SAS Institute, Cary, NC, USA). At 36 weeks, there were no significant differences in body weight (P > 0.05) between the two groups and the egg production rate of both groups reached 98%; however, the cumulative egg number in the HO group was much higher than that in the LO group (71.3 versus 18.5, respectively; P < 0.001). The following parameters decreased in the HO hens compared with the LO hens: the number of small yellow follicles (SYFs, P < 0.001) and large white follicles (LWFs, P < 0.01), mRNA expression of luteinizing hormone receptor (P < 0.001), and follicle-stimulating hormone receptor (P < 0.001), while the atretic rates of SYFs and LWFs increased (P < 0.001 and P < 0.01, respectively). In addition, compared with the LO group, the HO hens had reduced activity of superoxide dismutase (plasma: P < 0.01; liver: P < 0.001; ovary: P < 0.001) and glutathione peroxidase (plasma: P < 0.01; liver: P < 0.01; ovary: P < 0.01), while the levels of methane dicarboxylic aldehyde (plasma: P < 0.01; liver: P < 0.001; ovary: P < 0.001) and mRNA expression of mitochondrial transcription factor A (P < 0.001) in granulosa cells were higher. These results indicated that massive ovulation aggravated oxidative stress and had adverse effects on ovarian function in laying hens.

Normal ultrasonographic images of reproductive organs of female Japanese quails ( Coturnix coturnix japonica): a laboratory animal model.

Certain special biological characteristics of Japanese quails ( Coturnix coturnix japonica) could enable quicker and less expensive laboratory experiments than similar studies using mice or chickens. Moreover, due to some physiological similarities with humans, quails have been recognized as an ideal laboratory model for experiments in some fields such as immunology, endocrinology, and reproductive biology. The aim of this study was to acquire normal ultrasonographic images of reproductive organs of female Japanese quails in order to facilitate laboratory experiments on reproductive biology and to determine a non-invasive in-life alternative to carcass analysis. Thirty female Japanese quails of different ages were used for ultrasound scanning of ovaries, follicles, ova, oviducts and eggs. In addition, five quails were euthanized for experiments using a direct standoff imaging technique. It was possible to identify different sizes of follicles ranging from small white follicles (0.14 cm) to large yellow follicles (2.57 cm), post-ovulatory follicles (POFs), ova at various stages of development, oviducts, and also eggs within the oviducts. These findings demonstrate that ultrasound scanning of female Japanese quail reproductive organs might be a beneficial diagnostic tool for applications such as studying reproductive physiology, anticipating the beginning or the end of the breeding season, detecting any pathological disorders easily, and identifying non-productive females which could lead to more cost-efficient laboratory procedures.

High-throughput sequencing reveals differential expression of miRNAs in prehierarchal follicles of laying and brooding geese.

Broodiness is the primary factor influencing egg production in geese, in which several genes and miRNAs participate. Detailed spatiotemporal profiles of miRNAs encompassing follicle development levels, however, are lacking. In this study, we collected preovulatory follicles (classified as small white follicles, large white follicles, and small yellow follicles) from brooding and laying geese and aimed to analyze microRNA (miRNA or miR) during folliculogenesis. High-throughput sequencing and bioinformatics analysis were used to identify the miRNAs involved in follicle development. The let7 family, miR-10 family, and miR-143 family were abundant in these libraries, and they have been suggested to play a housekeeping role during folliculogenesis. Joint comparisons revealed 23 upregulated and 21 downregulated miRNAs (in at least two comparisons of follicles during brooding and laying, P < 0.1) in the laying stage. Unlike reproduction pathways reported for ovaries, GO and KEGG analysis suggested pathways for cell apoptosis and proliferation, such as the regulation of actin cytoskeleton, endocytosis, axon guidance, pathways in cancer, tight junctions, focal adhesion, the MAPK signaling pathway, cytokine-cytokine receptor interactions, and the Wnt signaling pathway in folliculogenesis. This study revealed the miRNAs that were directly involved in follicular atresia, and our results added to the understanding of the functional involvement of miRNAs during specific stages of follicle development.

Use of transcutaneous ultrasonography to characterize ovarian status, size distribution, and hierarchical status of follicles in Japanese quail (Coturnix coturnix japonica)

The present study was undertaken to evaluate the ovarian status of matured breeding female Japanese quail by means of B Mode portable ultrasound scanning. Active ovaries in various stages of hierarchical development and different morphological structure were observed. The large yellow follicles appeared as a cluster of dark circles with various intensity of hyperechoic concentric ring. Sonographically, these follicles were classified into F1, F2, and F3 measuring 16.20 ± 0.06 mm, 12.48 ± 0.09 mm, and 7.95 ± 0.16 mm, respectively. A comparative study on preslaughter and postslaughter ovarian follicular status revealed accuracy of follicles less than 10 mm, 10–15 mm, 15–18 mm, and greater than 18 mm as 26.31%, 78.9%, 93.75%, and 100%, respectively, with an overall accuracy of 71%. This is the first report on the application of transcutaneous ultrasonographic technique to monitor ovarian status on Japanese quail reporting that the ovarian follicular activity and morphological structure can be monitored nonintrusively throughout quail life which can used as model for reproductive and biomedical research.

Expression of Nerve Growth Factor (NGF) and Its Receptors TrkA and p75 in the Reproductive Organs of Laying Hens

In order to investigate the expression levels of nerve growth factor (NGF) and its receptors (TrkA and p75) in prehierarchical follicles and oviducts of hens, five 130-day-old laying hens were examined by immunohistochemistry and RT-PCR analysis. NGF and its receptors were expressed in theca cells and granulosa cells of prehierarchical follicles, and they were also expressed in the epithelial cells of oviducts. The expression of the genes NGF, TrkA and p75 were significantly different in prehierarchical follicles (p<0.05 or p<0.01), and NGF and TrkA gene expression was significantly different in different parts of oviduct (p<0.05 or p<0.01). The expression of NGF and p75 mRNA levels was highest in large white follicle (LWF), as well as the expression of TrkA in small yellow follicle (SYF). In the oviduct, the expression of NGF was the highest in infundibulum, and lowest in isthmus. These results suggest that NGF may play an important role in the regulation of hen reproduction.

Effects of Arginine Supplementation on Organ Development, Egg Quality, Serum Biochemical parameters, and Immune Status of Laying Hens

This experiment was conducted to study the effects of arginine supplementation on organ development, egg quality, blood parameters, and immune status of laying hens. A total of 360 25-week-old brown Leghorn laying hens were randomly divided into three groups with six replicates of 20 birds each and fed diets supplemented with 0, 8.5, or 17 mg of L-arginine/kg for 42 days. Results showed that the weight of proventriculus and duodenum in the treatment supplemented with 17 mg/kg L-arginine was heavier than that of 0 mg L-arginine/kg treatment (p<0.05). The weight of oviduct in the treatments supplemented with 17 mg/kg L-arginine was smaller than that of 0 and 8.5 mg L-arginine/kg treatment (p<0.05), and the small yellow follicle amount in the treatment supplemented with 17 mg/kg L-arginine was less than that of 0 mg L-arginine/kg treatment (p<0.05), while its yolk color was deeper than that of 0 mg L-arginine/kg treatment (p<0.05), and the IgY content showed the same tendency. Total cholesterol and triglyceride levels in the treatment supplemented with 8.5 mg/kg L-arginine were lower than that of 0 mg L-arginine/kg treatment (p<0.05). The concentration of IL-2 in the treatment supplemented with 17 mg/kg L-arginine were more than that of 0 mg L-arginine/kg treatment (p<0.05). The findings of this study show that 17 mg/kg L-arginine supplementation has beneficial effects onlayers' immune status and yolk IgY content, as well as on proventriculus and duodenum weight while no adverse effects were observed on laying performance, egg quality, or blood parameters.