The phytoestrogen daidzein may affect reproductive performance of Zhedong White geese by regulating gene mRNA levels in the HPG axis

Effect of Genistein and Glycitein on production performance, egg quality, antioxidant function, reproductive hormones and related-genes in pre-peak laying hens

Genistein (GEN) and Glycitein (GLY), are types of isoflavone extracted mainly from soy plants, although GEN is associated with stronger antioxidant and growth-promoting effects. The impact of dietary GEN and GLY on reproductive performance, egg quality, and bone quality were investigated in the study. Additionally, to explore the underlying mechanism of action, the serum hormone levels and reproductive-related genes were investigated. A total of 378 Hy-Line Brown laying hens (120 days old) were randomly allocated to 3 dietary groups (Control), (GLY, and GEN at 50 mg/kg respectively) for a period of 8 wk. Each treatment has 126 birds (7 replicates of 18 birds each). Results were analyzed in 2 phases: wk 1 to 4, and 5 to 8 of feeding trial. The results indicated that supplemental GEN significantly increased egg number, hen-day production (HDP), and egg mass during wk 1 to 4, whereas, both glycitein and genistein increased egg number, egg weight, egg mass, HDP and improved feed-egg-ratio during wk 5 to 8. Egg quality analysis revealed significant improvements in eggshell quality; gloss, thickness, strength, and albumen quality indices (albumen height, Haugh unit, thick albumen fraction) due to dietary treatments. Also, the tibia strength, Ca content in the tibia ash and bone mineral content, were significantly increased by the dietary treatments. Significant increases in the serum levels of E2, LH, FSH, T3, T4, and GH, and the activity of antioxidant enzymes; SOD, CAT, GSH while reducing the level of MDA, was notable with the treatments. Additionally, reproductive-related genes: ESR1, FSHR, PRLR, GNRH1 were significantly upregulated by the supplementation of GEN and GLY. The efficacy of GEN in relation to the evaluated parameters was superior to that of GLY. Conclusively, we speculate that the improvement on laying performance, egg quality and tibia quality may be related to promoting effect of isoflavones on calcium metabolism, antioxidant function, reproductive hormones and related genes. Therefore, supplemental GEN at a dosage level of 50 mg/kg, can be used to promote laying performance, sustain egg production and maintain the physiological function of young laying hens.

Molecular and transcriptomic analysis of the ovary during laying and brooding stages in Zhedong white geese (Anser cygnoides domesticus)

1. This study investigates the molecular mechanisms affecting brooding in Zhedong white geese by examining differences in reproductive endocrine levels, ovarian histology and transcriptomics.2. Twenty 18-month-old Zhedong white geese were selected to examine their ovaries using histological, biochemical, molecular biological, and high-throughput sequencing techniques during the laying and brooding periods.3. The results showed that the number of atretic follicles and apoptotic cells in the ovaries increased significantly (p < 0.05), the levels of follicle-stimulating hormone, luteinising hormone, gonadotropin-releasing hormone and oestradiol decreased significantly (p < 0.05), and the level of prolactin increased significantly (p < 0.01) during the brooding stage.4. In broody geese, the expression of CASP3, CASP9, P53, BAX, and Cyt-c were considerably higher (p < 0.05), but BCL2 expression was significantly lower (p < 0.05).5. In ovarian tissues, 260 differentially expressed lncRNAs, 13 differentially expressed miRNA and 60 differentially expressed mRNA were all discovered using transcriptome sequencing analysis. Functional enrichment analysis revealed that the differentially expressed mRNA and non-coding RNA target genes were primarily involved in ECM-receptor interaction, cell adhesion, cardiac muscle contraction, mTOR signalling, and the calcium signalling pathway.6. In conclusion, follicular atrophy and apoptosis occurred in the ovaries and serum reproductive hormone levels were significantly changed during the brooding period of Zhedong white geese. COL3A1, COL1A2, GRIA1, RNF152, miR-192, and miR-194 may be important candidates for the regulation of brooding behaviour, with the mTOR signalling pathway playing a key role.

Comparison of the effect of quercetin and daidzein on production performance, anti-oxidation, hormones, and cecal microflora in laying hens during the late laying period

This study aims to compare the effect of quercetin and daidzein on production performance, anti-oxidation, hormones, and cecal microflora in laying hens during the late laying period. A total of 360 53-week-old healthy Hyline brown laying hens were randomly divided into 3 groups (control, 0.05% quercetin, and 0.003% daidzein). Diets were fed for 10 wk, afterwards 1 bird per replicate (6 replicates) were euthanized for sampling blood, liver and cecal digesta. Compared with the control, quercetin significantly increased laying rate and decreased feed-to-egg weight ratio from wk 1 to 4, wk 5 to 10, and wk 1 to 10 (P < 0.05). Quercetin significantly increased the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) and decreased catalase (CAT) activity and malondialdehyde (MDA) content in serum and liver (P < 0.05) and increased content of total antioxidant capacity (T-AOC) in liver (P < 0.05). Quercetin increased content of estradiol (E₂), luteinizing hormone (LH), follicle-stimulating hormone (FSH), growth hormone (GH), insulin-like growth factor 1 (IGF-1), triiodothyronine (T₃) and thyroxine (T₄) in serum (P < 0.05). Quercetin significantly decreased the relative abundance of Bacteroidaceae and Bacteroides (P < 0.01) and significantly increased the relative abundance of Lactobacillaceae and Lactobacillus (P < 0.05) at family and genus levels in cecum. Daidzein did not significantly influence production performance from wk 1 to 10. Daidzein significantly increased SOD activity and decreased CAT activity and MDA content in serum and liver (P < 0.05), and increased T-AOC content in liver (P < 0.05). Daidzein increased content of FSH, IGF-1, T₃ in serum (P < 0.05). Daidzein increased the relative abundance of Rikenellaceae RC9 gut group at genus level in cecum (P < 0.05). Quercetin increased economic efficiency by 137.59% and 8.77%, respectively, compared with daidzein and control. In conclusion, quercetin improved production performance through enhancing antioxidant state, hormone levels, and regulating cecal microflora in laying hens during the late laying period. Quercetin was more effective than daidzein in improving economic efficiency.

Daidzein supplementation improved fecundity in sows via modulation of ovarian oxidative stress and inflammation

Adequate ovarian hormones secretion is essential for pregnancy success. Oxidative damage and following inflammation can destroy the ovarian normal function in mammals. Daidzein (DAI) is a classical isoflavonic phytoestrogen with specific oestrogenic activity. This study aimed to explore the effects of daidzein supplementation on fertility and ovarian characteristics of sows through biochemical analysis and RNA-seq technology. Twelve multiparous Yorkshire × Landrace sows were randomly divided into CON and DAI groups. We found that DAI increased total number of embryos as well as P4 and E2 levels of serum. DAI not only elevated the activities of T-AOC and GSH-Px, but also tended to decrease the content of MDA and IL-6 in the serum. In ovary, RNA-Seq identified 237 differentially expressed genes (DEGs), and GO analysis showed that these DEGs were linked to functions associated with immune dysfunction. Moreover, STRING analysis demonstrated that most interacting nodes were TLR-4, LCP2, and CD86. Furthermore, DAI decreased the content of MDA, IL-1β, IL-6, and TNF-α, and increased the activities of T-AOC and CAT in ovarian tissue. Interestingly, a partial mantel correlation showed that T-AOC was the strongest correlation between the ovarian dataset and selected DEGs. Additionally, DAI supplementation not only increased the protein expressions of Nrf2, HO-1, and NQO1, but also decreased the protein expressions of TLR-4, p-NFκB, p-AKT, and p-IκBα. Altogether, our results indicated that DAI could ameliorate ovarian oxidative stress and inflammation in sows, which might be mediated by suppressing the TLR4/NF-κB signaling pathway and activating the Nrf2/HO-1 signaling pathway.

Comparative Analysis of the Follicular Transcriptome of Zhedong White Geese (Anser Cygnoides) with Different Photoperiods

The laying performance of geese is mainly determined by follicular development and atresia, while follicular status is regulated by photoperiod. To understand the effect of photoperiod on the development of goose follicles, artificial light was used to change the photoperiod. In this study, ten healthy 220-day-old Zhedong white geese (Anser Cygnoides) with similar body weights and similar reproductive start times were reared for 60 days under long photoperiod (15 L:9 D) and short photoperiod (9 L:15 D) artificial light with the intensity controlled at 30 lux, and follicles were collected. Follicle development was analyzed by observing the morphology of follicle tissue, the localization of autophagosomes and autolysosomes, and the expression levels of apoptosis-related protein factors. Small white follicles (SWFs) were selected for RNA sequencing and bioinformatics analysis of the transcriptome. Under a long photoperiod, microtubule-associated protein 1 light chain 3 (LC3) and Caspase-3 were expressed in the granulosa cell layer and oocytes, respectively. LC3 and Caspase-3 protein expression was increased in SWF and large white follicles (LWFs), and there were more autophagosomes and autolysosomes in granulosa cells. RNA-seq found 93 differentially expressed genes (DEGs) in the short-photoperiod group, including 55 upregulated DEGs and 38 downregulated DEGs, distributed in 37 gene ontology categories. Kyoto Encyclopedia of Genes and Genomes-enriched signaling pathways revealed 5 pathways enriched in upregulated DEGs, including protein digestion and absorption, ECM-receptor interaction and regulation of lipolysis in adipocytes, and 4 pathways enriched in downregulated DEGs, such as fatty acid biosynthesis. Ten differentially expressed genes related to extracellular matrix and fatty acid metabolism (THBS2, COL12A1, MRC2, TUBA, COL1A1, COL11A1, HSPG2, FABP, MGLL, and OLAH) may be involved in the photoperiod regulation of follicle development in Zhedong white geese. The differentially expressed genes screened in this study will provide new ideas to further understand the molecular mechanism underlying photoperiod-mediated regulation of follicle development in Zhedong white geese.

Probiotics, Prebiotics, and Phytogenic Substances for Optimizing Gut Health in Poultry

The gut microbiota has been designated as a hidden metabolic ‘organ’ because of its enormous impact on host metabolism, physiology, nutrition, and immune function. The connection between the intestinal microbiota and their respective host animals is dynamic and, in general, mutually beneficial. This complicated interaction is seen as a determinant of health and disease; thus, intestinal dysbiosis is linked with several metabolic diseases. Therefore, tractable strategies targeting the regulation of intestinal microbiota can control several diseases that are closely related to inflammatory and metabolic disorders. As a result, animal health and performance are improved. One of these strategies is related to dietary supplementation with prebiotics, probiotics, and phytogenic substances. These supplements exert their effects indirectly through manipulation of gut microbiota quality and improvement in intestinal epithelial barrier. Several phytogenic substances, such as berberine, resveratrol, curcumin, carvacrol, thymol, isoflavones and hydrolyzed fibers, have been identified as potential supplements that may also act as welcome means to reduce the usage of antibiotics in feedstock, including poultry farming, through manipulation of the gut microbiome. In addition, these compounds may improve the integrity of tight junctions by controlling tight junction-related proteins and inflammatory signaling pathways in the host animals. In this review, we discuss the role of probiotics, prebiotics, and phytogenic substances in optimizing gut function in poultry.

Polymorphism analysis and expression profile of the estrogen receptor 2 gene in Leizhou black duck

Our previous study on the ovarian transcriptomic analysis in Leizhou black duck revealed that the ESR2 gene was involved in hormone regulation in reproduction and the estrogen signaling pathway related to reproductive performance was enriched. This suggested that ESR2 may have a functional role in the reproductive performance of the Leizhou black duck. Thus, this study aimed at evaluating the polymorphism of the ESR2 gene and its association with egg-laying traits and the distribution pattern of ESR2 mRNA in laying and non-laying Leizhou black ducks. In this study, genomic DNA was extracted from blood samples of 101 Leizhou black ducks to identify single nucleotide polymorphisms (SNPs) of the ESR2 gene to elucidate molecular markers highly associated with egg-laying traits. Four each of laying and non-laying Leizhou black ducks were selected to collect different tissues to analyze the ESR2 gene expression. A total of 23 SNPs were identified and association analysis of the single SNP sites showed that SNPs g.56805646 T>C and exon 3-20G>A were significantly (P < 0.05) associated with egg weight. Ducks with CT and AG genotypes had significantly higher (P < 0.05) egg weights than their respective other genotypes. Haplotype association analysis of g.56805646 T>C and exon 3-20G>A showed that the haplotypes were significantly associated with egg weight. Higher egg weight was seen in individuals with H3H4 haplotypes. In the hypothalamus-pituitary-gonadal (HPG) axis, the results of qRT/PCR showed that ESR2 mRNA was significantly (P < 0.05) expressed in the ovaries of both duck groups than in the hypothalamus and pituitary. In the oviduct, ESR2 was significantly (P < 0.05) higher in the infundibulum and magnum of laying and non-laying ducks respectively. This study provides a molecular marker for selecting Leizhou black ducks for egg production. In addition, it offers theoretical knowledge for studying the related biological functions of the ESR2 gene at the cellular level.

Isoflavones in Animals: Metabolism and Effects in Livestock and Occurrence in Feed

Soybeans are a common ingredient of animal feed. They contain isoflavones, which are known to act as phytoestrogens in animals. Isoflavones were described to have beneficial effects on farm animals. However, there are also reports of negative outcomes after the consumption of isoflavones. This review summarizes the current knowledge of metabolization of isoflavones (including the influence of the microbiome, phase I and phase II metabolism), as well as the distribution of isoflavones and their metabolites in tissues. Furthermore, published studies on effects of isoflavones in livestock species (pigs, poultry, ruminants, fish) are reviewed. Moreover, published studies on occurrence of isoflavones in feed materials and co-occurrence with zearalenone are presented and are supplemented with our own survey data.

Supplementing daidzein in diets improves the reproductive performance, endocrine hormones and antioxidant capacity of multiparous sows

Certain hormones play important roles in modulating mammalian reproductive behaviour. Daidzein is a well-known isoflavonic phytoestrogen that possesses oestrogenic activity. This study was conducted to probe the effects of daidzein supplementation in gestation diets on the reproductive performance in sows. A total of 120 multiparous sows (Landrace × Yorkshire) were randomly assigned to 2 groups (n = 60) and fed either a base diet (control) or one containing 200 mg/kg daidzein during gestation. We discovered that daidzein supplementation significantly increased the total number of piglets born per litter and number of piglets born alive per litter (P < 0.05), decreased the farrowing time (P < 0.05) and increased the serum oestrogen and progesterone concentrations (P < 0.05) at 35 d of gestation. Moreover, serum immunoglobulin G (IgG) concentration and superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities were higher in the daidzein-treated group than in the control group at 35 d of gestation (P < 0.05). Daidzein increased the serum SOD activity and total anti-oxidative capacity (T-AOC) at 85 d of gestation (P < 0.05). Interestingly, daidzein elevated the expression levels of the sodium-coupled neutral amino acid transporter 1 (SLC38A1) and insulin-like growth factor 1 (IGF-1) genes in the placenta (P < 0.05). These results suggest that daidzein ingestion could improve sow reproductive performance by changing serum hormones, elevating anti-oxidative capacity and up-regulating critical functional genes in the placenta.

Anti-neuroinflammatory effect of daidzein in human hypothalamic GnRH neurons in an in vitro membrane-based model

Phytoestrogens can control high-fat diet-induced hypothalamic inflammation that is associated with severe consequences, including obesity, type 2 diabetes, cardiovascular and neurodegenerative diseases. However, the phytoestrogen anti-neuroinflammatory action is poorly understood. In this study, we explored the neuroprotection mediated by daidzein in hypothalamic neurons by using a membrane-based model of obesity-related neuroinflammation. To test the daidzein therapeutic potential a biohybrid membrane system, consisting of hfHypo GnRH-neurons in culture on PLGA membranes, was set up. It served as reliable in vitro tool capable to recapitulate the in vivo structure and function of GnRH hypothalamic tissue. Our findings highlighted the neuroprotective role of daidzein, being able to counteract the palmitate induced neuroinflammation. Daidzein protected hfHypo GnRH cells by downregulating cell death, proinflammatory processes, oxidative stress, and apoptosis. It also restored the proper cell morphology and functionality through a mechanism which probably involves the activation of ERβ and GPR30 receptors along with the expression of GnRH peptide and KISS1R.

Characterization of ovarian morphology and reproductive hormones in Zhedong white geese (Anser cygnoides domesticus) during the reproductive cycle

Zhedong white goose (Anser cygnoides domesticus) is a native Chinese breed with strong broodiness and low egg production, which is related to the physiology of reproduction. However, thus far, the physiology of goose reproduction has not been well elucidated. In the present study, the ovarian morphology and reproductive hormones of Zhedong white geese were investigated during the reproductive cycle (the laying and brooding periods). The results showed that the surface of the ovary was atrophied and follicular atresia appeared to some extent in the brooding period compared with the laying period. The concentrations of follicle-stimulating hormone, progesterone and luteinizing hormone were significantly higher than those in the brooding period (p < 0.05). In contrast, the concentrations of prolactin (PRL) and anti-Müllerian hormone (AMH) in the laying period were significantly lower than those in the brooding period (p < 0.05). In addition, the mRNA expression levels of PRL, AMH, dopamine-β-hydroxylase (DβH) and cytochrome P450 side-chain cleavage enzyme (P450scc) were detected in the hypothalamus, pituitary and ovaries by using real-time polymerase chain reaction. The results showed that AMH mRNA was expressed specifically in ovary tissue. The expression levels of DβH and PRL in the brooding period was significantly higher than those in the laying period in the three tissues, especially in the early and middle stages of the brooding period. Moreover, AMH mRNA expression in the ovaries presented the same trend. In addition, P450scc mRNA was highly expressed in both the ovary and pituitary in the laying period. These results revealed the remarkable features of ovarian morphology and characterized the hormonal pattern and expression profile during the reproductive cycle, all of which contribute to understanding the differences in reproductive physiology between the laying and brooding periods in Zhedong white geese.

Daidzein supplementation enhances embryo survival by improving hormones, antioxidant capacity, and metabolic profiles of amniotic fluid in sows

Daidzein (DAI) is a kind of natural isoflavonic phytoestrogen with estrogenic activity. However, little is known about its influence on early fetal growth in mammalian animals. The current study aimed to explore the characteristics of amniotic fluid exposure to dietary DAI using ¹H NMR-based metabolomics and biochemical analysis. Here, we found that DAI supplementation at a dose of 200 mg kg^-1 significantly enhanced the number of viable embryos at the early gestation stage (P < 0.05). DAI significantly elevated the concentrations of estrogen (E) and insulin-like growth factor-I (IGF-I) in the amniotic fluid (P < 0.05). Moreover, DAI tended to increase the concentration of progesterone, but decrease the concentration of tumor necrosis factor α (TNF-α) in the amniotic fluid (0.05 < P < 0.10). Interestingly, the activity of glutathione peroxidase (GSH-Px) was higher in the DAI group than in the CON group (P < 0.05). An ¹H NMR-based metabolomics analysis identified and quantified more than 30 compounds in the amniotic fluid, and some critical metabolites such as arginine, creatine, and citrate were found to be significantly elevated upon DAI supplementation (P < 0.05). Importantly, the metabolic pathways involved in arginine and proline metabolisms were found to be significantly affected by DAI. Collectively, dietary DAI may improve embryo survival by improving hormones, antioxidant capacity, and metabolic profiles in the maternal amniotic fluid.

Seasonal differences in the transcriptome profile of the Zhedong white goose (Anser cygnoides) pituitary gland

In animals, the adaptation to breed at the time of greatest survival of the young is known as seasonal reproduction. This is mainly controlled by the photoperiod, which stimulates the hypothalamic-pituitary-gonadal axis and starts the breeding season. Herein, we have determined the seasonal changes in gene expression patterns of Zhedong white geese pituitary glands under a natural photoperiodism, conducted at autumn equinox (AE), winter solstice (WS), spring equinox (SE), and summer solstice (SS). Pairwise comparisons of WS vs. AE, SE vs. WS, SS vs. SE, and AE vs. SS resulted in 1,139, 33, 704, and 3,503 differently expressed genes, respectively. When compared with SS, AE showed downregulation of genes, such as vasoactive intestinal peptide receptor, prolactin receptor, and thyroid hormone receptor beta, whereas gonadotropin-releasing hormone II receptor was upregulated, indicating that these genes may be responsible for the transition from cessation to egg laying. In addition, the expression levels of 5 transcription factors (POU1F1, Pitx2, NR5A1, NR4A2, and SREBF2) and 6 circadian clock-associated genes (Clock, Per2, ARNTL2, Eya3, Dio2, and NPAS2) also changed seasonally. Gene Ontology term and Kyoto Encyclopedia of Genes and Genomes enrichment analysis revealed that “response to oxidative stress” and steroid biosynthesis pathway also participate in regulating the reproduction seasonality of geese. Overall, these results contribute to the identification of genes involved in seasonal reproduction, enabling a better understanding of the molecular mechanism underlying seasonal reproduction of geese.

Expression and analysis of ESR1, IGF-1, FSH, VLDLR, LRP, LH, PRLR genes in Pekin duck and Black Muscovy duck

In order to explore the influence of egg-laying regulatory genes on egg production in ducks at different laying stages, Pekin duck and Black Muscovy duck were used in this study, including early laying stage (20-30 weeks old), peak laying period (31-48 weeks old) and late laying stage (49-66 weeks old). Relative quantitative RT-PCR was used to detect the mRNA transcription level of selected egg-laying regulatory genes in the ovary tissues of ducks at different laying stages. Study shows: during the laying period of Pekin duck, ESR1, LRP1, IGF-1 and LHR were involved in the regulation of egg-laying, and the high expression of LRP1 in the late stage could inhibit egg production. Still, the expression products of the other three genes showed promoting effect. During the laying period of Black Muscovy duck, FSH, VLDLR, IGF-1, PRLR, LHR and LRP1 participated in the regulation of egg-laying, in which the expression products of the first five genes could promote egg production, while LRP1 showed inhibitory effect. Through our experiments, these data will provide strong theoretical support for the breeding of Pekin duck and Black Muscovy duck.

Genistein improves the reproductive performance and bone status of breeder hens during the late egg-laying period

Genistein (GEN), a type of soy isoflavones, is similar to estrogen structurally and functionally. The effects of dietary gen on the reproductive performance and bone status of breeder hens were investigated. A total pf 720 laying broiler breeder (LBB) hens were randomly allocated into 3 groups with supplemental dietary GEN doses (0, 40, 400 mg/kg). Each treatment has 8 replicates of 30 birds. The results indicated that supplemental GEN significantly improved the egg production and eggshell strength of LBB hens. Dietary GEN was deposited into the egg yolk, which decreased malonaldehyde in the follicle and egg yolk. The levels of vitellogenin (VTG), progesterone, and follicle-stimulating hormone in the serum of GEN-treated groups were elevated compared with the control group. Furthermore, GEN treatment downregulated the mRNA expression of insulin-like growth factor binding protein in the fallopian tube, whereas 40 mg/kg GEN treatment upregulated estrogen receptor α expression. Both the mRNA expression of VTG-II in the liver and mRNA expression of amphiregulin in the fallopian tube were upregulated after 40 and 400 mg/kg GEN treatment. In the 400 mg/kg GEN-treated group, the levels of calcitonin and alkaline phosphatase in the serum were increased compared with the control group, which was consistent with the increased levels of calcium and phosphorus in the tibia. Supplemental GEN (400 mg/kg) improved the tibia strength of LBB hens, whereas 40 mg/kg GEN had better effects on laying performance. In summary, dietary GEN could improve the egg production and quality, as well as the bone status of LBB hens during the late egg-laying period.

Comparative Transcriptome Analysis Suggests Key Roles for 5-Hydroxytryptamlne Receptors in Control of Goose Egg Production

To date, research on poultry egg production performance has only been conducted within inter or intra-breed groups, while those combining both inter- and intra-breed groups are lacking. Egg production performance is known to differ markedly between Sichuan white goose (Anser cygnoides) and Landes goose (Anser anser). In order to understand the mechanism of egg production performance in geese, we undertook this study. Here, 18 ovarian stromal samples from both Sichuan white goose and Landes goose at the age of 145 days (3 individuals before egg production initiation for each breed) and 730 days (3 high- and low egg production individuals during non-laying periods for each breed) were collected to reveal the genome-wide expression profiles of ovarian mRNAs and lncRNAs between these two geese breeds at different physiological stages. Briefly, 58, 347, 797, 777, and 881 differentially expressed genes (DEGs) and 56, 24, 154, 105, and 224 differentially expressed long non-coding RNAs (DElncRNAs) were found in LLD vs. HLD (low egg production Landes goose vs. high egg production Landes goose), LSC vs. HSC (low egg production Sichuan White goose vs. high egg production Sichuan white goose), YLD vs. YSC (young Landes goose vs. young Sichuan white goose), HLD vs. HSC (high egg production Landes goose vs. high egg production Sichuan white goose), and LLD vs. LSC (low egg production Landes goose vs. low egg production Sichuan white goose) groups, respectively. Functional enrichment analysis of these DEGs and DElncRNAs suggest that the "neuroactive ligand-receptor interaction pathway" is crucial for egg production, and particularly, members of the 5-hydroxytryptamine receptor (HTR) family affect egg production by regulating ovarian metabolic function. Furthermore, the big differences in the secondary structures among HTR1F and HTR1B, HTR2B, and HTR7 may lead to their different expression patterns in goose ovaries of both inter- and intra-breed groups. These results provide novel insights into the mechanisms regulating poultry egg production performance.

Molecular cloning of the goose GnRH gene and identification of GnRH polymorphisms associated with laying traits

1. Egg-laying traits are important economic characteristics in goose production (Anser cygnoides). The gene GnRH, which encodes gonadotropin-releasing hormone, is a strong candidate gene for egg-laying traits in avian species. 2. In this study, a 3520 bp genomic sequence and a 279 bp mRNA sequence for GnRH, which encoded 92 amino acids, were determined. The GnRH DNA sequence contains four exons and three introns, and the DNA and deduced amino acid sequences were highly conserved across mammals (human, macaque, cow, and sheep) and avians (chicken, fulmar and quail). 3. Using a direct sequencing method, 46 single nucleotide polymorphisms (SNPs) were identified in the GnRH genomic sequence that were shared between two Sichuan White goose populations (217 and 208 individuals). Furthermore, 44 haplotypes were constructed using a sliding window approach. Association analysis between the SNPs and haplotypes and egg-laying traits showed that 10 SNPs affected the first egg weight, average egg weight, egg number at 48 weeks and egg number at 64 weeks. 4. These results lay the foundation for further studies of the function of GnRH in geese and provide a theoretical basis for marker-assisted selection of egg-laying traits in the Sichuan white goose population.

Transcriptome sequencing reveals genetic mechanisms of reproduction performance stimulated by dietary daidzein in laying breeder hens

Daidzein (DA) is a kind of isoflavone that is extracted primarily from soy plants and that has become increasingly popular as a dietary supplement. The objective of this study was to evaluate the effects of dietary DA supplementation for laying breeder hens on laying performance, reproductive organ development, hatching performance of seed eggs, and growth performance of offspring and to investigate the underlying molecular mechanisms. A total of 180 55-week-old laying breeder hens were randomly divided into 2 treatment groups and, after 3 weeks of acclimation, were fed either a control diet (CON) or a DA-supplemented diet (DAS, CON+30 mg/kg DA) for a total of 12 weeks. DAS treatment improved the laying rate, luteinizing hormone (LH) levels, and small yellow follicle (SYF) numbers without negative effects on the hatchability of breeder eggs or the growth performance of offspring. High-throughput RNA sequencing was utilized to identify differentially expressed genes in the SYF granulosa layer in the two groups. Transcriptome analysis showed that 161 genes (fold change ≥2 or ≤0.5; P-value<0.05) were significantly differentially expressed between the two groups, including 139 upregulated genes and 22 downregulated genes. Gene ontology (GO) functional annotation analysis revealed potential genes, processes and pathways involved in cell proliferation and differentiation related to the improvement of laying performance stimulated by DA. Dietary DA supplementation for laying breeder hens improved laying performance and reproductive performance with no negative impacts on hatchability or offspring growth. A series of differentially expressed genes in SYF granulosa cells were significantly upregulated in the DAS group relative to the CON group. This study provides insight into the genetic architecture of the transcriptome of the SYF granulosa layer in layer breeding hens and proposes candidate genes that respond to dietary DA.

Dietary Daidzein Supplementation During Pregnancy Facilitates Fetal Growth in Rats

SCOPE

Daidzein, a natural isoflavone with estrogen-like activity, has been implicated in the regulation of reproductive performance in mammals. However, little is known about the molecular mechanisms involved. Here, the effects and potential mechanisms of daidzein supplementation on fetal growth in rats have been explored.

METHODS AND RESULTS

Thirty-six pregnant Sprague-Dawley rats are assigned to receive either an AIN-93M diet or an AIN-93M diet supplemented with 50 mg kg^-1 daidzein. Blood, placental, and fetus samples were collected on day 15 of gestation. It is shown that daidzein significantly improves the rat reproductive performance, which is associated with a higher fetus number, and the weight of the fetus and placenta (p < 0.05). Daidzein also increases the maternal serum estrogen and leptin concentrations, and the activity of superoxide dismutase (SOD) (p < 0.05). Notably, the isobaric tags for relative and absolute quantification (iTRAQ)-based proteomics analysis identifies 43 differentially expressed (DE) proteins in the placenta upon daidzein supplementation (p < 0.05). Interestingly, critical proteins involved in amino acid transport and metabolism, embryonic development, ubiquitination processes, and immune responses are upregulated in the daidzein group (p < 0.05).

CONCLUSION

These results not only indicate a beneficial effect of daidzein supplementation on reproductive performance but also offer potential mechanisms behind daidzein-facilitated fetal growth in rats.

Dietary Genistein Alleviates Lipid Metabolism Disorder and Inflammatory Response in Laying Hens With Fatty Liver Syndrome

This study investigated the molecular mechanism underlying the effect of dietary genistein (GEN) on fatty liver syndrome (FLS) in laying hens. Hens in the control group (CG) were fed a high-energy and low-choline (HELC) diet to establish the FLS model. The livers of the FLS hens were friable and swollen from hemorrhage. Hepatic steatosis and inflammatory cell infiltration were present around the liver blood vessels. Hens in the low-genistein (LGE) and high-genistein (he) groups were fed GEN at 40 and 400 mg/kg doses, respectively, as supplements to the HELC diet. GEN at 40 mg/kg significantly increased gonadotropin-releasing hormone (GnRH) mRNA expression in the hypothalamus, the serum estrogen (E2) level, and the laying rate, whereas 400 mg/kg of GEN decreased GnRH expression and the laying rate without significantly affecting E2, suggesting that high-dose GEN adversely affected the reproductive performance. Either high- or low-dose GEN treatment could alleviate metabolic disorders and inflammatory responses in FLS hens. GEN significantly decreased the serum ALT, creatinine, triglyceride (TG), total cholesterol (TC), and free fatty acid (FFA) levels. Accordingly, the TG and long-chain fatty acid (LCFA) levels, including long-chain saturated fatty acids (LSFAs) and monounsaturated fatty acids (MUFAs), and the n-6:n-3 polyunsaturated fatty acid (PUFA) ratio in the liver were reduced after the GEN treatments, whereas the levels of C22:0, n-3 family fatty acids, C20:3n6, and C20:4n6 were increased. These results indicated that dietary GEN downregulated the expression of genes related to fatty acid synthesis [sterol regulatory element-binding protein 1 (SREBP1c), liver X receptor alpha (LXRα), fatty acid synthase (FAS), and acetyl coenzyme A synthetase (ACC)] and the fatty acid transporter (FAT). Furthermore, GEN treatments upregulated the transcription of genes related to fatty acid β-oxidation [peroxisome proliferator-activated receptor (PPAR)α, PPARδ, ACOT8, ACAD8, and ACADs] in the liver and reduced PPARγ and AFABP expression in abdominal fat. Dietary GEN alleviated inflammatory cell infiltration in the livers of FLS hens and downregulated TNF-α, IL-6, and IL-1β expression. Moreover, GEN treatment increased SOD activity and decreased malondialdehyde activity in the liver. In conclusion, GEN supplementation in the feed inhibited fatty acid synthesis and enhanced β-oxidation in the liver through the PPAR-ACAD/ACOT and PPAR-LXRα-SREBP1c-ACC/FAS/FAT pathways. Dietary GEN alleviated metabolic disorder and inflammation in the FLS hens by improving the antioxidant capacity and fatty acid profile.

Effects of puerarin on estrogen-regulated gene expression in gonadotropin-releasing hormone pulse generator of ovariectomized rats

Effects of puerarin on the hypothalamic gonadotropin-releasing hormone (GnRH) pulse generator function is investigated, for the first time, in ovariectomized rats at the level of mRNA expression of estrogen-responsive genes, e.g., estrogen receptor (ER), GnRH and its receptor (GnRHR). Rats were treated orally for 90 days either with a soy-free diet containing two different doses of puerarin (low dose of 600 mg/kg and high dose of 3000 mg/kg) or estradiol benzoate (E2B) at either low dose (4.3 mg/kg) or high dose (17.3 mg/kg). Levels of mRNA expression in the medial preoptic area/anterior hypothalamus (MPOA/AH), mediobasal hypothalamus/median eminence (MBH/ME) and adenohypophysis were measured by quantitative TaqMan® real-time RT-PCR. Plasma levels of luteinizing hormone (LH) and prolactin (PRL) were measured by radioimmunoassay. In the MPOA/AH, both puerarin and E2B decreased ERα mRNA levels without any significant changes in ERβ and GnRH mRNA levels. Both puerarin and E2B did not significantly alter the expression levels of ERα, ERβ and GnRHR in the MBH/ME. E2B exerted significant effects on the down-regulation of adenohypophyseal GnRHR mRNA transcripts and serum LH levels. Puerarin did not cause significant changes in pituitary GnRHR mRNA transcripts and serum LH and PRL levels. This is the first study to demonstrate that in ovariectomized rat models of ovarian hormone deprivation, puerarin acted as a weak estrogen-active compound in the hypothalamic GnRH pulse generator through the downregulation of MPOA/AH ERα mRNA expression.

Effects of Dietary Daidzein Supplementation on Reproductive Performance, Serum Hormones, and Reproductive-Related Genes in Rats

The aim of this study was to investigate the effect of dietary daidzein supplementation on reproductive performance in rats. A total of twenty-four female Sprague–Dawley (SD) rats were randomly allocated to two groups and fed either with a basal diet (CON) or basal diet containing 50 mg/kg daidzein (DAI) from gestation until delivery stage. The results show that daidzein supplementation significantly increased the total litter weight and the total viable newborn weight (p < 0.05). Interestingly, daidzein supplementation acutely elevated the concentrations of serum estrogen, progesterone and insulin-like growth factor-1 (p < 0.01) after the maternal rats’ delivery. The concentrations of serum immunoglobulin A (IgA) and immunoglobulin G (IgG) were also significantly higher in the DAI maternal rats than in the CON maternal rats (p < 0.05). Moreover, daidzein significantly increased the total antioxidant capacity (T-AOC) in maternal rats’ sera and in newborns (p < 0.05) and elevated the concentration of superoxide dismutase (SOD) in both the maternal rats’ sera and their ovaries (p < 0.05). Importantly, daidzein supplementation significantly elevated the expression levels of estrogen receptor β (ERβ) and NR5A2 genes in maternal rats’ ovaries (p < 0.05) and downregulated the expression level of prolactin receptor (PRLR) in newborns (p < 0.05). These results suggest that dietary daidzein supplementation improves reproductive performance and fetal development in rats, which is associated with changes in serum hormones, tissue antioxidant capacity, and expression levels of reproductive-related genes, both in maternal rats and their offspring.

Grasslands: A Source of Secondary Metabolites for Livestock Health

The need for environmentally friendly practices in animal husbandry, in conjunction with the reduction of the use of synthetic chemicals, leads us to reconsider our agricultural production systems. In that context, grassland secondary metabolites (GSMs) could offer an alternative way to support to livestock health. In fact, grasslands, especially those with high dicotyledonous plant species, present a large, pharmacologically active reservoir of secondary metabolites (e.g., phenolic compounds, alkaloids, saponins, terpenoids, carotenoids, and quinones). These molecules have activities that could improve or deteriorate health and production. This Review presents the main families of GSMs and uses examples to describe their known impact on animal health in husbandry. Techniques involved for their study are also described. A particular focus is put on anti-oxidant activities of GSMs. In fact, numerous husbandry pathologies, such as inflammation, are linked to oxidative stress and can be managed by a diet rich in anti-oxidants. The different approaches and techniques used to evaluate grassland quality for livestock health highlight the lack of efficient and reliable technics to study the activities of this complex phytococktail. Better knowledge and management of this animal health resource constitute a new multidisciplinary research field and a challenge to maintain and valorize grasslands.

Transcriptome analysis of follicles reveals the importance of autophagy and hormones in regulating broodiness of Zhedong white goose

Broodiness, a maternal behavior and instinct for natural breeding in poultry, inhibits egg production and affects the poultry industry. Phenotypic and physiological factors influencing broodiness in poultry have been extensively studied, but the molecular regulation mechanism of broodiness remains unclear. Effective research strategies focusing on broodiness are hindered by limited understanding of goose developmental biology. Here we established the transcriptomes of goose follicles at egg-laying and broody stages by Illumina HiSeq platform and compared the sequenced transcriptomes of three types of follicles (small white, large white and small yellow). It was found that there were 92 up-regulated and 84 down-regulated transcription factors and 101 up-regulated and 51 down-regulated hormone-related genes. Many of these genes code for proteins involved in hormone response, follicular development, autophagy, and oxidation. Moreover, the contents of progesterone and estradiol in follicles were altered, and the autophagy levels of follicles were enhanced during the broody stage. These results suggest that hormone- and autophagy-signaling pathways are critical for controlling broodiness in the goose. We demonstrated that transcriptome analysis of egg-laying and broody Zhedong white goose follicles provided novel insights into broodiness in birds.

Evaluation of in vivo estrogenic potency of natural estrogen-active chemical, puerarin, on pituitary function in gonadectomized female rats

AIMS

Previous research has revealed that puerarin, the major phytoestrogen in tuberous roots of Pueraria lobata and Pueraria mirifica, acts as a selective estrogen receptor modulator that displays predominantly estrogenic potential for health benefit. However, little is known about the estrogenic potency of puerarin in pituitary, especially in the rat model of postmenopausal females.

MAIN METHODS

Plasma prolactin and growth hormone levels as well as mRNA expression levels of pituitary estrogen-regulated genes, such as estrogen receptor (ER) subtypes alpha (ERα) and beta (ERβ), truncated ER product-1 (TERP-1) and -2 (TERP-2) and gonadotropin alpha subunit, were examined using radioimmunoassay and TaqMan® real-time PCR, respectively. The effects were compared with the potent ER agonist, 17β-estradiol-3-benzoate (E2B), and both substances were supplemented at low and high doses, i.e., 0.6 or 3g puerarin and 0.0043 or 0.0173g E2B per kilogram of phytoestrogens-free rat chow, and applied to ovariectomized rats (five groups; 11-12 rats per group) for 12weeks.

KEY FINDINGS

Puerarin possessed weak E2B-like activities on pituitary function by acting as ERβ and TERP-1/-2 agonists, which resulted in the downregulation and upregulation of ERβ and TERP-1/-2 mRNA expressions, respectively, and elevation of growth hormone levels. There were trends of decreased levels of alpha subunit mRNA transcripts and increased levels of prolactin in puerarin-treated rats as observed in E2B-treated animals.

SIGNIFICANCE

This is the first report in ovariectomized rats the effects of puerarin on somatotropes and pituitary estrogen-responsive mRNA expressions, which are very weakly estrogenic by acting through ERβ- and TERP-1/-2 mediated pathways.

Potential risk of isoflavones: toxicological study of daidzein supplementation in piglets

As a main component of soy isoflavones, daidzein is rich in soy-derived products, which are widely used as feed ingredients in farm animals. However, little research has been conducted on the side effects of dietary daidzein, especially in young animals. In this study, the safety of daidzein was evaluated. Results show that ingesting 400 mg/kg of dietary daidzein for 70 days is associated with a lower average daily weight gain (kilogram) (0.47 ± 0.03 vs 0.54 ± 0.04, P < 0.05) and a higher splenic damage index (1.00 ± 1.10 vs 0.00 ± 0.00, P < 0.05) in young pigs compared with control. Female pigs receiving 200 and 400 mg/kg daidzein showed reduced serum testosterone levels (ng/L) on days 35 and 70 compared with the control group (day 35, 246 ± 74 and 224 ± 20 vs 362 ± 48, P < 0.05; day 70, 252 ± 38 and 219 ± 77 vs 374 ± 38, P < 0.05). Daidzein residue (μg/kg) in pig livers increased (243 ± 80 vs 142 ± 47, P < 0.05, day 70). These results suggest that dietary supplements of 400 mg/kg of daidzein negatively affect the weight gain and splenic morphology of pigs.