The Photoperiod-Driven Cyclical Secretion of Pineal Melatonin Regulates Seasonal Reproduction in Geese (Anser cygnoides)

Reproductive characteristics and methods to improve reproductive performance in goose production: A systematic review

In the past two decades, the high demand of and significance of poultry meat have promoted the development of the goose industry. Despite the continuous expansion of the goose breeding scale and the generation of large economic benefits by the goose industry, low reproductive efficiency remains a barrier to limit vigorous development of the goose industry. Poor reproductive efficiency can be attributed to breeding seasonality, strong broody behavior, and poor semen quality. Based on the reproductive endocrine regulation mechanism of geese, an overview of past studies that have developed various methods to achieve a significant improvement in goose reproductive performance including physical facilities for artificial illumination control and dietary nutrition manipulation to improve breeder reproductivity, and artificial incubation equipment and technology for better hatchability. The most recent advances utilize immunoneutralization to regulate critical hormones involved in goose reproduction. This review provides new information for industry and academic studies of goose breeding.

Photoperiod Management in Farm Animal Husbandry: A Review

This review aims to examine the effects of the photoperiod on farm animals and to provide insights into how lighting management can optimize production performance, reproduction, and welfare. The production performance of farm animals is influenced by a variety of factors, such as diet, breed, and environment. Among these, lighting is a crucial component of the feeding environment. With the advancement of intensive farming, lighting measures are increasingly receiving attention. The photoperiod regulates the biological rhythms of animals and affects the secretion of hormones within the animal's body, particularly melatonin. Melatonin regulates the secretion and release of several other hormones through various pathways, such as growth hormone, prolactin, and gonadotropins. Therefore, the environmental light cycle participates in a variety of physiological activities within animals. An appropriate photoperiod can enhance the production performance, reproduction performance, and welfare conditions of farm animals. Choosing the appropriate lighting duration based on different animals, physiological stages, and production purposes can enhance the economic benefits of farms. In this review, we summarized the recent findings on the impact of photoperiods in different farm animal feeding environments on animal husbandry, although research on the suitable photoperiod for some animals might be outdated and is also discussed in this article. For lactating dairy cows, calves, poultry, pigs (excluding boars), and rabbits, continuous light exposure exceeding 12 h per day can be implemented to enhance growth and production performance. In contrast, for boars and goats, daily light exposure should be limited to less than 10 h to optimize reproductive and productive efficiency. Overall, this review aimed to provide theoretical support for research on the optimal photoperiod for farm animals.

The hematopoietic function, histological characteristics, and transcriptome profiling of Wanxi white geese ovary during nesting and late-laying stages

Despite several factors influencing reproduction in geese, but the precise molecular mechanisms of egg cessation are not fully understood. In the present study, the hematopoietic parameters and serum hormone levels in Wanxi white geese were analyzed. RNA-Seq was utilized to identify the differentially expressed mRNAs (DEGs) and lncRNAs (DE lncRNAs) in the ovarian tissues associated with nesting in geese during the late-laying and nesting periods. Triglyceride (TG) and alkaline phosphatase (ALP) levels were higher in late-laying geese, while white blood cell (WBC), neutrophil (NEU), hemoglobin (HGB), and hematocrit (HCT) levels were significantly lower in late-laying geese. Serum levels of luteinizing hormone (LH), estrogen (E2), and progesterone (P4) increased significantly during the late-laying period, whereas prolactin (PRL) level was lower in the late-laying period than the nesting period. During the late-laying period, geese had a clear follicular hierarchy, with ovaries exhibiting mature and primary follicles. In the nesting period, the ovaries were degenerated and had many primary follicles without follicular development. Analysis of mRNA-lncRNA expression revealed 1,257 DEGs between the nesting and the late-laying stages, of which 841 were up-regulated and 416 were down-regulated DEGs. A total of 340 DE lncRNAs were identified between the nesting and the late-laying periods, with 113 being up-regulated and 227 down-regulated lncRNAs. DEGs, including TMEM, DRD3, IGFBP7, MAPK13, GnRHR2, HECTD3, KCNU1, OPRD1, and VCAM1, along with DE lncRNAs, including XR_001203613.1, XR_001206155.1, XR_001207759.1, XR_001213571.1 and XR_001214368.1 participate in reproduction in geese. Correlation analysis indicated that the cis-regulation of XR_001213096.1-ITPR3, XR_001203613.1-GALNT15, XR_001206155.1-COL6A3, XR_001207759.1-ANKS1B, and XR_001214368.1-VPS45 participate in the molecular mechanisms underlying nesting in geese. Functional enrichment analysis revealed the DEGs and DE lncRNAs associated with focal adhesion, extracellular matrix (ECM)-receptor interaction, cell adhesion molecules (CAMs), and PI3K-Akt signaling pathways, were responsible for the differences in the ovaries between the nesting and late-laying periods. This study offers valuable information on the roles of genes and lncRNAs, and the mechanisms underlying variations in reproductive performance between the late-laying and nesting periods.

Effect of active immunization with OPN5 on follicular development and egg production in quail under different photoperiods

OPN5 is one of the main deep brain photoreceptors (DBPs), converting photoperiodic information into neuroendocrine signals to regulate reproduction in birds. This study investigated the mechanism of OPN5-mediated photoperiodic regulation of reproduction by active immunization against OPN5. 96 female quail were divided into OPN5-immunized and control group under the same photoperiod: 16 L:8 D (d 1 to d 35), 8 L:16 D (d 36 to d 70) and 12 L:12 D (d 71 to d 126). OPN5-immunized group was conducted with OPN5 protein vaccination and control group was given a blank vaccine. Samples were collected on d 1, d 30, d 60, and d 126. Results showed switching photoperiod to 8 L:16 D decreased the laying rate, GSI%, numbers of YFs and WFs, serum levels of PRL, P4 and E2, and pituitary PRL and TSHβ protein expressions in both groups (P < 0.05). Whereas the OPN5-immunized group exhibited higher laying rates than the control group (P < 0.05). The control group showed reduced GnRHR and TSHβ gene expressions in the pituitary and increased GnIH and DIO3 transcript and/or protein abundance in the hypothalamus. (P < 0.05). The OPN5-immunized group had lower DIO3 expression at both mRNA and protein levels. (P < 0.05). Switching photoperiod from 8 L:16 D to 12 L:12 D increased the laying rates, GSI%, numbers of YFs and WFs, serum levels of PRL, and PRL protein expression in both groups (P < 0.05), and the responses were more pronounced in OPN5-immunized group (P < 0.05). In contrast to the control group, quail with OPN5-immunization had higher OPN5 and DIO2 transcript and/or protein levels but lower DIO3 expressions in the hypothalamus along the transition photoperiods (P < 0.05). The results revealed that OPN5 responds to photoperiod transition, and its activation mediates related signaling to up-regulate TSH-DIO2/DIO3 pathway and VIP-PRL secretion to prime quail reproductive functions.

Effects of Different Photoperiods on the Transcriptome of the Ovary and Small White Follicles in Zhedong White Geese

Photoperiod can regulate the broodiness of geese and thus increase their egg-laying rate. The laying performance of geese is mainly determined by ovary and follicle development. To understand the effect of photoperiod on the ovary and small white follicles, sixteen 220-day-old healthy female Zhedong white geese were randomly divided into two groups for long photoperiods (15L:9D) and short photoperiods (9L:15D). The geese were euthanized after two months of feeding, and their ovaries and follicles were collected for transcriptome sequencing. RNA-seq analysis identified 187 and 448 differentially expressed genes in ovaries and small white follicles of different photoperiod groups, respectively. A long photoperiod promotes high expression of SPP1, C6, MZB1, GP1BA, and FCGBP genes in the ovaries, and increases the expression of SPP1, ANGPTL5, ALPL, ZP1, and CHRNA4 genes in small white follicles. Functional enrichment analysis showed that photoperiod could affect respiratory system development, smooth muscle cell proliferation in ovaries, and extracellular matrix-related function in small white follicles. WGCNA revealed 31 gene modules, of which 2 were significantly associated with ovarian weight and 17 with the number of small white follicles. Our results provide a better understanding of the molecular regulation in the photoperiod affecting goose reproduction.

Comprehensive analysis of the whole-transcriptome landscape of the ovarian cortex from Mongolian horses that reproduce seasonally

The reproductive cycle of equines tends to be seasonal and is influenced by factors such as light and temperature. The process and methods of regulating the mare oestrous cycle in the anestrus period are still immature. The effects of noncoding RNAs and mRNAs on the oestrous cycle have aroused much interest, but corresponding analyses of seasonal mare ovaries have not been reported. Here, we report a whole transcriptome analysis of the Mongolian horse ovarian cortex collected in anestrus and diestrus periods. In total, 1081 mRNAs, 205 lncRNAs, 54 circRNAs, and 13 miRNAs were upregulated in winter anestrus ovarian cortex (WAO), and 1261 mRNAs, 90 lncRNAs, 29 circRNAs, and 40 miRNAs were upregulated in summer diestrus ovarian cortex (SDO). The GO and KEGG enrichment analysis of differentially expressed mRNAs and target genes of differentially expressed lncRNAs, circRNAs, and miRNAs revealed some key functions and pathways that may be related to follicle and oocyte development. We found that estrogen-related pathways were enriched in different RNAs. Our data were used to generate miRNA, circRNA, lncRNA, and mRNA databases from the Mongolian horse ovary and differential expression profiles between WAO and SDO; these results provide clues for exploring methods of estrus regulation in mares during the anestrus period.