Induction of reproductive activity and egg production by gonadotropin‐releasing hormone in non‐laying hens

Abstract

The current study was conducted to evaluate the effects of gonadotropin‐releasing hormone (GnRH) analogue (Receptal) injection on reproductive traits of fully mature layers hens (32 weeks) suffered from inactive ovaries. Ninety‐six non‐laying hens (TETRA‐SL brown egg layers), selected from a commercial flock, with similar body weight, were randomly assigned to four groups (n = 24). Hens in the 1st group served as a control. Hens of the 2nd, 3rd and 4th groups were individually intramuscularly injected every 4 days with 50, 100 and 150 µl of Receptal solution, respectively, for two times. The results stated that the injection of Receptal induced the non‐laying hens to produce eggs, but control birds did not produce eggs during the experimental period. The distance between pelvic bones and between the pelvic bone and keel bone of hens was significantly improved (p < .001) in groups received different GnRH levels compared with the control group. The best results were observed in the group injected with 100 µl Receptal. Levels of LH, FSH, oestrogen and progesterone hormones were significantly (p < .05) higher in Receptal‐treated groups than in the control group. Hens injected with Receptal had an increase in ovary%, yellow follicles number, oviduct% and oviduct length (p < .001) compared with the control. It was concluded that treating inactive ovaries in non‐laying hens with GnRH injections for two times, 4‐day intervals, is an effective procedure for inducing egg production and useful in cost reduction in layer farms, and the group treated with 100 µl Receptal had the best results.

Single-cell RNA sequencing revealed the liver heterogeneity between egg-laying duck and ceased-laying duck

“…Lower number of pvalue equates to higher enrichment. E Protein interaction modules of the top 10 marker genes in cluster 0, cluster 3, cluster 12 and cluster 15 and L_C. The high-quality transcriptomes, collectively expressing about 17 k genes, provided strong statistical power for unbiased decompositionof these cell populations.…”

“…Expression of thyroid-stimulating hormone β subunit (TSHB), deiodinase 2 (DIO2), organic anion transporting polypeptides (OATPs) are subsequently enhanced, which modulate gonadotropin-releasing hormone (GnRH) secretion from the hypothalamus [12][13][14]. GnRH regulates the release of gonadotropins, such as luteinizing hormone (LH), follicle-stimulating hormone (FSH), estrogen and progesterone hormones which subsequently arouses egg laying [15].…”

Molecular mechanisms of hypothalamic-pituitary-ovarian/thyroid axis regulating age at first egg in geese

“…The initiation of egg laying seems to be regulated by the hypothalamic-pituitary-ovarian ( HPO ) axis ( Gloux, et al, 2019 ), and the particular interconnected hormones or neuropeptides facilitate the secretion of sex hormones from the ovaries, thereby promoting oocyte maturation and ovulation ( Hanafy and Elnesr, 2021 ). Dunn, et al (2004) found that a 4bp indel on the NPY gene approximately 700bp upstream of the transcription start site had a significant dominant effect on AFE in broilers, with heterozygous individuals having earlier AFE.…”

Effects of salpingitis simulation on the morphology and expression of inflammatory-related genes of oviduct in laying hens

“…The main clinical characteristics of salpingitis of laying hens are decreased egg production, no or short maintenance time of peak of laying eggs, poor eggshell quality, increase of thin, soft and sandy shell eggs, which causes great economic losses to the poultry industry. The success of the poultry industry depends mainly on the reproductive status of the birds ( Hanafy and Elnesr, 2021 ; El Sabry et al., 2022 ). So the salpingitis is one of the frequent diseases threatening the healthy development of laying hens farming industry ( Fang et al., 2021 ).…”