Soya saponin improves egg-laying performance and immune function of laying hens

Abstract

Background Soya saponin (SS), an active compound in soybean meals, has been widely studied in the medical field. However, it was considered as an anti-nutritional factor in poultry diets. The objective of this experiment was to measure the effects of dietary SS using three dietary treatments on egg-laying performance and immune function of laying hens. Birds were fed a low soybean meal basal diet (CON), a low-SS diet (50 SS) containing 50 mg/kg SS, or a high-SS diet (500 SS) containing 500 mg/kg SS for 10 weeks. At the end of the 5th and 10th week of the trial, samples were collected for analysis. Results Results showed that with 50 mg/kg SS supplementation, the egg production rate, feed conversion ratio (FCR), and eggshell quality tended to be improved. Serum follicle stimulating hormone (FSH) and Interleukin-4 (IL-4) levels were also elevated as well as the peripheral blood LPS stimulation index, the proportion of B lymphocytes, and antibody titer of bovine serum albumin (BSA). We also found that mRNA levels of follicle stimulating hormone receptor (FSHR) in ovarian, nuclear transcription factor kappa B (NF-κB), Transforming growth factor (TGF-β) and interferon γ (IFN-γ) in spleen were up-regulated at the end of the trial. Additionally, dietary 50 mg/kg SS improved the ileal flora via up-regulating the relative abundance of Lactobacillus, Romboutsia and Lactobacillus delbrueckii. Although the immune related indicators were improved with 500 mg/kg SS supplemented, it seemed to have a negative influence on the laying-performance. Specifically, serum alanine aminotransferase (ALT), alkaline phosphatase (ALP), and the ratio of IFN-γ to IL-4 were increased in the 500 SS group at the end of the trial. The mRNA levels of gonadotropin releasing hormone 1 (GnRH1) in Hypothalamus, the estrogen related receptor (ERR) in ovaries were downregulated as well as the egg production rate during the trial with 500 mg/kg SS supplemented. Conclusions The egg production performance was improved by dietary supplemented with 50 mg/kg SS via increasing ovarian FSHR transcription level and serum estrogen level. A beneficial shift in intestinal microflora was recorded, and the immune function of laying hens was also improved with 50 mg/kg SS supplementation. Surprisingly, the long-term supplementation of 500 mg/kg SS exerted a negative impact on the laying performance and physiological functions of the liver of laying hens.

Soya saponin fails to improve the antioxidation and immune function of laying hens with antibiotics treated

“…Additionally, top 50 microbial genera were selected for calculation of Pearson's correlation coefficient, and then connections with a correlation coefficient greater than 0.6 and a significance level P < 0.05 were selected for network drawing (graphviz-2.38.0). It should be pointed out that the birds without antibiotics treated from our previous study ( Li et al., 2022b ) were bred together with the birds of the 2 treatment groups in this study, and their physical condition, diet and living environment are consistent.…”

“…To further study the influence of SS on the intestinal flora, the ileal flora data of laying hens with or without SS treated in the previous study ( Li et al., 2022b ) were used for co-occurrence network analysis. With SS supplementation, the dominant flora in the intestines was identified, and correlation analysis was carried out between this bacteria and related indexes of immunity and egg production performance.…”

“…According to the method described in previous study ( Li et al., 2022b ), the egg-laying rate and the feed to egg ratio were calculated. The egg quality tester DET-6000 (NABEL Co., Ltd, Japan) was used to measure the haugh unit, albumen height, eggshell strength (kg/cm 2 ), and egg yolk color after weighing the eggs.…”

“…While SS was regarded as an anti-nutritional factor in the animal husbandry field many years ago, which was not conducive to the digestion and absorption of the gastrointestinal tract of livestock and poultry ( Su et al., 2018 ). Interestingly, our previous study found that dietary 50 mg/kg SS improved the egg-laying performance and immune function, and high-dose SS did show a negative impact on the physiological functions of laying hens ( Li et al., 2022b ). The fact that SS was helpful to the immune function of birds had also been confirmed in the study of other scholars ( Naveed et al., 2020 ).…”

Lipoamide Alleviates Oxidized Fish Oil-Induced Host Inflammatory Response and Oxidative Damage in the Oviduct of Laying Hens

“…Moreover, several studies found that egg-laying rates in the late egg-laying period have a positive correlation with serum estrogen levels ( 1 , 45 ). Li et al ( 46 ) found that the egg production performance was improved by dietary supplements with soya saponin via increasing serum estrogen level. It is concluded that the addition of antioxidants to the diet can improve egg production to some extent by improving estrogen secretion.…”