RESUMO
OBJECTIVE: In the present study, we aimed to investigate the effects of enzymolysis fermentation of Chinese herbal medicines (CHMs) on egg production performance, egg quality, lipid metabolism, serum reproductive hormone levels, and the mRNA expression of the ovarian hormone receptor of laying hens in the late-laying stage. METHODS: A total of 360 Hy-Line Brown laying hens (age, 390 days) were randomly categorized into four groups. Hens in the control (C) group were fed a basic diet devoid of CHMs, the crushed CHM (CT), fermented CHM (FC), and enzymatically fermented CHM (EFT) groups received diets containing 2% crushed CHM, 2% fermented CHM, and 2% enzymatically fermented CHM, respectively. RESULTS: Compared with crushed CHM, the acid detergent fiber, total flavonoids, and total saponins contents of fermented CHM showed improvement (p<0.05); furthermore, the neutral and acid detergent fiber, total flavonoids, and total saponins contents of enzymatically fermented CHM improved (p<0.05). At 5 to 8 weeks, hens in the FC and EFT groups showed increased laying rates, haugh unit, albumin height, yolk color, shell thickness, and shell strength compared with those in the C group (p<0.05). Compared with the FC group, the laying rate, albumin height, and Shell thickness in the EFT group was increased (p<0.05). Compared with the C, CT, and FC groups, the EFT group showed reduced serum total cholesterol and increased serum luteinizing hormone levels and mRNA expressions of follicle stimulating hormone receptor and luteinizing hormone receptor (p<0.05). CONCLUSION: These results indicated that the ETF group improved the laying rate and egg quality and regulated the lipid metabolism in aged hens. The mechanism underlying this effect was likely related to cell wall degradation of CHM and increased serum levels of luteinizing hormone and mRNA expression of the ovarian hormone receptor.
RESUMO
Feedstuffs are severely contaminated by zearalenone (ZEA) worldwide. A specific dietary level of ZEA could cause malformations of the reproductive organs of sows, false estrus, decreased litter size, and abortion. However, the underlying mechanisms are still not clear. The objectives of the present study were to assess the effects of ZEA on morphology, distribution, and expression of estrogen receptors (ERα and ERß) in the ovaries of postweaning piglets. Furthermore, the relationship between ERs/glycogen synthase kinase (GSK)-3ß-dependent pathways mediated by ZEA and the Wnt-1/ß-catenin signaling pathway was examined. Forty healthy weaning piglets were allocated to the following four treatment groups: piglets fed with basal diet only (control), and ZEA0.5, ZEA1.0, and ZEA1.5, which were fed basal diets supplemented with ZEA at 0.5, 1.0, and 1.5 mg·kg-1, respectively. Then, the expression of GSK-3ß, ERα, ERß, and Wnt-1/ß-catenin were examined histomorphologically and immunohistochemically. Results showed that the proportion of primordial follicles (PrF's) decreased ( p < 0.001) but that of atretic primordial follicles (APFs) increased ( p < 0.001) with increasing dietary ZEA levels. More interestingly, the immunopositivity of ERß in the ovaries was stronger than that of ERα with the same treatment. The relative mRNA and protein expression levels of ERα, ERß, Wnt-1, ß-catenin, and GSK-3ß in the ovaries of postweaning gilts increased linearly ( p < 0.05) as dietary ZEA concentrations increased. Moreover, the accumulation of Wnt-1 and ß-catenin in the ovaries indicated that ZEA activated the Wnt-1/ß-catenin pathway, mediated by ERs/GSK-3ß. Our results strongly suggested that ovarian follicles in the ZEA (0.5-1.5 mg·kg-1)-treated groups were highly proliferative state, indicating that ZEA promoted ovarian development. The results also suggested that ZEA activates the ERs/GSK-3ß-dependent Wnt-1/ß-catenin signaling pathway, indicating its important role in accelerating development of the ovaries.