Dietary oregano essential oil supplementation improves intestinal functions and alters gut microbiota in late-phase laying hens

Abstract

Background Dietary essential oil (EO) supplementation can exert favorable effects on gut health in broilers. However, it is unknown whether EO could improve intestinal functions, consequently beneficial for egg performance and quality in late-phase laying hens. This study was aimed to investigate the potential effects of EO on production performance, egg quality, intestinal health and ileal microbiota of hens in the late phase of production. A total of 288 60-week-old Hy-line Brown laying hens were randomly divided into 4 groups and fed a basal diet (control) or basal diets supplemented with oregano EO at 100, 200 and 400 mg/kg (EO100, EO200 and EO400). Results Dietary EO supplementation resulted in a quadratic decrease (P < 0.05) in feed conversion ratio with lower (P < 0.05) feed conversion ratio in EO200 group than the control during weeks 9–12 and 1–12 of the trial. Compared to the control, EO addition resulted in higher (P < 0.05) eggshell thickness at the end of week. 4, 8 and 12 and higher (P < 0.05) chymotrypsin activity. There was a quadratic elevation (P < 0.05) in ileal chymotrypsin and lipase activity, along with a linear increase in villus height to crypt depth ratio. Quadratic declines (P < 0.05) in mRNA expression of IL-1β, TNF-α, IFN-γ and TLR-4, concurrent with a linear and quadratic increase (P < 0.05) in ZO-1 expression were identified in the ileum with EO addition. These favorable effects were maximized at medium dosage (200 mg/kg) of EO addition and intestinal microbial composition in the control and EO200 groups were assessed. Dietary EO addition increased (P < 0.05) the abundances of Burkholderiales, Actinobacteria, Bifidobacteriales, Enterococcaceae and Bacillaceae, whereas decreased Shigella abundance in the ileum. Conclusions Dietary EO addition could enhance digestive enzyme activity, improve gut morphology, epithelial barrier functions and modulate mucosal immune status by altering microbial composition, thus favoring feed efficiency and eggshell quality of late-phase laying hens.

Dietary Oregano Essential Oil Supplementation Combined with Cinnamaldehyde Improves Production Performance and Alters Gut Microbiota in Late-Phase Laying Hens

“…It has been reported that dietary essential oils could significantly increase the eggshell thickness [20,29]. In our study, the eggshell thickness of EO1 and EO2 was lower (P < 0.05) than that of control and AGP at week 4, but the difference disappeared at week 8, which may be due to altered flora structure [30].…”

Fermented Corn–Soybean Meal Mixed Feed Modulates Intestinal Morphology, Barrier Functions and Cecal Microbiota in Laying Hens

“…Alloprevotella is known as an opportunistic pathogen; however, previous studies have noted that the increased abundance of Alloprevotella genera was linked to better intestinal health [ 50 ]. Besides this, the genus Romboutsia is a valuable intestinal biomarker maintaining host health, and Enterococcus with natural antimicrobial probiotic properties could prevent diarrhea in animal production [ 51 ]. However, their roles in gut health and functions of birds need to be explored.…”

Phytogenic Feed Additives in Poultry: Achievements, Prospective and Challenges

“…This increase could be considered beneficial as Clostridia are not only dominant in ceca [ 126 ], but they also contribute to the maintenance of overall gut function, especially through butyrate production [ 127 ]. Deinococcus , Bacillaceae and Caulobacteriales were increased in ileal digesta of laying hens fed on a dietary supplementation of EOs, promoting an increase of digestive enzyme activity leading to improved feed utilization efficiency [ 128 ]. Moreover, although some authors reported a decrease of the relative abundance of beneficial commensal bacteria such as Lactobacillus by plant extract supplementation [ 43 , 129 ], several others found Clostridiales and/or Lactobacillales to be higher in broilers supplemented with EOs of carvacrol and thymol [ 130 , 131 ] or thymol, eugenol and piperine [ 121 ].…”