Effect of dietary essential oil of oregano on performance parameters, gastrointestinal traits, blood lipid profile, and antioxidant capacity of laying hens during the pullet phase

Many benefits have been found in supplementing essential oils such as oregano oil (EOO) to poultry, including increased body weight gain, antioxidant activity, and better gastrointestinal morphology. However, few studies tested the influence of EOO supplementation on laying hens and reported conflicting results regarding its efficacy in improving their health and performance. Therefore, we aimed to explore the effects of dietary EOO on performance, gastrointestinal (GIT) traits, blood lipid, and antioxidant capacity in laying hens during the rearing phase. A total of 300-day-old Hy-line-Brown chicks were used, and treatment diets consisted of corn-soybean based either without (CON) or with EOO (Ecodiar®, 0.275 g/kg diet). Birds were randomized across treatments with five pens/treatment and 30-birds/pen. Pen weights and feed rejected were recorded every two weeks (1-17 weeks of age), to calculate daily feed intake (ADFI), body weight (BW), and daily weight gain (ADWG). At 11 and 14 weeks of age, blood samples were collected from 3 birds/pen and analyzed for blood lipids and antioxidant levels, and 5-birds/treatment were euthanized, and GIT traits were tested. Differences in measured parameters across weeks and between treatments were assessed using GLMM with Tukey’s Post hoc test applied to significant results in R 3.3.1 (α set at 0.05). Body weights at weeks 3, 11, 13, and 17 were significantly higher in the EOO group compared to the CON group (all P ≤ 0.05), ADWG was significantly higher in EOO birds compared to CON birds at 9 and 13 weeks old (all P ≤ 0.05), while no significant differences in ADFI were observed between treatments across weeks of the trials. At both 11 and 17 weeks old, triglyceride levels were significantly lower, while high-density-lipoprotein levels were higher in EOO (all P ≤ 0.05). Malondialdehyde levels were lower in the EOO group versus CON (p=0.01), while EOO birds had higher glutathione levels (p=0.01) than CON. Finally, at 12 weeks old, the weight of the entire GIT and empty gizzard were higher in the EOO group versus CON (all P ≤ 0.05), while liver and spleen weights were not significantly different between groups. In conclusion, dietary oregano supplementation exerted promoting effects on the performance of Hy-Line Brown pullets.

Effects of dietary methyl sulfonyl methane and selenium on laying performance, egg quality, gut health indicators, and antioxidant capacity of laying hens

Objective

This study investigated the effects of dietary methyl sulfonyl methane (MSM) and selenium (Se) on the laying performance, egg quality, gut health indicators, egg yolk Se content, and antioxidant markers in laying hens.

Methods

One hundred ninety-two 73-wk-old laying hens were randomly divided into four groups with eight replicates of six hens each. Four diets were prepared in a 2×2 factorial arrangement with or without MSM and Se. The trial lasted for 12 wk.

Results

There were no interaction effects or main effects (p>0.05) on laying performance and egg quality. However, feed intake increased in Se-fed hens (p = 0.051) and decreased in MSM-fed hens (p = 0.067) compared with that of hens in the control group. Dietary MSM increased (p<0.05) the ileal villus height and villus height:crypt ratio in hens compared with those receiving the non-supplemented control diet. Dietary MSM and Se did not affect the percentage of short-chain fatty acids in the ileal contents. Dietary Se enriched the Se content in egg yolk compared with that of the non-supplemented control diet (p<0.05). Dietary Se increased (p<0.05) glutathione peroxidase levels in the liver and serum samples compared to the control diet. The total antioxidant capacity in the liver increased (p<0.05) in laying hens that were fed MSM-supplemented diets than in hens fed the control diet. Dietary MSM significantly increased the relative superoxide dismutase levels in serum samples (p<0.05).

Conclusion

Supplementation with either MSM or Se independently improved the antioxidant capacity of laying hens. Furthermore, dietary Se produced Se-enriched eggs, but this effect was neither additive nor synergistic with dietary MSM.

Effects of essential oil/palygorskite composite on performance, egg quality, plasma biochemistry, oxidation status, immune response and intestinal morphology of laying hens

The current study aimed to assess the effects of different levels of essential oil/palygorskite composite (EO-PGS) supplementation on performance, egg quality, oxidative status, immunity and intestinal morphology of laying hens. A total of 480 laying hens aged 65 wk were randomly assigned into 4 groups (6 replicates of 20 hens each). Hens were fed the basal diet supplemented with 0 (control diet), 0.5, 0.75 or 1.0 g/kg EO-PGS for 56 d. Data were analyzed by One-way ANOVA. Results showed that birds fed with diet supplemented with EO-PGS had increased the egg production (P < 0.05) more than birds fed with control diet. The yolk index and shell thickness were increased in 0.75 and 1.0 g/kg EO-PGS groups at d56 (P < 0.05). There was no significant difference in plasma biochemical parameters among all groups. Compared with the control group, supplementation of EO-PGS increased the immunoglobulin-G and interleukin-2 levels in plasma (P < 0.05). The total antioxidant capacity in plasma and liver, the plasma catalase concentration, the activity of total superoxide dismutase in the liver and the activity of glutathione peroxidase in the spleen were increased in the EO-PGS groups (P < 0.05). The concentration of malondialdehyde in the liver was decreased with the increasing level of EO-PGS (P < 0.05). The crypt depth of ileum and duodenum of birds fed with EO-PGS supplemented diet had a tendency to decrease (0.05<P < 0.1) and the villus height to crypt depth ratio of ileum increased (P < 0.05), compared with birds fed with control diet. In summary, EO-PGS supplementation improved the egg production, enhanced antioxidation and immune functions, and ameliorated egg quality and intestinal morphology of laying hens, and a level of 0.75 g/kg EO-PGS was recommended in laying hens diets.