Effects of Oregano (Origanum vulgare) Essential Oil Supplementation on Growth Performance of Zebrafish (Danio rerio) Fed a High-Inclusion Soybean Meal Diet.
Study Goal
The researchers aimed to investigate whether oregano essential oil (OEO) could mitigate the negative effects of high-inclusion soybean meal diets in zebrafish, focusing on growth performance and inflammation.
Results Summary
OEO supplementation at 2% and 3% improved growth performance (weight, feed conversion ratio, and total length) compared to the soybean-only diet, though inflammation-related gene expression did not significantly differ. The 3% OEO group showed results comparable to the fish meal-based diet.
Population
Zebrafish
Effective Dosage
1%, 2%, and 3% OEO supplementation in diet
Duration
Not specified
Interactions
None mentioned
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
Soybean meal (SBM) at high inclusions | decrease | feed intake | - | - | has been shown to have negative impacts presenting as reduced | #1 |
Soybean meal (SBM) at high inclusions | increase | intestinal inflammation | - | - | has been shown to have negative impacts presenting as | #2 |
Medicinal plant extracts, namely essential oils | increase | growth performance | - | - | have been used to promote | #3 |
Medicinal plant extracts, namely essential oils | increase | immune response | - | - | have been used to promote | #4 |
Fish meal (FM)-based diet | increase | growth performance | zebrafish | - | had overall better | #5 |
OEO3 diet (SBM-based diet supplemented with 3% oregano oil) | no change | mean weight | zebrafish | - | mean weight was not significantly different from | #6 |
OEO3 diet (SBM-based diet supplemented with 3% oregano oil) | no change | feed conversion ratio | zebrafish | - | feed conversion ratio was not significantly different from | #7 |
OEO3 diet (SBM-based diet supplemented with 3% oregano oil) | increase | mean weight and feed conversion ratio | zebrafish | - | were significantly improved compared with | #8 |
OEO2 diet (SBM-based diet supplemented with 2% oregano oil) | no change | total length | zebrafish | - | total length was not significantly different from | #9 |
OEO2 diet (SBM-based diet supplemented with 2% oregano oil) | increase | total length | zebrafish | - | total length was significantly higher than | #10 |
OEO groups (SBM-based diets supplemented with oregano oil) | no change | expression of inflammation-related genes | zebrafish | - | Expression of inflammation-related genes did not significantly differ between | #11 |
OEO2 and OEO3 groups (SBM-based diets supplemented with 2% or 3% oregano oil) | increase | growth performance | zebrafish | - | displayed improved | #12 |
inclusion of OEO at or above 2% inclusion | decrease | common symptoms induced by a high-inclusion SBM diet | zebrafish | - | may help to alleviate | #13 |
Soybean meal (SBM) has become a common dietary replacement for fish meal (FM) in aquafeed. However, at high inclusions, SBM has been shown to have negative impacts presenting as reduced feed intake and intestinal inflammation. Medicinal plant extracts, namely essential oils, have been used to promote growth performance and immune response. The objective of this study was to investigate the potential therapeutic effects of oregano (Origanum vulgare) essential oil (OEO) inclusion on utilization of a high-inclusion SBM diet using zebrafish as a model. Five diets were used in this study: reference-FM-based diet, control-55.7% inclusion SBM diet, and three experimental SBM-based diets OEO1, OEO2, and OEO3 that were supplemented with 1%, 2%, or 3% of oregano oil, respectively. The FM group had overall better growth performance when compared with the other treatment groups; however, the OEO3 mean weight and feed conversion ratio were not significantly different from the FM group (p > 0.05) and were significantly improved compared with the SBM group (p < 0.05). Similarly, OEO2 total length was not significantly different from FM (p > 0.05) but significantly higher than the SBM group (p < 0.05). Expression of inflammation-related genes did not significantly differ between the OEO groups and the SBM-only group. However, the OEO2 and OEO3 groups displayed improved growth performance compared with the SBM group, suggesting that inclusion of OEO at or above 2% inclusion may help to alleviate common symptoms induced by a high-inclusion SBM diet.