Effects of Aqueous Extract of Panax quinquefolium Stems and Leaves in Diet on Growth and Meat Quality of Quails

  Objective   Effects of inclusion of an aqueous extract from stems and leaves of Panax quinquefolium L. in forage on growth and meat quality of quails were investigated.

  Methods   One-hundred-fifty one-day-old quails were randomly divided into 5 groups with three replicates in each group and 10 birds per replicate. The groups included a blank control that was fed with the basic diet (CON), an antibiotic control (KSS) with 100 mg·kg⁻¹ amoxicillin added to the feed, one trial group supplemented with 1% of the extract (SD), one with 1.5% of the extract (SZ), and another with 2% of the extract (SG). The feeding lasted for 50 d that included a 5 d preliminary adaptation period.

  Results  On growth performance, the quails in the SZ group significantly increased the average daily body weight gain (P＜0.05), while reduced the feed to meat ratio (P＜0.05). On meat tenderness, the shear force on the breast and leg muscles of the birds in the treatment groups was significantly lower than that of CON or KSS (P＜0.05) with the quails in the SZ group being the most tender. On nutritional value, the breast meat of the SG quails had the significantly higher protein than that of CON counterparts (P＜0.05), whereas those of the SZ and SG quails significantly higher fat than that of the CON or KSS birds (P＜0.05). However, the leg muscles of either CON or KSS quails contained significantly less protein than SZ and SG quails (P＜0.05) and less fat than SZ quails (P＜0.05). No significant differences among the groups in the moisture content of breast and leg meats (P＞0.05) were observed. Compared with the CON group, the unsaturated fatty acid content in the chest muscle of quails in each experimental group was not significantly reduced (P> 0.05 ), and the unsaturated fatty acid content in the leg muscle of quails in the SZ group was significantly increased (P< 0.05 ) . The content of inosinic acid in quail muscle, the content of inosinic acid in breast muscle and leg muscle of SZ group was significantly higher than that of KSS group (P< 0.05 ). Contents of essential amino acids and flavor amino acids in breast muscle and leg muscle of quails in SD, SZ and SG groups were significantly higher than those in KSS group (P< 0.05 ). The H. E. staining showed no abnormality in the liver and kidney of the quails under treatment. The expression of growth hormone (GH) gene in the treatment birds was significantly higher than that in CON group (P＜0.05) with that of the SZ quails having the highest.

  Conclusion   Addition of the aqueous extract of P. quinquefolium L. stems and leaves in the feed accelerated the growth, improved the meat tenderness, accentuated the meat flavor of the quails without adverse effect on the liver or kidney of the birds. The plant extract appeared to be a highly safe diet supplement applicable to replace antibiotics in raising quails.