The use of cold pressed oils as eco-friendly alternatives for antibiotics in high and low-CP diets of laying Japanese quail

A trial was conducted to access the impact of varying levels of dietary protein (CP) and cold-pressed oil on hematological parameters, liver and kidney function, antioxidant and immunoglobulin indices and lipid profile of Japanese quail at the laying period. A number of 324 mature ten-week of age Japanese quails (216 females and 108 males) were selected. The red blood cells were increased in response to marjoram and thyme oil applied separately or together when comparing with control group (p < 0.05). Cholesterol, triglyceride, low-density lipoprotein and total lipid levels were decreased significantly in response to these oils in birds 2 to 5 month of age compared to the comparing group. Superoxide dismutase activity increased in response to dietary supplementation with marjoram and thyme compared to zero additives group and other groups (p < 0.01). The glutathione and malondialdehyde levels (p < 0.01) decreased due to supplementation with thyme oil alone and in combination with marjoram oil compared to the control and other groups in 2- to 5-month-old birds. It could be concluded quails fed a diet encompassing 18 or 20% CP or supplemented with marjoram or thyme oil exhibited improved antioxidant indices and lipid profile without any harmful influence on the other parameters.