Fennel (Foeniculum vulgare) is an ancient medicinal plant and a seasonal herb that belongs to the Apiaceae (Umbelliferae) family. Fennel originates from the southern Mediterranean region as an aromatic plant and through naturalization and cultivation grows wild throughout the northern, eastern and western hemispheres, especially in Asia, North America and Europe. Fennel is widely used in traditional medicine for a wide range of ailments. It is cultivated in Mediterranean regions for its taste and is used in traditional medicine and as a spice.
Fennel has the properties of stimulating appetite, strengthening digestive enzymes, antioxidant and liver protective effects in poultry, and with other plants of the Apiaceae family, it is an alternative to antibiotics. Its seeds contain various phytochemicals with beneficial biological properties. Fennel in poultry diet can improve growth performance, feed efficiency and carcass quality. It also increases the proliferation of immune cells, reduces oxidative stress and increases the antibody titer against infectious diseases. In addition, it positively affects blood parameters, increasing the number of red blood cells and hemoglobin. Fennel essential oil has strong antibacterial properties, especially against Gram-positive bacteria.
The effect of fennel on poultry performance:
-Improving the final weight and feed efficiency of broilers with a diet containing fennel (1-3 g/kg)
-Reduction of heterophil to lymphocyte ratio in chicken with fennel by 2-3 g/kg
-Addition of 0.75% and 1% in egg laying: significant improvement of feed conversion factor, egg weight, albumen weight and Hough unit, egg shell thickness, yolk weight percentage and whiteness index
-Reducing the adverse effects of heat stress on laying hens due to its antioxidant properties
-Improvement of carcass traits such as breast muscle and fat deposition in broilers with fennel at a low level (0.15%)
-Positive effect on the growth and morphology of the small intestine in broilers with an average level (0.30%)
-Increasing the growth rate of broilers and reducing the temperature of breast meat in chronic heat stress conditions with 3.2% fennel powder.
-Heat stress: Fennel may be a useful food supplement for laying hens in hot weather to reduce the adverse effects of heat stress related to egg quality. A 2015 study of 120 40-week-old White Leghorn laying hens found that adding 10 to 20 grams per kilogram of fennel to bird feed for 30 days was beneficial. In addition, this study showed that independent of heat stress, consumption of fennel by chickens significantly reduced cholesterol and triglyceride levels in egg yolk.
-Anti-coccidial: Studies show that it may be useful against coccidiosis in chickens.
