Effect of Ethanolic Extracts of Olive Leaf, Garlic and Roselle on Performance, Blood Parameters and Immune Response of Broilers under Ascites Induction Conditions

Increasing the growth rate, shortening the breeding period and improving feed efficiency in broiler chickens has provided the basis for the occurrence of a number of metabolic disorders such as ascites syndrome. This experiment was carried out to investigate the effect of medicinal plants (ethanolic extracts of Olive leaf, Garlic, Roselle and a combination of them) on performance, blood parameters and immune response of broilers under ascites induction conditions.

A number of 360 male broiler chickens of Hubbard strain were used in a completely randomized design with six treatments and four replications and 15 chickens per each replication. Experimental treatments include 1) control diet, 2) diet containing 500 mg/kg vitamin C, 3) diet containing 500 mg/kg Olive leaf powder extract, 4) diet containing 500 mg/kg Garlic extract, 5) diet containing 500 mg/kg Roselle extract. 6) Diets contained a combination of three plant extracts. To induce ascites, all chickens were exposed to 15 °C cold stress from 15 to 42 days of age. During the breeding period, performance traits (body weight, feed intake) were recorded weekly. To measure blood biochemical parameters and thyroid hormones, at the end of the experiment, 2 blood samples were prepared from the chickens of each replication. To measure The Cutaneous Basophil Hypersensitivity response (CBH), Phytohemagglutinin-P (PHA-P) were injected intradermally into the wattle.

The results showed that the experimental treatments had no significant effect on body weight and feed consumption, but the treatments of Garlic extract, Roselle extract and vitamin C improved the feed conversion ratio (p<0.05). Visceral organs were not affected by the experimental treatments, but the ratio of the right ventricle to the whole ventricle increased as a result of cold stress (p<0.05) and the use of antioxidant compounds caused its relative improvement. Blood parameters of glucose, cholesterol and aspartate aminotransferase enzyme were not affected by experimental treatments. As a result of cold stress, blood albumin and triglyceride concentration decreased and blood uric acid concentration increased (p<0.05). The use of antioxidant compounds, especially vitamin C, decreased the lipid peroxidation index and increased the cutaneous basophilic sensitivity response (p<0.05). The use of the combination of three plant extracts reduced the serum concentration of T3 hormone (p<0.05).

The use of vitamin C and a combination of three extracts of Olive leaf powder, Garlic, and Roselle improves performance, blood and immune parameters under ascites induction conditions.