Potential use of plant extracts and propolis to be natural growth promoter in broiler chicks diets

The present study was conducted to determine whether potential use of dietary supplemental natural plant extracts and propolis would be used as alternative growth promoters to antibiotics in broiler chicks. Four concecutive trials were carried out with Ross 308 male broiler chicks for 42 days of period for each. In the first experiment; plant extracts Yucca schidigera, Oreganum vulgare, Thymus vulgaris, S. aromaticum, Z. officinale were used at 120 ppm level. Supplementation of 120 ppm Z. officinale improved body weight gain and feed conversion efficiency and increased the number of gut lactic acid bacteria. In the second experiment, S. aromaticum and Z. officinale esantial oils, which produced the most superior results in the first experiment were used in different combinations or alone. Increased dose of Z. officinale (240 ppm) increased broiler performance and gut villi length. In the thirth experiment, different dietary levels (0, 500, 1000, 2000 ppm) of propolis were used. Supplementation of propolis at 1000 ppm significantly improved body weight gain, feed conversion efficiency and gut villi length. In the fourth experiment, different doses of Z. officinale and propolis were used alone or in combinations as growth promoters. Supplementation of 240 ppm Z. officinale and 1000 ppm propolis improved body weigh gain, feed intake and feed conversion efficiency, the improvements was found to be similar to those values achieved by supplemental antibiotics used as a control in the trial. It was concluded that 240 ppm Z.officinale esantial oils as plant extract and/or 1000 ppm propolis have great potentials to replace antibiotic growth promoters in broilers.