Natural extracts improve broiler conversion and yield

The use of low levels of antibiotics in poultry diets improves growth performance and reduces animal disease and death. Consumer pressure and health concerns over the development of antibiotic-resistant bacteria have resulted in development of non-antibiotic feed additives. Potential non-antibiotic additives include organic acids, essential oils and other phytogenic compounds that are derived from natural sources. The current study tested two commercial natural growth promoters (Biostrong 505+ and Biostrong 510) for their effect on broiler performance and carcass quality. Biostrong 505+ is a proprietary blend of plant extracts (essential oils, bitter substances, pungent substances) and an acid. Biostrong 510 is also a blend of plant extracts and is designed to be used in conjunction with an antibiotic to optimize performance.


Essential oils are natural extracts that protect plants against infection, bitter substances stimulate gastric juices and the pungent compounds from spices such as paprika, garlic and onion stimulate blood circulation. In this study there was a maximum yield version and a least cost version of each diet. This was a well-designed experiment with a total of 1,344 broilers used to test 8 different diets with each diet having a starter, grower and finisher ration. As expected, the maximum yield diets improved broiler performance and carcass quality compared to the least cost diets. Broilers on the maximum yield + Biostrong 505+ had a lower feed conversion and higher breast yield compared to any other treatment. In fact, the addition of Biostrong 505+ to either diet improved feed conversion and breast yield. Live weight gain, mortality and feed intake were not negatively affected by the inclusion of either phytogenic feed additives. The addition of Biostrong 510 increased the incidence of fat pad lesions in both the maximum yield and least cost diets. Biostrong 510 showed little or no advantage by its addition to the broiler diets. Biostrong 505+ showed promise for the use of natural extracts to replace or reduce the use of antibiotics in animal diets.

Buchanan, N.P., Hott, J.M., Cutlip, S.E., Rack, A.L., Asamer, A., and Moritz, J.S. 2008. The effects of a natural antibiotic alternative and a natural growth promoter feed additive on broiler performance and carcass quality. Journal of Applied Poultry Research 17(2): 202-210.