investigation the effects of using protexin, propionic acid growth promoters and blend of them on broilers performance

this experiment was conducted to investigate the effects of using protexin, propionic acid growth promoters, and a blend of them on broilers performance. in a completely randomized design, three hundreds and twenty unsexed 1-d-old chicks were divided into four groups. dietary treatments were consisted of 1) control diet without any supplement, 2) the control diet + 0.01 % protexin, 3) the control diet + 0.2 % propionic acid, 4) the control diet + 0.01 % protexin + 0.02 % propionic acid. body weight gain and feed intake were measured weekly. in the first week, the use of protexin and propionic acid increased body weight. in the fourth week, the group fed a diet supplemented with propionic acid had lower feed intake and feed conversion ratio than the others groups. in the fifth week, the broilers fed with protexin and a blend of protexin and propionic acid had better feed conversion ratio compared to the others experimental units. the birds fed with all of the feed additives, especially propionic acid, had betted energy intake and energy efficiency ratio than control diet. based on the results of this experiment, these feed additives, especially propionic acid, can be suggested as suitable growth promoters in broiler chickens nutrition.