This experiment was conducted to investigate and compare the efficacy of different feed additives on performance, tibial
dyschondroplasia (TD) incidence and tibia characteristics of male broilers fed low-
calcium diets. A completely randomized design, with six treatments and five replicates of five chicks per each was used. Experimental treatments were: (i) Basal diet containing recommended level of
calcium (0.9%) as control treatment (Ctrl), (ii) low-
calcium (0.67%) diet without any additive (LC), (iii) low-
calcium diet + probiotic (2 g/kg diet), (iv) low-
calcium diet +
prebiotic (2 g/kg diet), (v) low-
calcium diet + synbiotic [mix of probiotic and
prebiotic (each 2 g/kg diet)], (vi) low-
calcium diet + organic
acid (1.5 g/kg diet). Birds were reared in an open-sided house system under natural tropical condition until 21 days of age. Feeding with low-
calcium diet negatively influenced broiler performance (
body weight,
body weight gain and feed conversion ratio) and tibia characteristics, whereas dietary inclusion of all feed additives had beneficial effects on above-mentioned parameters and helped the birds to overcome problems related to low-
calcium diets. Different treatments had no effect on TD incidence.