The following research was performed with aim to evaluate the effect of lactosuero, supplied in liquid form in drinking water as a supplement in feeding for broiler chickens: was used a completely randomized design (DCA), with four treatments (10% lactosuero, 15% lactosuero, 20% lactosuero and a control), and two repetitions, parameters evaluated were: initial weight, food consumption, water consumption, final weight, weight gain and feed conversion. In addition were used two different types of food: 20% of PT and 3200 Kcal / Kg. Containing fish meal as protein source, for the control treatment and 20% of PT and 28000 Kcal / Kg. Containing only soybean meal as protein source. For treatments (T1, T2, T3). The best rates for weight gain and feed conversion were recorded for T3 (20% lactosuero), with a weight gain of 1603.125 g. And feed conversion of 2.05, which do not differ statistically...