<p>Probiotics has been used to substitute antibiotic treatments used as growth promoters and to improve productive performance. The term probiotic is used to namelive micro-organisms such as microbes and bacteria with beneficial effects to livestock farms when consumed as dietary supplements. This review investigates the evidence for the use of probiotics in sheep’s final body weight gain combined with livestock grazing management system with yeast (Saccharomyces cerevisiae). Twenty one native sheep were chosen randomly for this study, with an average weight of 14.71 kg ± 1.9 under continuous grazing; the meadows are used as sheep pastures where Kikuyo grass grows (Pennisetum clandestinum) and water ad libitum. Sheep were classified in three<br>different treatments: T1, control treatment, without adding yeast; T2, added with 5 g/day of yeast; and T3, supplemented with 15 g/day of yeast. Throughout this study was possible to find a beneficial effect on final weight and average daily gain. The results were compared by ANOVA with a significance level of 95%. A significant difference was observed on final body weight of sheep for T3 (p ≤ 0.05). In addition, it was found that daily weight gain was 100 g, 120 g and 220 g for T1, T2 and T3 respectively. This research leads us to conclude that the addition of 15 g of yeast improves daily bodyweight gain and final weight of grazing native sheep.</p>