A study was conducted to evaluate the effect of fermented feed addition and crude protein level on the performance of local chickens in the south of Vietnam. It was (3*2*3 factorial) with 2 factors. Factor fermentation: Yeast-fermented maize (YM), Yeast-fermented broken rice (YR), Probiotic fermented maize (PM). Factor protein level: 20% (CP20) and 16% (CP16). One hundred and eighty Noi chickens at 6 weeks of age (334±9.5 g/bird), and 10 birds per unit (balanced sex) were in the treatment. All treatments were added 4% (DM) of fermented feed to the basal diet. The trial lasted 9 weeks with Noi chickens from 6 to 14 weeks of age. The results showed when adding yeast feed at 4% (DM) to the diet of Noi chickens, there is an increase the weight and decrease in FCR of Noi chickens. Especially the PM treatments had the best results. At crude protein level, the CP20 treatments was better than the CP16 treatments. Microorganisms of chicken manure, especially the PM treatments was the highest Lactobacilli and the PM treatments was the best results (E. coli and Clostridium the lowest). It was concluded that in Noi chickens from 6 to 14 weeks of age, the treatment probiotic fermented maize (PM) supplement at 4% (DM) and diet with 20% crude protein had the most positive outcomes.

Keywords | Noi chickens, Fermented, Lactobacilli, E. coli, Clostridium