Abstract

Effective microorganism (EM) is a combination of more than 80 different types of beneficial microorganisms contributing to a wide range of applications in medicine, environment, and agriculture (livestock sector, crop sector, and forestry). This experiment was conducted to evaluate the effects of EM supplementation on hen day egg production and egg quality traits of Bovans Brown laying hens. At the age of 16 weeks, 144 pullets were purchased from small-scale poultry farms in Debre Markos. The chickens were divided into four treatments, each of which was replicated three times and contained 12 chickens. The treatment groups were T1 (control, commercial ration only), T2 (supplemented 16 ml EM per liter of drinking water), T3 (supplemented 5 Bokashi in feed), and T4 (supplemented 16 ml EM per liter of drinking water and 5 Bokashi in feed). Prior to collecting the actual data, the layer chickens had 2 weeks of adaptation. The hen day egg production was evaluated, and laboratory analysis was conducted to detect the external and internal egg quality. The results showed no significant difference among treatments on hen day egg productions, which ranged from 74 to 80 percent. Among the external egg quality traits, T4 had the highest egg weight, compared to other treatment groups. The T3 and T4 treatments had the highest shell weight. The shell thickness ranged from 0.37 to 0.39 mm. The shape index ranged from 76.81 to 79.11, with no difference among the groups. Moreover, T4 had a significantly higher egg mass than T1 and T2. The specific gravity of an egg ranged from 1.06 to 1.08 g/cm3. Among the internal egg quality traits, the albumin weights of T3 and T4 were significantly higher than those of T1. The highest and the lowest Hough units were observed in T4 and T1, respectively. The highest yolk weight was observed in T4 among the groups. The yolk index ranged from 0.45 to 0.49. The yolk color ranged from 5.27 to 7.33. Finally, overall egg quality parameters in T4 were better than in non-supplemented groups. © The Author(s) 2023