Effects of water supplemented with Bacillus subtilis and photosynthetic bacteria on egg production, egg quality, serum immunoglobulins and digestive enzyme activity of ducks.

We investigated the effects of water supplemented with Bacillus subtilis and photosynthetic bacteria (PSB) on egg production, egg quality, serum immunoglobulins and digestive enzyme activities of Jinyun ducks. A total of 400 healthy Jinyun ducks (all aged 58 weeks) were randomly allotted to 5 treatments, with 4 replicates per treatment and 20 ducks in each replicate. The ducks were fed a standard diet for 15 days and the experimental diet for 54 days. Experimental design is as follows: negative-control group C1 was given no supplementation, control group C2 was given pool water (PW) with added PSB but not B. subtilis. Test groups T1, T2 and T3 were given the same amount of PSB in the PW and varying levels of B. subtilis in drinking water. Results suggest that PSB combined with B. subtilis had beneficial effects on the laying rate, feed-to-egg ratio, serum IgG, egg quality, especially in albumen height and Haugh unit. Additionally, PSB alone can increase the yolk-to-egg ratio, albumen height and Haugh unit. [ABSTRACT FROM AUTHOR]