Probiotics are increasingly perceived as an important alternative to antibiotics in poultry nutrition. Although there is extensive research on broilers, such information is rather scarce for layer hens. But, gut health and eggshell quality are of paramount importance in egg production as loose excreta leads to dirty eggs with minimal value or increased inputs for washing.
A recent Brazilian study was conducted to evaluate the effects of different dietary levels of Bacillus subtilis (BS) on performance, egg quality and excreta quality (moisture) in laying hens. A total of 240 layers, between 25 and 45 weeks of age, were distributed according to a randomized block experimental design into four treatments with 10 replicates of six birds each.
The following treatments were evaluated:
- Control diet with no probiotic (T1)
- Control diet with the addition of BS at 8×105 CFU/g feed (T2
- Control diet with the addition of BS at 4×105 CFU/g feed (T3
- Control diet with the addition of BS at 3×105 CFU/g feed (T4)
Production parameters evaluated included: feed intake (FI), egg production (EP), egg weight (EW), egg mass (EM), feed conversion ratio per dozen eggs (FCRD), feed conversion ratio per egg mass (FCRM), yolk, eggshell, albumen and excreta dry matter (EDM) content.
Results indicated that feed intake, FCRD, and egg components were not influenced (P>0.05) by any of the treatments. Dietary supplementation with BS at 8×105 CFU/g feed (highest dosage) compared to control increased (P<0.05) EP (g/kg) by 2.63 percent and EM by 3.96 percent. Dietary supplementation with BS increased (P<0.05) EW by 1.20 percent. There was not an improvement (P>0.05) in FCRM. Excreta dry matter was on average 4.67 percent higher (P<0.05) with BS than with control diet. Regretably, the percentage of dirty eggs was not part of this study, but in general, drier excreta is accepted as a means of reducing the production of dirty eggs.