The efficacy and safety of a novel Subtilisin protease from a Bacillus sp.produced in Bacillus licheniformis was investigated in broiler chickens, and a range of toxicological tests, respectively.The B.licheniformis production strain culture supernatant was not found cytotoxic in a Vero cell assay.
Subtilisin was non-mutagenic Gooseneck Pot and non-clastogenic in in-vitro tests, and did not exhibit irritating potential to the eye or skin in ex-vivo/in-vitro models.Oral administration of Subtilisin to rats did not cause any adverse effects in Nutrition a 13-week sub-chronic toxicity study.In addition, a 35-day dose response broiler performance trial conducted with Subtilisin (30,000 and 60,000 NFP/kg diet), showed a significant linear improvement in both body weight gain and feed conversion ratio up to 35 days of protease supplementation.In conclusion, there are no safety concerns using this novel Subtilisin as a feed additive, and the protease is efficient in improving broiler growth performance, making it a good candidate for use as a feed additive.