Brine shrimp bioassay as a preliminary assessment tool for development of herbal growth promoter formula for poultry

Growth promoters play an important role in the animal agriculture industry as they facilitate to improve productivity mainly through reduction of pathogenic bacterial load in the gut. Ban and restrictions on the usage of Antibiotic Growth Promoters (AGP) due to public health concerns has made it essential to search alternatives from the herbal sources. But at the same time it is tricky to choose the best active molecule or combination from the wide range of herbs and extracts available. In this context, there is a requirement to have a simple bench top bioassay tool to screen these active molecules. Brine shrimp is one such method proposed as a simple bioassay tool for natural product evaluation. The procedure determines LC50 values in μg/ ml of actives in the brine media. Activities of a broad range of known active compounds are noticed as toxicity to the shrimp. In the present study, brine shrimp bioassay model has been adopted to evaluate the bioactivity of lipid soluble and water soluble fractions of garlic and found that the former was potent with LC50 value of 23.9μg/ml. Brine shrimp bioassay was also conducted on the formulation made using the above mentioned bioactive lipid soluble fraction of garlic as a major ingredient and found to be bioactive with LC50 value of 179.1μg/ml. The same was further confirmed in an In vivo trial conducted in poultry in comparison with popular AGP.