High Performance Liquid Chromatography (HPLC)-Based Detection and Quantification of Free Isoflavones (Daidzein and Genistein) in Livestock Feed Ingredients

Phytoestrogens are naturally occurring plant compounds, predominantly found in legumes and grains. They can bind to estrogen receptors in the body, either imitating or inhibiting the effects of oestrogen. This study aimed to detect and quantify free isoflavones, specifically genistein and daidzein, which are found in commonly used feed ingredients such as maize, soybean meal (SBM), de-oiled rice bran (DORB), groundnut cake (GNC), gingelly oil cake (GOC), dried fish and wheat bran, which are often included in livestock and poultry feed formulations.

Feed ingredients commonly used in livestock feed mills were randomly selected from the market and analysed for daidzein and genistein levels using high-performance liquid chromatography (HPLC) at the Central Instruments Laboratory, College of Veterinary and Animal Sciences, Mannuthy, Thrissur. The average concentrations of daidzein varied from undetectable (UD) to 567.94 µg/100g, while genistein levels ranged from UD to 551.02 µg/100g across the various feed ingredients. The findings of this study revealed that soybean meal contained significantly higher levels of both daidzein and genistein compared to other ingredients used in livestock and poultry feed formulations. This study provides crucial data on the levels of phytoestrogens in common livestock feed ingredients, which can impact animal health and productivity. It is one of the first to comprehensively quantify isoflavones like genistein and daidzein across a wide range of feed ingredients, particularly in the context of animal nutrition. The findings can be used to optimise feed formulations, ensuring that phytoestrogen levels are managed to support the desired outcomes in livestock and poultry production.