Supervisors: Yin Sze Lim(PI) (Biosciences, UNM), John Brameld (Biosciences, UK), Tim Parr(Biosciences, UK), Andy Salter (Biosciences, UK)
Based in School of Biosciences, Semenyih, University of Nottingham Malaysia (with potential opportunity for field work at our Campus in UK)
Currently livestock are fed high quality feed ingredients (such as soya) in order to achieve their genetic potential for growth. The alternative plant-based feed ingredients, such as Bambara groundnut, are often of low nutrient quality compared to soybean. These alternative feed ingredients not only contain a low density of essential amino acids, but also relatively high concentrations of anti-nutritional factors (ANFs). These ANFs include inhibitors of proteolytic enzymes, but also compounds that interfere with the bio-accessibility and bio-availability of not only amino acids but also minerals and other micronutrients. We have demonstrated (unpublished data) that these poor quality crops can be fed to insects which has the effect of concentrating the essential amino acids.
In addition, we have shown that growth of insects can be improved by partially reducing ANFs in these relatively nutrient poor feed ingredients (unpublished data). Fermentation of standard soybean based feeds has been demonstrated to reduce ANFs (12), but also elevates the concentrations of lactic acid and several volatile fatty acids (VFA; acetic acid, butyric acid, and propionic acid), as well as increasing the numbers of lactobacilli and lowering the pH of the digesta (13), all of which have positive effects on animal growth. Fermentation has been shown to have positive effects on growth of production animals when applied to standard feeds, but little work has been done on the effects on alternative feed ingredients that contain high concentrations of ANFs.
Our hypothesis is that microbial fermentation technology will improve the nutrient quality of alternative crops. We will investigate the effects of fermentation of the alternative crops and plant by-products with a range of lactic acid bacteria to determine their impact on composition. For example Lactobacillus plantarum and Pediococcus spp., often used for inoculations to produce fermented liquid feed, will be used to determine the changes in nutrient composition of feeds, particularly the presence of organic acids and any effect on ANFs. We will then determine the impact of fermentation using Aspergillus niger, which has been reported to be an effective way to reduce undesired substances including phytic acid, glucosinolates, as well as tannins (12).
The second phase of the project will utilise these fermented products as feed ingredients to determine their effects on insect growth. Utilising the nutrient composition information on the generated fermented products we will formulate experimental mealworm diets combining a range of ingredients to provide the required nutritional profile that best facilitates mealworm growth. Our research team is currently working on the manipulation of traditional feed ingredients for mealworms, but also have access to black soldier fly larvae, crickets (silent, black and banded) and locusts. Of particular interest will be the effect of these modified feed ingredients on the protein content (especially the essential amino acid composition) as well as micronutrient composition.
This work will therefore seek to determine the viability of enhancing the production of insects (and potentially other species), a future alternative animal feed or potential human food, using feed sources which are not currently utilised in livestock production systems.
For further information, please contact Dr Yin Sze Lim: [email protected]