Feed & Additive Magazine Issue 4 May 2021

SPECIAL STORY FEED & ADDITIVE MAGAZINE May 2021 33 tegrity. Butyric acid constitutes 15% of total short chain fatty acids produced in the intestinal lumen and is taken up by the intestinal epithelial cells to provide a source of ATP without undergoing the car- boxylic acid cycle (also known as the citric acid cycle or the Krebs cycle). The energy produced drives a sodium pump which maintains osmotic balance in the gut, allowing water to be absorbed producing a more solid faecal matter. Butyric acid not only provides energy to the intes- tinal epithelial cells but is also involved in processes such as cell differentiation, gut tissue development, gene expression, immune modulation, diarrhoea, and enteric pathogen control. The energy produc- tion of butyric acid consumes oxygen and produces carbon dioxide, leading to a hypoxic (low oxygen) environment, favouring anaerobic bacteria such as the Clostridium butyricum. The decrease in pH by butyric acid also suppresses growth of non-favour- able bacteria such as salmonella and E. coli. Furthermore, butyric acid is also utilized by the gut microbiota, the population of Clostridium bu- tyricum, lactobacillus etc. allowing for increase in the population of these bacteria thus increasing gut fibre fermentation and further increasing butyric acid production in the gut – secondary acidification. HYDROLYSABLE TANNIN Tannins are a complex group of polyphenolic com- pounds found in a wide range of plant species and are characterized by astringent and tanning proper- ties. Tannins are classified into two main types – the condensed tannins and hydrolysable tannins. Con- densed tannins are non-hydrolysable and often asso- ciated with being anti-nutrients because of its abili- ty to precipitate proteins, inhibit digestive enzymes and decrease utilization of vitamins and minerals. Condensed tannins are also known to inhibit several digestive enzymes such as amylases, cellulases, pecti- nases, lipases, and proteases. Hydrolysed tannins, as the name suggests, can be hydrolysed by acids and enzymes, and are found in smaller amounts in plants compared to condensed tannins. In recent research, hydrolysable tannins have been proposed as an alternative to antibiotics because of its antimicrobial properties which can inhibit extracellular microbial enzymes, deprive mi- crobes of substrates required for microbial growth and inhibit microbial metabolism. Furthermore, hydrolysable tannins could be used in lieu of antibiotics because bacterial such as Clos- tridium perfringens cannot develop resistance to them. Besides that, hydrolysable tannin has also been reported to have antioxidant properties, chelate metals, and antibacterial properties which enable it to prevent conditions such as diarrhoea and gastri- tis. Hydrolysable tannins have also been revealed to improve intestinal microbial ecosystem and enhance gut health hence increasing production performance "Piglets post weaning diarrhoea (PWD) is usually bacterial microbial scours and/or nutritional scours and remains a big problem for most swine farms worldwide. In severe cases, PWD increases piglet mortality causing direct economic impact to the farm."