Feed & Additive Magazine Issue 3 April 2021

ISSUE FOCUS FEED & ADDITIVE MAGAZINE April 2021 33 the gut health of the chick, feeding Mannan Rich Fractions (MRF, Alltech Inc. USA) to the breeder has been shown to positively alter the microflora in both the breeder herself and her offspring. FEEDING A FAVOURABLE ENVIRONMENT Once a favourable population of microorganisms has been established in the gut, it is important to ensure that the surrounding environment is optimal for their growth and replication. Most beneficial mi- croflora are acid tolerant, and therefore grow best at lower pH, whereas potentially pathogenic organisms such as Clostridia and Campylobacter are intolerant to acidic conditions. Feeding a buffered weak organic acid compound provides a competitive disadvantage to the unfavourable bacteria, allowing organisms ben- eficial to gut health to prosper. Using a weak acid en- sures that it is not inactivated whilst passing through the proventriculus and gizzard, allowing it to reach the small intestine and provide maximum benefit. As colonisation of the gut with favourable bacteria con- tinues, organisms attach to the epithelial gut lining and form an interlinked mat over the surface creating a barrier, preventing pathogens access to attach and colonise. With reduced pathogen colonisation there would be reduced disease pressure, and so the need for antibiotic usage is lowered. WEEDING OUT UNFAVOURABLE ORGANISMS Through using ‘Seed’ and ‘Feed’ we can establish a healthy population of microorganisms in the gut, however throughout the life of the bird there will be stressors which cause slight alterations to the gut en- vironment, for example after vaccination, post thin or coming into lay. It is vital to maintain favourable gut conditions with the correct balance of microbial species throughout the life of the bird, in order to prevent challenges causing a decline in performance. Balance is maintained through the ‘Weed’ princi- ple, feeding with a selective exclusion product, such as an MRF, which removes the unfavourable bacte- ria. For a pathogen to cause disease it first needs to adhere to the gut epithelial lining. It does this via type-1 fimbriae projections which recognise specific carbohydrate molecules on the gut cell wall. Once attached the pathogen is able to replicate which can then lead to inflammation, alteration of villi struc- ture and a reduction in absorption in the bird. MRF products are competitive inhibitors of pathogenic bacteria, through binding to the type- 1 fimbriae, preventing them binding to the epithe- lium. The agglutinated bacteria are then excreted. MRF products have also been shown to improve ab- sorptive capacity through increasing villi height and surface area and improving villi to crypt ratio, al- lowing an improved absorption of nutrients leading to improved performance. ‘Weeding’ programmes, such as those using MRF products, are an important factor in reducing antibiotic usage whilst also main- Through using ‘Seed’ and ‘Feed’ we can establish a healthy population of microorganisms in the gut, however throughout the life of the bird there will be stressors which cause slight alterations to the gut environment, for example after vaccination, post thin or coming into lay.