Dietary fibre effects and the interplay with exogenous carbohydrases in poultry nutrition

A comprehensive understanding of the role of dietary fibre in non-ruminant animal production is elusive.Equivocal and conflated definitions of fibre coupled with significant analytical complexity,interact with poorly defined host and microbiome relationships.Dietary fibre is known to influence gut development,feed intake and passage rate,nutrient absorption,microbiome taxonomy and function,gut p H,endogenous nutrient loss,environmental sustainability,animal welfare and more.Whilst significant gaps persist in our understanding of fibre in non-ruminant animal production,there is substantial interest in optimizing the fibre fraction of feed to induce high value phenotypes such as improved welfare,live performance and to reduce the environmental footprint of animal production systems.In order to achieve these aspirational goals,it is important to tackle dietary fibre with the same level of scrutiny as is currently done for other critical nutrient classes such as protein,minerals and vitamins.The chemical,mechanical and nutritional role of fibre must be explored at the level of monomeric sugars,oligosaccharides and polysaccharides of varying molecular weight and decoration,and this must be in parallel to standardisation of analytical tools and definitions for speciation.To further complicate subject,exogenous carbohydrases recognise dietary fibre as a focal substrate and have varying capacity to generate lower molecular weight carbohydrates that interact differentially with the host and the enteric microbiome.This short review article will explore the interactive space between dietary fibre and exogenous carbohydrases and will include their nutritional and health effects with emphasis on functional development of the gut,microbiome modulation and host metabolism.

An early feeding regime and a high-density amino acid diet on growth performance of broilers under subclinical necrotic enteritis challenge

Broilers that have early access to feed have been shown to have enhanced immune system and gut development and heightened resilience against necrotic enteritis(NE). This study examined the effect of early feeding a high amino acid density diet on performance of broilers under a sub-clinical NE challenge model. Ross 308 broilers(n = 576) were assigned to a 2 × 2 × 2 factorial design with 2 feeding regimes(feed access either within 6 h post-hatch or after 48 h post-hatch), 2 diets(control diet or the control diet with an additional 10% digestible amino acids [HAA]) and either presence or absence of NE challenge.Oral administrations of Eimeria species(d 9) and a field strain of Clostridium perfringens(d 14) were used to induce NE, Broiler performance was analysed at d 13.23.30 and 35, Intestinal lesion score and bacterial count were analysed on d 16. The NE challenge reduced overall bird performance and induced severe intestinal lesions, without causing notable mortality. At d 23 bird weight was significantly lower(P < 0.001) in the challenged birds compared with the unchallenged birds, but by d 30 the challenged birds had recovered and challenge no longer had an impact on bird performance. Birds fed the HAA diet had greater body weight by d 35 and heightened Lactobacillus content in the ileum at d 16(P < 0.05).Birds that were fed the HAA diet after a period of fasting performed better in terms of feed conversion ratio(FCR) under challenge. The findings from this study suggest there are beneficial effects of feeding high amino acid diets to birds in response to external stresses, such as post-hatch fasting and subclinical NE.