Probiotic and Prebiotic Applications in Equids

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1 Probiotic and Prebiotic Applications in Equids Dr Jo Anne Murray Content Natural environment and domestication of the horse Overview of equine digestive tract Importance of gastrointestinal health/factors affecting Maintaining gastrointestinal health Application of prebiotics and probiotics 1

2 Natural environment of the horse Roam up to 80 km/day (nomadic animals) Domesticated horses at pasture = ~ 20 km/day ~ 2 mouthfuls in one spot Graze little and often Grazing 16 to 20 hours/day quality feeds, fibre Seen to select fibre forages Domestication of the horse Current use of the horse: Recreational purposes Breeding Sport Meat production (to some extent) Dietary management: energy feeds Improved pastures Meal feeding Large meal sizes 2

3 Summary natural environment & domestication Departure from natural state Continually grazing and moving Not voluntarily confine Diet fibre nutri onal quality Equine digestive tract as a whole Oesophagus ( m long) ~ 30 metres long in mature horse Total volume ~ 200 litres Changes in diameter at various sections Lined with mucous membranes Classified as non ruminant herbivore Non ruminants = enzymatic digestion (limited fibre degradation in LI) Ruminant = fibre digestion in the rumen Horse = sits between these Consists of 3 functional regions: Stomach Small intestine Large intestine (hindgut) Stomach (~ 8 %) Small intestine (~ 30 %) Large colon (~ 37 %) Caecum (~ 15 %) Small colon (~ 10 %) Rectum Photo: 3

4 Foregut Mouth: Mastication par cle size (essen al for diges on) Horse chews times/min Saliva produced by chewing (30 40 litres per day) Function = lubrication and buffering of stomach contents Stomach: Size relatively small and inelastic Capacity of ~ 8 15 litres (~ size of a rugby ball) Non glandular region: ph = ~ 6 7 (buffered by saliva) Suscep ble to damage if ph reduced (e.g. by fas ng, cereal grains etc) Glandular region: ph = ~ (Hydrochloric acid produced; protected by mucous layer) Small intestine: Duodenun/Jejenum/Ileum Starch and simple sugars/fats and oils/proteins Molars (n = 12) Pre molars (n = 12) The large intestine (also known as the hindgut) Three main parts: Caecum/Large colon/small colon (plus rectum) Microbes over 400 species (probably more) Bacteria/Fungi/Protozoa Need time to adapt to changes in diet ph of LI = 6 to 7 (important to maintain correct ph) No digestive enzymes microbial fermentation feed residues from SI VFAs (used as an energy source) and gases Designed to digest fibre Problems occur when fibre and starch and sugars fed 4

5 Factors that affect gastrointestinal health Feed type and composition NSC content Processing Tinker et al., 1997 Meal feeding/meal size Fasting Disruption to hindgut Abrupt changes to diet Disruption to hindgut risk of colic/lamini s Max: < 1 g starch/ kg BW* Min: 1 kg DM forage/ 100 kg LW * Vervuert et al. (2009) Factors that affect gastrointestinal health Abrupt changes to diet Affects microbial populations GIT disturbance (e.g. acidosis) diet diges bility Ill health (e.g. colic/laminitis) Changes observed Most significant changes after few hours of conc abruptly added 1 Changes in forage batches can also affect microbial populations 2 Change from grass hay to grass silage = number of lactobacilli 2 No. of lactobacilli in abrupt forage changes than abrupt addi on of conc. 3 1 de Fombelle et al. (2001); 2 Munhonen et al, (2009); 3 de Fombelle et al. (2003) 5

6 Maintaining gastrointestinal health Use of prebiotics and probiotics in equid diets Potential to influence intestinal microflora Prevent/treat disease Reduce use of antimicrobials Prebiotics Types Fructo oligosaccharides (FOS) Galacto oligosaccharides (GOS) Reported changes with scfos* streptococci counts in stomach lactobacilli & streptococci counts in colon gastric ph (5 versus 4.5) ph in colon No modification in cellulolytic bacteria *Respondek et al. (2007 & 2008) 6

7 Probiotics Many products limited studies Lactobacillus Bifidobacterium Enterococcus Saccharomyces (majority of studies conducted with S. cerevisiae) Issues with quality control* Poor labelling, many don t list specific microorganisms Many products do not contain listed products Some have organisms not listed Many fail to meet their label claims in terms of viable micro organisms Many commercial horse feeds claim to contain probiotic organisms *Weese & Martin (2001) Probiotics bacteria Digestibility Propionibacteria & Lactobacillus plantarum diges bility in adult horses 1 Microflora No effect of Bacillus cereus on foal diarrhoea, faecal microbes or serum IgG 2 diarrhoea in foals given Enterococcus faecium & Lactobacillus rhamnosus 3 diarrhoea, inappetence & colic in foals given Lactobacillus pentosus WE7 4 Clinical applications Potential probiotic bacteria inhibit enteric pathogens in vitro (Bacillus subtillis & Lactobacillus salivarius) But: Lactobacillus pentosus WE7 also showed positive results in vitro! 1 Goachet et al., (2010); 2 John et al. (2012); 3 Gunther et al, (2012); 4 Weese et al. (2005) 7

8 Probiotics Yeast (SC) Digestibility fibre diges bility 1 VFA produc on 2 ra o of acetate+butyrate: propionate 3 Microflora celluloly c bacteria 4 lactate u lising bacteria (s mulatory pep des as in ruminants?) 3 lactate producing bacteria 3 effect of environmental changes on LI (e.g transpor ng) 4 Clinical applications Effects on pathogens and infectious diarrhoea not been looked at in horses 1 Julliand (2006); 2 Medina et al. (2002); 3 Jouany et al. (2009); 4 Julliand & Zeyner (2008) Conclusion What we know: Diet is integral to health fibre and NSC Consistent amounts and types Gradual dietary/management changes Use of pre/probiotics has potential What we need to know: Microbial populations Environmental effects on microbial populations Relationships between diet and disease Use of pre/probiotics 8

9 Thank you for listening 9