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Ruminant digestive system and rumen ecology. Prof. Dr. Metha Wanapat Dr. Anusorn Cherdthong. 130740 Tropical Feed Resources and Feeding Technology. Department of Animal Science, Faculty of Agriculture Khon Kaen University. Ruminant Nutrition and Feeding:. Feeds , Rumen, Microorganisms
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Ruminant digestive system and rumen ecology Prof. Dr. Metha Wanapat Dr. Anusorn Cherdthong 130740 Tropical Feed Resources and Feeding Technology Department of Animal Science, Faculty of Agriculture KhonKaen University
Ruminant Nutrition and Feeding: Feeds , Rumen, Microorganisms Productivity
Left or Parietal Surface Dorsal curvature Dorsal coranary groove reticulo-ruminal fold Caudo-dorsal blind Sac Cranial groove esophagus Caudal groove Cranial Sac L.Longitudinal grooveVentral Sac Caudo-ventral blind Sac reticulum Ventral coronary groove abomasum
Right or Visceral surface Diaphragm R.Longitud- inal groove Cranial pillar Duodenum Pylorus Omasum Abomasum
1 11 2 3 6 4 10 7 5 9 8 1= esophagus 2= cardia 3-4 =esophageal groove 5= reticulum 6=space between reticulum and rumen cranial sac 7= cranial sac of rumen 8= ventral of rumen 9= caudal-ventral blind sac 10= caudal-dorsal blind sac 11= dorsal of rumen
A B A C B A= reticulo-ruminal fold A = cardia B=esophgus B= reticulo-amasal orifice C= esophagus/reticular groove
Factors affecting on reticulo-rumen development : I. Type of feeds - Solid/dry feed - Roughage stimulate rumen contraction as “ physical stimulant ” rumen weight and thickness papillae development
II. Fermentation process: • - Continuous fermentation to • produce volatile fatty acids • (VFAs), C2,C3C4 • -C4 > C3 > C2 as “ chemical stimulant” • - VFAs increase osmotic pressure • of stratum basal cells thus • mitogenic effect
Time spent for activities in ruminants • Eating/grazing 1/3 • Resting 1/3 overlapping • Ruminanting 1/3 Eructating
Reticulo-rumen motility/contraction • Schalk and Amadon (1928) “ Biphasic contraction” • Primary contraction or Mixing cycle • Secondary contraction or Eructation contraction many or many not occur after CP
P~ 50-60 sec S~30 sec P S 0 1 2 3 4 5 Ret R R R R Biphasic contractions Schalk and Amadon(1928)
Reticulo-rumen motility • Phillipson (1939) Cyclical activity of rumen • Phillipson and Reid (1960) reported four major patterns of contractions • 1-R,D • 2-R,D,V • 3-R,D,D,V • 4-R,D,V,D,V • R = reticulum, D = dorsal, V= ventral
Dziuk and McCauley (1965) 1- R, Dp, CDBp, Vp 2-R, Dp, CDBs, Ds,Vs 3-R, Dp, CDBp, Vp, CDBs, Ds, Vs p= primary, s= secondary 2,3,4 (Phillipson and Reid) = 1,2,3 (Dziuk and McCauley) CDB = caudo-dorsal blind sac
Wyburn (1980) Illustrated on sequential rumen contractions 1 21 steps 1 16 (A contraction) rumination 17-21 (B contraction) eructation A contraction is independent of B contraction A and B can occur simultaneously
Rumination process: • Regurgitation • Swallowing • Re-mastication • Re-insalivation • Reswallowing
Mechanics of rumination and eructation:How………. • Initial contraction of reticulum as biphasic • Increase fluid pressure around cardia • More fluid flows to cardia
Rumination…….. • Diaphragm sharply contracts creates negative pressure in trachea • Esophageal becomes flat except area connecting to cardia start to enlarge
Rumination……... • Ingesta/digesta in rumen flows back to esophagus • Regurgitation occurs, ingesta moves back to esophagus by antiperistalic wave
Triphasic contraction • TC occurs as an extrareticular contraction and occurs during resting or eating phase , prior to usual biphasic /primary contraction • Thus stimulates rumination to occur regurgitation
Rumination is essential and useful: • Mastication of particles for finner, mix well for efficient fermentation • Increase salivary secretion thus enhance rumen buffering capacity
Rumination…….. • Increase rate of passage (RT), decrease rumen retention time (RRT) thus improve DM intake • Maintain rumen microbial population for a balanced rumen/optimal rumen ecology • Enhance volatile fatty acids (VFAs) production
Saliva and rumen buffering capacity NaCl + H2 CO3 weak acid +HCl NaHCO3 +NaOH Na2CO3 + H2O weak alkaline
Optimal rumen ecology • pH 6.5-7 (6.7) • temperature 39oC • Continuous fermentation • rumen NH3-N (15-30 mg%)
Mechanics of eructation • E belching/ getting rid of fermentation gases • E occurs during secondary contraction of rumen peak of fermentation > two secondary contractions occur
Eructation………. • Gas produced in adult cattle 2 l/min in adult sheep 5 l/h • Major gases CO2 (40-70%), CH4 (25-45%) others (O2, N, H2, H2S)
2 DAYS 4 DAYS 12-20 DAYS 8-10 DAYS UREA POLYCENTRIC FUNGI CELLULOLYTIC CONSORTIA PROTOZAO OXYGEN ZOOSPORE 38 hr MONOCENTRIC FUNGI MYCOPLASMAS Diagrammatic representation of the sequential development of the microbial ecology of the newborn ruminant.
Rumen microorganisms (Hungate, 1966) • 1010 -1012 cells/ml rumen fluid • cellulolytic bacteria • amylolytic • proteolytic • NH3-N utilizing • etc
Major species of rumen bacteria degrading cell-wall polysaccharides.Cell wall polysaccharide Species Cellulose Bacteroides succinogenes Ruminococcus flavefaciens Ruminococcus albus] Butyrivibrio fibrisolvens Cillobacterium cellulosolvens\ Clostridium lochheadii Cellulomonas fimi Eubacterium spp. Hemicellulose Batyrivibrio fibrisolvens Ruminococcus albus Ruminococcus flavefaciens Bacteroides ruminacola Peptic substances All the cellulolytic and hemicellulolytic species plus: Lachnospira multiparus Streptococcus bovis Succinovibrio dextrinosoluvens Source: Cheng et al. (1984)
Protozoa • Ciliated protozoa • 104-106 cells/ml • larger > bacteria 38 micron in length 15 micron in width • moves rapidly
Holotrich- Subclass • absorbs sugar • Entodinimorph (tuft) • digest starch • stores surplus CHO • Can not use NPN • engulf bacleria 200-106 cells/h 1% bacteria/min • defaunation
Rumen fungi • ~ 8% of total rum microbes • ~ 20 genera • low in number • digest fiber with bacteria
Feed particle A= randomly association or by chemoattractants B= by bacterial glycocalyx and binding protein C = produce sister cells/digestive pits are visible D= form rich biofilm, digestion accelerated e= Portion of biofilm dissociate from feed particles F= others remained on feed particles and pass to lower digestive tract
ADHERENT CELL NONADHERENT CELL Glycocalyx Cell Cell Cellulose
Distribution of rumen bacteria 75% = bacteroa; adjered tp feeds 20% = flow in rumen fluid 5% = adhered to inner surface fo rumen epithelium