Rumen Motility Church: 67-106, 108-116, 468-474 Van Soest: 237-244 Ruckebusch and Thivend: 35-51 Sjersen et al.: 155-164 Susenbeth et al. 1998. Energy Requirement for Eating in Cattle. J. Anim. Sci. 76:2701-2705. http://jas.fass.org/cgi/reprint/76/10/2701.pdf Cheng et al. 1998. A Review of Bloat in Feedlot Cattle. J. Anim. Sci. 76:299-308. http://jas.fass.org/cgi/reprint/76/1/299.pdf Majak et al. 1995. Pasture Management Strategies for Reducing the Risk of Legume Bloat in Cattle. J. Anim. Sci. 73:1493-1498. http://jas.fass.org/cgi/reprint/73/5/1493.pdf
Rumen Motility. Church: 67-106, 108-116, 468-474 Van Soest: 237-244 Ruckebusch and Thivend: 35-51 Sjersen et al.: 155-164 Susenbeth et al. 1998. Energy Requirement for Eating in Cattle. J. Anim. Sci. 76:2701-2705. http://jas.fass.org/cgi/reprint/76/10/2701.pdf - PowerPoint PPT Presentation
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Rumen Motility
Church: 67-106, 108-116, 468-474
Van Soest: 237-244
Ruckebusch and Thivend: 35-51
Sjersen et al.: 155-164
Susenbeth et al. 1998. Energy Requirement for Eating in Cattle. J. Anim. Sci. 76:2701-2705. http://jas.fass.org/cgi/reprint/76/10/2701.pdf
Cheng et al. 1998. A Review of Bloat in Feedlot Cattle. J. Anim. Sci. 76:299-308. http://jas.fass.org/cgi/reprint/76/1/299.pdf
Majak et al. 1995. Pasture Management Strategies for Reducing the Risk of Legume Bloat in Cattle. J. Anim. Sci. 73:1493-1498.
• Inhibition of ruminal contractions– Abomasal distension
– Hyperglycemia
Factors affecting ruminal contractions• Feeding
– Increases frequency and amplitude of contractionsActivity Contractions/min Amplitude P/S mm HgResting 1.2 18.2 -Feeding 2.0 22.1 1:1Ruminating 1.1 10.4 -Fasting .3 Weak 5:1
• Diet– Feeding a finely ground forage
• Reduced rate of contractions• Reduced amplitude of contractions
– Requires 2-6 weeks to adapt
• Volatile fatty acids– Acetic, propionic, and butyric acids at 90, 50, and 37 mM
given separately or at 33.5, 29.3, and 21.1 mM given as a mixture will inhibit primary contraction
• Metabolic problems– Hardware disease, hypocalcemia, or hyperglycemia will
inhibit ruminal contractions
Need for eructation• Gas production
– Peak • Occurs 30 min to 2 hr
post-feeding
• 12-27 l/min
– Average• 1-2 l/min
• Approximately ¼ to 1/3 of CO2 produced in rumen is absorbed into blood and removed through the lungs
• Only 1/5 of the CH4 is removed through the lungs
• Composition of rumen gas
__Gas__ _%__
CO2 65.35
CH4 (variable) 27.76
N2 7.00
O2 (at wall) .56
H2 .18
H2S .01
Mechanism of eructation• Biphasic contraction of reticulum• Modified primary contraction of rumen• Secondary contraction of rumen• Ruminal gas pocket forced forward• Anterior fold and reticuloruminal fold rise to hold
digesta away from cardiac sphincter• Cardiac sphincter relaxes allowing esophagus to
fill with gas• Rapid reverse peristallsis of the esophagus
– Diaphragmatic and Pharyngeal sphincters open– Nasopharyngeal sphincter closes
• Epiglottis opens while thoracic muscles contract – Cause 80% of gas to enter trachea– Acts as a muffler
• Animal exhales
Control of eructation
• Stimulus– Gaseous distension of the reticulum and rumen
• Inhibition– Presence of digesta near the cardiac sphincter
• Affects all three sphincters
• Prevents digesta from entering lungs
– Epinephrine– Histamine
• Inhibition of eructation will cause the animals to bloat– Ruminal pressures will increase to 45 to 100 mm Hg.
Bloat• Types of bloat
– Free gas bloat• Gas pocket over the digesta is normal, but can’t be
eructated because of a physical obstruction in the esophagus or anatomical abnormality
– Frothy bloat• Gases form a foam over the digesta that inhibits eructation
when it touches the reticular wall near the cardiac spincter
• Two types– Feedlot bloat– Pasture or legume bloat
Feedlot bloat• Etiology
– Occurs in ruminant animals fed high grain diets particularly during adaptation to the diets
• Causes– Digesta becomes viscous and gel-like that trap gas as a foam
• Viscosity increased by– The presence of bacterial capsules on some gram + starch-digesting
bacteria such as Streptococcus bovis and lactobacilli» Streptococcus bovis and lactobacilli only found in large
numbers in animals not adapted to high grain diets– The presence of short-chain starches (dextrans)
– Increased concentrations of VFAs• Reduce ruminal motility
– Increased intake of a dense diet• Lowers cardiac sphincter
– Increased numbers of mucinolytic bacteria• Mucin will prevent foam
– Reduced outflow rate
• Prevention– Slowly adapt animals to high grain diets– Feed adequate fiber– Use less fermentable grains
• Wheat or barley > Corn or sorghum
• Steam-flaked > Coarse ground
– Feed ionophores (Monensin or Salinomycin)• Decreased growth of Streptococcus bovis and lactobacilli
• Decreased feed intake
• Decreased methane production
Pasture bloat• Occurs in ruminant animal consuming fresh legumes
such as alfalfa, white clover and red clover or the small grain wheat when immature or immediately after a frost
• Causes– Presence of high concentrations of soluble protein present in
chloroplasts increases surface tension causing foam• Earlier research implied that a protein named ribulose-1,5-
biphosphate carboxylase oxygenase (also called the 18S protein)– 3 – 6% of DM in bloat-causing legumes
• Recent research shows that total soluble protein concentration is more highly related to bloat
– Rapid cell wall digestion• Rapid release of chloroplasts• Rapid release of cell wall fragments that get trapped in foam
– Pectin• A cell wall component in high concentration in legume cell walls• Pectin metabolism
– Pectin fermented to Pectic acid (binds 2000x its weight in water increasing viscosity)
– Pectic acid rapidly fermented to methane
– Minerals• K, Ca, Ni, Zn, and Mg stabilize foam• Frosted legumes
– K is released into cytoplasm– Decreased Na:K ratio results in increased binding between proteins– Increases surface tension causing bloat
• Triphasic contraction of the reticulum– Forces digesta to cardia
• Animal inhales with epiglottis closed– Produces a vacuum of 60 to 80 mm water in esophagus
• Cardia opens and esophagus dilates– Negative pressure sucks digesta into esophagus
• Rapid reverse peristalsis moves digesta to mouth• Bolus is rechewed
– Chewing is slower and more deliberate than during eating• Digesta reinsalivated
– Saliva composition is different than during eating• Parotid glands secrete more saliva during rumination than eating
– Saliva from parotid glands secrete more HCO3- than other glands
• Reswallowing– After reswallowing, the rumen undergoes a primary
contraction to move it back in the rumen– 20 to 65% of the DM is released in a fine state and will not
return to the mouth again
Control of rumination
• Controlled by tactile receptors (epithelial receptors) near the cardiac sphincter, reticuloruminal fold and anterior sac
• Stimulated by scratching of feed against the rumen wall
• Reflex is semiautomatic– Can be stopped anytime
• EEG resembles sleeping
Rumination time• Average times for a grazing animal– Eating – 8 hours– Ruminating – 8 hours– Resting – 8 hours
• Ruminating time is quite variable• Factors affecting rumination time– Fiber content of diet– Physical form of diet
Effects of diet on rumination
• Increasing the proportion of grain in the diet will decrease rumination Chews/day
Hay 50,100
Dried grass 36,100
Concentrate 11,000
• Increasing the maturity of the forage in a diet will increase rumination
• Decreasing the particle size of the diet will decrease the rumination time
• Increasing feed intake will reduce the rumination time per gm of feed consumed
• Cattle ruminate less per kg NDF than sheep or goats
Roughage value index
Total chewing, min/kg DM
Alfalfa hay,
Chopped 44.3
Long 61.5
Pelleted 36.9
Oat straw 160
Cottonseed hulls 30.1
Alfalfa silage
Fine chop 22.3
Medium chop 26.0
Corn-ground 5.1
Soybean meal 6.0
Minerals 0
Molasses 0
Urea 0
Effects of rumination of the animal• Saliva flow
– More saliva secreted during rumination than eating– Affects
• Rumen pH– Fiber digestion– Microbial growth– VFA and methane production– Maintenance of intake– Structure of rumen epithelium– Prevention of liver abscess and laminitis
• Liquid rate of passage– Efficiency of microbial growth within the rumen
• DM intake– Ruminating time is a limiting factor controlling intake of
high fiber diets Maximum time, hours Ruminating 10-11 Grazing 13– Lower rumination efficiency (min/g CWC) limits intake of
smaller and growing animals
Body weight Rumination Max. CWC intake/d
Animal kg kg.75 min/g CWC g/kg BW g/kg.75 BW
Lambs 40 16.0 2.05 5.8 14.6
Goats 39 15.6 1.30 9.4 23.7
Mature sheep 82 27.3 1.18 4.9 14.9
Calves 119 35.9 .78 5.2 17.2
Heifers 1 213 55.7 .42 5.4 20.8
Heifers 2 342 79.6 .19 7.4 31.8
Heifers 3 456 98.6 .16 6.5 29.9
Mature cows 561 115.0 .10 8.2 40.1
• Energy cost– Total chewing
• increases maintenance cost by .24 kcal/hr/kg BW and accounts for 30% of maintenance requirement
• Accounts for difference in maintenance energy requirements of cattle fed high grain or high forage diets.
– Contribution of rumination to energy cost of total chewing varies
Time, min/kg DM consumedFeedstuff Eating RuminatingOat straw 41-58 94-133
Medium quality hay 20-40 63-87 Good quality hay 27-31 55-74 Concentrates, pelleted 4-10 0-25