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28 Cards in this Set
- Front
- Back
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What is eructation?
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Oral removal of air or gas out of stomach
(burping) |
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How many hours a day does a cow spend ruminating?
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8-10 hrs
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What conditions does the rumen need?
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Osmotic pressure - slightly hypotonic
pH - 6.5-7 Temperature - above rectal temperature |
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How much saliva does a cow produce a day?
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100-150l
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What are the types of rumen microbes found in the rumen?
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Anaerobic bacteria
Protozoa Anaerobic fungi |
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Why is the relationship between cow and microbes symbiotic?
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Microbes get energy and substrates as do cows for maintenance and growth
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What happens in the rumen at pH below 6
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Microbes are depressed
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What are the products of fermentation by microbes?
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Volatile fatty acids (CHOs) -
Propionate Butyrate Acetate Amino acids and ammonia (proteins) |
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What is rumen undegradable protein?
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Protein not digestible by rumen microbes.
RUDP passes straight to abomasum for enzymatic digestion |
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Which gases are produced?
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CO2
Methane Ammonia |
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What happens to the end products of fermentation?
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VFAs - absorbed through forestomach wall
- taken to liver for metabolism Ammonia - made into microbe protein Microbial cells - digested in abomasum and intestine Gases - eructated |
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Name each layer of the rumen
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1 - liquid layer - fine particles under 2mm
2 - finely ground material 3 - fibrous mat - long strands, recently eaten food, microbe-digesting food 4 - gas cap - methane and CO2 |
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What is the main innervation of rumen contractions?
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Vagal nerve
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What are the 4 main functions of rumen contraction?
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Mixing food material
Moving food material Eructation Rumination |
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Which cycle is responsible for mixing food material?
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A cycle
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Which cycle is responsible for eructation?
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B cycle
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Describe the movement of an A cycle
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Clockwise
Reticulum contraction Rumenoreticular fold contracts and shortens Contraction of caudal blind sacs Contraction of ventral sac of rumen |
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How long do A cycles last and how often?
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20 seconds
Every minute |
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Describe the movement of a B cycle
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Anti-clockwise
Contraction of caudoventral blind sac Contraction of caudodorsal blind sac Contraction of dorsal sac Contraction of ventral sac |
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How often does a B cycle occur?
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One every 2 A cycles
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What needs to happen in order to eructate?
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Cardia needs to be covered by gas cap - contraction of rumenoreticular fold
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When does the frequency of rumen contractions increase?
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During eating
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When does rumination start in a calf?
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2-3 weeks if given access to solid food
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How much methane an hour does a cow produce?
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30l per hour
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What happens to gas in the rumen?
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Most eructated
25% absorbed into hepatic portal blood |
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Describe eructation during a B cycle
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Gas moved to cardia
Lower oesophageal sphincter relaxes and dilation of diaphragmatic part of oesophagus Lower oesophageal sphincter contracts, pharyngeal opening relaxes, antiperistalsis >50% enters lungs and is absorbed Gas enters pharynx, nasopharyngeal sphincter closes |
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What are the 2 types of bloat/rumen tympany?
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Frothy bloat
Free gas bloat |
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What clinical example could give a ping noise on the LHS of the abdomen?
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Displaced abomasum
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