Flashcards
Ruminant and Midgut Fermentation inc. motility
Flashcards do conjunto (46)
- 1Why have motor patterns in ruminants been studied in detail?commercial pressure to understand the rumen better for economic production
- 2What are rumenal contractions fully dependent on?ANS - if the connection to the vagus nerve is lost then the animal cannot survive
- 3Motility of the rumen is reduced by which feelings?Stress and Pain, making rumination a key factor for diagnosing well being
- 4What is the main purpose of primary contractions?mixing of reticulorumen contents
- 5Where do primary contractions start?begin in the reticulum and sweep aborally over the rumen
- 6The reticular muscle walls contract how often in a 5-10 second period?twice
- 7What is the action of the first reticular contraction?forces coarse fibrous material from the top of the reticulum into the central/dorsal rumen
- 8What does the second reticular contraction do?empties the reticulum of well-fermented content into the bottom part where it is then transferred into the cranial sac
- 9What is the general movement patterns of primary contractions?figure 8 patter
- 10What are the strength of primary contractions in proportion to?the fill of the rumen, increasing in frequency and strength as the rumen becomes more full
- 11At what point during the movement of food ingesta does the reticulum relax?once ingesta has passed to both the cranial sac of the rumen and a small volume to the omasum
- 12Where do the first contractions take place that only move through the rumen?start in the cranial sac and cranial pillar, spreading dorsally and caudally across the upper sac
- 13What structure is ingesta repeatedly passed over before entering the omasum?the reticulorumenal fold
- 14At peak contractions, how many contractions are there within each sac per minute?one
- 15What is the main purpose of secondary contractions?eructation
- 16Eructation is a combined effect of which three factors?contractions within the rumen, contraction of respiratory muscles during inspiration, antiperistaltic contractions of the oesophagus
- 17What is the frequency of secondary contractions like compared to primary contractions?usually half, but the ratio can be 1:1 with high fermentation rates
- 18Where do secondary contractions originate from?caudal sac, moving forward
- 19What must be cleared in the stomach to allow the passage of gas in eructation?the 'gas tap' must be cleared of the cardiac sphincter to move into the oesophagus
- 20What is rumination based on/ what brings it about?based on reflexes that are triggered when coarse feed stimulates nerve endings in the area around the oesophageal opening
- 21What is the action of the extra reticular contraction during rumination?contraction removes newly-swallowed food from the oesophageal opening and replaces it with semi-liquid feed from the reticulum that's been partially fermented
- 22What two changes need to be generated in the abdomen and thorax to allow rumination?a negative pressure in the thoracic cavity and an increase in abdominal pressure
- 23What happens once the bolus reaches the oral cavity?fluid is immediately re-swallowed and the rest is masticated for around 40 seconds before being re-swallowed
- 24Why is rumination needed?to allow particles to become small and dense enough to sink to the bottom of the reticulorumen to be passed to the omasum
- 25What does the rumination time increase with?the crude fibre/coarseness of the diet
- 26Why is rumination to decrease particle size important?it increases the surface area of food particles so that they can be attacked by microbes more easily
- 27Why is releasing gas from food particles an important effect of rumination?increases the density of food particles so that they drop down into the omasum
- 28How else does the reduced particle size of food increase the efficiency of ruminants?smaller particles have a reduced transit time and so the rumen is emptied more quickly, which stimulates further eating
- 29What is the balance between reducing transit time and reducing extracted nutrients?reducing the transit time reduces the time for fermentation, so less energy is extracted - but overall being able to eat more food more often cancels out this downside
- 30What does eructation allow the liberation of?CO2 and Methane
- 31What happens when there is a failure within the eructation mechanism?rumen distension and bloat as the pressure builds up due to gases
- 32What happens to the majority of eructated gas?it is inhaled into the lungs and then expelled with exhalation
- 33What is the primary function of the omasum?water absorption and absorbing around 50% of VFA that enters it
- 34How does liquid absorption in the omasum benefit the function of the abomasum?it reduces the load on the abomasum as there is less of a dilution effect so less acid needs to be secreted to create the appropriate pH
- 35What are the disadvantages of midgut fermentation?many microbial products are lost, especially proteins that are not broken down fully/absorbed and so pass out in faeces
- 36What are coprophagic animals?Animals in which the gut produces two types of faeces, with one being eaten again to extract nutrients
- 37What type of faeces are re-eaten by coprophagic animals?caecotophes that are high in protein and vitamins (B & K)
- 38Where are caecotrophs stored in the body?Fundic Region
- 39What protects caecotrophs from being broken down in the stomach?covered in mucous that gives protection against break down by proteases and stomach acid
- 40Where does the majority of fermentation take place in the horse?Colon
- 41What is flatulent colic/flatus in the horse?poor removal rate of gas in the gut compared to its production rate
- 42What is the difference in how dietary protein is utilised in horse compared to ruminants?more efficiently utilised in horses as they have to rely on it instead of the microbial protein they lose during digestion
- 43Why is it common at the start of lactation for glucose levels to fall too low?glucose is the substrate for lactose that's needed to meet the milk demands
- 44What are the metabolic solutions to a lack of glucose?gluconeogenesis (from muscle protein or OAA) and a switch to 'glucose sparing' ketone bodies
- 45What can a grain overload in ruminants cause?Lactate Acidosis and Acidemia
- 46—
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- Animal Disease 1 Veterinary Medicine FlashCards sobre Ruminant and Midgut Fermentation inc. motility, criado por Louise Mason em 07-03-2017.
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- Louise Mason
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