This week’s edition will torchlight something we all have seen always, though when I was a kid I never stopped wondering why some animals mouth never stop dancing. I know you might be curious too… Just hop on.
My last article highlighted Coprophagy which means the consumption of faeces but in the case of rabbit which was our sole purpose, it refers to as Caecotrophy because the mucus like pellet they consume helps in distributing certain nutrients locked within the feed (fibre). Read more on this distinctive attribute here.
If you were an animal, what would be your favourite grass?
Rumination is the process of regurgitating swallowed foods to enhance further breakdown and availability of nutrients to the animal’s body. Animals like cattle, harvest grasses and forages using their tongue where it is buffered by saliva. This is made possible by the dual function of the oesophagus. When the animal chews the grass for the first time, it does for a very long time. Later, it goes into a conducive, quiet and serene environment to regurgitate. Rumination is possible with relaxation of distal oesophageal sphincter which allows easy access of the bolus (food) back to the mouth.
How would you feel if humans can chew their favourite food over and over again before swallowing for finally digestion?
Rumination involves the following outlined stages namely Regurgitation, Resalivation, Re-mastication (rechewing) and Re-swallowing. Regurgitation is the process of bringing back the cud from the rumen, this involves anti peristalsis of bolus in the rumen after undergoing fermentation from the rumen to the reticulum and large indigestible fractions has been sorted and moved back to the rumen for rechewing; resalivation is the process of buffering the forage with saliva again where it provides adequate circulation on nutrients to the rumen; remastication involves the process of re chewing the food all over again, which is usual done while they sit quietly after long hours of grazing; the last phase of rumination involves re swallowing the chewed cud or bolus but this time it goes directly into the digestive system for usage by the body and easy access to the nutrients.
To simplify the sentence above…
While a cattle is resting she brings back the previously grazed forage which has undergone fermentative processes in the rumen, buffers it with saliva, chews it over and over again before swallowing it. The previously chewed grass had undergone fermentative process in the rumen and passed through the reticulum before it was drawn back to the mouth for re-chewing. This is usually the moment where we see the cattle lying down especially on their left side called sternal recumbency chewing continuously. They use this moment to take a nap and it has proved to help keep them healthy and for a faster gut motility. This helps the digestive tract to properly breakdown the cellulose within the plant or forage and for easy movement in the stomach.
Imagine this process isn’t possible, how would they properly grind those tough grasses or digest them faster?
Just like Rumination helps the cattle in getting full acces to a forage, another distinctive process by the rumen is Eructation
Eructation known as belching and it involve secondary contraction of the rumen where the gases stored in the rumen are discharged easily. The cattle produces up to 50litres of gas while rumination takes place and anything that interrupts with this process can lead to the animal’s death. This gases released by the cattle is methane and it helps in greenhouse production and stability of the atmosphere contributing up to 20%. When eructation is hindered, this process leads to a disorder called BLOAT also known as Ruminal tymphany.
Bloat is further classified into primary (frothy) and secondary bloats (free gas); where the gases are trapped within the material is classified as the former and when it is blocked by the oesophagus it is classified as the later. It leads to a lot of discomfort including breathing blockage and death if not treated properly. Treatment method involves use of sodium bicarbonate or antifoaming agents e.g vegetable oil.
As the oesophagus opens, the animal belches; this means belching interferes with the animal’s breathing.
In rabbits, consumption of night faeces known as Caecotrophy; involves movement of Chyme (Digested bolus) through their digestive system i.e. from mouth to caecum where it is acted upon by the microbes and the undigested fragments are caecotrophes which is shiny mouldy pellets with an ammonia taste rich in vitamin B and VFA. It is picked directly from the anus and involves Peristalsis i.e. it chews the faeces like normal food and it undergoes the normal digestion process over again. The digesta spends about eight hours in the caecum before it is passed out but Rumination involves anti-peristalsis i.e movement from the rumen back to the oesophagus then to the mouth where it is re-chewed and re-swallowed. Majorly, the rabbit (Caecotroph) has the caecum which processes the bolus/chyme but the cattle (ruminant) has the rumen which does the primary function in digestion.
CONCLUSION
Healthy cows perform rumination at a specified interval to ensure high productivity. Their Rumen contains microbial population which digests the forage; then moves the bolus to the reticulum where it is passed back to the oesophagus through anti peristalsis. This process helps the animal to properly grind the forage to easy movement in the gut. When the microbial population acts on the bolus (food) it is called Primary contractions and this ensures proper utilization of plants. While Rumination involves primary contractions, belching (eructation) involves secondary contractions of the rumen and this helps the animal reduce the gases int the rumen.
Cattles have being marked to contribute massively to the production of methane and stability of the ecosystem and this process involves eructation. So, as the rumen dispense the gas is released but at this moment the animal is unable to breathe, so anything that interferes with eructation can pose as threat to the animal. Ruminal Tymphani called Bloat is one major disorder which can be solved with patience, visits to the veterinary doctor and use of antifoaming agents. Feeding cattle with too much legumes, clover and alfalfa can lead to bloat which in turns interferes with the animal’s being.
So, the next time you see a cattle chewing its cud (regurgitating/ruminating) or to maintain a healthy livestock production, remember the lessons you learnt from this article. Don’t forget to “Do Agric, It Pays”.
Thank you for reading.
REFERENCE
Rumination
Managing a ruminating cow
Biology: Rumination
Rumination
Rumination
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