ruminant animals

ruminant animal

1. Digestion in ruminants Submitted By:- Gurleen bhinder (L-2018-BS-235-M ) Submitted To:- DR. NEENA CHAWLA Course No:- BIOCHEM 509 Course Title:- ANIMAL BIOCHEMISTRY

2. Definition - What does  Ruminant Animals  mean? Ruminant animals are animals that chew and regurgitate their food more than once, and digest it multiple times in different stomachs. These animals are quadruped mammals with even toes, hooves and chew the cud. They generally have four stomachs with different characteristics, which are used at different stages in digestion. These animals include cattle, sheep, buffalo, antelopes, giraffe, and camels.

3. 5% of the population of domesticated ruminants constitute species: cattle, sheep and goats 9

4. Pathway of food through digestive system:- Mouth Esophagus Rumen Reticulum Back to mouth for chewing of cud Omasum Abomasum Small Intestine Large Intestine

5. The digestion process in Ruminants begins by chewing its food in mouth. Ruminants do not completely chew the food they eat, but just consume or gulp as much they can

6. After the food is broken down into smaller particles it is swallowed and passes through the esophagus using muscle contractions known as peristalsis

7. The stomach of these Ruminants is divided into 4 chambers:- 1. Rumen, 2. Reticulum, 3. Omasum 4. Abomasum.

8. The process of digestion begins with the first two chambers of the stomach, the rumen and reticulum by softening the ingested matter. Later the microbes present in the rumen produces the cellulase enzyme required to digest the cellulose. An important characteristic of ruminants digestive system is the occurrence of the microbial fermentation prior to the gastric and intestinal digestion activity. Rumen has a complex environment composed of microbes. Rumen microorganisms usually adhere to feed particles and form biofilms to degrades plant material. These animals have highly diversified rumen microbial ecosystem consisting of bacteria, ciliate protozoa, anaerobic fungi and bacteriophages

9. The feedstuffs consumed by ruminants are all initially exposed to the fermentative activity in the rumen, the place of more or less complete microbial fermentation of dietary components. Ruminal fermentation initially results in the degradation of carbohydrates and protein to short-term intermediates such as sugars and amino acids. The products of this initial degradation are readily metabolized to microbial mass and carbon dioxide, methane, ammonia and volatile fatty acids (VFA): primarily acetate, propionate and butyrate and to a lesser degree branched chain VFA and occasionally lactate

10. Once the plant fibers have been broken down to provide vitamins, proteins, and other organic acids, the nutrients are absorbed into the animal’s bloodstream. Coarse plants are sent further into the next chamber for further digestion. Here is where the further bacterial action takes place and the food is formed into soft chunks called the cud. This cud produced is regurgitated back into the animal’s mouth where they can be chewed again The saliva of the cow greatly aids in digesting the cud. After chewing, the food bypasses the two chambers of the stomach and directly enters the third chamber. The walls of the third chamber mash and compact the food molecules further, and then pass it to the fourth chamber – the abomasum. The final digestion in the stomach is carried by the abomasum and then passed to the intestine.

11. The Ruminant Digestive System Small Animal Nutrition TM 14 Esophagus Rumen Reticulum Omasum Abomasum Small intestine Cecum Colon Rectum

12. The Non-Ruminant Digestive System Small Animal Nutrition TM 15 Esophagus Stomach Small intestine Cecum Colon Rectum

13. Vertebrates lack the ability to hydrolyse the beta [1–4] glycosidic bond of plant cellulose due to the lack of the enzyme cellulase. Thus, ruminants must completely depend on the microbial flora, present in the rumen or hindgut, to digest cellulose. Digestion of food in the rumen is primarily carried out by the rumen microflora, which contains dense populations of several species of bacteria, protozoa, sometimes yeasts and other fungi – 1 ml of rumen is estimated to contain 10–50 billion bacteria and 1 million protozoa, as well as several yeasts and fungi. Since the environment inside a rumen is anaerobic, most of these microbial species are obligate and facultative anaerobes that can decompose complex plant material, such as cellulose, hemicellulose, starch and proteins. The hydrolysis of cellulose results in sugars, which are further fermented to acetate, lactate, propionate, butyrate, carbon dioxide, and methane .

14. As bacteria conduct fermentation in the rumen, they consume about 10% of the carbon, 60% of the phosphorus, and 80% of the nitrogen that the ruminant ingests. To reclaim these nutrients, the ruminant then digests the bacteria in the abomasum. The enzyme lysozyme has adapted to facilitate digestion of bacteria in the ruminant abomasum. Pancreatic ribonuclease also degrades bacterial RNA in the ruminant small intestine as a source of nitrogen. During grazing, ruminants produce large amounts of saliva – estimates range from 100 to 150 litres of saliva per day for a cow. The role of saliva is to provide ample fluid for rumen fermentation and to act as a buffering agent. Rumen fermentation produces large amounts of organic acids, thus maintaining the appropriate pH of rumen fluids is a critical factor in rumen fermentation. After digesta pass through the rumen, the omasum absorbs excess fluid so that digestive enzymes and acid in the abomasum are not diluted.

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