Digestion in Ruminants

Digestion in Ruminants

1. Digestion in Ruminants Herbivores such as cows, sheep and goats are ruminants.                                                                           Www.RCVetS.com

2. The problem with cellulose Herbivore food contains a lot of cellulose e.g.grass Mammals cannot produce cellulase Ruminants have a large storage chamber called a rumen The rumen contains a large number of bacteria which do produce cellulase The bacteria and the ruminant both benefit from this relationship This is known as mutualism

3.  glucose O C H OH H OH O C H OH H OH H 2 O Condensation of 2  glucose molecules What is the difference between cellulose and starch?

4.  glucose H 2 O Condensation of 2  glucose molecules O C H OH H O C H H OH O Glycoside bond

5. 1 Chewed grass 2 rumen 3 reticulum 4 Food chewed a second time Grass is ground up by chewing It is swallowed and passes into the rumen                                                                          

6. 4 Food chewed a second time 5 Abomasum ‘true stomach’ duodenum 6                                                                           =chewing the cud

7. 1 Chewed grass 2 rumen 3 reticulum 4 Food chewed a second time 4 Food chewed a second time 5 6 Abomasum ‘true stomach’ duodenum The pathway the grass takes

8. What happens in the rumen Cellulose is hydrolysed to glucose by cellulase Bacteria in the rumen secrete cellulase Glucose is used by the bacteria for anaerobic respiration Providing energy for growth of bacteria cellulase cellulose glucose

9. Bacteria absorb glucose Glucose used in anaerobic respiration Fatty acids and methane produced as waste product Fatty acids absorbed by ruminant Provides energy for ruminant glucose fatty acids absorbed by ruminant and used in respiration methane

10. Fermentation in the rumen e.g. C 6 H 12 O 6 2CH 3 COOH + CO 2 + CH 4 e.g. C 6 H 12 O 6 2CH 3 COOH + CO 2 + CH 4 Hexose sugar e.g. C 6 H 12 O 6 2CH 3 COOH + CO 2 + CH 4 Ethanoic acid methane

11. How cattle can survive on a diet low in protein? Some bacteria in the rumen use urea as a source of nitrogen to make protein Nitrogen may be taken that is not part of protein e.g.urea Some bacteria are swallowed with the chewed cud The bacterial protein is then digested in the abomasum and duodenum as in other mammals Amino acids produced are absorbed in the small intestine and used to make cow protein This protein is used for bacteria reproduction The bacteria have converted the waste urea into protein to supplement their diet

12. Nitrogen metabolism in the ruminant Some urea from deamination is recycled Liver Deamination of amino acids urea urine Saliva + urea rumen

13. grass+saliva+urea cellulose bacteria bacteria grow excess bacteria glucose cellulase methane+CO 2 +fatty acid protein peptides urea+grass protein fatty acids rumen abomasum+ duodenum absorbed +respired amino acids absorbed +made into protein some protein

14. Now have a go at these 1. What is likely to be the main respiratory substrate of a cow? (1) 2. Explain how it is possible for cows to survive on a diet poor in protein. (2) 3. Give three ways in which the rumen of a cow is like an industrial fermenter used to produce enzymes. (3) 4. What are the sources of non-protein nitrogen the bacteria in the rumen may use to produce protein? (2) Click on the question to check your answer Click here to end

15. 1. Fatty acids – waste products from the bacterial respiration Back to question 2. Bacteria in the rumen use non protein nitrogen to make protein for growth; Some of these bacteria are passed to the abomasum, along with the partially digested grass ; Back to question

16. Temperature is controlled in both pH is kept constant in both The contents of both are kept moving 3. Any 2 from Urea; ammonia; nucleic acids; 4. Back to question

17. ALLAH HAFIZ