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Beef Cattle: Managing Ruminants. Beef Cattle Industry Advanced Animal Science: Principles of Industry Sutherlin AST September 13, 2011. The Ruminant Stomach. Rumination. Ruminants bite off forage and swallow quickly, then process the food Result of evolution – why?
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Beef Cattle:Managing Ruminants Beef Cattle Industry Advanced Animal Science: Principles of Industry Sutherlin AST September 13, 2011
Rumination • Ruminants bite off forage and swallow quickly, then process the food • Result of evolution – why? • The following steps are called rumination
Rumination • “Chewing the Cud” • Animal regurgitates large boluses of food which were earlier swallowed • Re-chewing food breaks down for easier conversion by bacteria/microbials
Rumination • “Chewing the Cud” • Added benefit: saliva acts as a “base” to counteract rumen acid (more later)
Reticulum • Honeycomb-like interior surface
Reticulum • Helps to remove foreign matter from the food material • Material that “sinks” into the reticulum is there for the life of the animal Telephone Cord
Reticulum • Some material can cause damage, called “hardware disease” • Solution: bolus magnet is slipped into animal to collect material, stays inside for life
Rumen • A large fermentation tank • pH is about 6, depending on diet
Rumen • Allows for bacterial and chemical breakdown of fiber • A very thick, muscular wall • Fills most of the left-side of the abdomen
Rumen • Walls of the rumen contain papillae • This where the bacteria live • Up to 1cm long • The rumen can be up to 55-65 gallons in size • About 80% of adultstomach, but only30% of calf stomach
Rumen • Microbials process plant matter that normally couldn’t be digested • Products released include VFA (Volatile Fatty Acids) • absorbed directly into bloodstream for energy
Omassum • Round and muscular • “Grinds” the food material and prepares it for chemical breakdown • Removes excess water
Abomassum • Very similar to the stomach of non-ruminants • About 7-8% of total stomach • Majority of chemical breakdown of food material occurs
Abomassum • Mixes in digestive enzymes (pepsin, rennin, bile, etc) • pH is closer to 2.4
Rumen Microbes There are 1010 to 1012 cells/mL Continuous culture fermenters Live in pH of 6.8-7.0 39 degrees C
Rumen Microbes Divided between three kingdoms Bacteria Protista Fungi
The Relationship Microbes and ruminants have a symbiotic relationship Both gain from the partnership
The Relationship Microbes provide to the ruminant: Digestion of cellulose Couldn’t digest roughages without microbes!
The Relationship Microbes provide to the ruminant: Production of high quality protein 50-80% of Nitrogen (N) is absorbed from microbes Protein has high value
The Relationship Microbes provide to the ruminant: Produce B vitamins Meets ruminants needs in most conditions
The Relationship Microbes provide to the ruminant: Detoxify toxic compounds Example – Mimosine in Leucaena cause problems in animals (poor growth, reproduction/hair loss)
The Relationship Microbes provide to the ruminant: Detoxify toxic compounds Hawaiian ruminants, but not Australian ruminants, have microbes that degrade mimosine so Leucaena can be fed Transferred rumen fluid to Australia Inoculated rumen Fed Leucaena
The Relationship Ruminants provide to the microbes: Housing Reliable heat (39 degrees C +/- 2) Guaranteed for 18 to 96 hours depending on diet/animal Straw-fed water buffalo – longest rumen residence time Small selective browsers (mouse deer) – shortest time
The Relationship Ruminants provide to the microbes: Garbage removal Absorption of VFA’s (energy for ruminant) Eructation Release of gas (CO2 and CH4) Passage of indigestible residue/microbes
The Relationship Ruminants provide to the microbes: Nutrients Animal eats! Saliva provides urea (N source for bacteria)
The Relationship Ruminants provide to the microbes: Neutral environment pH 6.5 to 7.0 Saliva contains bicarbonate/phosphate buffers to balance acid from microbes
The Relationship Ruminants provide to the microbes: Neutral environment If the pH was 5.7 rather than 6.5… 50% less microbe activity Rate of carbohydrate use decreased
Factors that Reduce Microbial Growth Rapid ration change Takes 3-4 weeks for microbes to stabilize Feed restricted amounts
Factors that Reduce Microbial Growth Feed lots of unsaturated fat Bacteria do not use fat for energy Feed lots of non-cellulose carbohydrates Causes rumen acidosis
Factors that Promote Microbial Growth Maximum dry matter intake Balanced carbohydrate and protein fractions Bacteria need both energy and N for amino acid synthesis Gradual ration changes Maintain rumen pH Keep feed available at all times
Nutritional Disorders Pamphlet • Read the MSU Extension Handout (on website) • Summarize and make a pamphlet for cattle ranchers explaining the: • Cause • Symptoms • Treatment For each of the three diseases!