Introduction to Cattle Digestion | 10 Things To Know

Image via extension.umn.edu

Image via extension.umn.edu

Forages are the number one source of nutrition for cattle. Cattle are able to utilize a great number of forages, plants, and crop by-products as feed that humans cannot digest. They’re great recyclers and by utilizing cattle we’re able to produce food on millions of acres that otherwise wouldn’t be suitable for growing crops. Cattle are ruminants, meaning they digest feeds through microbial processes, compared to digestion through enzymes in monogastrics like horses, pigs and humans. Many scientists dedicate entire careers to the understanding of ruminant nutrition and are continually learning more about helping cattle to be more efficient and optimal producers through their diets.

Cattle have the capacity to consume 2-3% of their body weight in dry forages each day. That’s 24-36 pounds for a 1,200 lb animal. Less mature, higher quality forages will be digested more quickly and increase capacity for consumption. Lower quality feeds, high in lignin require more time for digestion and slow intake.

  1. Cattle have 1 stomach with four compartments – rumen (major digestion site), reticulum (honeycomb structure), omasum (has many folds, major site of water absorption), abomasum (true stomach, acid producing).
  2. The rumen is similar to a fermentation vat that can contain up to 50 gallons of material in adult cattle. The other stomach compartments regulate particle size. Once small enough, particles are allowed to pass from the rumen, to the other stomach compartments for continued digestion and absorption.
  3. Cattle spend about 8 hours each day “chewing the cud. They are regurgitating food boluses from the rumen and chewing up fibrous materials making them smaller for quicker digestion. This action stimulates saliva production, up to 45 gallons per day, that helps to maintain proper pH levels for rumen function.
  4. Most digestion in cattle occurs through bacteria and protozoa present in the rumen that digest feedstuffs to produce nutrients that the animal utilizes. The lining of the rumen is filled with finger-like projections called papillae that increase absorption capacity of the products of microbial digestion.
  5. Cattle are able to utilize a great number of feed sources because of the rumen microbes. Two basic groups of rumen bacteria exist to digest either structural (cellulose or hemicellulose from forages) or nonstructural (starch from grains) carbohydrates to obtain energy. Other feedstuffs broken down in the rumen include sugar, organic acids, protein or fat.
  6. Volatile Fatty Acids are the major products of rumen digestion and supply 80% of the animal’s energy requirements. The primary VFAs produced are acetic acid (60%), propionic acid (up to 20% on a high grain diet), and butyric acid (12-18%). Other products include heat, gases, amino acids and B-complex vitamins.
  7. The digestion of rumen microbes supply 60% of the animal’s protein requirement. To maintain microbial growth and function in the rumen, a minimum of only 7% crude protein from dietary intake is required. Excess protein in the diet is an inefficiency in the cattle diet and is broken down and excreted as ammonia through the urine.
  8. Fistulated cow with nutrition researcher examining rumen contents. Image via ans.iastate.edu

    Fistulated cow with nutrition researcher examining rumen contents. Image via ans.iastate.edu

    The balance of microbe populations in a proper diet keeps rumen pH in a range of 5.8 to 6.4. An abrupt change in major components of cattle diets (i.e. forages to grains), can result in excess acid production, resulting in a condition known as acidosis.  A transition period allows adjustment of rumen microbe populations and prevents this condition.

  9. Much of the information we learn about cattle digestion is learned through research using a fistula. This is a hole placed in the side of a cow where a rubber seal and plug are surgically placed. The plug can be removed and researchers can observe and sample rumen activity and contents. The fistula doesn’t harm or injure the cow and they are rarely used outside of research efforts.
What questions do you have about cattle digestion and the feeds they eat? Leave a comment below or email [email protected]. This is part of a month-long series of 10 Things to Know about Cattle. To read other posts in the series, click the image below.
Click this image to view all posts in the 30-day blogging series, 10 Things to Know About Cattle

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Introducing Dr. Megan Van Emon – Montana State Extension Beef Specialist

megan van emon msu extension beef specialistDr. Megan Van Emon began as the MSU Extension Beef Cattle Specialist located at the USDA-ARS Fort Keogh Livestock and Range Research Laboratory in Miles City, MT on August 1.

Megan grew up on a small farm in northeast Indiana, where they raised pigs and dairy steers. She was a 10-year 4-H member and showed rabbits, goats, and beef. She studied Animal Science at Purdue University and graduated with her BS in 2006. Megan continued her education at Purdue with Dr. Scott Lake, studying ruminant nutrition and graduating with her MS in 2008. Her research topic was the optimization of protein quality of dried distillers grains with solubles for ruminants.

Megan moved to Hettinger, ND in May of 2009 to begin her Ph.D. in ruminant nutrition with Drs. Chris Schauer and Kim Vonnahme. Using sheep as a model for cattle, her research focus was supplementing metabolizable protein to ewes during late gestation and determining the effects on the offspring.

While in Hettinger, she also conducted research in weaning strategies with Angus calves and ram fertility. In May of 2013 Megan graduated from North Dakota State University with her Ph.D. After graduating from NDSU, she moved to Iowa State University as a Post-Doctoral Associate with Drs. Stephanie Hansen and Dan Loy in beef feedlot nutrition. Megan’s main research focus at ISU was to determine the effects of feeding algae meal to beef steers on digestibility, preference, and performance.

Megan says, “I’m excited to be here in Miles City and I’m looking forward to getting around the state to discuss the opportunities available here in Montana. Please call, email, text, and stop by.”

Megan’s Contact Information: Megan Van Emon; Office: 406-874-8286; Cell: 701-928-1096; Fax: 406-874-8289; Email: [email protected].

Derrell Peel is the Charles Breedlove Professor of Agribusiness in the Department of Agricultural Economics

MSGA 2013 Convention Highlights – Thursday

2013 Montana Stockgrowers Convention Trade ShowHave you registered for the 2013 Montana Stockgrowers Convention and Trade show? Registering and quick and easy through the MSGA Events page!

Over the next few weeks, we’ll be highlighting each day of the convention and introducing the featured speakers. A full agenda and schedule is also available on the MSGA Events page.

The 2013 MSGA Convention kicks off on Thursday, December 12 with Registration beginning at 7:00 a.m. and the Trade Show opens at 11:00 a.m. Many committee meetings fill Thursday’s schedule:

  • 8:00 a.m. MSGA Board of Directors Meeting
  • 9:00 a.m. Montana Public Lands Council Annual Meeting
  • 10:00 a.m. Beginning Farmers and Ranchers Training Workshop
  • 10:00 a.m. MT Red Angus Commercial Cattlemen’s Symposium
  • 10:00 a.m. Steer of Merit Committee Meeting
  • 1:00 p.m. Land Use & Environment Committee Meeting
  • 1:00 p.m. Membership Development & Services Committee Meeting
  • 1:00 p.m. Silent Auction Opens

Beginning at 4:00, we have a few great speakers as part of the Zoetis Cattlemen’s College.

Rebuilding the U.S. Beef Industry: Challenges and Opportunities

Derrell Peel is the Charles Breedlove Professor of Agribusiness in the Department of Agricultural Economics

Dr. Darrell Peel

Derrell Peel is the Charles Breedlove Professor of Agribusiness in the Oklahoma State University Department of Agricultural Economics. He has served as the Extension Livestock Marketing Specialist since arriving at OSU in 1989. He has B.S. and M.S. degrees from Montana State University and a Ph.D. from the University of Illinois. He previously served as the Superintendent of the Southeastern Colorado Range Research Station in Springfield, Colorado. His main program areas at Oklahoma State University include livestock market outlook and marketing/risk management education for livestock producers.

Derrell also works in the area of international livestock and meat trade with particular focus on Mexico and Canada and the North American livestock and meat industry. He lived in Mexico on sabbatical in 2001 and has developed an extensive knowledge of the Mexican cattle and beef industry and the economics of cattle and beef trade between the U.S. and Mexico.

ZOETIS RANCH- An Interactive Cow Calf Game Designed to Explore Profit Opportunity From EPDs and HD50K Genetic Tests

Zoetis Cattlemen's College at Montana Stockgrowers ConventionDan Ellis was raised on a purebred Hereford Ranch in Columbus, Montana and received an Animal Science degree from Montana State University. Dan is a Genetics Consultant at Zoetis Animal Health and Administrator of GenomeXchange.com. Ellis’ accomplishments include serving as C.O.O. and Angus Division Manager at Beartooth International and Livestock Manager for Northern International Livestock Show until 1997. In 1992, Dan served as President and founded Western Management, renamed Ellis Management Group (EMG) in 2002 to accommodate commercial feeder cattle brokerage. EMG provides consulting services for management, genetics, and marketing for purebred clients. 

Larry Gran, Regional Manager for Zoetis Animal Genetics, covering South Dakota, North Dakota, Montana, Wyoming, and Idaho, grew up on a cow/calf yearling operation in Western Nebraska. Larry currently still has an interest in the family’s Registered Red Angus Operation. Larry Gran started with Bovigen, which is now Zoetis in July of 2007. Previously he was the General Manager, Editor and Sales consultant for Tri-state Livestock News and Graduated from University of Wyoming with a BS in Ag Business. Larry has also managed and owned a back grounding feedlot along with his own Red Angus cows.

Thursday’s schedule wraps up with a Young Stockgrowers meeting and social, the Leaders & Legends Dinner at 5:00 p.m. and the Trade Show Opening, Dinner and NFR viewing starts at 6:30.

Many more events are planned for the week at the 2013 MSGA Convention. Be sure to get your registration sent in. Stay tuned on the blog next week for meeting details for Friday and Saturday’s events! View the full agenda  on the Montana Stockgrowers Website.