• DVM360_Conference_Charlotte,NC_banner
  • ACVCACVC
  • DVM 360
  • Fetch DVM 360Fetch DVM 360
DVM 360
dvm360 | Veterinary News, Veterinarian Insights, Medicine, Pet Care
dvm360 | Veterinary News, Veterinarian Insights, Medicine, Pet Care
By Role
AssociatesOwnersPractice ManagerStudentsTechnicians
Subscriptions
dvm360 Newsletterdvm360 Magazine
News
All News
Association
Breaking News
Education
Equine
FDA
Law & Ethics
Market Trends
Medical
Politics
Products
Recalls
Regulatory
Media
dvm360 LIVE!™
Expert Interviews
The Vet Blast Podcast
Medical World News
Pet Connections
The Dilemma Live
Vet Perspectives™
Weekly Newscast
dvm360 Insights™
Publications
All Publications
dvm360
Firstline
Supplements
Vetted
Clinical
All Clinical
Anesthesia
Animal Welfare
Behavior
Cardiology
CBD in Pets
Dentistry
Dermatology
Diabetes
Emergency & Critical Care
Endocrinology
Equine Medicine
Exotic Animal Medicine
Feline Medicine
Gastroenterology
Imaging
Infectious Diseases
Integrative Medicine
Nutrition
Oncology
Ophthalmology
Orthopedics
Pain Management
Parasitology
Surgery
Toxicology
Urology & Nephrology
Virtual Care
Business
All Business
Business & Personal Finance
Hospital Design
Personnel Management
Practice Finances
Practice Operations
Wellbeing & Lifestyle
Continuing Education
Conferences
Conference Listing
Conference Proceedings
Upcoming dvm360 Conferences
Resources
CBD in Pets
CE Requirements by State
Contests
Partners
Spotlight Series
Team Meeting in a Box
Toolkit
Top Recommended Veterinary Products
Vet to Vet
Veterinary Heroes
  • Contact Us
  • Fetch DVM360 Conference
  • Terms and Conditions
  • Privacy
  • Do Not Sell My Information
  • About Us

© 2023 MJH Life Sciences and dvm360 | Veterinary News, Veterinarian Insights, Medicine, Pet Care. All rights reserved.

Advertisement
By Role
  • Associates
  • Owners
  • Practice Manager
  • Students
  • Technicians
Subscriptions
  • dvm360 Newsletter
  • dvm360 Magazine
  • Contact Us
  • Fetch DVM360 Conference
  • Terms and Conditions
  • Privacy
  • Do Not Sell My Information
  • About Us
  • MJHLS Brand Logo

© 2023 MJH Life Sciences™ and dvm360 | Veterinary News, Veterinarian Insights, Medicine, Pet Care. All rights reserved.

Starch management in dairy diets (Proceedings)

August 1, 2011
Jonathan Townsend, DVM, PhD, DABVP

Providing properly balanced and successful dairy rations can be a challenging job. One must track a large number of nutrients and make sure that they present in adequate levels yet not in excess where they can lead to reduced performance or animal health.

Providing properly balanced and successful dairy rations can be a challenging job. One must track a large number of nutrients and make sure that they present in adequate levels yet not in excess where they can lead to reduced performance or animal health. Such nutrients include acid detergent and neutral detergent fiber, metabolizable protein, and macro- and micro-minerals to name a few. Starch definitely fits into this category. In the past, the primary concern about starch as diets were constructed was the potential for rumen acidosis due to excessive starch levels. In recent years starch has gained more scrutiny due to the ability to better measure starch degradability and Dr. Mike Allen's proposed hepatic oxidation theory (HOT) to explain dry matter intake regulation. This paper will briefly summarize the hepatic oxidation theory and explain how the concepts within the theory can be used to construct rations that do a better job of targeting specific groups of cows based on their ability to utilize starch and different starch degradabilities.

Many theories have been utilized to help explain dry matter intake regulation in dairy cows. Recently, Dr. Mike Allen at Michigan State University has proposed what he calls the "hepatic oxidation theory" or HOT for short. While somewhat complicated, the basics of HOT are fairly straightforward. The vagus nerve carries impulses from the liver to the feeding centers in the brain. The firing rate of the nerve can therefore control feeding behavior, with increased rates associated with hunger and intake stimulation. The firing rate of the vagus nerve is stimulated by the oxidation of "fuels" in the liver and the production or depletion of ATP. As fuels are oxidized and ATP is produced the firing rate of the vagus nerve decreases and satiety is stimulated. As ATP is depleted the firing rate of the vagus increases and the feeling of hunger and intake are stimulated. A number of fuels can be oxidized within the liver, including amino acids, fatty acids, lactate, and propionate. As we consider starch utilization, propionate obviously becomes a very important oxidative fuel.

Advertisement

If propionate is accepted as being a very important oxidative fuel and dietary starch is a major determinant for level of propionate production it therefore becomes very important for those constructing dairy diets to consider starch levels, sources, and degradabilities. Propionate is converted to glucose within the liver, but when it is delivered to the liver at levels that exceed it's rate to be converted to glucose the excess will be oxidized, potentially signaling satiety and decreasing intake. It becomes imperative then, that nutritionists consider the stage of lactation of a group of cows and the capacity of those cows, based on their stage of lactation, to utilize glucose.

So what does all this mean in the construction of rations for lactating dairy cows? For early lactation cows through mid-lactation intake is controlled to a greater degree by rumen fill than propionate production. Cows in this stage of lactation have very high demands for glucose due to the high level of milk production during this stage of lactation. Because of this, these cows tend to utilize propionate very quickly for the production of glucose and there is little propionate that is left to be oxidized and potentially stimulate satiety. Rations can therefore be constructed to provide greater fermentability, with higher overall starch levels and utilizing sources of starch with higher rumen digestibility. High moisture corn fits this situation very well as a starch source. As cows move past mid-lactation and milk production decreases, rumen fill becomes less of a determinant of intake and propionate production becomes more important. In these cows, it is desirable to have more consistent supply of nutrients to the liver so that more fuels are partitioned to milk rather than excessive body condition stores. To deliver lower levels of propionate at more consistent levels the nutritionist should consider starch sources with lower rumen fermentability but high digestibility within the small intestine. Such sources will provide glucose precursors but will limit propionate production. Dry, ground corn fits this role very nicely. While debated, HOT would recommend that cows that have just freshened should receive a diet with low levels of highly fermentable starch because of the concern of producing enough propionate to depress intake. Again ground, dry corn would fit this role nicely as it has just moderate rumen fermentabilty but high small intestine digestibility.

The realization that cows handle starch differently at different stages of lactation underscores the advantages of creating rations for cows based on stage of lactation. An early lactation group diet could have both higher levels of starch and starch sources, such as high moisture corn, that have higher rumen fermentability. A later lactation diet would consider starch sources that both supported milk production and limited body condition gain, which becomes extremely important as we look to maximize transition cow health. Dry, ground corn would such a source. While many farms may avoid making separate diets due to labor concerns or the number of cows that fit into a group, HOT does point to advantages in feeding groups of cows differently and thereby better targeting nutrients to the needs of cows. Utilizing grouping strategies can also allow for the targeted use of feed additives that produce higher levels of milk or better animal health. Dairy veterinarians can utilize their understanding of physiology to help coach their clients through these feeding and grouping decisions, and if they wish, develop the diets for their clients.

References

Allen, M.S. and B.J. Bradford. 2009. Nutritional control of feed intake in dairy cattle. Proceedings of the 20th Annual Florida Ruminant Nutrition Symposium. 138-148.

Allen, M.S., B.J. Bradford, and M. Oba. 2009. The hepatic oxidation theory of the control of feed intake and its application to ruminants. J. Anim. Sci. 87:3317-3334.

Related Content:

Medical
Dog owners are not getting proactive OA information from their veterinarians
Dog owners are not getting proactive OA information from their veterinarians
Performing a health exam on geriatric parrots
Performing a health exam on geriatric parrots
Case study: A new year to keep pets safe from alcohol poisoning
Case study: A new year to keep pets safe from alcohol poisoning

Advertisement

Latest News

Comparing treatments for restoring the skin barrier in atopic dogs

Increasing efficiency and productivity in uncertain times

AAVMC awards almost $100,000 in diversity scholarships

News wrap-up: This week’s headlines, plus Maryland Zoo welcomes baby addra gazelle

View More Latest News
Advertisement