Polyphenols – Nature’s Answer to the Veterinary Feed Directive


By Patti Wilson, Contributing Editor

By now we are all aware of – if not being affected by – the Veterinary Feed Directive (VFD) that went into effect Jan. 1, 2017. The federal law severely restricts the use of antibiotics in livestock feed. Without going into detail, it basically requires veterinary oversight of all medicated feedstuffs, more strictly enforces label directions and requires a whole lot of paperwork.

Cattle people may count themselves lucky, as compared to swine and poultry producers; the fact that we raise our product in open spaces (as opposed to confinement units) makes our dependence on fed antibiotics less critical than those who take off their coats to feed livestock indoors. Wind and sunshine are wonderful disinfectants.

PolyphenolsIf fed antibiotics are, for the most part, off the table, where can we turn to find an acceptable alternative? The answer may lie in compounds produced by nature in various plant species. We need only to search them out.

What’s a Polyphenol?

To begin at the beginning, it is a complicated subject that I have tried to simplify for the purpose of this article. Most of my information came from a paper published in July 2016 in the Journal of Animal Physiology and Animal Nutrition, in the European Union. It was written by D.K. Gessner, R. Ringseis and K. Elder and entitled “Potential of Plant Polyphenols to Combat Oxidative Stress and Process in Farm Animals.”

According to the article, polyphenols are secondary plant metabolites that have been shown to exert  antioxidative and anti-inflammatory effects in cell cultures. Since stress and inflammation are common in livestock, polyphenols are considered promising as feed additives that require no drug withdrawal or risk to the consumer of milk, eggs or meat.

Why do we need them?

Stress of any kind will cause a reaction in animals clear to the cellular level. This is a long and complex process, the details of which I waded through with difficulty. Stress causes oxidants, the bad components, to build up in cells. Oxidants cause damage to basic cell structures (DNA, proteins and carbohydrates) that leads to tissue damage through inflammation. Polyphenols are antioxidants that actually clean cells of this detritus, help alleviate inflammation and offer protection against further damage when consumed on a regular basis.

Common causes of stress include exposure to bacteria, viruses, ultraviolet radiation (too much sun), or contact with pesticides and mycotoxins (moldy feed) are just a few that can trigger oxidative stress. Chronic disorders are easily developed by stressors, including pneumonia, ketosis, metritis, mastitis and joint disease. Some human disorders stemming from chronic stress are asthma, COPD, inflamed bowels and rheumatoid arthritis. You see, oxidative stress happens across the board for all mammals. Polyphenols are good for all of us.

Consistency matters

Why do we need to use polyphenols on a daily basis?  Stress occurs even when we aren’t looking. It’s easy to spot a steer with an ear down, but insidious side effects happen right under our noses that we can’t see. Systemic (bloodstream) inflammation leads to the anorexia or reduced appetite. Complex chemical reactions involving neurons in the brain suppress appetites in ways we don’t see, even when cattle are lined up at the bunk. The effect of stress continues on to the gut, where gastrointestinal secretions and movement are hindered, harming digestion. The daily use of polyphenols provides a constant supply of antioxidants to counteract these problems.

To the rescue

Polyphenols provide protection against invasive pathogens and toxins. They prevent damage to cellular DNA and repair damage due to intense sunlight. There are more than 8,000 kinds of these antioxidants. Typically good sources are fruits, vegetables, leaves, legume seeds and beans. People are fond of tea, tropical fruits and berries, spinach, rosemary, artichokes and onions. Soybeans, juices and wines are rich in the compound.

A good source of polyphenols for livestock is agricultural byproducts from fruit juices, wine and beer making. Pomace, peels, seeds, stems and brewery waste are excellent, as well as co-products from grains, seeds and nuts. Husks and hulls from rice, buckwheat, almonds and coconuts also serve the purpose well.

What’s the downside?

As compared with the great amount of research that’s been done with swine, studies involving the use of polyphenols in ruminants is scarce.

Polyphenols, themselves, are at risk of being oxidized when feed is stored over long periods of time, losing their effectiveness. This is particularly true during hot weather.

Certain antioxidative compounds such as tannins are toxic. They can negatively affect feed intake, digestibility and efficiency of production.

Although many useful plants contain this pesky chemical, they are mostly present in small enough amounts not to be harmful. Those to watch for, however, include the leaves of oak, maple, birch, willow and pine trees. Large amounts of tannin may be found on the surface wax of these plants.

A bright future

Polyphenols are natural compounds that help keep our cells clean. They provide protection for our livestock from bacteria, fungi, molds and viruses. Helping reduce stress at the cellular level gives our cattle greater immunity, enables their kidneys and livers to regulate waste more efficiently, increases appetite and boosts our bottom line. In their natural simplicity, they don’t involve drug residues or require a prescription to use. They may become one answer to the government’s VFD.