Feed Additives In Small Ruminants: What do they do?

One of the most confusing parts of feeding animals is the astounding array of feed additive products that are available. It is easy to wonder what they do and why they matter. Since each of these categories has enough information to fill its own textbook, we will provide a general examination of their uses and the reasons to utilize them in your rations. While our focus is on the most common additives, it is important to realize that there are virtually limitless combinations and options. Feed additives is a category in animal nutrition that is constantly evolving, which is why producers should use reputable companies that have scientifically based products.

Yeast Products
The number of yeast products in the marketplace increases by the day. Often, name brand recognition is what sells a specific yeast product. Yet there remain questions about the different types of yeast products and what they do. The most common yeast products contain Saccharomyces cerevisiae and are utilized to improve nutrient digestion, reduce acidosis, and enhance animal performance in the ruminant animal. In general, yeast products are supposed to help create a favorable rumen environment, reduce specific bacteria numbers in the animal and increase immune system function. They are often referred to as “probiotics” or “direct fed microbials”. While there are several subsections of yeast (live yeast vs dead yeast, cell walls vs extracts), we will focus on live yeast and yeast cell walls. It will be important to remember that not all yeast products are created equal.

Saccharomyces cerevisiae
Live Yeast
• Encourages beneficial bacterial growth.
• Reduces certain bacteria numbers.
• Supports immune system.
• Very beneficial in maintaining a consistent bacterial population in the rumen during transition and high stress  periods such as lambing, weaning and heat stress.

Yeast Cell Walls
• Quality/components used will vary by company. General, yeast cell walls:
o Bind certain mycotoxins.
o Bind Gram negative bacteria.
o Increase immune system function/response.
Certain S. cerevisiae products are essentially the carbohydrates from the cell walls of the yeast, blended with fermentation products from culturing that yeast. Ultimately, they are a nutrient source for the gut microbiota that lends itself to improve performance, productivity and increases gut health and immunity.

Lactobacillus targets the lower intestine and is meant to stabilize the gut microbiota.

MOS (mannan oligosaccharides), or sugar structures, come from the cell wall of yeast (S. cerevisiae usually) and can be utilized by bacteria in the digestive tract. They are supposed to bind to attachment sites on pathogens like E.coli and Salmonella and keep them from binding to the gut wall. This reduces pathogen load and/or damage to digestive tract and stimulates the immune system.

The current buzzword in minerals is “chelates”. Yet not all minerals are chelates, and not all chelates are created equal. What are the  differences between mineral types? Our traditional inorganic minerals (sulfates and oxides) are the cheapest source to use, however, also the least bioavailable to the animal. On the other hand, organic minerals are much more bioavailable to the animal. Organic minerals can be bound to a variety of organic compounds including amino acids, proteins, and polysaccharides.  The trend of using “chelated” minerals gained popularity because these minerals are more readily absorbed by the animal, and true “chelates” are more protected from antagonists and ensure optimal absorption. Antagonists are defined as “a substance that interferes with or inhibits the physiological action of another.” Antagonists would include other minerals, anti-nutritional factors, or mycotoxins that compete for absorption or bind to each other and cause interference. The goal is to keep animals healthy and ensure that stressful periods such as lambing, weaning, finishing lambs in adverse weather, breeding, pasture drying up, etc. do not create mineral issues. Minerals play an important role in an animal’s health and well-being. The pricing of organic minerals can be very prohibitive, which is the reason that it is common to see a variety of mineral sources used in a product.

Essential Oils
Essential oils, aka phytonutrients, are a very new category which has seen limited research and regulation. There is no regulatory organization to place requirements on the amount of nutrient per pound of product. Therefore, the consistency of product can be in question. At the same time, individual components from plants like oregano, thyme, cinnamon, and others show a lot of promise. As the availability of antibiotics decreases, essential oils are being used as part of the “replacement”. In general, essential oils are marketed as appetite increasers and bacterial growth inhibitors, while also used to affect the microbial populations to improve the efficiency of energy and protein utilization in the rumen. Animals under stress from weather, disease issues, movement into the feed lot, etc. often consume less feed which can lead to acidosis and reduced immune responses, which ultimately means more dead or sick animals. Essential oils are being utilized to keep the rumen healthy, therefore keeping the animal healthier. More research is needed on essential oils before they will be readily endorsed. Once again, not all products are created equal, yet as we continue have more experience with essential oils, they may earn their place at the small ruminant table.

Toxin Binders
One of the most under-recognized issues in small ruminants is the impact from mycotoxins. Mycotoxins are toxic products of molds generally split into the two categories of field fungi and storage fungi. Traditionally, mycotoxins have been a major concern for swine, poultry, and dairy producers. Under the assumption that the rumen in other ruminants helps negate the toxin issue, and those animals do not consume enough feed to feel the effects of the toxins, many have thought that other ruminants do not have a mycotoxin problem. However, research continues to show that mycotoxins impact all species. Issues resulting from mycotoxins can be hard to pinpoint in beef cattle and small ruminants. We see an increase in mycotoxin issues every year. Since the problem is not going away, some wonder about taking proactive measures by using a binder in the hopes of avoiding a train wreck. The issue stems from the fact that most of the effects might be subclinical, such as lower growth performance, altered feed intake, etc. Picture the animal that never seems to live up to its full potential yet was in the same pen as others that were performing beautifully. Ultimately toxin binders “bind” mycotoxins to prevent toxicity and absorption in the gut, which prevents them from entering the blood stream of the animal. If you are feeding by-products of grains such as distillers or screenings, take care because mycotoxins tend to show up in higher concentrations in by-products.

Feed additives are a moving target. The number and variety of quality is mind-boggling. This was a very basic rundown of some of the most  important and common feed additives available and used in livestock production. If there are questions regarding the use of some of these  technologies in your operation, feel free to reach out to us. We can easily discuss the differences and where certain products might be a good fit.