Editorial

Nutritional Tools for Improvement of Beef Cattle Performance

BY Dr. Stephen Blezinger | | Comments (0)

Cattle producers commonly ask questions such as: “What can I do to save money?” or “How can I be more productive?”  This has been especially true over the last few years when forages have been in short supply due to drought conditions around the country, feed costs have been high because of competition with ethanol production demands, and numerous other contributing factors.  Producers who are in the business to be profitable or at least to survive in the current economy are forced to examine all avenues that can improve efficiency and help the productivity and performance of their herds.

Producers are increasingly aware of beef production evolving into a highly technical and science-driven proposition.  Aside from the basic management, reproduction, health and nutritional principles that the industry is built on, a wide variety of “tools” have been developed over the years that are available to the producer to improve performance and production efficiency.  Many of these tools have become standards and are used daily.  Others are still in the stage where both producers and researchers are working to understand application and results.  Regardless of which category they fall into, a wide range of tools are available for use in beef cattle production.  We’ll discuss a number of these below.

Nutritional tools, for the purpose of this article, can be defined as products of various types which can be fed to the animal to improve digestion and/or absorption of various critical nutrients or serve some other valuable function.  Some of these work in the animal’s digestive system (particularly the rumen) to modify the ruminal fermentation or the digestive process to more extensively break down nutrients or to modify the end products produced from digestion.  Additionally, a variety of products are available to enhance the performance of the animal’s immune system.  Finally, there are still other products that can modify the animal’s metabolism to improve the efficiency of protein and fat accretion and deposition in the animal to enhance carcass characteristics.

This article will discuss many of these “tools.”

The Standards

A number of products have been available for years and continue to be a staple of the beef cattle nutrition industry.  Some of these include:

1)    Ionophores*.  Ionophores are technically antibiotic products that are fed to cattle to modify the microbial population in the rumen to enhance the fermentation process.  This change reduces the number of bacteria that tend to produce waste products (gasses, acids, heat, etc.) that cannot be used efficiently by the animal as a nutrient source.  This change in the microbial population also results in increased numbers of the bacteria that produce beneficial products (other organic acids, microbial protein, etc.).  Approved ionophores include monensin (Rumensin®), lasalocid (Bovatec®), laidlomycin propionate (Cattlyst®), bambermycin (Gainpro®), and virginiamycin (V-max®).  These products are designed to be fed daily at only milligrams per head per day to achieve the desired result, which is normally an improvement in feed efficiency, although there are claims for other benefits such as the reduction in coccidiosis and bloat control.

2)   Antibiotics*.  A number of antibiotics are available that are fed to the animals to reduce the presence and effects of certain pathogenic organisms such as anaplasmosis, e. coli, salmonella, etc.  Antibiotics can be used at continuous low levels for improvements in rate of gain and efficiency.  Higher levels of antibiotics typically are fed for prevention and treatment of diseases or conditions such as scours, coccidiosis, shipping fever, anaplasmosis, foot rot, and liver abscesses.  Chlortetracycline (Aureomycin® and others), neomycin sulfate/oxytetracycline (Terramycin®), bacitracin (Albac 50®) and tylosin (Tylan®) are examples of antibiotics intended for specific disease prevention or treatment.

3)   Beta Agonists*.   Beta agonists for beef cattle became commercially available in 2004.  They are growth promoters which primarily change partitioning of energy from feed to muscle instead of fat deposition.  This increases weight gain, rib eye area, and total red meat yield when used. Their feeding also tends to produce a leaner carcass.  The two approved products include ractopamine hydrochloride (Optiflexx®) and zilpaterol hydrochloride (Zilmax®) and are designed to be fed to finishing cattle the last 20 to 42 days prior to harvest (depending on the product).

4)   Coccidiostats*.  Coccidiosis is a common problem is calves caused by the protozoal organisms Eimeria bovis and Eimeria zuernii resulting in gut inflammation, reduced nutrient absorption and diarrhea.  Subsequent effects are moderate to severe dehydration and death.  Amprolium (Corid®), decoquinate (Deccox®) are two coccidiostats that are effective in the control of these organisms.

5)   Estrus Suppressant*.  Melengestrol acetate (MGA®) is a feed additive that suppresses estrus (heat or cyclic sexual activity) and improves gain and feed efficiency in beef females.  Practical application of MGA® is in heifer estrus synchronization programs; however, feedlots also use MGA in finishing diets to reduce heifer riding behavior and associated production losses.

6)   Bloat Prevention*.  Poloxalene (Bloat Guard®) can be fed to beef cattle to help prevent bloat on legume and other lush pasture.  Poloxalene can be mixed with feed or different supplements or offered in block form.  As with most additives, for product effectiveness, cattle must consume adequate quantities of poloxalene, so proper intake control is important.

7)   Yeast Cultures.  Yeast has been fed to cattle for years and has been shown to exhibit a variety of beneficial properties.  Yeast cultures (most commonly, strains of Saccharomyces cerevisiae) have been shown in a wide variety of studies to improve feed efficiency, gains, and overall health in cattle.  Yeast cultures and yeast fermentation products also affect dry matter intake, rumen pH, and nutrient digestibility.   Production applications of yeast cultures include use in receiving diets of both low- and high-stress cattle, inclusion in mineral and other cow supplements, and in feeds for all-natural and organically fed cattle.

8)   Organic or Chelated Trace Minerals.  Organic trace minerals (also referred to as complexes or chelates) are trace mineral (TM) sources where the key nutrient metal (copper, zinc, selenium*, etc.) have been combined with an organic “ligand” or carrier.  This may be an amino acid, peptide (combination of amino acids), carbohydrate or other organic acid.  The goal of feeding an organic TM source is to improve the absorption of the TM through the intestinal wall as compared to inorganic TM sources.  Research has shown that improving the TM status of the animal by improving absorption has positive effects on reproduction, health and growth.

9)   Buffers.  Buffers can be added to beef cattle diets to reduce fluctuations in rumen pH.  Sources such as sodium bicarbonate help reduce the incidence of acidosis when adapting cattle to high grain diets or when feeding cattle high starch rations including corn or wheat at high levels.  Buffers are commonly used in dairy cattle rations.

10)   Fly Control*.  Oral larvicides can be fed to cattle through feed, supplements and minerals to kill fly larvae as they hatch in the manure.  They are effective only when animals consume the proper amount of the active ingredient.  Oral larvicides do not control migrating adult flies. Adult flies can still be a problem if a producer is using an oral larvicide but a neighbor is not practicing any fly control.  Insect growth regulators that disrupt fly life cycles are another fly control product available as a feed additive.  These products include (S)-Methoprene (Altosid®), tetrachlorvinphos (Rabon®) and diflubenzuron (Clarifly®).

11)   Internal Parasite Control*.  Three anthelmintics (dewormers) are available as feed additives.  Delivery of anthelmintics is advantageous when animal handling for direct delivery of dewormers is difficult.  As with other feed additives, effectiveness of anthelmintics delivered through feed depends on cattle consuming adequate quantities of the product.  Fed anthelmintics include fenbendazole (Safeguard®), levamisole hydrochloride (Tramisol®) and morantel tartarate (Rumatel®)

12)   Mycotoxin Binders.  The negative effects various mycotoxins have on cattle performance and health is well documented.  A number of products have shown effectiveness on binding of mycotoxins such as aflatoxin, vomitoxin, DON, etc.  However, the regulatory environment for these types of products in the United States is varied and often unclear.  The producer should discuss the options with a qualified nutritionist.

An important point: The product types and products themselves listed above and denoted with an “*” are subject to regulation by the FDA as well as other federal and state regulatory bodies.  These various products may only be used at approved levels, for approved applications and approved combinations to be considered legal.  If the producer desires to use one or more of these additives, it is strongly recommended to do so with the assistance of a qualified nutritionist.  This person can assist with proper product selection, formulation into supplements, feeding methodology, and so on.  Additionally, these products should be fed according to label guidelines in order to improve the likelihood of the desired responses.

Newer Options

With the regulatory and consumer pressure placed on the use of antibiotics and other “chemically-based” feed additives, other additives have been identified that have shown promise in enhancing animal performance (gain, health, reproduction, etc.).  Many of these products are microbially-based or have their origin in microbial fermentation. Many of these fall into the category of direct fed microbial (DFM).  In most cases, these products are only fed at rate of grams per head per day.

1)   Bacterial Cultures. Feeding of microbial cultures to beef cattle is not new.  A wide variety of bacteria are available for feeding and have shown to produce varying results including improved average daily gains and feed efficiency and reductions in ruminal upset (bloat, acidosis caused by excessive lactic acid production). These bacteria are available in freeze dried culture form or as a fermentation product which may or may not include live bacterial cells.  The most commonly fed DFMs are Lactobacillus acidophilus (and other Lactobacillus species), L. casei, Enterococcus diacetylactis, Propionibacterium freudenreichii, and Bacillus subtilis.  Much of the research in feeding bacteria has involved feeding lactobacillus-based DFMs to young calves fed milk, calves being weaned, or cattle shipped to the feedyard, since these conditions were often classified as times of high stress.

2)   Fungal DFMs.  While yeasts may also be considered a fungal product, they have been differentiated here for ease of discussion.  Fungal DFMs include products such as Aspergillus oryzae (AO) and Aspergillus Niger (AN), both of which have been used in a number of applications, largely to improve fiber digestion with some work showing that feeding OA to beef cows helped improve the digestion and subsequent nutrient availability when fed poorer quality forages.  Also, some research has shown the potential to increase average daily gain in feedlot cattle fed AO under certain circumstances, mainly due to an improvement in dry matter intake.  Other positive effects have included improved microbial protein yield from the rumen, increased lactic acid uptake (rumen pH stabilization), and increased volatile fatty acid production in the rumen (predominant source of energy for cattle).

3)   Mannan Oligosaccharides (MOS).  Mannan Oligosaccharide (MOS) is a molecular structure extracted from the cell walls of yeast.  The most common of these yeasts is Saccharomyces cerevisiae as discussed above.   The MOS works at the surface of the animal’s intestinal wall and is involved in interactions with the animal’s immune system, and, as result, enhances immune system activity.  They also play a role in animal antioxidant and antimutagenic (cell mutation) defense.  In some cases, this MOS attachment can aid with nutrient absorption.  In other situations, it can prevent pathogenic organisms from binding to the intestinal membranes where they can invade the body (competitive inhibition).  Finally, MOS can function to enhance the performance of the immune system.

4)   Beta-glucans. Beta (β)-glucans are major structural components of the cell wall of yeast, fungi and some cereals such as barley and oats.  β-Glucans are similar to and, in many cases, confused with MOS.  They are significantly different and function in the body differently.  Of these β-glucans, those from yeast cells are the most common.   β-glucans are known as “biological response modifiers” because of their ability to activate the immune system.  Research has shown beneficial effects on the stimulation of the immune system by compounds of microbial or plant origin, such as β-glucans, with the potential to minimize the incidence of disease in livestock.

5)   Enzymes.  Enzymes are protein molecules that catalyze specific chemical reactions.  The use of enzymes in the feeding industry is not new.  In most cases, feeding enzymes is believed to increase the rate and extent of digestion of certain nutrients.  Several digestive enzymes have been studied for use as additives to enhance animal performance with success in poultry and swine diets.  In cattle, enzyme feeding is thought to help in improving fiber digestion as well as that of other nutrients, such as protein, starch and other carbohydrates and fats, especially in the rumen.    Enzymes are commonly derived from the fermentation of bacteria, fungi, yeasts and other microbes.

Other feed additives that are used as nutritional tools include supplemental fats, minerals and a list of miscellaneous materials that have shown at least some response in certain situations.  Many of these products are effective in cattle production but can be variable and only create the responses under specific circumstances.

Conclusions

The cattle producer has a significant list of tools to enhance the performance of the animals in his care.  It is important to become familiar with these products and enlist appropriate advice in determining which can provide the greatest response, and, more importantly, return on investment in the herd.

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