Beef Cattle Mythbuster
Thinking Critically About Opportunities with Low-Quality Forages
Dr. Don Llewellyn Livestock Extension Specialist
Director, WSU Lincoln County Extension, Davenport, WA
I visit with a lot of producers. Often, the subject of our conversations came to the ever- increasing cost of feeding cattle. Essentially the producers are asking: How is it possible to reduce feed costs and still meet their production goals? It’s late summer so let’s start thinking about fall and winter feeding and get an early start preparing for that period in the cows’ annual production cycle.
Beef cattle possess the means to survive, and in many cases thrive on low-quality feeds. As ruminants they have the innate ability to utilize fibrous material to maintain, grow, lactate, and reproduce. For beef producers in the Pacific Northwest, grasses and legumes are predominate sources of forage, although other alternative forages have been investigated, but in most cases the alternate forages are of moderate to high quality. Forages come in many forms including rangeland and pastures (native and introduced species; irrigated and non-irrigated), harvested forages (hays and silages), stockpiled forages, and a host of crop residues (including corn stover, small grain straws, and residues from the grass seed industry). Included in the mix are the so-called roughages which are forages that are particularly high in fiber content.
From a nutritional standpoint, an understanding of the chemical composition of the forage will go a long way in assisting producers in making decisions about the relative value of their forage. That is why I typically recommend forage analysis. In total, a producer needs to know what he/she has before it is known what is needed! Emphasis must be placed on knowing the nutrient requirements of the particular class of beef cattle you are dealing with, understanding what is present in the forage (and if the requirements can be met), and to correct for any nutrient imbalances.
While forage analyses can provide a lot of information, if a producer focuses on a few chemical characteristics, it is possible to make good decisions about utilizing low-quality forages. When interpreting forage analysis of low-quality forages, focusing on crude protein (CP), and also the fibrous portion of the feed (neutral detergent fiber [NDF] and acid detergent fiber [ADF]), and antiquality components (i.e., lignin, cutin, silica) it will go a long way in assessing the capabilities of the forage. The negative relationships between NDF and intake, and ADF and digestibility are well established. This means that as NDF and ADF increase in the forage, intake and digestibility decrease, respectively. The antiquality components have beneficial protective and structural roles in plants but can exert negative effects on digestion and utilization of forage by beef cattle.
What constitutes low-quality forage? In general, research suggests that forages with a CP content of less than 7% should be considered low in quality (a dry, pregnant cow in the mid- gestation requires at least 7% CP in the diet). When feeding low-quality forages, protein is commonly regarded as the first-limiting nutrient. This means that when protein in forage is not present in sufficient quantities, maximizing beef cattle performance cannot occur even if all of the other essential nutrients are present in adequate amounts.
In grazing scenarios, facilitating nutrient intake to assist in meeting the nutrient requirements of beef cattle is challenging because of the ever-changing availability of nutrients within the forages as well as changing nutrient demand by the cattle. These changes are the result of both declining forage quality due to advancing maturity (i.e., from immature to full vegetative maturity) and from the point in the beef cattle production cycle at which the nutrient requirements are assessed (i.e., growing heifers, pregnant and lactating cows, dry and pregnant, etc.). While the nutrient content of stored forages may be somewhat stable, stimulation of rumen metabolism may still be required to optimize utilization (in other words, correcting for nutritional deficiencies).
A common misconception is that low-quality forages serve only as fillers. In the beef cattle world, the term filler is often used synonymously with roughages. If it were universally true that these feeds provided no nutritional value, wild ruminants would not be able to survive on forages of limited quality. Wild ruminants are highly adapted to their environs, but domesticated ruminants have the ability to perform on some pretty marginal feed as well. In a practical sense, the so called fillers are able to meet the nutritional requirements of beef cattle in varying degrees. For discussion purposes, let’s consider the difference between a high-quality feed such as alfalfa hay, and a low-quality feed like wheat straw. If the gross energy contained in both feeds is similar, why do cattle perform so differently on the two feeds? The all- encompassing answer is utilization. The main concern in effectively utilizing low-quality forages is being able to unlock as much potential nutritional value from the feed as possible.
Producers’ main focus in utilizing low-quality forages is to manage cattle to maximize intake of low-quality forages and to digest as much as possible of what they consume. Impediments to utilization of low-quality forages can be reflected by both insufficient nutrient content which can compromise intake, and as with the antiquality components, which are physical or chemical barriers to digestion. Both are related directly to the efficiency of the rumen microbial populations to reproduce and effectively digest the forage fiber. Although managing cattle to utilize low-quality forages may be straight-forward in theory, planning is central to practical application.
While low-quality forages may not be able to maintain cattle as the sole source of nutrition at various points in the beef cow production cycle, their use can certainly reduce the overall feed costs especially during phases in the production cycle when nutrient requirements of the cattle are low. The key point in utilizing low-quality forages is that producers need to know what the nutrient content of the forage is (i.e. forage analysis). Likewise, knowledge of beef cattle nutrient requirements is essential in determining which requirements are being met and which are not. The most comprehensive publication for nutrient requirements and feed composition is the National Research Council’s (NRC) Nutrient Requirements of Beef Cattle, Eighth Revised Edition, updated in 2016. It is available from the National Academy Press and I strongly encourage producers to add this publication to their resource library. Also, several applied nutrient balancers for beef cattle based on the NRC data are available for free use online (I’m happy to help you find a suitable ration balancer that you can run on your computer and provide assistance in how to run it). In total, this information will allow producers to correct for deficiencies that cannot be supplied by the available forage. Correcting for these deficiencies in low-quality forages will likely revolve around providing supplemental protein in order to stimulate the rumen microbes to efficiently digest forage fiber. I’m available to assist producers in gaining access to resource materials and programs, and to guide the design of management systems to optimize forage use.
Low-quality forages have great potential to supply nutrition to beef herds if managed effectively. The success of their utilization will depend upon whether producers are knowledgeable about the nutrients contained in their forages and their ability to determine if nutrient deficiencies exist and if so, to employ feeding and management strategies to correct for the deficiencies.
If you all have any questions or ideas that can result in an article, please share your thoughts.
Please let me know if I can assist you with your cattle, forages, and feed. Don Llewellyn, 509- 725-4171, don.llewellyn@wsu.edu