Winter feeding costs are usually the most expensive component of annual costs in a cow-calf operation. Hay feeding is commonly used and provides a viable source of nutrients when pasture growth is typically slow or dormant during the winter months. When it comes to surviving the current drought, however, managing hay costs is especially important. One key to success is knowing the quality of hay being bought, sold or used and the cost of alternative feed sources. Hay should be sampled and nutritive value determined prior to its use in the cattle operation.
Estimating Hay Value Based on Chemical Analysis is decision tool that estimates the economic value of a hay sample based on its percent total digestible nutrients (TDN) and crude protein (CP) content (a link to free download instructions is in the Summary paragraph). The value of energy and protein in the hay sample is calculated based on TDN replacement cost from an energy source such as corn and CP replacement cost from an alternative source such as cottonseed meal.
A chemical analysis for TDN and CP for base alfalfa hay and alternative prairie hay are entered in the example shown; thus, a low quality prairie hay sample is contrasted with higher quality alfalfa hay (Figure 1). An alternative energy concentrate source such as corn along with its market price, % DM (percent dry matter), CP % DM (percent crude protein on a dry matter basis) and TDN % DM (percent total digestible nutrients on a dry matter basis) are also entered. The same data inputs are specified for a crude protein concentrate source such as cottonseed meal.
The analysis value of the alfalfa hay ($217.96) and sample prairie hay ($133.08) is calculated by computing the pounds and value of both the replacement TDN source (corn) and the replacement source of crude protein (cottonseed meal) necessary to replace the pounds of TDN and CP in a ton of hay. It is important to note that the values do not account for differences in the efficiency of protein or energy utilization between hay of various qualities or between primary hay replacement sources of TDN or crude protein. However, the analysis does provide a more realistic comparison between the two alternatives given the adjustments based on the calculated values of crude protein and TDN. In addition, an estimated market price for prairie hay is provided ($105.12 per ton) which illustrates its value in a comparative sense to the known alfalfa market price.
When the situation does arise where nutrient deficiencies exist and a critical nutrient such as protein should be supplemented, a lower priced harvested forage may not turn out to be much of a bargain nutrient–wise. The graph shown in Figure 2 illustrates that important point. In this example, low quality prairie hay translates into protein costs of $1.31 per pound whereas alfalfa provides a more economical source of protein at $.48. Cottonseed at $370 per ton and 48% CP is even less expensive at $.39 per pound. Of course, these costs ultimately depend on storage and feeding losses which can be significant.
One of the keys to managing hay costs is knowing forage quality and the relative cost of alternative feed sources. This is especially true when hay supplies are tight and expensive. Estimating Hay Value Based on Chemical Analysis, a free spreadsheet from the Agricultural Extension website http://www.agecon.okstate.edu/extension/, is a decision tool designed to provide a rapid method for determining the economic value of a feed sample based on its basic nutrient content. Nutritional feed value is determined by nutrient concentration and nutrient digestibility. Oklahoma State University’s Beef Cattle Manual (Table 12.1, page 115) contains average nutrient concentration values for numerous feeds that are common in Oklahoma. Values in the table represent averages from numerous sources, such as the National Research Council’s Nutrient Requirements of Beef and Dairy Cattle publications, commercial laboratories, research trials, and other publications. Beef magazine also publishes a Feed Composition Guide that is updated annually.
Values published in any table are typical averages and variation among grains, oilseeds, byproducts, and in particular forages and roughages can be extreme. Furthermore, various processing methods may also alter the digestibility. For this reason, producers are advised that feeds and forage testing for nutrient composition by commercial laboratory is valuable.
Source: Roger Sahs, OSU Extension Specialist