Cattle producers occasionally find themselves out of their "comfort zone" as they go into winter especially after a dry summer and fall. Many have marginal or inadequate forage supplies. However, others may find themselves with forage of unknown origin (because they justifiably felt the need to purchase whatever hay they could find) and therefore of unknown quality.

Perhaps the most frightening "unknown" about hay is the potential for nitrate accumulation in some hay crops. Johnsongrass, millets, forage sorghums, sudan hybrids may have been heat or drought stressed before harvest. Any of these plants when stressed can accumulate toxic levels of nitrate. Read more about this topic in OSU Fact Sheet F-2903 Nitrate Toxicity in Livestock available at any OSU County Extension Office.

Forage analysis can be a useful tool to remove some of the mystery concerning the hay that producers will feed during winter. Testing the grass hays for protein and energy content will help the producer design winter supplementation programs most appropriate for the forage supply that is available. Any of the potential nitrate accumulating hays should be tested for nitrate concentration.

There are several good methods of sampling hay for forage analysis. Most nutritionists would prefer to use a mechanical coring probe made specifically for this purpose. The coring probe is usually a stainless steel tube with a serrated, cutting edge. It is 1 inch in diameter and is designed to fit on a 1/2 inch drill or brace. Cordless drills make these tools quite mobile so that the hay bales to be tested do not have to be hauled to be near an electrical outlet. The hay samples are placed in paper or plastic bags for transfer to a forage testing laboratory. Cores are taken from several bales at random to obtain a representative sample to be analyzed.

Grab samples can also be obtained and tested. To receive the best information, grab several samples by hand from about 6 inches into the open side of the bale or the middle third of a small round bale. Place all of the sample in the bag. Do not discard weeds or stems, just because they look undesirable. They are still part of the hay that you are offering to the livestock. Be certain to label the forage samples accurately and immediately, in order for the laboratory analysis to be correctly assigned to the proper hay piles or bales. Obviously the more samples that are sent to the laboratory for analysis, the more information can be gained. Just as obvious is the fact that as the number of samples increase, the cost of forage testing increases.

Samples can be taken to the OSU County Extension office near you and then sent to the OSU Soil, Water, and Forage Testing laboratory in Agricultural Hall on the campus at Stillwater. There are other commercial laboratories available in the midwest that also do an excellent job of forage analysis.

Producers may notice some hay has mold. All homegrown feeds contain some fungal spores. When the temperature and humidity are right, these spores will grow and multiply to create mold. Mycotoxins come from these fungal molds and can reduce animal health and productivity.

Many molds found in feeds are not toxic, but some varieties produce substances that can result in disease when they are ingested. Of the thousands of molds that grow on stored grains and forages, only a few will produce mycotoxins. Producers that find moldy hay or have concerns about mycotoxins in forages should take hay samples to their local veterinarian. These samples then can be forwarded to the Oklahoma Animal Disease Diagnostic Laboratory in Stillwater for mycotoxin analysis and appropriate recommendations.