To obtain improved yields and forage quality goals must be set. Routine forage testing, involvement in the Indiana Forage council, and participation in forage quality contests can help in setting these goals. To make the greatest improvements in dairy profitably, sample and test the forages you are feeding this year and set a goal for the next cutting and for next year. Good stands and management of alfalfa and legume grass mixtures are critical to obtaining quality hay and hay crop silage.

The forage test most commonly used in marketing hay and judging quality of forages by dairy farmers is protein percent. This if considered alone, can be deceiving as an estimate of a forage's milk producing potential. Fiber level of the forage is another quality measurement which should be considered. Acid detergent fiber (ADF) is the measure which is most closely related to the forages digestibility. This is extremely important in gauging the total amount of energy that will be available to the cow. Neutral detergent fiber (NDF) is more closely related to dry matter intake (DMI) of forages than is ADF. Neutral detergent fiber is a measure of the total cell wall content of a forage. The concept that this represent the "space occupying" characteristic of a feed which limits dry matter intake of dairy diets has been questioned by recent research at several universities. Animal factors such as body weight change, milk yield, and stage of lactation have been shown to modify the dairy cow’s intake of forage NDF. Judging a forage's quality by either its ADF or NDF content alone can be as misleading as looking only at protein content.

Combining the results of several tests is the best approach. Some dairy producer’s goal is to produce an alfalfa hay or silage that is 20% crude protein, 30% ADF, 40% NDF,  a "20-30-40" forage. This kind of forage (fed with or with out corn silage) has been shown in many trials to support high levels of feed intake and milk production when fed with a grain mix designed to balance the total diet to meet nutrient requirements. Forage of this quality can not be produced from a hay crop that contains much grass, regardless of its maturity. Grass contains a much higher ratio of NDF to ADF to CP than does alfalfa. Hay containing grass and legumes can be used in rations for high producing cows but adjustments in the amount of grain and protein supplement will have to be made based on forage test results.

The question that many farmers who produce quality alfalfa ask is how much of this forage can be fed? 50%, 60%, even 80% of the ration? This topic has been addressed by a series of research trials conducted at the USDA Dairy Forage Research Center and the University of Wisconsin. In one study rations of 55% up to 86% immature alfalfa hay crop silage were fed to high producing cows in early lactation. In this study all rations used alfalfa silage cut at a early vegetative stage of maturity as the sole forage source and were balanced to contain 21.5% CP. Results are shown in the table below.

These results show that even with the use of alfalfa cut at the early vegetative stage of maturity, milk production and dry matter intake were reduced when grain was replaced by too much forage. Several recent studies at the USDA Forage Research center have shown that the addition of roasted soy bean meal or whole roasted soy beans as a "by-pass" protein source can boost milk yield of cows on high forage rations. This is true even when early vegetative alfalfa, over 20% crude protein, is the only forage. The "by-pass" protein value of alfalfa is low, only about 18 to 25 %. Because of this, the addition of protein which escapes breakdown in the rumen (undegraded or "by-pass" protein) can increase the amount of total protein and essential amino acids presented to the small intestine for absorption. The research answering all the questions about optimum ration degradable and undegadable protein content and the high producing cow's amino acid requirements are still being developed. Supplying the cow with highly digestible forage can optimize rumen microbial protein production helping the lactating cow meet amino acid requirements for milk production.

In summery from a practical stand point Indiana dairy producers can use forage testing to set goals in the area of forage quality. The single most important factor  in improving forage test results is cutting at an early stage of maturity. As the old saying goes, "Garbage in garbage out". You can not improve the nutritional value of a feed during drying or by method of storage above what was originally present in the field. A second critical benefit to forage testing is that it allows the balancing of the dairy ration for multiple components. These include crude protein, net energy of lactation, minerals, and a minimum fiber content to maintain rumen function and milk fat test. At this time accurate tests for rumen degradable and undegradeable "by-pass"protein are not available. There is a substantial body of evidence that suggests that especially when feeding high forage diets, addition of a high "by-pass" protein supplement will increase milk yield during early lactation.