Overview

New things have a way of unsettling us. This is especially true when we've worked with something for a number of years and have gotten comfortable with it. We have a natural resistance to anything that would attempt to replace what we've grown to feel is dependable - something we know how to "drive".

Nothing could be more true of dairy ration software.

Every new thing, simply by virtue of being new, has an associated learning curve. The NRC 2001 model is no exception. Its methods are markedly different from NRC 1989 in many respects including how maintenance level digestibilities net energy values are determined.

However, NRC 2001 has a great deal to offer. It significantly advances the initial effort toward refining our ability to address ruminant protein nutrition taken by the 1989 model. For this reason, if for no other, it offers us the opportunity to move forward in a substantial way. For any dairy ration software to remain relevant, its development must incorporate what NRC 2001 offers us.

Finding Commonality

One of the obstacles that faces us when we consider moving to the NRC 2001 model is finding points of commonality. Both the 1989 and 2001 models express energy for lactation as NE(l) and baseline digestibilities as TDN but the table values we look at for a given feed are not the same between the two models.

A great many words could be written to explain differences between the models. It is not our intent to do so.

Formulate2 is ration software that has been configured to help bridge the "model gap" by providing you with the capability to constrain and work with both models simultaneously in a single ration record. Doing so is perhaps the most efficient and direct method of getting to know NRC 2001 and settling into the driver's seat.

The NRC 1989 mineral requirement equations are incorporated into Formulate2 and are used to generate the total basis mineral requirements. The balance of the 1989 prediction equations are not implemented but feed records have fields for 1989 NE(l), UIP and DIP coefficients and ration records have constraint fields for these same items.

You may constrain these NRC 1989 values along with the NRC 2001 values to produce a solution based on both. This provides you an opportunity to see in "real time" how the two models relate to one another.

Since all ration analysis is done with NRC 2001 you also have the opportunity to see how 1989 items are evaluated by the new model.

Feed Table Differences

While the feed tables of the two models have many items in common there are differences even with feeds that share a common name or description but not a common international ID. We have attempted to provided values for NRC 1989 NE(l), UIP and DIP where there was a clear correspondence of items between model tables. And in some cases where a feed stuff is widely used, such as corn, we have used names and descriptions only as a basis for supplying NE(l) values. Other feeds have no 1989 NE(l) values. In such instances you will have to supply the 1989 NE(l) values you wish to use.

Providing UIP and DIP values was even less straight forward since the list of feed items for which these values are provided in the NRC 1989 publication is rather limited. Consequently, not all feeds have UIP/DIP values. As a result, if UIP/DIP values are not present in a given feed record you will have to supply the values you wish to use.

Of course, you are free to supply or revise any value you wish and it is expected that you will do so. In providing what we have, we did not wish to stray too far from the printed data - that is your domain. Our objective has been simply to provide you the ability to use NRC 1989 values along side NRC 2001 values.