The tighter we program herd diets, the more important is the information on which feed programs are based.
By Jim Peck
Tighter economic conditions keep us looking at feed cost as one of the ways to control the cost of milk production.
Working with reduced input standards for protein, minerals and other ration factors offer both economic and environmental benefits. On one hand they offer opportunities, on the other hand, they represent an increased risk of reduced performance.
The conventional management strategy was to be sure there was sufficient allowance, called a safety factor, to cover any nutritional shortfall. However, that may be too expensive under current conditions. The challenge is to identify and manage those areas of risk that can cause less than optimum performance.
It starts with knowing with a reasonable degree of certainty the feed value of all the ingredients of your cow’s diets. Just analyzing the feeds is not enough. We need to have feedstuff analysis that truly reflects the feed that our livestock consume.
In the past few years, there have been several studies and applied experiences to better understand how important sampling protocols and appropriate analysis are in developing relatively accurate information on forages for use in developing tighter rations. The bottom line is one feed analysis of a given feed is seldom of much more value than traditional book values.
Sampling forages is the biggest challenge. Bunk storages, upright silos, and bags all require different approaches to sampling. Bunk storages which are filled horizontally would tend to average the load by load or field by field differences. The sampling of bunks should include three or more samples from the bunk face within a week to establish a base line and then regular weekly sampling to monitor those silages. A rolling average of recent analysis is the best practice.
Uprights and bags tend to maintain variations making it much more difficult to manage the predictions of what is to be fed. For uprights and bags, sampling as harvested and then monitoring as fed out is the best available strategy. Even then it becomes more about what was fed then about predicting what is coming up to be fed.
Using NIR technology for analysis of routine forages is appropriate. However, special feeds and unusual circumstances should be done with wet chemistry. Constant and consistent checking of the forage dry matter by Koster Tester or microwave is fundamentally important.
Hays, straw and other dry forages require some special thinking about potential variation and sampling. In reality every bale is different, core sampling of multiple bales and a rolling average of analysis from large lots is the best protocol.
A single sample is statistically a poor bet. Because of their high dry matter content, even a few pounds in a diet are important.
Dry ingredients such as soybean oil meal, distiller’s grains, and cottonseed products are much more consistent. There may be variations between suppliers or processors, but they tend to be consistent. Enough sampling should be done to establish a base line and then feeds need to be monitored.
Grains such as corn, barley and whole soybeans are also more consistent and monitoring them to compare with standard values usually is sufficient. Remember that ingredients that make up larger portions of the diets should be analyzed and monitored more frequently.
Sampling and analyzing the TMR from the mixer or at the feed bunk would seem to be a good practice. Reality is, it is difficult to get good, consistent samples and a single sample may be misleading in terms of the nutrient accuracy of the mix.
Sampling at multiple points in the feed bunk and from multiple mixes, if possible, is the best protocol. Using wet chemistry on TMRs to account for the mineral content is very important.
The bottom line is the tighter we program our diets, the more important is the information that we base the programs on.
Sample and analyze often and understand how to evaluate and use the results to minimize the risks.