Virginia Ishler Livestock & Environment

The phrase “best management practices” is used frequently when discussing how producers work their fields, plant their crops, apply manure and feed their animals.

There is a lot of effort right now in documenting the best management practices that have been implemented in the Chesapeake Bay watershed.

The objective is to more accurately identify the nutrient loads for nitrogen, phosphorus and sediment that are not finding their way into surface waters.

It makes good business sense to implement practices that keep nutrients where they belong. Farming is one big revolving cycle, and BMPs in all areas are critical control points, even feed management.

Pennsylvania has had one of the more successful feed management programs in the United States through USDA’s Natural Resources Conservation Service.

But the producers who decided to take advantage of this program are not the only dairy or beef farmers who are implementing feed management or precision feeding successfully.

People outside our industry who are not familiar with livestock feeding think that having a nutritionist means a farm is implementing precision feeding.

Anyone in the nutrition business knows this is not the case. Many variables — planned and unplanned — can occur between the formulated ration and what the cow actually consumes.

Many nutritionists have been refining their approach to protein and phosphorus feeding. Producers know the value of precision feeding, and the benefits to their cows and profit margins.

However, a disconnect remains with some producers who are reluctant to change their approach to formulating rations to account for protein and phosphorus.

In 2009, I conducted a project with producers where we evaluated dairy herds for production, dry matter intake, and protein and phosphorus content in the ration.

Back then, the one missing piece was the tie to economics. Currently, the Extension dairy business management team is conducting an intensive project evaluating cropping practices, feeding management and economics.

With the data collected to date, 2009-2015, the level of phosphorus in lactating cows’ diets is remaining fairly consistent at 0.38 percent on average on a dry matter basis.

The protein content of the analyzed total mixed rations has dropped from 16.9 percent in 2009 to 15.7 percent in 2015 on a dry matter basis with average milk production rising from 73.9 to 74.3 pounds.

I think producers in our industry for the most part are on the same page regarding lactating cows. Some of the problems are with dry cows and the phosphorus levels being formulated.

For 12 years, I formulated the rations for the Penn State dairy herd. The phosphorus levels in the dry cow rations ranged between 40 and 54 grams, or 0.27 to 0.36 percent on a dry matter basis.

No phosphorus was ever added to the rations, and the range mostly reflected the forages being fed at a particular time.

Minimal health and metabolic problems occurred, and those were the result of implementing precision feeding and focusing on feeding management.

Recently, I’ve heard that phosphorus is being fed at 60 to 70 grams per day to dry cows. This can be a contentious issue amongst nutritionists, but I have seen too many successes at lower levels not to wonder why we are taking several steps backward.

Water quality concerns are not going away and if anything will probably continue to be a hot topic for many years to come.

It is in our industry’s best interest not to become complacent and to ensure we are in a proactive rather than reactive position.

Virginia “Ginny” Ishler is a nutrient management specialist and manager of Penn State University’s dairy complex.


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