Balancing Nutrition with Environmental Stewardship

Gone are the days when one could simply balance a dairy ration with no-holds-barred milk production as the primary goal. Today, the waste that comes out of a cow, and how it is managed, is equally as important as nutrients going in.

According to Michel Etchebarne, PhD, consulting dairy nutritionist based in Modesto, Calif., environmental concerns regarding animal waste are no longer a “California-only” problem. “We may have a head start, but now livestock producers throughout the West, and most of the rest of the country, are faced with the dual challenge of efficiently feeding animals, and utilizing manure byproducts in an environmentally responsible manner,” he says.

Fortunately, the two factors are not entirely at odds with one another. To the contrary, Cornell University professor of animal science Larry Chase, PhD, says that formulating dairy rations close to requirements, with minimal safety factor, can both decrease environmental overloading with nitrogen and other nutrients, and promote efficient use of nutrients in dairy cattle. “It used to be common to feed higher-than-necessary protein levels in the quest for higher milk production,” says Chase. “We have now learned that protein levels can be reduced without affecting cow performance. The result is less nitrogen to manage in manure, plus cost savings in feedstuffs.”

Maximizing input, minimizing output
Chase notes that protein is typically the most expensive component of the purchased feeds used in dairy rations. “It is important to remember that dairy cows do not have a protein requirement,” he advises. “They really need amino acids available in the small intestine to support tissue growth and milk production. But how the desirable level of amino acids is achieved can vary greatly among feed inputs, with some resulting in considerably lower levels of nitrogen excretion than others.”

Etchebarne says a key method of promoting nitrogen efficiency is via production feeding. “It remains common practice in our industry to feed all lactating cows one ration,” he says. “But an early lactation animal’s nutritional requirements are quite different than those of her herdmates in later lactation. The same applies for replacement heifers. Indiscriminant nitrogen feeding serves as a potential nitrogen pollutant and an unnecessary feeding expense.”

Microbial protein can provide 50 to 80 percent of the amino acids required in the intestine by the dairy cow. Chase says optimizing microbial protein helps increase the efficiency of nitrogen use in the cow, and control feed costs. To achieve optimum levels of microbial protein in the ration, he suggests using a metabolizable protein system (versus the more common crude protein model) to evaluate and balance rations. “This system better fits the biology of the cow,” he states. “The challenge is that it is not tabular, and requires the use of computer programs to calculate both metabolizable protein requirements, and the metabolizable protein supplied by feeds and microbial protein. But I believe it is worth the extra effort to employ this approach, in terms of both improving the efficiency of protein use in dairy cattle, and decreasing both nitrogen excretion and ammonia emissions.”

What about phosphorus?
The ethanol boom in the Midwest has created a sudden abundance of distiller’s grains available for feedstuffs. One concern associated with this shift in nutrient sources is the potential for overloading the environment with excess phosphorus. For both Chase and Etchebarne, feeding distiller’s grains is not a new concept.

“We’ve fed distiller’s grains in the Northeast for more than 100 years, mostly as co-products from the liquor distilling industry,” says Chase. “Whether or not phosphorus becomes a problem depends on what you’re replacing with distiller’s grains. If it’s soybean meal, the increase is relatively small. Replacing canola meal actually will cause the phosphorus load to go down. But substituting for corn grain will cause the phosphorus levels to go up, and will limit the amount of distiller’s you can use.”

Etchebarne says more work is needed to quantitatively assess the impact of excess phosphorus, if any. “Only when specific phosphorus concentrations are defined and means of accurately monitoring and enforcing these levels are established, will the questions about phosphorus be fully answered.”

Environmental Regulations are Spurring Industry Changes

By Michel A. Etchebarne, PhD. Consulting Dairy Nutritionist, Modesto, Calif.

The direct relationship between nutrition, and its potential negative consequences when nutrients are excessively fed, continues to gain greater attention from dairy producers in the West. This level of interest is due largely to new laws designed to enforce nutrient management practices that aid in the reduction of specific-element waste disposal and potential environmental pollutants.

The most successful nutrient managers are also the most sensitive to environmental compliance. They explore all measures that enable both nutrient conservation and safe, efficient disposal. These producers start by actually feeding their animals based on production requirements, then follow up with careful management of solids extraction, storage, and determining land and crop-use management.

California also is undergoing a very rigorous air-quality control program. For example, the air quality districts require dairy operations in the San Joaquin Valley to control air emissions and renegade dust. Air pollution permits now are required and conservation management plans (CMPs) for controlling particulate matter and dust also must be filed. While additional regulations are typically not welcome in any business, the upside is that a spirit of cooperation and collectivity has emerged in our state’s dairy industry as a result. Incentives for replacing fuel-driven pumps with electric units are available from local power companies. The California Cooperative Extension service and several dairy organizations also are working together to help dairy producers meet the requirements imposed.

A more team-based approach between dairy producers, nutritionists and agronomists can prove beneficial to all. Recently, the agronomist working with one of my long-term dairy clients experienced a cropping issue regarding a specific nutrient concentration. Working together, the three of us were able to address the issue by utilizing new technology to monitor, predict and manage nutrient flows. We all learned something in the process, and I think we all are now doing a better job for the dairy as a result.

The era for collaborative planning has arrived. With new, stringent nutrient management laws coming into play, integrated management and communication will be prerequisites for everyone responsible for determining nutrient requirements and their subsequent disposal.

What is the Best Age to Freshen Heifers?

Calving heifers and placing them in the milking string provides their first opportunity to contribute positively to a dairy’s bottom line.

Getting them there as quickly as possible would be a logical goal. But if that accelerated trip to the milking parlor results in a poor-quality animal with calving problems and substandard milk production, the net effect to the dairy could be a negative one.

The Bovine Alliance on Management and Nutrition (BAMN) examines the issue of ideal heifer development in a new publication, “Heifer Growth and Economics: Target Growth.”

Using the Target Growth model, nutritional requirements are linked to an animal’s rate of gain and current body size relative to mature size. Its steps include:

1) Determine mature body weight of cows in herd (by breed).

2) Multiply mature weight by 0.82 to determine target weight after first calving.

3) Set calving age target.

4) Multiply mature weight by 0.55 to determine target weight at breeding.

5) Set target age at breeding (nine months less than target age at calving).

6) Develop nutrition and management program to achieve desired targets for breeding age and weights.

The authors note that heifers have the greatest capacity for frame growth in their first six months of life, so focusing on early nutrition to support the desired rate and composition of body weight gain is important. To do so, more expensive rations may be called for in younger heifers. If the number of total pre-freshening days on feed is reduced, the overall cost of raising replacements may not change significantly.

To read more about nutrient requirements and ration formulation using the Target Growth model, click here (PDF format).

Monitoring NDF Digestibility

Evaluating forages for neutral detergent fiber (NDF) digestibility is becoming a more widespread practice among forage-analysis laboratories. University of Wisconsin Extension Dairy Scientist Patrick Hoffman cites three reasons why monitoring NDF digestibility, and not just content, is of value in selecting feedstuffs and formulating lactating dairy rations:

(1) Research has demonstrated that lactating dairy cows will eat more dry matter and produce more milk when fed forages that have higher NDF digestibility.

(2) While lignin and acid detergent fiber (ADF) have been used in the past to estimate potential NDF digestibility and total forage digestibility, recent research has demonstrated that these factors alone do not account for all the variation in NDF digestibility.

(3) Forage digestibility is calculated in the 2001 NRC requirements using a summative approach where energy contributed from protein, fat, non-fiber carbohydrate (NFC) and NDF are summed. An NDF digestibility value is required to use this forage-evaluation method.

Hoffman notes that there are a few variations in how NDF digestibility assessment is performed. The NRC-recommended method is a 48-hour in vitro incubation in rumen fluid, but 30 or 24-hour incubations can be used as long as the user understands the effects of shortening the incubation time on NDF digestibility values.

“It is important to remember that total NDF forage content still is a dominant factor in determining overall forage quality,” says Hoffman. “For example, a forage that contains 40 percent NDF is generally of higher quality than a forage that contains 60 percent NDF.”

He adds, however, that at the next level, NDF digestibility impacts total forage digestibility, and potentially subsequent milk production. As an example, he presents the following scenario:

“In older forage evaluation systems, both forages were viewed as being identical,” says Hoffman. “But when NDF digestibility is taken into account, dairy cows would consume more dry matter from forage #1 because higher forage NDF digestibility has been demonstrated to improve dry-matter intake. That additional dry-matter intake could result in five pounds per cow per day of increased milk yield.”

See Figure 1 for a comparison of NDF digestibility among common forage species. Growing conditions can have a major influence, with cooler conditions in the northern latitudes favoring higher NDF digestibility.

As part of our SoyChlor quality control we have wet chemical analyses done several times each week. The results for January are listed below. We are proud to say that with changes in our plant instituted in June and July 2007, issues with discolored SoyChlor or SoyChlor that heats up upon delivery have not occurred since July 2007. We will strive to keep it that way!

SOYCHLOR Shortens Its Name

Beginning in February, you may have noticed a name change to SoyChlor^® 16-7. West Central is pleased to announce the shortening of the product’s name to SoyChlor.

In the past there have been several different variations on the SoyChlor product, each having its own specific name based on the protein level and chloride content of the product. As SoyChlor production and use has evolved, West Central has refined the manufacturing to a single higher chloride product. SoyChlor is guaranteed to contain a minimum of 21% protein and 8.85% chloride. For this reason, the name of the product you’ve come to know and trust will be shortened to SoyChlor.