Read the current Progressive Forage digital edition

Transitioning forage production and livestock feeding programs to non-GMO

Joe Lawrence for Progressive Forage Published on 29 November 2018
Chopping corn

The continued market pressure on agricultural commodities has farmers and food processors looking for ways to differentiate their products.

This includes farmers being asked to consider the production of crops without the use of genetically modified organisms (GMO), or more accurately, genetically engineered (GE). This request is from companies wishing to market both the crops and products (notably milk and meat) derived from feeding the crops as non-GMO.

This is a marketing option that seems to be gaining momentum despite the lack of peer-reviewed evidence that the presence of GE crops in livestock feeding programs have resulted in any health or safety concerns in the animal or human food chain since their commercial release in 1996.

Forage growers and livestock producers being asked to forfeit a valuable management tool, such as GE crops, should consider a number of potential impacts on their business, from production changes to market access. There are real concerns about the negative impacts these marketing strategies have on consumer confidence. Like many decisions in agriculture, the best decision at the farm (micro) level today can have negative impacts at the macro level later on.

Most of the GE technology has been focused on row crops, but they also have an impact on forages and, more broadly, on livestock feeding programs. Corn silage is considered an important source of forage on many farms, and livestock feeding programs often rely on purchased feeds to supplement diets.

The high percentage of acreage growing major feed commodities such as corn, soybeans, cotton and canola at the national level assures that feed ingredients derived from GE crops are very common on any dairy or livestock farm that is not actively working to exclude them (see Table 1).

Genetically engineeredAdditionally, the advancements in GE alfalfa traits (herbicide tolerance and low lignin) are of growing interest in perennial forages.

Non-GMO standard compliance

In the absence of a common standard for what constitutes a non-GMO food in the U.S., there are a myriad of non-GMO standards and labels on the grocery store shelf. Producers exploring non-GMO markets need to work closely with the entity that will purchase their products to ensure that their cropping system and feeding program is in compliance with the specific set of non-GMO standards the buyer is following.

This communication should start at the earliest stages of planning to help guide seed purchasing, crop and feed management decisions. Failure to communicate and plan in advance may result in a final product (grain, forage, milk, meat) that is not marketable as non-GMO.

With many food companies opting to work with third party verifiers (such as the Non-GMO Verified Project) for their certification, record-keeping requirements are crucial and often quite involved for both crops produced on the farm and purchased feeds.

Crop management

Growers have and can continue to manage crops without GE technology; however, this ignores the fact that the most sustainable cropping programs are realized when producers have access to, and properly utilize, all available management tools. The loss of currently available tools creates a void in the toolbox that may expose a crop production program to increased variability in yields, production cost and environmental impact.

The loss of GE tools may require a return to the use of older, often less desirable tools. These include certain families of pesticides and intensive tillage, which has fallen out of favor as growers have put a greater emphasis on conservation and soil health. For livestock producers who need to ensure adequate feed inventories for their herd, additional acreage may be needed to compensate for increased seasonal production volatility.

Strategic planning will be needed to compensate for the absence of GE tools. Each farm will need to carefully evaluate the expected impacts, both on field production and economics, specific to their operation.

Pest management

In the absence of herbicide-tolerant row crops, growers will need to rely heavily on a well-planned pre-emergence herbicide program to minimize the impact of weeds. This will necessitate a greater understanding of specific weed populations in each field to customize the pre-program for the weeds present.

While post-emergence products exist for control of emerged weeds in non-herbicide-tolerant crops, their cost, specificity and window of effectiveness are all highly variable relative to the options present in herbicide-tolerant crops. Rotation restrictions on these herbicides will also need to be considered in planning forage crop rotations.

The control of key insect pests in the absence of Bt traits (Bacillus thuringiensis) will require an emphasis on short crop rotations and an increased reliance on insecticides, including application through the planter, which may necessitate additional application equipment.

Post-emergence control measures may involve additional passes over the field and may require specialized high-clearance spray equipment. Farm owners and employees may need to hold pesticide application licenses in their state to legally apply insecticides, applied through the planter or by spray equipment.

Managing crops to reduce pollen drift

There are two points where genetic drift can be a concern for achieving compliance with non-GMO crop production standards.

First, many non-GMO standards require the use of non-GMO certified seed. Therefore, seed growers and seed retailers need to manage pollen drift in order to produce seed that can be sold as non-GMO.

Second, growers need to ensure crops grown on-farm or purchased are not pollinated by GE crops.

Two major livestock feeds, alfalfa and soybeans, are of little concern. Alfalfa harvested for forage should be harvested in the vegetative stage, and soybeans are largely self-pollinated.

Corn is the crop of major concern for pollen drift, and given that one pollen pollinates one kernel, the risk of contamination on a percent of weight basis is greater for grain than it is for whole-plant silage.

Given the nature of pollen drift from one cornfield to another, there is no practice that will ensure zero pollen drift; however, there are some general guidelines that can significantly reduce the chances of non-GE corn being pollinated by pollen from a GE field.

Utilizing the buffer guidelines for certified seed production can be effective; these can be found from state and federal agencies. Communication with neighbors on crops planted in nearby fields and temporal separation of the fields are important. Corn silks emerge a couple of days prior to local pollen shed, creating the most likely window for pollination from outside pollen, if neighboring fields are at a more advanced stage.


The ability of farmers to produce crops for non-GE markets is feasible with the economic and environmental outcomes of doing so highly tied to specific growing conditions, which will vary by farm and growing season.

Producers considering this production system should recognize the added planning, management and record keeping required, the chances of increased variability in crop performance and cost, and the broader implications these decisions may have on access to these technologies in the future of food production.

A list of field crops relevant to dairy production and the corresponding traits derived from conventional and GE techniques was developed for a PRO-DAIRY forage management factsheet (Table 1).  end mark

PHOTO: Demand for non-GE crops, and lack of standardization in non-GMO labeling, may impact access to GE technologies in the future. Photo by Lynn Jaynes.

Joe Lawrence
  • Joe Lawrence

  • Dairy Forage Systems Specialist
  • Cornell University
  • Email Joe Lawrence