Focus on Feed Safety: Labeling of Free Choice Feeds

This quarter’s ‘Focus on Feed Safety’ provides labeling recommendations and special considerations for the hazard analysis of free choice feeds.

Free choice is a feeding system by which animals are given unlimited access to supplemental feed such as loose minerals, blocks, and liquid tubs.  For many operations in California, free choice supplementation is necessary to provide essential minerals, vitamins, and/or protein to ruminant livestock grazing seasonal forage. It is well known that over consumption of free choice supplementation may lead to toxicity, illness, and death in grazing animals.

Guidance materials from the Safe Animal Feed Education (SAFE) Program are provided for educational purposes only and do not guarantee adequacy of procedures or compliance with regulations.

Labeling

Feed labels are crucial to communicate intended use and warnings to the end-user and may help to prevent unsafe over consumption of free choice feeds.  SAFE recommends the following when labeling free choice feeds:

• A purpose statement which describes the intended use of the feed, including:
  • Species and animal class.
  • The words “free choice.” 
• Adequate directions for use including:
  • The intended consumption rate per head per day, or equivalent (i.e., a weekly consumption rate per 10 head).
• • To stop feeding if consumption exceeds a level that is safe.
• • A precautionary statement including the risks of feeding starved or debilitated animals, and/or suggestions for an adjustment period.
• If there are any hazards associated with free choice feed formulation it is recommended that the label have a warning statement in prominent bold type, for example: WARNING: EXCESSIVE CONSUMPTION MAY RESULT IN ADVERSE TOXIC REACTION. USE ONLY AS DIRECTED.

Hazard Analysis Considerations

The consumption rate of free choice feeds is typically controlled by the level of salt and/or phosphorus in the formulation. However, it is well known that the actual consumption rate of free choice feeds varies depending on the interaction between the formulation, the animal’s nutrient demands, and availability of seasonal forage. The hazard analysis should evaluate toxicity due to unsafe consumption levels of free choice feeds with heightened likelihood of occurrence, especially when the formulation includes, but is not limited to, the following: 

• Source of Protein and/or Energy: Over consumption is likely to occur when a free choice formula includes protein and/or energy, and animals have limited forage availability. Hungry animals can easily exceed the expected intake of salt and phosphorous to meet their protein or energy needs, potentially resulting in toxic levels of other components of the formula.
• Minerals: Too much of any mineral can be toxic. However, copper, selenium, molybdenum, sodium chloride, and sulfur are ranked as “high” concern for animal health by the National Research Council “Mineral Tolerances of Animals” (2005), and sensitivity varies by species.
  • Selenium is regulated under 21 CFR 573.920 to not exceed the following in salt-mineral mixtures for free choice feeding:
    • Sheep: Up to 90 parts per million in a mixture for free choice feeding at a rate not to exceed an intake of 0.7 milligrams per head per day.
    • Beef cattle: Up to 120 parts per million in a mixture for free choice feeding at a rate not to exceed an intake of 3 milligrams per head per day.
• Non-Protein Nitrogen (NPN): Ruminants are most sensitive to developing NPN toxicosis. Liquid molasses, large protein blocks, range cubes, or improperly maintained lick tanks may lead to consumption of lethal amounts of NPN (Merck Veterinary Manual).
• Medicated Feed: The specific formulation of any medicated free choice feed must be approved by the United States Food and Drug Administration (U.S. FDA) (21 CFR 510.455).
• Custom Formula Feeds: It is the feed manufacturer’s responsibility to verify the formulation is not likely to result in nutrient deficiency or toxicity, even with custom formulations provided by the customer. With free choice feeds, this includes consideration that formulation and labeling is not likely to result in unsafe over consumption.