Tail Biting in Pigs

Posted: June 15, 2020 | Written By: Mark Whitney, Ph.D., Form-A-Feed Nutrition and Production Specialist

tail biting

Anyone that has ever walked through a pen of pigs knows that they are naturally inquisitive, using their mouth to investigate their surroundings, coupled with a natural tendency to chew.  This can lead to problems if animals change their focus to chewing and biting on pen-mates’ tails.  Tail biting can seem to start without cause, involving one or two animals, or an entire pen or several pens of pigs.  The occurrence of tail biting may be almost non-existent (if you are lucky) or a never-ending problem, causing significant stress and frustration to the people in charge of caring for the animals.  Tail biting can be a very costly event in any pig operation, and costs the U.S. swine industry millions of dollars each year in lost pig performance, development of secondary infections, carcass cut-out and condemnation, and in severe cases, euthanasia of affected animals.  A recent commercial study found that over 16% of grow-finish pigs in the U.S. have evidence of tail biting, with 60% of those resulting in severe lesions.

Research has also shown that pigs are attracted to both the visual sign and taste of blood.  If blood is drawn by accidental biting of a pen-mate’s tail, it becomes more attractive for continued chewing and biting, resulting in tissue damage and infection.  Tail biting is considered a “vice” behavior in pigs – i.e. aberrant aggressive behavior that can be considered an indication of the pig’s frustration over its environment.  A change or less than optimal level of any of a number of factors, resulting in stress in the pig, can contribute towards tail biting.

  • Out of Feed: Feeders going empty for any amount of time is by far the number one contributing factor to tail biting observed in modern production units today. Routinely checking feed bin levels and feed bridging, along with timely ordering of feed, is essential to decrease the occurrence of tail biting in the barn.
  • Space: Increased stocking rates or crowding in pens can trigger or contribute towards tail biting. Not only is lack of space to freely move around an issue, but so can limitations to access feed and water.  Setting feeders too tight, or not having adequate water flow rate, can bring about vice behaviors.  When pigs first approach market weight, gate cut the heaviest pigs out of each pen to provide additional room for remaining pigs.  Check feeders and waterers daily to ensure correct operation.
  • Environment: Extreme temperatures or fluctuations in temperature can trigger vice behavior, as can inadequate ventilation. Proper ventilation, allowing the uniform movement of fresh air throughout the barn, is necessary to keep gas (ammonia) levels down, while minimizing drafts.  Ensure ventilation is operating correctly by observing pig behavior daily and analyzing the air in the barn.
  • Nutrition: Improper nutrient levels in the diet, or poor feed quality, can contribute to vice behavior.  The presence of mycotoxins in feed has long been known to trigger tail biting, as has inadequate levels of amino acids and other nutrients.  Ensure diets are formulated to current genetics and growth performance, and that the correct diets are fed at the correct time, while following quality assurance guidelines.
  • Genetics and Gender: Selection for faster-growing lean pigs currently has inadvertently also selected for more aggressive pigs, which is why we tend to see more issues with tail biting today than we observed in the past. Additionally, barrows tend to be more aggressive and thus exhibit vice behavior at a higher rate than gilts.

tail bitingForm-A-Feed has two products that provide tools for pork producers to help prevent and minimize tail biting.  Chomp is a feed additive that contains specialty ingredients to improve satiety, accelerate gut tissue recovery and wound healing, and reduce overall stress in the pig.  Providing 10 lb/ton in the grow-finish diet for 5 – 7 days, followed by 5 lb/ton for 7 – 14 days can significantly reduce behavior and wounds associated with tail biting.

Most recently, the Dura-Block was developed and is available.  This 40 lb. molasses-based block is designed to be placed in a pen of 20 – 40 pigs.  It works against tail biting two ways: 1) active components promote calming and contentment as the pigs chew the block, and 2) the block provides tactile stimulation, directly averting pig curiosity and vice behavior away from pen-mates.

Tail biting must be curtailed first by ensuring the pig’s needs are being met, including sufficient space, correct environmental temperature and ventilation, appropriate and adequate feed and water.  Once tail biting is observed, it is important that actions be taken immediately to avoid further problems.  Chomp and Dura-Block are two technologies that are available to prevent and minimize the effects of tail biting and vice behavior in pigs, resulting in greater productive performance and more full-value pigs being marketed.