Mini Pig Conformation – Breeding For Quality


Conformation and Structural Soundness 

Mini Pigs – Breeding for Quality  

Photo Credit: Wittle Piggies 

Todays mini pig breeders hold a great responsibility. The American Mini Pig Association’s Registered Breeders are helping to shape the genetic diversity and structural soundness of their own piglets, as well as the future generations of mini pigs. Breeding responsibly includes selecting proper breeding stock. These selections should be based on health, size, disposition, conformation, and structural soundness. The breeding choices made today will impact the lives of mini pigs and their families for generations. 


Conformation is a term used to describe the outward physical appearance of an animal in which it’s skeletal structure, muscles, joints, and ligaments come together to form the complete animal. The animal depends on this structural soundness to live a long, healthy, comfortable life.  American Cowboy Chronicles states, “Conformation essentially means how well an animal is put together. An animal’s conformation is the blending of the various body parts. It’s all about how well they fit together visually and physically.” External visual cues give insight to the internal structure and soundness of the animal as a whole. 


A mini pig may have “good” or “poor” conformation. When the conformation is poor, it places weakness and strain on various areas of the body. This may result in poor growth, joint pain, leg weakness, lameness, arthritis, and increased injuries. The conformation of a mini pig is not always a disctinct answer of “good” or “poor”. The ideal conformation is based on soundness in all areas. This ideal should be strived for with every breeding pair. 


Breeding sows and boars are selected to compliment each other’s strengths while countering the weaknesses. Mini pigs with hereditary defects should NEVER be bred. These pigs should be responsibly altered (spayed or neutered) to protect future generations.  Not all mini pigs are breeding quality. Only the best of the best should be considered for a breeding program. Selecting for quality will ensure the betterment of mini pigs as a whole. 



Mini Pig Conformation





Good leg conformation is essential for proper alignment and movement. 



When the angle of the hip, stifle and hock joints is too small, the deficiency is called “sickle-hocked.” Description provided by Iowa State University.  View photos here.


Post Legged

When the angle of the hip, stifle and hock is too large, the animal is described as “post-legged.” Description provided by Iowa State University. View photos here.


Weak or Dropped Pasterns

Weak rear pasterns are considered undesirable. In severe cases, damage to hocks and dew claws can result. Description provided by Iowa State University. View photos here.



When the hocks of the rear legs turn inward, the condition is described as “cow-hocked.” Description provided by Iowa State University. View photos here.



Straight front legs often cause knee joints to buckle, often called “buckkneed.” Description provided by Iowa State University. View photos here.



The tendency of the front toes to point outward is commonly called “splay-footed. Description provided by Iowa State University. View photos here.



The tendency of the front toes to point inward is commonly called “pigeon-toed”. View photos here





The toes are the foundation of the pig. Proper foot and toe conformation will help mini pigs keep their hooves naturally trim while avoiding painful uneven overgrowths. 


Toes should be proportional, even, and well spaced to balance the weight of the mini pig. Uneven toes, with one toe larger than the other, will cause uneven growth that shifts the stance of the foot putting strain on the joints, bones, ligaments, and muscles along the legs. Toes that are too close together or spaced too far apart will cause problems for the mini pig. 




Back and Top Line 


Mini pigs should have a straight, strong back with little to no sway or rise along the top line. Length should be proportionate to height. 


View photos and sketches of the skeletal structure related to swine conformation here





Any visible defect to the reproductive tract should be deemed unfit for breeding. 



Boars should have two evenly descended testicles. Dr. Carr says “Avoid any abnormalities including difference in size between testes. Avoid loose testicals”.



Any abnormalities to the vulva should be deemed unfit for breeding. 



Mini pigs should havea minimum of 6 nipples on each side, paired, prominent, evenly spaced, and straight. Extra nipples on one side or the other and uneven nipples are poor conformation indicators. Proper teat conformation diagrams are available on The Pig Site


Inverted nipples

From the North Carolina State University: “Inverted nipples are of the greatest concern. This condition is characterized by failure of nipples to protrude from the udder surface. The teat canal is held inward, forming a small crater so that normal milk flow is prevented. This abnormality has a genetic cause, but the number of pairs of genes involved is unknown. Individuals with a high proportion of inverted nipples should not be placed in the breeding herd.”




Visible Defects


Any visible defects should be avoided in breeding stock. Examples 

  • Atresia ani
  • Dipped shoulder
  • Missing limbs
  • Extra toes
  • Extremes in skeletal size
  • Extremes in nose shortness similar to Brachycephalic Syndrome in dogs. Further reading, here
  • Narrow rib and chest floor







Mini pigs with proper conformation should have free movement. If there is stiffness, slowness, arthritis, or other restriction of movement, the mini pig is not desirable as a breeder. 


Virginia State mentions, “Lack of mobility can contribute to the presence of concrete blisters, calluses, or abrasions on leg joints because such pigs have a tendency to dog-sit”.




Further Reading


Excellent photos and diagrams of proper swine conformation from The National Hog Farmer


Hereditary Defects in mini pigs by the American Mini Pig Association 


Swine conformation by Dr. Carr


Iowa State University 


Virginia State University 


Zinpro Lameness identification 



Visit our website to learn more about mini pigs, find a registered mini pig breeder, become a member of the AMPA and register your mini pig in the official mini pig registry! 


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