E. Gus CothranDept. Veterinary Integrated Biosciences

College of Veterinary Medicine and Biomedical Science

Texas A&M University

Genetic Testing of Feral Horses

Testing began in early 1990s.Usually at the request of an individual from a

specific HMA or a private individual.Used blood group and biochemical

polymorphisms. This required taking two blood samples from

every horse.Information supplied by the BLM ranged from

none to herd management plans. Usually just a form like the following.

17 loci were routinely tested.Sample sizes varied but were usually between

25 to 75 animals.Standard measures of genetic variability

were calculated for each herd.The values were compared to those of

domestic horse breeds and to other feral herds.

  N Ho He Fis Ae TNV15 Mile Herd 2000 29

0.431 0.416 -0.037 2.128 33

15 Mile Herd 1991 47 0.379 0.365 -0.038 1.847 34White Mountain 40 0.340 0.368 0.077 2.249 37McCullough Peaks 41 0.405 0.431 0.060 2.205 34Green Mountain 40 0.380 0.339 -0.120 1.883 27Muskrat Basin 38 0.374 0.352 -0.061 1.876 30             Thoroughbred 265 0.294 0.288 -0.019 1.780 34Arabian 117 0.307 0.327 0.061 1.846 38Andalusian 140 0.348 0.362 0.039 1.993 44Shetland Pony 50 0.368 0.407 0.095 2.210 38Welsh Pony 42 0.388 0.387 -0.002 2.127 47American Saddlebred 259 0.404 0.409 0.013 2.354 54Peruvian Paso 141 0.451 0.445 -0.014 2.506 46Belgian Draft 82 0.427 0.415 -0.028 2.279 35             Feral Horse Mean 54 0.360 0.351 -0.035 1.913 30.0Standard Deviation   0.051 0.053 0.118 0.246 6.72Domestic Horse Mean 118 0.371 0.365 -0.014 2.076 36.4Standard Deviation   0.049 0.043 0.065 0.240 7.37

Genetic variability measures.

Genetic similarity and distance measures also are calculated.

These are compared to the major domestic breed groups.

Depending upon the State comparisons to other herds from the area or State may be done.

Dendrograms are given showing similarity to domestic breeds or other feral herds from the state.

  Mean S Std Minimum MaximumLight Racing and Riding Breeds 0.792 0.024 0.744 0.822         Oriental and Arabian Breeds 0.800 0.023 0.765 0.844         Old World Iberian Breeds 0.797 0.024 0.775 0.816         New World Iberian Breeds 0.805 0.023 0.754 0.833         North American Gaited Breeds 0.808 0.023 0.771 0.835         Heavy Draft Breeds 0.813 0.021 0.751 0.867         True Pony Breeds 0.785 0.025 0.743 0.845

Rogers’ genetic similarity of the McCullough Peaks feral horse herd to major groups of domestic horses.

+--MORGAN HORSE +----| | | +----STANDARDBRED PACER | +------| - +--| +------STANDARDBRED TROTTER | | | | +----AMERICAN SADDLEBRED | | +---| | +--| +-------ROCKY MOUNTAIN HORSE | | | +-------TENNESSEE WALKER | +--| +--QUARTER HORSE | | | | | +--| +----HANOVARIAN | | | | | | | | | | +--------TRAKEHNER | | | +--| +--| | | | | | | +-----------HOLSTEIN | | | | | +--| | | | +--| | +-----THOROUGHBRED | +--| | +--| | | | +----WIELKOPOLSKI +--| | | | | | +-------SELLA FRANCAIS | | | | | | +-----KHUZESTAN ARABIAN | | | +--| | | | | | +ARABIAN | | +---| +--| | | | +---------SHAGYA ARABIAN --| | | | | +----------KURD | | | | +---------------AKHAL TEKE | +--| | | +-----------CASPIAN PONY | +--| | +-----TURKOMAN | +---------MCCULLOUGH PEAKS

SIMILARITY.76 .80 .84 .88 .92 .96 1.00----+----+----+----+----+----+----+----+----+----+----+---+ +-------------------------- Stewart Creek +-----| | +-------------------------- Eagles Nest +----| | | +----------------------- Cooper Creek +-| +--------| | | +----------------------- Green Mountain +--------| | | | +------------------------------------- White Mountain +--| | | | +--------------------------------------- Happy Creek Springs +-| | | | +------------------------------------------------ 15 Mile Herd +-| | | | +--------------------------------------------------- Cedar Ridge Trap | | +| +----------------------------------------------------- Tilley Creek || || +-------------------------- McCullough Peaks || +-| +|+--------------------------| +-------------------------- Whistle Creek || | || +---------------------------- Dry Creek || |+-------------------------------------------------------- Cold Springs Trap | +--------------------------------------------------------- Muskrat Basin ----+----+----+----+----+----+----+----+----+----+----+---+.76 .80 .84 .88 .92 .96 1.00

All genetic testing is now done by DNA microsatellite loci.

DNA testing allows the use of pulled mane or tail hairs as samples.

DNA results are analyzed in essentially the same way as blood protein data.

N Ho He Fis Ae TNV MNA Ra %RaAugusta Mountains NV 29 0.77 0.756 -0.018 4.28 79 6.58 16 0.202

Cleveland Bay 47 0.610 0.627 0.027 2.93 59 4.92 16 0.271American Saddlebred 576 0.740 0.745 0.007 4.25 102 8.50 42 0.412Andalusian 52 0.722 0.753 0.041 4.26 79 6.58 21 0.266Arabian 47 0.660 0.727 0.092 3.81 86 7.17 30 0.349Exmoor Pony 98 0.535 0.627 0.146 2.87 66 5.50 21 0.318Friesian 304 0.545 0.539 -0.011 2.56 70 5.83 28 0.400Irish Draught 135 0.802 0.799 -0.003 5.19 102 8.50 28 0.275Morgan Horse 64 0.715 0.746 0.041 4.19 92 7.67 33 0.359Suffolk Punch 57 0.683 0.711 0.038 3.88 71 5.92 13 0.183Tennessee Walker 60 0.666 0.693 0.038 3.66 87 7.25 34 0.391Thoroughbred 1195 0.734 0.726 -0.011 3.92 69 5.75 18 0.261

Feral Horse Mean 126 0.716 0.710 -0.012 3.87 72.68 6.06 17 0.222Standard Deviation 0.056 0.059 0.071 0.66 13.02 1.09 7.98 0.088Minimum 0.496 0.489 -0.284 2.15 37 3.08 0 0Maximum 0.815 0.798 0.133 5.25 96 8.00 33 0.400Domestic Horse Mean 80 0.710 0.720 0.012 4.01 80.88 6.74 23.8 0.283Standard Deviation 0.078 0.071 0.086 0.74 16.79 1.40 10.1 0.082Minimum 0.347 0.394 -0.312 1.78 26 2.17 0 0Maximum 0.822 0.799 0.211 5.30 119 9.92 55 0.462

SELLE FRANCAIS

THOROUGHBRED

HOLSTEIN

HANOVARIAN

TRAKEHNER

QUARTER HORSE

MORGAN HORSE

STANDARDBRED

MOUNTAIN PLEASURE HORSE

ROCKY MOUNTAIN HORSE

AMERICAN SADDLEBRED

AUGUSTA MOUNTAIN

TENNESSEE WALKER

ARGENTINE CRIOLLO

BRAZILIAN CRIOLLO

CHILEAN CRIOLLO

VENEZUELAN CRIOLLO

CAMPOLINO

MANGALARGA MARCHADOR

PANTANEIRO

PUERTO RICAN PASO FINO

PERUVIAN PASO

COLOMBIAN PASO FINO

GARANNO

ARABIAN

KURD

TURKOMAN

CASPIAN PONY

ANDALUSIAN

AKHAL TEKE

LUSITANO

DALES PONY

FELL PONY

SHIRE

NEW FOREST PONY

HAFLINGER

PERCHERON

SUFFOLK PUNCH

ICELANDIC

NORWEGIAN

SHETLAND PONY

AMERICAN CREAM DRAFT

EXMOOR PONY

POLISH PRIMITIVE

SIMILARITY .60 .64 .68 .72 .76 .80 .84 .88 .92 .96 1.00 +----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+ *************************** CALLAGHAN austin *************** * *************************** HALL CREEK **** * * ********************************* CALLAGHAN east * * ****** *** **** ********************************* GRASS VALLEY * * * * * ************************************** BALD MOUNTAIN ** * ** ******************************************** RODEO CREEK ** ** ************************************** STONE CABIN *********** ** ************************************** NELLIS ** *** ******************************************* NEW PASS/RAVENSWOOD ******* ** ******************************************* SAULSBURY *** ************************************************** BEATYS BUTTE OR ***** * ************************************************** MILLER MTN SWC * * * ************************************************** SOUTH SHOSONE ** ****************************************************** SAND SPRINGS EAST **** * ****************************************************** ROCKY HILLS * * * ****************************************************** SHAWAVE MOUNTAINS ** ********************************************************* AUGUSTA MOUNTAINS ** ********************************************************* MARVEL GAP SWC *** * ********************************************************* ROBERTS MOUNTAIN * * ** ********************************************************* VIRGINIA RANGE ** ** ***************************************************** FISH CREEK ******** **** ***************************************************** LITTLE OWYHEE TWIN * * * * ************************************************** GRANITE RANGE2 * * ******** * **** ************************************************** GRANITE RANGE1 * * * ********************************************************* SILVER PEAK * *************************************************************** REVEILLE ** ** ************************************** BLACK ROCK WEST ** ********* ** *********** ************************************** BLACK ROCK EAST ** * * ********** ********************************************** WARM SPRINGS CANYON ** * ** ******************************************************** CHIMNEY CREEK ** ** ************************************************* JOHNNIE ** ************** **** ************************************************* WHEELER PASS ** * ** ************************************************************** RED ROCKS ** ** ****************************************** DOLLY VARDEN ** ********* ** ***** ****************************************** ANTELOPE VALLEY *** * * ************** ************************************************** SPRUCE PEQUOP ** * ** ****************************************************** GOSHUTE ** ** *************************************************************** LITTLE OWYHEE FAIRB ***** * *************************************************************** LITTLE OWYHEE LAKE * ** *********************************************************** LITTLE FISH LAKE ********** ** *********************************************************** SEVEN MILE ** **** **************************************************************** CALICO MOUNTAINS * ***** * * **************************************************************** CATNIP HERD * * *** * ****************************************************** SNOW STORMS CASTLE * * *************** * * ****************************************************** LITTLE HUMBOLT * * ***** ********************************************************************** BUFFALO HILLS * * * * ************************************** PAYMASTER * * ******************************* *** ***** ************************************** MONTEZUMA PEAK * * * * * ******************************************************************** STILLWATER ** * ** **************************************************************************** LAHANTON RESERVOIR ** ******************************************************************************** ROCK CREEK ** ** ************************************************************************** PINENUT MOUNTAIN *********** * * ************************************************************************** DESATOYA MOUNTAIN * * * ******************************************************************************** JAKES WASH * ************************************************************************************ SNOW STORMS DRYHILL +----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+ .60 .64 .68 .72 .76 .80 .84 .88 .92 .96 1.00

DNA loci give somewhat higher variability measures so are not directly comparable to protein loci.

Rank levels of variation are similar.Allelic measures of diversity are more

important for mSat loci.Overall DNA gives data that is as useful for

population genetic analysis as blood typing.

Over 100 population analyses were made using blood protein loci.

Some herds were tested more than one time.DNA testing was done on some herds

analyzed using blood proteins during transitional period for lab.

Have DNA data for ~180 herds, again, some tested more than once.

Burro testing is very similar to that for horses. The same mSat loci are used although not all work for burros.

Only have four domestic breeds to compare to.

Most burro herds show very low variability.

Population Ho He Fis Ae TNV Ar

Butte Valley .422 .496 .148 2.369 31 .22

Panamints .446 .465 .041 2.380 28 .27

Salin Valley .479 .518 .074 2.504 34 .23

             

Poitou Donkey .533 .515 -.036 2.501 42 37

Mammouth Jack .585 0602 .028 2.602 35 .37

Miniature Donkey .562 .623 .099 3.483 57 .40

Standard Donkey .539 .565 .046 2.900 40.6 .30

             

Domestic Mean .539 3565 .046 2.900 40.6 .30

             

Feral Mean .397 .445 .104 2.198 30.7 .20

Genetic variation measures.

  ********************************* Poitou * * *********************** Pannaments CA * **** **** * *********************** Butte Valley CA * * ***** * * * * *********************** Saline Valley CA * * * **** * **** * *************** Slate Range CA * * ********* ********* * *************** Centennial Ca * * * * * ****************************** Clark Mtn. CA * * * * *********** Picacho CA * * **************** * * * *********** Chocolate Mule CA * *********** *** * *********************** Sinbad UT * * **** * * *********************** Yuma 1 AZ * * * * ********************** Minniature * * ******** ***** * ***** ********************** Standard * * * * * * * ************ ***************************** Ossabaw GA * * * * * ********************************* Cibola/Trigo 1 AZ ****************************** * * * * ********************************* Mammoth Jack * * ************** * * ********************************* Sardinian ********** * * * * ***************************** Chemehuevi CA * * ********************** *** * ***************************** Park Moab CA * * * * * ******************************************************************************* Blue Wing NV ** * ** **************************************************************************************** Wikieup AZ ** ************************************************************************************************ Kingman AZ * * * * ********************************************************************************** Seven Tanks NV ** ********** ** ********************************************************************************** East Mohave CA **** * ************************************************************************************************* Ed's Camp Az *** * * * ************************************************************************************************* Yuma 2 AZ * * * *************************************************************************************************** Havasu AZ * ***************************************************************************************************** Cibola/Trigo 2 AZ  

The majority of herds have moderate to high genetic variability.

This is probably due to the mixed origins of the herds.

About 18% of herds have variation levels that are low enough to be of concern. Most of these are just below that level.

Only about 3% have exceptionally low variation.

Horse Summary

Variation is usually correlated with population size.

Sometimes variation is high is small populations but this is due to recent reductions.

Most herds have not shown changes in variation levels between two or more sampling periods. This is probably due to not enough time having elapsed for a change to take place.

No large changes in variation level have been seen in any BLM herd to this point.