E. Gus Cothran
Dept. Veterinary Integrated Biosciences
College of Veterinary Medicine and Biomedical
Science
Texas A&M University

 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.

Genetic variability measures.
15 Mile Herd 2000
15 Mile Herd 1991
White Mountain
McCullough Peaks
Green Mountain
Muskrat Basin
Thoroughbred
Arabian
Andalusian
Shetland Pony
Welsh Pony
American Saddlebred
Peruvian Paso
Belgian Draft
Feral Horse Mean
Standard Deviation
Domestic Horse Mean
Standard Deviation
265
117
140
50
42
259
141
82
N Ho
29 0.431
47
40
41
40
38
0.379
0.340
0.405
0.380
0.374
0.294
0.307
0.348
0.368
0.388
0.404
0.451
0.427
54
118
0.360
0.051
0.371
0.049
-0.019
0.061
0.039
0.095
-0.002
0.013
-0.014
-0.028
Fis
-0.037
-0.038
0.077
0.060
-0.120
-0.061
-0.035
0.118
-0.014
0.065
0.288
0.327
0.362
0.407
0.387
0.409
0.445
0.415
He
0.416
0.365
0.368
0.431
0.339
0.352
0.351
0.053
0.365
0.043
1.780
1.846
1.993
2.210
2.127
2.354
2.506
2.279
Ae
2.128
1.847
2.249
2.205
1.883
1.876
1.913
0.246
2.076
0.240
34
38
44
38
47
54
46
35
TNV
33
34
37
34
27
30
30.0
6.72
36.4
7.37

 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.

Rogers’ genetic similarity of the McCullough Peaks feral horse herd to major groups of domestic horses.
Light Racing and Riding Breeds
Oriental and Arabian Breeds
Old World Iberian Breeds
New World Iberian Breeds
North American Gaited Breeds
Heavy Draft Breeds
True Pony Breeds
Mean S
0.792
0.800
0.797
0.805
0.808
0.813
0.785
Std
0.024
0.023
0.024
0.023
0.023
0.021
0.025
Minimum
0.744
Maximum
0.822
0.765
0.775
0.754
0.771
0.751
0.743
0.844
0.816
0.833
0.835
0.867
0.845

-
+--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.

Augusta Mountains NV
Cleveland Bay
American Saddlebred
Andalusian
Arabian
Exmoor Pony
Friesian
Irish Draught
Morgan Horse
Suffolk Punch
Tennessee Walker
Thoroughbred
Feral Horse Mean
Standard Deviation
Minimum
Maximum
Domestic Horse Mean
Standard Deviation
Minimum
Maximum
N
29
Ho
0.77
47 0.610
576 0.740
52
47
0.722
0.660
98 0.535
304 0.545
135 0.802
64 0.715
57
60
0.683
0.666
1195 0.734
126 0.716
0.056
0.496
0.815
80 0.710
0.078
0.347
0.822
He Fis Ae TNV MNA Ra %Ra
0.756
-0.018
4.28
79 6.58
16 0.202
0.627
0.745
0.753
0.727
0.027
2.93
59 4.92
16 0.271
0.007
4.25
102 8.50
42 0.412
0.041
4.26
79 6.58
21 0.266
0.092
3.81
86 7.17
30 0.349
0.627
0.146
2.87
66 5.50
21 0.318
0.539
-0.011
2.56
70 5.83
28 0.400
0.799
-0.003
5.19
102 8.50
28 0.275
0.746
0.041
4.19
92 7.67
33 0.359
0.711
0.693
0.038
0.038
3.88
3.66
71
87
5.92
7.25
13
34
0.183
0.391
0.726
-0.011
3.92
69 5.75
18 0.261
0.710
-0.012
3.87 72.68
6.06
17 0.222
0.059
0.071
0.66 13.02
1.09
7.98 0.088
0.489
-0.284
2.15
37 3.08
0
0.798
0.133
5.25
96 8.00
33
0
0.400
0.720
0.071
0.012
4.01 80.88
6.74
23.8 0.283
0.086
0.74 16.79
1.40
10.1 0.082
0.394
-0.312
1.78
26 2.17
0
0.799
0.211
5.30
119 9.92
55
0
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.

Genetic variation measures.
Population
Butte Valley
Panamints
Salin Valley
Ho
.422
.446
.479
He
.496
.465
.518
Poitou Donkey
Mammouth Jack
Miniature Donkey
Standard Donkey
.533
.585
.562
.539
.515
0602
.623
.565
Domestic Mean
Feral Mean
.539
3565
.397
.445
Fis
.148
.041
.074
-.036
.028
.099
.046
.046
.104
Ae
2.369
2.380
2.504
2.501
2.602
3.483
2.900
42
35
57
40.6
TNV
31
28
34
2.900
2.198
40.6
30.7
37
.37
.40
.30
Ar
.22
.27
.23
.30
.20

********************************* 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.

 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.