1. 2002 Paul M. VanRaden Animal Improvement Programs Laboratory Agricultural Research Service, USDA, Beltsville, MD paul@aipl.arsusda.gov Extreme Inbreeding at Beltsville 1912-1949

2. NAAB Dairy Trade Mission – Extreme Inbreeding (2)P.M. VanRaden 2002 Experimental Design  8 consecutive generations of mating sires to their daughters, and dams to their sons  Highest inbreeding coefficients ever obtained in cattle (maximum F = 75.1%)  Foundation Guernsey sire (Prince Billy) imported from the Isle of Guernsey in 1910  Foundation Holstein sire (Lad 11th) purchased from Minnesota in 1912

3. NAAB Dairy Trade Mission – Extreme Inbreeding (3)P.M. VanRaden 2002 Pictures From The Study  Early matings within the Guernsey and the Holstein lines  The 8 Holstein herd sires used. Sire 1 was the sire, maternal grandsire, and maternal great grandsire of sire 2. Further inbreeding led to sire 8 with coefficient F = 62.5%  Pedigree of an example cow with F = 64.6%  Pedigree of the highest cow with F = 75.1%

4. NAAB Dairy Trade Mission – Extreme Inbreeding (4)P.M. VanRaden 2002 USDA Tech. Bulletin No. 339 Early Matings in the Guernsey Line

5. NAAB Dairy Trade Mission – Extreme Inbreeding (5)P.M. VanRaden 2002 USDA Tech. Bulletin No. 339 Early Matings in the Holstein Line

6. NAAB Dairy Trade Mission – Extreme Inbreeding (6)P.M. VanRaden 2002 USDA Tech. Bulletin No. 927 Eight Herd Sires Used

7. NAAB Dairy Trade Mission – Extreme Inbreeding (7)P.M. VanRaden 2002 Sire 1 Appears 50 Times (64.6% F)

8. NAAB Dairy Trade Mission – Extreme Inbreeding (8)P.M. VanRaden 2002 6 6 6 2 3 1 1 1 A26 1 1 2 Most inbred cow ever (F = 75.1%)

9. NAAB Dairy Trade Mission – Extreme Inbreeding (9)P.M. VanRaden 2002 Other Highly Inbred Lines  Prospector line of Herefords, max F = 66.3% in 1984 at Colorado State  Anxiety 4th line of Herefords, F > 50% in 1980 at North Dakota State  Duchess family of Shorthorns, mean F of 40% in 1800’s by Thomas Bates, England  Current maximum F in each dairy breed is 40–50% in USA

10. NAAB Dairy Trade Mission – Extreme Inbreeding (10)P.M. VanRaden 2002 Conclusions  Guernsey line died due to lethal recessive and Brucellosis epidemic  Holstein birth weights decreased from 37 kg to 29 kg  Milk yield decreased by 7% and fat yield by 17% with inbreeding levels near 50%  “Continued inbreeding of whole herds, however, is almost certain to be disastrous.”

11. NAAB Dairy Trade Mission – Extreme Inbreeding (11)P.M. VanRaden 2002 References  Woodward, T.E. and R.R. Graves. 1933. Some results of inbreeding grade Guernsey and grade Holstein-Friesian cattle. USDA Tech. Bulletin No. 339  Woodward, T.E. and R.R. Graves. 1946. Results of inbreeding grade Holstein- Friesian cattle. USDA Tech. Bulletin No. 927  Swett, W.W., C.A. Matthews, and M.H. Fohrman. 1949. Effects of inbreeding on body size, anatomy, and producing capacity of grade Holstein cows. USDA Tech. Bulletin No. 990

12. NAAB Dairy Trade Mission – Extreme Inbreeding (12)P.M. VanRaden 2002 Acknowledgements  Max Paape rediscovered the original records at the Beltsville research farm.  Batchimeg Tseveenjav, Mike Bishop, and Mike MacNeil supplied information on inbred beef lines.  Kim Fletcher-Carroll arranged the graphics.