1. 2004 2006 R. L. Powell Animal Improvement Programs Laboratory Agricultural Research Service, USDA, Beltsville, MD rlpowell@aipl.arsusda.gov Historical perspectives on genetic fitness research ADSA Pioneer

2. ADSA-ASAS 2006 Joint Annual Meeting (2)R. L. Powell 20042006 Fitness (Dictionary.com)  The state or condition for being fit; suitability or appropriateness  Good health or physical condition  The extent to which an organism is adapted to or able to produce offspring in a particular environment

3. ADSA-ASAS 2006 Joint Annual Meeting (3)R. L. Powell 20042006 Common understanding of fitness traits  Nonproduction  Functional  But what makes a dairy cow more fit and functional than production?  We may strain the dictionary definition, but we know what we mean

4. ADSA-ASAS 2006 Joint Annual Meeting (4)R. L. Powell 20042006 Conformation or type  Anecdotal observations for eons  What “we” thought cow should look like  Linear scoring began around 1980  Promoted research on real value of type traits

5. ADSA-ASAS 2006 Joint Annual Meeting (5)R. L. Powell 20042006 Longevity  Justification for type emphasis  Direct observation  Indicator traits

6. ADSA-ASAS 2006 Joint Annual Meeting (6)R. L. Powell 20042006 Somatic cell/mastitis  SCS is convenient trait for selection for reduced mastitis  Clear importance and relatively ready acceptance of research  Like yield, obvious milking-to-milking impact on income (profit)

7. ADSA-ASAS 2006 Joint Annual Meeting (7)R. L. Powell 20042006 Fertility  Should we have foreseen problems?  Some natural selection  Tribolium pupa weight study (1976)  Negative response in family size  “Eventual extinction … by generation 16”

8. ADSA-ASAS 2006 Joint Annual Meeting (8)R. L. Powell 20042006 Calving ease  Giving birth is most traumatic time in a cow’s life  Can minimize negatives by reducing calvings or by mating plan  Better yet, reduce frequency of bad genes (daughter calving ease)

9. ADSA-ASAS 2006 Joint Annual Meeting (9)R. L. Powell 20042006 Genetic evaluations TraitYear Yield1935 Final score type1964 Calving ease1978 Linear type1980—83 Productive life1994 Somatic cell score1994 Daughter pregnancy rate2003 Stillbirths2006

10. ADSA-ASAS 2006 Joint Annual Meeting (10)R. L. Powell 20042006 Indexes  Consider all traits with a single number  Vital with so many traits  Needs to be appropriate for market  Needs to be “reasonably” accurate  Many correlated traits complicate process

11. ADSA-ASAS 2006 Joint Annual Meeting (11)R. L. Powell 20042006 History of USDA indexes TraitsYear Milk, fat1971 + Protein, solids-not fat1976 + Productive life, somatic cell score1994 + Type composites2000 + Daughter pregnancy rate,2003 calving ease + Stillbirths2006

12. ADSA-ASAS 2006 Joint Annual Meeting (12)R. L. Powell 20042006 Deleterious genes  Mulefoot  Bovine leukocyte adhesion deficiency (BLAD)  Uridine monophosphate synthase deficiency (DUMPS)  Complex vertebral malformation (CVM)  Weaver  Limber leg  Rectovaginal constriction (RVC)

13. ADSA-ASAS 2006 Joint Annual Meeting (13)R. L. Powell 20042006 Learning from history  Obsession with production  Low heritability vs. no heritability  High economic value  Large variation  Breed for yield, cull for function  We got what we asked for

14. ADSA-ASAS 2006 Joint Annual Meeting (14)R. L. Powell 20042006 Learning from history (cont.)  Beware of pendulum swinging too far back  Theoretically, index weights based on research  correct index  optimum progress