genetic selection for reproduction:

H. Duane NormanAnimal Improvement Programs LaboratoryAgricultural Research Service, USDA, Beltsville, [email protected]

Dairy Cattle Reproductive Council Convention (1)

2007

Genetic selection for reproduction:Current reproductive status

of the national herd;Application of selection

indexesfor dairy producers

H.D. Norman 2007Dairy Cattle Reproductive Council Convention (2) H.D. Norman 2007Dairy Cattle Reproductive Council Convention (2)

Current reproductive status

of the national herd

H.D. Norman 2007Dairy Cattle Reproductive Council Convention (3)

Bull fertility Estimated Relative Conception Rate

(ERCR) 70-day nonreturn rate (NRR) Phenotypic evaluation Source:− DRMS (Raleigh, NC), 1986−2005− USDA (Beltsville, MD), 2006−present

Western Bull Fertility Analysis 75-d veterinary-confirmed conception rate

Source: AgriTech (Visalia, CA), 2003 −present


ERCR distribution (Aug. 2007)


Survey of AI organizations Does your organization rate bulls on fertility from field data? Where do you obtain the data you use to evaluate them? How long a time period is included in your evaluation? What do you publish? How many nonreturn days are in your calculation? Is your evaluation derived from first or all services? Do you eliminate cows sold before a specific number of days

after insemination? Do you eliminate cows in herds that go off test before a

specific number of days after insemination? Is information on services from natural service bulls that

follow AI breedings available to you to document failures of those AI breedings?


Survey results All had programs to monitor bull fertility, but few

relied completely on in-house information Most received some information from technician breedings

One purchased breeding records from a dairy records processing center

Another obtained breeding records directly from cooperating herds

Most common fertility measure was NRR Varied from 59 to 90 days for first breeding Some organizations used a range of days


Survey results (cont.) Conception rate (CR) used by one because of

availability of pregnancy-check records

Time period for data included in a bull’s fertility evaluation varied from 1 year to no limit

Equal number included only first services compared with all services

Data from technician breedings Not adjusted for cow departures because of culling or when a herd discontinued production testing

No access to data that showed when natural service followed an AI mating


New USDA service sire evaluation Based on conception rate rather than NRR

More accurate Inseminations from most of the United

States All services (not just first) Additional model effects included

Available early 2008

Documentation at ftp://aipl.arsusda.gov/pub/outgoing/BullFert/


Cow fertility trends

Year

bred

Calving to 1st

breeding (d)

70-d NRR for1st service

(%)1st service

CR (%)

Services perlactation

(no.)Holstei

nJerse

yHolstei

nJerse

yHolstei

nJerse

yHolstei

nJerse

y

1996

89 82

1997

91 84

1998

91 85

1999

92 85

2000

90 84

2001

92 85

2002

88 81

2003

88 83

2004

86 84

2005

86 84

2006

85 83



Year

bred

Calving to 1st

breeding (d)


(%)1st service

CR (%)


(no.)Holstei

nJerse

yHolstei

nJerse

yHolstei

nJerse

yHolstei

nJerse

y

1996

89 82 54 57

1997

91 84 55 57

1998

91 85 54 56

1999

92 85 53 55

2000

90 84 53 55

2001

92 85 52 56

2002

88 81 50 53

2003

88 83 48 53

2004

86 84 48 53

2005

86 84 46 52

2006

85 83 … …



Year

bred

Calving to 1st

breeding (d)


(%)1st service

CR (%)


(no.)Holstei

nJerse

yHolstei

nJerse

yHolstei

nJerse

yHolstei

nJerse

y

1996

89 82 54 57 36 39

1997

91 84 55 57 34 37

1998

91 85 54 56 32 36

1999

92 85 53 55 31 35

2000

90 84 53 55 31 35

2001

92 85 52 56 31 36

2002

88 81 50 53 29 35

2003

88 83 48 53 30 36

2004

86 84 48 53 31 36

2005

86 84 46 52 30 35

2006

85 83 … … … …



Year

bred

Calving to 1st

breeding (d)


(%)1st service

CR (%)


(no.)Holstei

nJerse

yHolstei

nJerse

yHolstei

nJerse

yHolstei

nJerse

y

1996

89 82 54 57 36 39 2.1 2.0

1997

91 84 55 57 34 37 2.1 2.1

1998

91 85 54 56 32 36 2.2 2.1

1999

92 85 53 55 31 35 2.3 2.1

2000

90 84 53 55 31 35 2.3 2.1

2001

92 85 52 56 31 36 2.3 2.1

2002

88 81 50 53 29 35 2.5 2.2

2003

88 83 48 53 30 36 2.5 2.3

2004

86 84 48 53 31 36 2.5 2.3

2005

86 84 46 52 30 35 2.6 2.4

2006

85 83 … … … … … …


Parity averages (2005 breedings)

Parity

Calving to 1st

breeding (d)

70-day NRR for 1st

service (%)1st-service

CR (%)


(no.)Holstei

nJerse

yHolstei

nJerse

yHolstei

nJerse

yHolstei

nJerse

y1 85 852 85 833 87 824 88 845 90 85

>5 92 88



Parity

Calving to 1st

breeding (d)

70-day NRR for 1st


CR (%)


(no.)Holstei

nJerse

yHolstei

nJerse

yHolstei

nJerse

yHolstei

nJerse

y1 85 85 48 542 85 83 45 523 87 82 45 524 88 84 45 505 90 85 45 51

>5 92 88 45 49



Parity

Calving to 1st

breeding (d)

70-day NRR for 1st


CR (%)


(no.)Holstei

nJerse

yHolstei

nJerse

yHolstei

nJerse

yHolstei

nJerse

y1 85 85 48 54 32 372 85 83 45 52 29 363 87 82 45 52 29 354 88 84 45 50 28 345 90 85 45 51 27 32

>5 92 88 45 49 25 30



Parity

Calving to 1st

breeding (d)

70-day NRR for 1st


CR (%)


(no.)Holstei

nJerse

yHolstei

nJerse

yHolstei

nJerse

yHolstei

nJerse

y1 85 85 48 54 32 37 2.6 2.32 85 83 45 52 29 36 2.7 2.33 87 82 45 52 29 35 2.6 2.44 88 84 45 50 28 34 2.6 2.45 90 85 45 51 27 32 2.6 2.4

>5 92 88 45 49 25 30 2.7 2.5


Holstein NRR (2005 breedings)

Parity

70-day NRR (%)1st

service

2ndservice

3rd servi

ce4th

service

5th servi

ce1 48 46 43 41 392 45 43 41 40 383 45 44 42 41 394 45 44 43 41 395 45 43 42 41 40

>5 45 43 43 41 39


Holstein CR (2005 breedings)

Parity

CR (%)1st

service

2ndservice

3rd servi

ce4th

service

5th servi

ce1 32 33 31 29 262 29 30 29 28 263 29 30 30 28 264 28 30 29 27 265 27 28 28 26 25

>5 25 26 26 25 25


Holstein regional averages (2005 breedings)

Region

Calvingto 1st

breeding

(d)

70-dayNRR for

1st service(%)

CR(%)

Servicesper

lactation(no.)

Preg-

nancy

rate(%)

Mideast 92Midwest 86Mountain 93Northeast 85Northwest 76Southeast 89Southwest 73



Region

Calvingto 1st

breeding

(d)

70-dayNRR for

1st service(%)

CR(%)

Servicesper

lactation(no.)

Preg-

nancy

rate(%)

Mideast 92 47Midwest 86 46Mountain 93 48Northeast 85 46Northwest 76 42Southeast 89 44Southwest 73 36



Region

Calvingto 1st

breeding

(d)

70-dayNRR for

1st service(%)

CR(%)

Servicesper

lactation(no.)

Preg-

nancy

rate(%)

Mideast 92 47 29Midwest 86 46 30Mountain 93 48 27Northeast 85 46 31Northwest 76 42 29Southeast 89 44 23Southwest 73 36 27



Region

Calvingto 1st

breeding

(d)

70-dayNRR for

1st service(%)

CR(%)

Servicesper

lactation(no.)

Preg-

nancy

rate(%)

Mideast 92 47 29 2.7Midwest 86 46 30 2.7Mountain 93 48 27 2.8Northeast 85 46 31 2.6Northwest 76 42 29 2.8Southeast 89 44 23 3.0Southwest 73 36 27 2.8


Pregnancy rate (PR) Percentage of nonpregnant cows that become pregnant

during each 21-day period Advantages over days open (DO)

Easily defined Information from nonpregnant cows included more

easily Larger (rather than smaller) values desirable

PR = [21/(DO − voluntary waiting period + 11)]100 Voluntary waiting period assumed to be 60 days Factor of +11 adjusts to middle day of 21-day cycle

Examples Herd with average of 133 DO has PR of 25% Herd with average of 154 DO has PR of 20%



Region

Calvingto 1st

breeding

(d)

70-dayNRR for

1st service(%)

CR(%)

Servicesper

lactation(no.)

Preg-

nancy

rate(%)

Mideast 92 47 29 2.7 19.0Midwest 86 46 30 2.7 21.5Mountain 93 48 27 2.8 19.6Northeast 85 46 31 2.6 22.4Northwest 76 42 29 2.8 23.4Southeast 89 44 23 3.0 17.3Southwest 73 36 27 2.8 23.7


Herds with synchronized breeding

Synchroni-zationstatus

Calvingto 1st

breeding

(d)

70-dayNRR for

1st service(%)

CR(%)

Servicesper

lactation(no.)

Preg-nanc

y rate(%)

None 90 46 30 2.6 20.2Possible 78 40 27 2.9 21.8Probable 74 38 27 2.9 22.4Synchroniz

ed72 35 25 3.1 21.7


Current breed averages

Breed PR (%) DO (d)Gestation length (d)

Calving interval

(d)Ayrshire 23.2 140 281.7 422Brown Swiss

20.3 152 287.5 440

Guernsey 19.1 157 285.8 443Holstein 22.0 145 279.5 425Jersey 26.4 127 280.0 407Milking Shorthorn

24.8 134 281.3 415


USDA pregnancy rate Linear approximation

PR = 0.25 (233 − DO) 1% higher PR = 4 days fewer open


Daughter pregnancy rate (DPR) First USDA genetic evaluations in 2003 Same across-breed animal model as for yield traits,

productive life (PL), and somatic cell score (SCS) Heritability of 4% Predicted transmitting abilities (PTAs) reported as

percentages Daughters of bull with PTA DPR of 1 expected to be 1%

more likely to become pregnant during estrous cycle than if bull had PTA DPR of 0

Each increase of 1% in PTA DPR equivalent to decrease of 4 days in PTA DO

PTA DO approximated by −4 × PTA DPR Example: Bull with PTA DPR of +2.0 would have PTA DO of

−8


DPR trend (August 2007 base)


Bull PTA DPR frequency (Aug. 2007)


Application of selection indexes

for dairy producers


Lifetime merit indexes

Trait Units

Relative value (%)Netmeri

tCheese

merit

Fluid

merit

Protein Pounds 23 28 0Fat Pounds 23 18 23Milk Pounds 0 −12 24PL Months 17 13 17SCS Log −9 −7 −9Udder Composite 6 5 6Feet/legs Composite 3 3 3Body size Composite −4 −3 −4DPR Percent 9 7 8Calving ability Dollars 6 4 6


Genetic merit of high-DPR Holstein bulls

Trait

All active

AI bulls

Active AIbulls withPTA DPRof ≥2.0 %

Top 50% of active AI

bulls based on lifetime net merit(>$245)


bullswith PTA DPR of ≥2.0%

based onPTA DPR(>2.3 %)

Bulls (no.) 684

PTA milk (lb) 838

PTA fat (lb) 32PTA protein (lb) 25PTA SCS 2.94PTA PL (mo) 1.1PTA DPR (%) −0.4PTA DO (derived) 1.6Net merit ($) 24

2Semen price ($/unit)

24



Trait

All active

AI bulls







Bulls (no.) 684

41

PTA milk (lb) 838

287

PTA fat (lb) 32 14PTA protein (lb) 25 17PTA SCS 2.94 2.86PTA PL (mo) 1.1 4.2PTA DPR (%) −0.4 2.5PTA DO (derived) 1.6 −10.0Net merit ($) 24

2346

Semen price ($/unit)

24 25



Trait

All active

AI bulls







Bulls (no.) 684

41 342

PTA milk (lb) 838

287 1,125

PTA fat (lb) 32 14 43PTA protein (lb) 25 17 34PTA SCS 2.94 2.86 2.88PTA PL (mo) 1.1 4.2 2.1PTA DPR (%) −0.4 2.5 −0.1PTA DO (derived) 1.6 −10.0 0.4Net merit ($) 24

2346 357


24 25 25



Trait

All active

AI bulls







Bulls (no.) 684

41 342 20

PTA milk (lb) 838

287 1,125 179

PTA fat (lb) 32 14 43 13PTA protein (lb) 25 17 34 16PTA SCS 2.94 2.86 2.88 2.84PTA PL (mo) 1.1 4.2 2.1 4.4PTA DPR (%) −0.4 2.5 −0.1 2.9PTA DO (derived) 1.6 −10.0 0.4 −11.6Net merit ($) 24

2346 357 350


24 25 25 21



Trait

All active

AI bulls






based onlifetime net

merit (>$386)

Bulls (no.) 684

41 342 20

PTA milk (lb) 838

287 1,125 735

PTA fat (lb) 32 14 43 31PTA protein (lb) 25 17 34 30PTA SCS 2.94 2.86 2.88 2.84PTA PL (mo) 1.1 4.2 2.1 5.1PTA DPR (%) −0.4 2.5 −0.1 2.6PTA DO (derived) 1.6 −10.0 0.4 −10.4Net merit ($) 24

2346 357 476


24 25 25 26


DPR benefits over productive life Additional calves produced

Decreased units of semen needed per pregnancy

Decreased labor and supplies for heat detection, inseminations, and pregnancy checks

Higher yields because more ideal lactation lengths


Lifetime value Factors in determining economic value

Loss of about $1.50/DO 2.8 lactations per cow No breedings for half of cows during final

lactation Correlation of heifer and cow fertility (0.3) Value of extra calves Other unmeasured health expenses

Total lifetime merit value of $21/PTA DPR unit


Total Performance Index (TPI) Calculated by Holstein Association

USA (Brattleboro, VT)

Emphasis of 19% on early breeding 10% on PL 8% on DPR −1% on dairy form

95% correlation between USDA lifetime net merit and Holstein TPI


Conclusions


Service sires Using bulls with higher conception rates returns

profit fairly quickly Premium of $2 could be paid for semen per

1% improvement in fertility Unit of semen from bull with ERCR of +2

worth $8 more than unit from bull with ERCR of −2

Little genetic improvement in male fertility expected over time

Use bull fertility as a secondary selection trait after production and economic indexes


Selection for cow fertility Selection for improved fertility possible and

recommended

Most benefits delayed for 2 years or more

Select service sires for overall lifetime merit that includes daughter fertility rather than for daughter fertility alone

Producers with herd fertility problems may choose to emphasize DPR extensively, which can be done with little loss in overall net merit


Benefits of improved reproduction Lower semen cost

Improved ability to optimize lactation and lifetime yields

Reduced culling due to delayed or failed conception

More herd replacements


Fertility emphasis Service-sire fertility and DPR important for

all management systems, but most important for grazing herds with seasonal calving

Use of a few bulls that average 3.0% for PTA DPR (equivalent to a decrease of 12 DO) could recover much of genetic decline in fertility from use of high-yield bulls for 40 years

General recommendation still is to select for overall merit based on genetic-economic index appropriate for current milk market

genetic selection for reproduction:

Documents