# Presentation: 048982

## Longevity and Fertility

## History of Productive Life

**January 1994 – ****Single-trait PL for bulls**
**July 1994 – ****Multi-trait PL at HA for all bulls**
**January 1995 – ****Base change of 0.9 months**
**January 1996 – ****Cow PL PTA’s first published**
**August 2000 – ****New multi-trait methods at USDA**
**August 2000 – ****Base change of 0.8 months**
**November 2000 – ****Genetic correlations reduced**

## PTA Productive Life

**Productive Life (PL) = **
**	****Total months in milk by seven years of age, including up to 10 months per lactation.**
**Multi-trait PL includes correlated traits**
**Milk, fat, protein**
**SCS**
**Type composites (udder, feet & legs, size)**
**Cull rate gradually replaces correlated traits**

## Calculation of Multi-trait PL

**PTA PL**** = ****	****PA PL ****+ ****Cov****(****true PL**** – ****PA, PTA**** – ****PA****) ****	****	****	****Var**** -1****(****PTA**** – ****PA****) (****PTA ****– ****PA****)**
**Begin with PA, regress on PTA – PA**
**Direct (single trait) PL and 7 indirect traits included in vectors**
**Weight on PTA – PA for each trait is determined by correlations, heritabilities, and reliabilities**
**	****Decline to zero as single-trait REL for PL approaches 99%**

##  Heritabilities and Correlations

|  | Milk | Fat | Protein | PL | SCS | Size | Udder | F&L |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Milk | .30 |  .65 |  .90 | .29 |  .20 |  .01 | -.20 | -.02 |
| Fat | .77 |  .30 |  .76 | .26 |  .20 |  .01 | -.20 | -.02 |
| Protein | .93 |  .82 |  .30 | .30 |  .20 |  .01 | -.20 | -.02 |
| PL | .34 |  .29 |  .34 | .085 | -.40 | -.04 |  .30 |  .19 |
| SCS | -.10 | -.10 | -.10 | -.30 |  .10 | -.11 | -.33 | -.02 |
| Size | .06 |  .06 |  .06 | .03 | -.11 |  .40 |  .26 |  .22 |
| Udder | -.10 | -.10 | -.10 | .08 | -.33 |  .26 |  .27 |  .10 |
| F&L | .01 |  .01 |  .01 | .19 | -.02 |  .22 |  .10 |  .15 |

**Genetic Correlation above diagonal**
**Heritabilities on the diagonal**** ****(for Holsteins)**
**Phenotypic Correlation below diagonal**

##  Example Data for PL

|  | Milk (lb) |  |  | Fat (lb) | Protein (lb) | PLa (mo) | SCS | Size | Udder | F&L |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| PTA | +1,947 |  |  | +61 | +61 | +1.1 | +3.38 | +.52 | +.90 | +.99 |
| REL % | 81 |  |  | 81 | 81 | 61 | 66 | 75 | 71 | 67 |
| PA | +588 |  |  | +44 | +28 | -.4 | +3.31 | +.73 | +.56 | +.81 |
| RELPAb % |  |  | 48 | 48 | 48 | 46 | 47 | 48 | 48 | 47 |
|  |  |  |  |  |  |  |  |  |  |  |
|  |  |  |  |  |  |  |  |  |  |  |

**a****PTA is single trait, PA is multi-trait **
**b****REL****PA**** max = 50%**

##  Example Weights for PL

|  | Milk (lb) |  | Fat (lb) | Protein (lb) | PLa (mo) | SCS | Size | Udder | F&L |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| PTA | +1,947 |  | +61 | +61 | +1.1 | +3.38 | +.52 | +.90 | +.99 |
| REL % | 81 |  | 81 | 81 | 61 | 66 | 75 | 71 | 67 |
| PA | +588 |  | +44 | +28 | -.4 | +3.31 | +.73 | +.56 | +.81 |
| RELPAb % |  | 48 | 48 | 48 | 46 | 47 | 48 | 48 | 47 |
| Relative wt. % |  | 3 |  4 |   5 |   54 | -5 |   -8 |   16 |    4 |
| Multi-Trait PTA |  |  |  |  | +1.4 |  |  |  |  |
| RELMT % |  |  |  |  | 63 |  |  |  |  |

**a****PTA is single trait, PA is multi-trait **
**b****REL****PA**** max = 50%**

## Stability of PL Evaluations

**Update of 1997 study by Ryan Starkenburg**
**August 2001 evaluations compared for:**
**January 1995 active AI bulls**
**February 1997 active AI bulls**
**PTA protein adjusted to true protein**
**Bulls with sample code ‘0’ excluded**
**August 2001 PL reliability ******** 90%**
**Regressions ****(*****expected to be 1*****)**
**Correlations ****(*****hoped to be high*****)**

## High PTA PL Bulls from 1995

|  | PL 19951 |  | PL 20012 |  | PTA PL |  |
| --- | --- | --- | --- | --- | --- | --- |
| Bull | Daus | REL | Daus | REL | 19951 | 20012 |
| C-E Bell Jake | 103 | .72 | 8461 | .99 | 3.4 | 2.8 |
| P-R Roebuck | 50 | .63 | 21,282 | .99 | 3.4 | 2.0 |
| E S-W-D Eagle | 10,823 | .99 | 13,542 | .99 | 3.3 | 2.5 |
| B-H MarkOPolo | 538 | .86 | 11,520 | .99 | 3.2 | 2.3 |
| B Ethan | 39 | .57 | 9687 | .99 | 3.0 | 1.4 |
| V-V Cleitus Bert | 42 | .56 | 12,956 | .99 | 2.9 | 1.4 |
| L-B Abel | 50 | .57 | 3013 | .98 | 2.8 | 1.2 |
| J Secret Kody | 28 | .48 | 1410 | .96 | 2.8 | 1.1 |

**1****January 1995 Evaluation**
**2****August 2001 Evaluation**

## Low PTA PL Bulls from 1995

|  | PL 19951 |  | PL 20012 |  | PTA PL |  |
| --- | --- | --- | --- | --- | --- | --- |
| Bull | Daus | REL | Daus | REL | 19951 | 20012 |
| P Ijon Dakota | 2817 | .94 | 4086 | .99 | -2.0 | -4.0 |
| BigAlLouRahls | 47 | .53 | 809 | .94 | -1.3 | -0.5 |
| M Enhanc. Tater | 49 | .57 | 650 | .92 | -1.1 | -3.5 |
| W-R Chalet-Red | 131 | .73 | 3346 | .98 | -1.0 | -1.2 |
| S Ijon Vision | 86 | .68 | 1363 | .96 | -0.9 | -1.4 |
| L-Ro-D Reid | 120 | .73 | 1124 | .96 | -0.8 | -0.8 |
| R Rotate Jimmy | 66 | .62 | 706 | .92 | -0.8 | -0.5 |
| O Rambo | 199 | .66 | 1839 | .96 | -0.6 | 0.0 |

**1****January 1995 Evaluation**
**2****August 2001 Evaluation**

## High PTA PL Bulls from 1997

|  | PL 19971 |  | PL 20012 |  | PTA PL |  |
| --- | --- | --- | --- | --- | --- | --- |
| Bull | Daus | REL | Daus | REL | 19971 | 20012 |
| E Meadowlord | 73 | 65 | 932 | 93 | 3.4 | 1.0 |
| R-VU Emperor | 64 | 63 | 7016 | 99 | 3.3 | 2.6 |
| SFL Sndwtr Itm | 97 | 66 | 2396 | 97 | 3.2 | 2.8 |
| Ked Juror | 80 | 68 | 9766 | 99 | 3.2 | 1.1 |
| I-C B Troy Cash | 71 | 67 | 1348 | 95 | 3.1 | 3.2 |
| Prices Bonus | 54 | 65 | 5142 | 99 | 3.1 | 1.2 |
| H-B Clei Aspen | 56 | 65 | 1154 | 94 | 3.1 | 1.9 |
| H Aristides | 87 | 69 | 10,428 | 99 | 3.0 | 2.0 |

**1****February 1997 Evaluation**
**2****August 2001 Evaluation**

## Low PTA PL Bulls from 1997

|  | PL 19971 |  | PL 20012 |  | PTA PL |  |
| --- | --- | --- | --- | --- | --- | --- |
| Bull | Daus | REL | Daus | REL | 19971 | 20012 |
| M-B C Geoffry | 64 | 64 | 3299 | 98 | -1.4 | -1.8 |
| Peticote Lance | 1803 | 95 | 22,298 | 99 | -1.2 | -3.1 |
| S-B N-B Mascot | 10,460 | 99 | 31,021 | 99 | -1.0 | -2.7 |
| Q-P Madison | 320 | 81 | 637 | 92 | -1.0 | -2.8 |
| L Rex Richard | 117 | 74 | 6581 | 99 | -0.9 | -1.5 |
| J Rotate Jed | 429 | 85 | 8951 | 99 | -0.8 | -0.7 |
| P Desperado | 621 | 89 | 1027 | 94 | -0.6 | -1.1 |
| R Rte Juggler | 2249 | 96 | 13,486 | 99 | -0.6 | -1.7 |

**1****February 1997 Evaluation**
**2****August 2001 Evaluation**

## Current and Past EvaluationsRegressions and Correlations

| August 2001 Regressions | Milk | Fat | Protein | PL | SCS |
| --- | --- | --- | --- | --- | --- |
| February 1997 | .90 | .93 | .85 | .88 | .94 |
| January 1995 | .92 | .93 | .88 | .87 | .96 |
|  |  |  |  |  |  |
| August 2001 Correlations |  |  |  |  |  |
| February 1997 | .81 | .86 | .82 | .62 | .83 |
| January 1995 | .78 | .85 | .81 | .58 | .80 |

## PL and Lifespan Defined

**PL**
**Credit  for maximum 10 mo per lactation**
**Records ******** 305d weren’t stored in database**
**Long calving intervals unprofitable**
**Lifespan**
**Credit for months between lactations**
**Higher yield and bST allow longer lactations**
**Embryo donors not penalized**

## Lifespan and PL Compared

**Heritability**
**6.7% for lifespan**
**7.6% for PL**
**(8.5% official PL estimate since 1994)**
**Genetic correlations of lifespan**
**.986 with PL**
**More correlated than PL with yield**
**Less correlated than PL with SCS**
**Less correlated with fertility (-.46 vs -.59)**

## Cow Fertility

**Days Open**
**Calving interval – 280 days**
**Lower limit of 50 days, upper limit 250**
**Sold for reproductive problems = 250**
**Genetic parameters**
**3.7% heritability**
**.32 correlation with protein**
**.30 correlation with SCS**

## Bulls with Low Daughter Fertility

| Bull | PTA Days Open | PTA PL |
| --- | --- | --- |
| P Lance | 15.9 | -3.0 |
| J Rte Jed | 11.1 | -0.6 |
| K-M Bell Joy | 11.0 | -0.5 |
| E Rte Duke | 10.9 | -1.4 |
| R Rte Juggler |   9.7 | -1.7 |
| J-S Mark Anthony |   9.5 | -1.8 |
| H Mr Mark Cinder |   9.0 | -0.1 |
| A-R Ever-Ready |   8.0 | -0.7 |

## Bulls with High Daughter Fertility

| Bull | PTA Days Open | PTA PL |
| --- | --- | --- |
| E C Valiant | -7.2 | 1.2 |
| S Mark Arthur | -6.0 | 3.4 |
| O Chrmn Monitor | -5.4 | 0.4 |
| S Valiant Winken | -5.3 | 0.7 |
| T-H Valiant Rockie | -5.2 | 0.9 |
| C-W Valour | -5.1 | 1.5 |
| C Emerald Target | -5.0 | 1.6 |
| L-M Centurian | -4.8 | 0.7 |

## Foreign Longevity Evaluations

**Measures of longevity:**
**	****Survival, herd life, stayability, durability, PL**
**Most countries adjust for yield**
**Evaluated in 13 Countries:**
**	****Australia, Austria, Canada, Denmark, France, Germany, Great Britain, Israel, Italy, Netherlands, New Zealand, Sweden, Switzerland, USA**

## Foreign Bull Productive Life

**Options **
**Set PL equal to zero  or breed average**
**Simple regressions on yield (1995-2000)**
**Use parent average from domestic PL data (August 2000)**
**Combine PA with Interbull yield and type (November 2000)**
** ****Include also Interbull SCS (May 2001)**
**MACE for longevity (Dutch research)**

## Conclusions

**Longevity rankings have high value but lower accuracy than other traits. **
**Cow fertility has low heritability (3.7%) but high genetic correlation with PL      (-.59).**
**Selection on PL is effective, but cow fertility evaluations could increase lifetime profit. Credit for embryo donors may be needed.**