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Cow Fertility and Effect on Longevity - Animal Improvement

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					      Cow Fertility and
     Effect on Longevity

PAUL VANRADEN
Animal Improvement Programs Laboratory
Agricultural Research Service, USDA, Beltsville, MD
paul@aipl.arsusda.gov


  PLACE, DATE (1)                                     2001
            Fertility / Longevity Data
   Cows born 1992-1994
      Cows sold for dairy purposes excluded

      1,062,791 cows remained

   Sired by 3080 sires
      Progeny tested bulls with > 60 daughters

      Older bulls to provide ties and relationships

   Multiple-trait REML analysis
     Heritabilities and correlations

     Highest and lowest PTA’s (for bulls with > 2000
      daughters)

HOLSTEIN GAC, 2001 (2)                         Paul VanRaden   2001
                         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




HOLSTEIN GAC, 2001 (3)                   Paul VanRaden   2001
Bulls with Low Daughter Fertility
                                      PTA Days
                              Bull      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


HOLSTEIN GAC, 2001 (4)                                Paul VanRaden   2001
Bulls with High Daughter Fertility
                             PTA Days
                      Bull     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


HOLSTEIN GAC, 2001 (5)                       Paul VanRaden   2001
            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




HOLSTEIN GAC, 2001 (6)                  Paul VanRaden   2001
        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)



HOLSTEIN GAC, 2001 (7)                     Paul VanRaden   2001
                         Conclusions
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.

   Embryo donors may need special edits or
    extra credit in longevity and fertility
    evaluations.



HOLSTEIN GAC, 2001 (8)                     Paul VanRaden   2001

				
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posted:1/18/2012
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