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- H. D. NORMAN and J. R. WRIGHT
- Animal Improvement Programs Laboratory
- Agricultural Research Service, USDA
- Beltsville, MD 20705-2350
- dnorman@aipl.arsusda.gov
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- An overview of the survival rate to various parities and herd life by
breed and year was reported previously.
- Hare, E., Norman, H.D., Wright, J.R. “Survival rates and herdlife of
dairy cattle in the United States”. J. Dairy Sci. (accepted)
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- A recent study shows how producers value yield and fitness traits when
culling cows.
- Norman, H.D., Hutchinson, J.L., Kuhn, M.T., Wright, J.R., Lawlor, T.J.
“Selection on yield and fitness traits when culling Holsteins during the
first three lactations”. J. Dairy
Sci. (submitted)
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- Relative
emphasis on trait
- Milk Fat Protein Days Dystocia Final
- Year yield yield yield SCS open
score score
- 1984 100 83 97 -- -21 -9 29
- 1988 100 82 99 -19 -18 -8 26
- 1992 100 76 101 -25 -23 -9 24
- 1996 100 74
100 -26 -30 -9 23
- 1997 100 83 91 -31 -61 -11 33
- 2000 100 78 95 -33 -74 -15 33
- From: Norman et.al., J. Dairy Sci. (submitted)
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- To examine some additional factors to determine how they impact herd
life in Holsteins.
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- Herd participated in DHI testing for 1 year prior to cow’s first calving
and remaining on test throughout the cow’s lactations
- Cows first calving 1980 to 1995 and remaining in same herd
- Cows culled for dairy purposes excluded
- No missing lactations (required 270–650 days between lactations)
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-
Region
- Mid- Mid- Mtn.- North- North- South- South-
- Year east west Prairie east west east west
- 1980 3.24 3.09 3.03 3.43 3.23 3.14 3.22
- 1984 3.03 2.91 2.95 3.23 3.04 3.01 3.14
- 1988 2.90 2.74 2.81 3.06 2.91 2.82 2.97
- 1992 2.80 2.71 2.78 2.95 2.83 2.67 2.90
- 1995 2.72 2.67 2.69 2.92 2.82 2.58 2.85
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- Cows in herd (no.)
- 51– 101– 201–
501– 1001– 2001–
- Year 5–50 100 200 500 1000 2000 5000
- 1985 3.05 3.02 2.99 3.03 3.02 2.87 2.82
- 1987 2.95 2.94 2.92 2.95 2.96 2.86 2.60 1989 2.85 2.85 2.85 2.92 2.88 2.84 2.73
- 1991 2.83 2.82 2.82 2.85 2.89 2.80 2.64
- 1993 2.82 2.79 2.77 2.80 2.89 2.81 2.77
- 1995 2.81 2.78 2.73 2.77 2.81 2.75 2.71
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- Inbreeding coefficient (%)
- 0.1- 1.1- 2.1- 3.1- 4.1- 5.1- 7.1- 10.1
- Year 0 1.0 2.0 3.0 4.0 5.0 7.0 10.0
15.0 >15.0
- 1980 3.33 3.14
3.26 3.31 3.24
3.13 3.09 2.98
2.88 2.91
- 1984 3.15 3.04
3.02 3.00 2.96
2.98 2.90 2.87
2.74 2.78
- 1988 2.98 2.91
2.86 2.84 2.82
2.81 2.79 2.74
2.59 2.60
- 1992 2.96 2.89
2.82 2.79 2.80
2.80 2.73 2.65
2.55 2.61
- 1995 3.02 2.92
2.83 2.76 2.74
2.76 2.70 2.64
2.60 2.49
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- Only data from Dairy Records Processing Centers reporting complete data
(DIM >305)
- Cows culled for dairy purposes excluded
- Cows exiting herds during 2002-2005
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