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2006Mid-Atlantic Dairy Grazing Conference, 2006 (1)
Is There a Need forDifferent Genetics inDairy Grazing Systems?
H. D. Norman, J. R. Wright, R. L. Powell
Animal Improvement Programs LaboratoryAgricultural Research Service, USDABeltsville, MD 20705-2350
[email protected] 301-504-8334
What genetic programs work well for U.S. graziers?
2006Mid-Atlantic Dairy Grazing Conference, 2006 (2)
Mid-Atlantic Dairy Grazing Conference, 2006 (3) 2006
Grazier breeding
Objective
– Cattle with better fertility or other desired characteristics
Approaches (occasional use)
– Bulls from countries that practice grazing
– Bull breed different from cow breed to capitalize on heterosis
– Effectiveness in grazing herds?
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Phenotypic trend in days open
100
120
140
160
65 70 75 80 85 90 95 00
Year
Day
s open
12345
Lactation
Mid-Atlantic Dairy Grazing Conference, 2006 (5) 2006
Comparison study
Daughter performance within herd
– New Zealand AI Holstein/Friesian bulls
– Other AI Holstein bulls (predominantly U.S.)
Cows included
– Records in AIPL national database
– Calved (1st parity) before May 2005
– Time to express the performance traits
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Traits examined
–Milk, fat, protein
–Somatic cell score
–Days open
–Conformation traits
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Yield and SCS data
First-lactation daughters (159 herds)– 552 sired by 26 New Zealand bulls– 6266 sired by 1119 U.S. bulls
Second-lactation daughters (136 herds)– 394 sired by 19 New Zealand bulls– 5212 sired by 1464 U.S. bulls
Third-lactation daughters (90 herds) – 213 sired by 14 New Zealand bulls– 3170 sired by 1036 U.S. bulls
Mid-Atlantic Dairy Grazing Conference, 2006 (8) 2006
Yield results
Milk U.S. daughter superiority– First lactation 1060 lb***– Second lactation 1261 lb***– Third lactation 1056 lb***
Fat New Zealand daughter advantage– First lactation 2 lb– Second lactation 2 lb– Third lactation 7 lb
Protein U.S. daughter superiority/advantage– First lactation 11 lb**– Second lactation 15 lb*** – Third lactation 11 lb
Mid-Atlantic Dairy Grazing Conference, 2006 (9) 2006
Economic value
Current U.S. milk prices
MFP$ = 0.016 milk + 1.50 fat + 1.95 protein
U.S. daughter MFP$ advantage– First lactation $35.41– Second lactation $46.43– Third lactation $27.85
Mid-Atlantic Dairy Grazing Conference, 2006 (10) 2006
SCS results
First lactationU.S. daughter superiority of 0.22***
Second lactationU.S. daughter advantage of 0.10
Third lactationU.S. daughter advantage of 0.06
Mid-Atlantic Dairy Grazing Conference, 2006 (11) 2006
Days open data
First-lactation daughters (148 herds)– 513 sired by 25 New Zealand bulls– 5823 sired by 1078 U.S. bulls
Second-lactation daughters (122 herds)– 357 sired by 19 New Zealand bulls– 4663 sired by 1338 U.S. bulls
Third-lactation daughters (79 herds) – 183 sired by 14 New Zealand bulls– 2767 sired by 931 U.S. bulls
Mid-Atlantic Dairy Grazing Conference, 2006 (12) 2006
Days open results
First lactationNew Zealand daughter superiority of 7 days*
Second lactationNew Zealand daughter superiority of 8 days*
Third lactationNew Zealand daughter advantage of 2 days
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Type data
First-lactation daughters
– 79 sired by New Zealand bulls
– 308 sired by U.S. bulls
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Type results
Final scoreU.S. daughters higher by 1.6 points*
StatureU.S. daughters taller, by 2.3 points*
Rear udder heightU.S. daughter superior by 2.6 points*
Udder depthU.S. daughter superior by 3.2 points**
Mid-Atlantic Dairy Grazing Conference, 2006 (15) 2006
Yield results from spring calvers Milk U.S. daughter superiority– First lactation 774 lb***– Second lactation 1186 lb***– Third lactation 1642 lb***
Fat New Zealand daughter advantage– First lactation 7 lb– Second lactation 4 lb– Third lactation 13 lb
Protein U.S. daughter superiority/advantage– First lactation 9 lb– Second lactation 18 lb* – Third lactation 29 lb**
Mid-Atlantic Dairy Grazing Conference, 2006 (16) 2006
SCS results for spring calvers First lactation
U.S. daughter superiority of 0.24*
Second lactationU.S. daughter advantage of 0.16
Third lactationU.S. daughter advantage of 0.11
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Days open for spring calvers
First lactationNew Zealand daughter advantage of 6 days
Second lactationNew Zealand daughter advantage of 1 days
Third lactationNew Zealand daughter advantage of 1 days
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Genetic alternative
To achieve top fertility, consider direct selection for Daughter pregnancy rate (DPR) from US bulls or those from all sources
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Definitions
Days open = days from calving to conception
Daughter pregnancy rate (DPR) = percentage of those open (non-pregnant) cows that are between 50 and 250 days in milk that become pregnant within 21 days
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Days open and DPR by breed
Breed Avg. days open Avg DPR (%)
– Ayrshire 143 22.4 – Brown Swiss 143 22.4 – Guernsey 151 20.5– Holstein 148 21.2– Jersey 127 26.5– Milking Shorthorn 135 24.5
DPR = 0.25 (233 – days open)
Mid-Atlantic Dairy Grazing Conference, 2006 (21) 2006
High DPR vs. Active-AI Holsteins
Traits High DPR bulls All Active-AI
– Milk (lbs) 349 824 – Fat (lbs) 14 32– Protein (lbs) 19 26– SCS 2.84 2.95– Productive Life (mo) 4.1 0.8– DPR (%) 2.3 -0.3– Net Merit Dollars 359 236
# of bulls (DPR≥2.0)24 692
Mid-Atlantic Dairy Grazing Conference, 2006 (22) 2006
High DPR vs. All Active-AI Jerseys
Traits High DPR bulls All Active-AI
– Milk (lbs) -6 619 – Fat (lbs) 46 40 – Protein (lbs) 18 27– SCS 2.94 2.95– Productive Life (mo) 2.3 1.7– DPR (%) 1.5 -0.1– Net Merit Dollars 302 269
# of bulls (DPR≥1.0) 11 96
Mid-Atlantic Dairy Grazing Conference, 2006 (23) 2006
Higher DPR vs. High Active-AI HO
Traits Higher DPR bulls High All Active-AI
– Milk (lbs) 748 1142 – Fat (lbs) 28 44– Protein (lbs) 29 35– SCS 2.82 2.90– Productive Life (mo) 4.8 1.8– DPR (%) 2.3 0.0– Net Merit Dollars 462 358
# of bulls (DPR≥2.0)12 346
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Conclusions
Strain differences between U.S. Holsteins and New Zealand Friesians for several traits
Higher milk and protein yields for U.S. bull daughters
Lower first-lactation SCS for U.S. bull daughters
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Conclusions (continued)
Fewer first- and second-lactation days open for New Zealand bull daughters
Smaller body size for New Zealand bull daughters
Better udders for U.S. bull daughters
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Caution
Strain differences influenced by individual bulls chosen from each country
Found the New Zealand bulls chosen were slightly more selective than the US bulls used
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Recommendations to breeders Don’t select bulls solely on one trait
because many traits have economic value
Consider economic value of all performance traits in your own market when making genetic choices
For seasonal calving, use an index that puts more weight on daughter fertility than those recommended for the general industry
Thank you!
2006Mid-Atlantic Dairy Grazing Conference, 2006 (28)