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AIPL RESEARCH REPORT
K2-04 (3-06)		 State and National Standardized Lactation Averages by Breed for Cows Calving in 2004

H.D. Norman and L.L.M. Thornton
Animal Improvement Programs Laboratory, ARS-USDA, Beltsville, MD 20705-2350
301-504-8334 (voice) ~ 301-504-8092 (fax) ~ inquiry@aipl.arsusda.gov ~ http://aipl.arsusda.gov

Standardized lactation yields have been used to compare dairy cows having different lactation characteristics (i.e., age at calving, days milked, milking frequency, etc.) in an equitable manner. Average of standardized yield is compared in this report for each State and the nation for calvings in 2004 by breed. The data available originated in herds enrolled in the Dairy Herd Improvement (DHI) Program. The test-day data, used by the Animal Improvement Programs Laboratory to determine lactation records, are processed and provided by the dairy records processing centers (DRPC). DHI participation and DRPC activity have also been summarized using the same data source.

Only data used in calculation of national genetic evaluations are included in these State and national averages. Thus, records beyond fifth lactation or by cows that lacked either a first lactation record or lacked valid sire identification were excluded. For other editing requirements, see complete evaluation documentation.

Lactation records were calculated using the best prediction method starting in 1997 and were standardized for age-parity, calving month, previous days open, and times milked per day. Records shorter than 305 days were extended to 305 days as part of the best prediction process. Prior to 1997 the records were calculated using the test interval method. This change was responsible for a portion of the increases in yields observed between 1996 and 1997 because the current method gives a more favorable prediction for the lower producing cows. Protein testing for records contributing to genetic evaluations is at or near 100% except in California (87% for Guernseys, 88% for Holsteins, and 83% for Red and Whites) and Nevada (85% for Holsteins). Component percentages were computed from averages of standardized yields for milk and components.

Numbers of records and averages for yields and component percentages are in Tables 1 through 7 by State for Ayrshires, Brown Swiss, Guernseys, Holsteins, Jerseys, Milking Shorthorns, and Red and Whites, respectively. Numbers of records and national averages are in Tables 8A-8F by breed for selected years.

Breed yields are different between this report and the herd-average report because this report summarizes standardized lactation yield, whereas the herd-average report is determined from actual herd yields. Records contributing to herd-averages are not restricted to those usable for national genetic evaluations. Herd-average report is impacted also by the length of dry period. Relative yields among breeds differ between the two reports because of large breed differences in percentage of usable records and differences in age-parity factors. Also, herd-average reports tend to be more current (about 6 mo) than standardized yield published at the same time.

Ayrshire calvings were down 5.6% from last year, falling below the previous low set in 2001. Calvings for Ayrshires, Guernsey, and Red and Whites declined in 2004, dropping 5.6%, 4.7%, and 8.0%, respectively from the previous year. Numbers have declined steadily in the latter two breeds falling by nearly 50% since 1995. Jersey calvings increased 4.7% for 2004, picking up their earlier trend after experiencing little growth in 2003. Holstein calvings were up 2.1% over 2003 and 0.5% over 2002.

Milk yield increased slightly for all breeds except Milking Shorthorn, but differences from last year were 1% or less. While fat % was down slightly (<1%), higher milk production balanced fat production. Protein % remained at 2003 levels, thus protein production increased slightly. While feed availability and operating costs, milk and beef prices, Government programs, and characteristics of herds entering and leaving eligible testing programs can affect production averages in either direction, genetic change continues to have a positive effect on yield. The leveling off of average yields most likely reflects changes in management strategies due to feed availability and somewhat more emphasis on other traits such as health and longevity. For instance, average somatic cell count during 2004 was below 300,000 cells/ml for the first time in 10 years (Herd somatic cell count report). Interpretation of trends in lactation averages should be made in view of other changes affecting profitability.

DHI Lactation Averages for Ayrshire  
Table 1. Ayrshire State and National Standardized Lactation Averages for Cows Calving in 2004 With Records
Used in National Genetic Evaluations.

  Records Milk Fat Protein
State (no.) (lb) (%) (lb) (%) (lb) Reporting
Alabama 3 15,018 3.36 505 3.11 468 100
Arkansas 26 17,663 3.52 622 3.10 547 100
California 25 22,714 3.85 874 3.14 714 100
Colorado 9 18,788 3.64 685 3.10 583 100
Connecticut 112 19,213 3.99 767 3.27 628 100
Delaware 4 16,804 4.07 684 3.23 543 100
Florida 5 15,355 3.70 568 3.18 488 100
Idaho 1 14,261 4.14 590 3.10 442 100
Illinois 234 18,231 3.66 667 3.15 573 100
Indiana 64 16,514 3.88 641 3.21 530 100
Iowa 569 19,410 3.73 725 3.14 610 100
Kansas 65 17,081 3.67 628 3.18 544 100
Kentucky 74 15,190 3.62 549 3.19 484 100
Louisiana 11 15,531 3.80 590 3.15 488 100
Maine 125 17,121 3.72 638 3.00 514 100
Maryland 321 20,253 3.94 798 3.12 632 100
Massachusetts 13 18,030 4.01 722 3.23 583 100
Michigan 56 20,894 3.84 803 3.10 648 100
Minnesota 180 17,481 3.89 679 3.08 538 100
Missouri 82 15,608 3.76 587 3.10 484 100
Nebraska 77 16,777 3.77 633 3.11 522 100
New Hampshire 136 19,617 3.62 710 3.16 620 100
New Jersey 8 18,690 4.27 797 3.10 579 100
New Mexico 242 14,259 3.79 541 3.14 448 100
New York 1,113 17,371 3.84 666 3.09 536 100
North Carolina 73 13,021 4.24 551 3.05 397 100
North Dakota 7 19,252 3.76 724 3.16 607 100
Ohio 437 18,233 3.71 677 3.13 571 100
Oklahoma 84 22,881 3.41 780 3.09 707 100
Oregon 31 17,269 3.78 653 3.10 535 100
Pennsylvania 890 17,956 3.82 687 3.14 563 100
Rhode Island 21 14,690 3.96 581 3.14 461 100
South Carolina 5 19,377 3.87 751 3.15 611 100
Tennessee 40 15,064 3.79 571 3.13 472 100
Texas 102 19,242 3.91 752 3.33 641 100
Utah 20 13,987 4.03 564 3.25 455 100
Vermont 375 17,801 3.85 686 3.15 561 100
Virginia 49 15,694 3.60 566 3.11 488 100
Washington 12 18,542 3.65 677 3.20 593 100
West Virginia 30 16,958 3.75 636 3.15 534 100
Wisconsin 459 17,650 3.84 677 3.13 552 100
US 6,190 17,885 3.80 680 3.13 560 100 

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DHI Lactation Averages for Brown Swiss  
Table 2. Brown Swiss State and National Standardized Lactation Averages for Cows Calving in 2004 With Records
Used in National Genetic Evaluations.

  Records Milk Fat Protein
State (no.) (lb) (%) (lb) (%) (lb) Reporting
Alabama 5 20,069 3.66 735 3.08 618 100
Arizona 102 21,466 3.90 837 3.18 682 100
Arkansas 141 17,874 3.69 659 3.31 592 100
California 437 21,271 3.90 829 3.34 709 98
Colorado 57 23,166 4.04 935 3.30 765 100
Connecticut 54 20,392 3.99 814 3.34 682 100
Delaware 13 17,649 4.36 770 3.45 609 100
Florida 17 20,250 3.81 771 3.29 666 100
Georgia 84 19,663 3.92 771 3.31 651 100
Idaho 195 21,836 3.88 847 3.43 749 100
Illinois 547 21,651 4.00 867 3.33 720 100
Indiana 468 22,539 4.10 925 3.36 756 100
Iowa 1,460 21,337 4.02 858 3.35 714 100
Kansas 216 23,136 3.74 866 3.35 776 100
Kentucky 117 19,080 3.77 720 3.29 627 100
Louisiana 27 15,806 3.48 550 3.22 509 100
Maine 30 16,526 3.80 629 3.34 552 100
Maryland 359 21,535 3.91 843 3.29 708 100
Massachusetts 107 21,117 3.81 805 3.35 708 100
Michigan 307 23,869 4.01 957 3.29 785 100
Minnesota 1,271 20,765 4.08 846 3.29 683 100
Mississippi 7 17,276 3.57 616 3.00 519 100
Missouri 371 19,944 4.00 797 3.38 673 100
Nebraska 211 21,253 3.93 835 3.26 693 100
New Hampshire 106 17,490 3.88 678 3.31 579 100
New Jersey 6 19,169 4.44 851 3.26 625 100
New Mexico 13 19,021 3.82 727 3.36 640 100
New York 953 19,777 4.00 791 3.28 649 100
North Carolina 56 19,537 4.11 803 3.29 642 100
North Dakota 73 18,555 3.97 737 3.38 626 100
Ohio 1,488 21,109 3.98 841 3.31 699 100
Oklahoma 106 17,913 3.74 670 3.28 588 100
Oregon 207 21,622 3.99 862 3.31 717 100
Pennsylvania 1,373 20,092 3.93 790 3.30 662 100
Puerto Rico 89 14,167 3.19 451 3.31 469 100
South Carolina 8 21,300 3.72 793 3.18 677 100
South Dakota 193 19,276 4.31 831 3.38 651 100
Tennessee 302 17,984 3.96 712 3.26 586 100
Texas 482 19,589 3.97 779 3.33 653 100
Utah 94 16,849 4.39 739 3.39 571 100
Vermont 332 19,419 4.08 792 3.34 648 100
Virginia 155 21,825 3.70 808 3.29 718 100
Washington 221 21,287 3.86 822 3.40 724 100
West Virginia 9 18,311 4.01 735 3.46 634 100
Wisconsin 2,902 21,279 4.05 861 3.31 704 100
US 15,771 20,757 3.99 828 3.32 688 >99 

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DHI Lactation Averages for Guernsey  
Table 3. Guernsey State and National Standardized Lactation Averages for Cows Calving in 2004 With Records
Used in National Genetic Evaluations.

  Records Milk Fat Protein
State (no.) (lb) (%) (lb) (%) (lb) Reporting
Alabama 1 21,119 3.56 752 3.03 639 100
Arizona 20 20,373 4.06 827 3.10 632 100
Arkansas 17 15,205 4.02 612 3.39 515 100
California 395 18,638 4.35 812 3.38 644 87
Colorado 5 16,103 4.16 670 3.19 514 100
Connecticut 41 16,996 4.34 738 3.31 563 100
Delaware 3 17,973 3.79 681 3.11 560 100
Florida 24 16,131 4.30 693 3.24 523 100
Georgia 9 17,153 3.52 604 3.26 559 100
Idaho 15 16,117 4.28 691 3.39 547 100
Illinois 184 16,895 4.43 748 3.22 544 100
Indiana 298 17,076 4.38 747 3.32 567 100
Iowa 586 18,231 4.40 803 3.27 596 100
Kansas 52 17,150 4.29 736 3.30 565 100
Kentucky 23 18,467 4.10 758 3.24 599 100
Louisiana 43 14,747 4.36 642 3.35 493 100
Maine 36 15,043 4.68 704 3.39 510 100
Maryland 326 16,350 4.56 746 3.34 546 100
Massachusetts 10 14,793 4.63 685 3.36 498 100
Michigan 27 15,352 4.12 632 3.15 484 100
Minnesota 377 15,157 4.51 683 3.27 496 100
Mississippi 1 15,054 3.83 577 2.99 450 100
Missouri 326 15,237 4.31 657 3.36 512 100
Nebraska 73 18,517 4.46 826 3.24 600 100
New Hampshire 10 17,202 4.20 722 3.21 552 100
New Jersey 2 21,115 5.17 1091 3.14 663 100
New York 455 15,888 4.45 707 3.22 511 100
North Carolina 39 16,623 4.45 739 3.27 544 100
North Dakota 1 21,420 3.84 822 3.11 666 100
Ohio 263 16,960 4.39 744 3.35 568 100
Oklahoma 86 14,754 4.02 593 3.23 476 100
Oregon 351 18,183 4.44 807 3.30 600 100
Pennsylvania 776 15,918 4.33 690 3.26 519 100
South Carolina 47 15,943 4.27 681 3.30 527 100
South Dakota 58 13,464 4.28 577 3.22 434 100
Tennessee 92 17,202 4.20 723 3.16 543 100
Texas 91 16,501 4.10 677 3.17 523 100
Utah 3 20,322 4.12 838 3.11 633 100
Vermont 170 15,538 4.45 692 3.29 512 100
Virginia 131 14,538 4.37 636 3.22 468 100
Washington 143 17,791 4.46 793 3.29 586 100
West Virginia 15 15,333 4.56 700 3.45 529 100
Wisconsin 1,883 16,872 4.51 761 3.30 556 100
US 7,508 16,692 4.42 737 3.29 549 99 

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DHI Lactation Averages for Holstein  
Table 4. Holstein State and National Standardized Lactation Averages for Cows Calving in 2004 With Records
Used in National Genetic Evaluations.

  Records Milk Fat Protein
State (no.) (lb) (%) (lb) (%) (lb) Reporting
Alabama 1,161 21,904 3.41 747 2.97 650 100
Arizona 18,897 24,548