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AIPL RESEARCH REPORT
K2-05 (2-07)		 State and National Standardized Lactation Averages by Breed for Cows Calving in 2005

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

Lactation yields are often standardized to provide a reasonably equitable comparison of dairy cows having different lactation characteristics (i.e., age at calving, days milked, milking frequency, etc.). Average of standardized yield is compared in this report for each State and the nation for calvings in 2005 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 97 to 100% except in California (89% for Guernseys and Holsteins, and 85% for Red and Whites) and Nevada (75% 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 for milk and component yields and component percentages 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 the herd-average reports 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, the herd-average reports tend to be more current (about 6 mo) than the standardized yield reports published at the same time.

Ayrshire calvings were down 3.2% from last year Tables 8A. Calvings for Guernsey and Red and Whites declined also in 2005, dropping 3.5 and 4.4%, respectively from the previous year. Brown Swiss, Holstein, and Jersey calvings were up from last year, increasing by 1.6, 3.3 and 5.7%, respectively.

Milk yield increased for all breeds ranging from 1.8% for Milking Shorthorn to 3.1% for Brown Swiss. Both Holsteins and Jerseys showed an increase of 2.0%. Fat % were unchanged for Guernesy and Red and Whites, showed a 0.01% increase for Brown Swiss, Holstein, and Milking Shorthorn, and a 0.02% increase for Ayrshire and Jerseys. Breed fat yield increased from 2.3 to 3.4%. Protein percentage was lower by 0.01 to 0.02 % for 4 breeds, remained the same for Jersey and Milking Shorthorn, and increased by 0.01 for Red and Whites. Increases in breed average protein yield ranged from 1.9 to 2.8%. 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 2005 dropped considerably from 2004 (Herd somatic cell count report). Interpretation of trends in lactation averages should be made in view of other changes affecting profitability, and will be impacted by changes in number of records across years as well.

DHI Lactation Averages for Ayrshire  
Table 1. Ayrshire State and National Standardized Lactation Averages for Cows Calving in 2005 With Records
Used in National Genetic Evaluations.

  Records Milk Fat Protein
State (no.) (lb) (%) (lb) (%) (lb) Reporting
Alabama 3 16,719 3.42 572 3.04 509 100
Arkansas 27 18,123 3.99 723 3.11 564 100
California 21 23,577 3.81 898 3.13 737 100
Colorado 3 22,231 3.57 793 3.09 687 100
Connecticut 124 18,979 3.95 749 3.23 614 100
Delaware 2 19,236 4.02 774 3.24 623 100
Florida 3 15,389 3.43 528 3.06 471 100
Illinois 214 18,279 3.71 679 3.12 571 100
Indiana 62 16,550 3.84 636 3.14 520 100
Iowa 532 20,540 3.80 780 3.13 643 100
Kansas 70 16,866 3.62 611 3.19 538 100
Kentucky 62 14,257 3.62 516 3.17 453 100
Louisiana 13 15,664 3.79 594 3.23 506 100
Maine 119 17,078 3.74 639 3.03 517 100
Maryland 329 20,145 3.87 780 3.09 623 100
Massachusetts 28 18,102 4.02 728 3.23 585 100
Michigan 48 19,961 3.88 775 3.12 623 100
Minnesota 165 17,322 3.86 669 3.08 533 100
Missouri 85 16,831 3.92 659 3.18 534 100
Nebraska 69 16,729 3.73 624 3.21 536 100
New Hampshire 141 19,027 3.85 732 3.09 588 100
New Jersey 6 15,443 4.17 644 3.12 482 100
New Mexico 198 14,823 3.79 562 3.11 461 100
New York 1,103 17,915 3.82 685 3.09 553 100
North Carolina 72 13,839 4.18 579 3.10 428 100
Ohio 406 19,081 3.83 731 3.11 594 100
Oklahoma 94 21,831 3.46 756 3.09 676 100
Oregon 37 16,951 3.77 640 3.12 530 100
Pennsylvania 864 18,760 3.87 725 3.13 588 100
Rhode Island 26 16,828 4.00 673 3.19 537 100
South Carolina 8 20,416 3.83 782 3.15 643 100
Tennessee 30 15,382 3.67 565 3.11 479 100
Texas 73 18,847 3.92 738 3.29 620 100
Utah 24 13,741 3.90 536 3.26 448 100
Vermont 365 17,727 3.84 681 3.14 556 100
Virginia 35 17,062 3.63 619 3.10 530 100
Washington 13 18,773 3.60 675 3.23 606 100
West Virginia 28 17,642 3.84 677 3.15 556 100
Wisconsin 487 17,862 3.82 681 3.10 554 100
US 5,989 18,303 3.82 700 3.12 571 100 

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DHI Lactation Averages for Brown Swiss  
Table 2. Brown Swiss State and National Standardized Lactation Averages for Cows Calving in 2005 With Records
Used in National Genetic Evaluations.

  Records Milk Fat Protein
State (no.) (lb) (%) (lb) (%) (lb) Reporting
Alabama 6 19,328 3.80 734 3.18 615 100
Arizona 106 22,357 3.86 863 3.20 715 100
Arkansas 120 18,916 3.71 703 3.30 624 100
California 437 21,821 3.92 855 3.32 723 98
Colorado 90 21,899 4.20 920 3.38 740 100
Connecticut 49 20,231 3.88 785 3.27 662 100
Delaware 4 20,771 4.19 871 3.42 710 100
Florida 16 19,768 3.76 743 3.20 633 100
Georgia 79 19,284 3.97 765 3.30 636 100
Idaho 198 21,526 3.97 855 3.41 734 100
Illinois 618 21,910 4.01 879 3.31 724 100
Indiana 486 23,303 4.09 953 3.32 774 100
Iowa 1,460 22,233 4.00 889 3.31 737 100
Kansas 213 22,734 3.80 864 3.34 759 100
Kentucky 133 19,697 3.71 732 3.29 648 100
Louisiana 40 16,374 3.62 593 3.23 529 100
Maine 30 16,203 3.83 621 3.27 529 100
Maryland 366 21,901 4.02 881 3.28 718 100
Massachusetts 115 22,332 3.85 861 3.31 740 100
Michigan 316 24,516 3.97 972 3.27 801 100
Minnesota 1,294 21,432 4.06 870 3.28 703 100
Mississippi 12 17,062 3.83 653 3.16 539 100
Missouri 382 20,629 4.00 826 3.33 686 100
Montana 2 19,025 4.10 781 3.50 667 100
Nebraska 166 21,732 4.00 869 3.29 714 100
Nevada 1 23,445 4.59 1076 3.25 762 100
New Hampshire 114 18,861 4.02 758 3.29 620 100
New Jersey 5 26,809 4.62 1239 3.26 874 100
New Mexico 8 22,205 4.17 926 3.33 739 100
New York 1,001 20,435 4.01 820 3.29 672 100
North Carolina 64 20,239 3.95 799 3.28 664 100
North Dakota 74 18,854 3.91 737 3.34 629 100
Ohio 1,482 21,647 3.96 858 3.30 713 100
Oklahoma 97 18,224 3.70 674 3.31 602 100
Oregon 200 21,975 4.01 882 3.32 740 97
Pennsylvania 1,291 21,214 3.98 845 3.29 698 100
Puerto Rico 45 14,333 3.17 454 3.33 477 100
South Carolina 22 21,758 3.67 798 3.10 675 100
South Dakota 196 19,126 4.39 840 3.41 653 100
Tennessee 256 17,644 4.18 737 3.31 585 100
Texas 455 20,394 3.97 810 3.32 677 100
Utah 83 18,142 4.17 756 3.36 610 100
Vermont 346 20,071 4.15 832 3.37 677 100
Virginia 147 23,268 3.83 891 3.27 761 100
Washington 236 20,645 3.91 807 3.41 705 100
West Virginia 10 16,810 3.98 669 3.30 554 100
Wisconsin 3,158 21,879 4.02 880 3.29 719 100
US 16,029 21,405 4.00 856 3.30 707 >99 

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DHI Lactation Averages for Guernsey  
Table 3. Guernsey State and National Standardized Lactation Averages for Cows Calving in 2005 With Records
Used in National Genetic Evaluations.

  Records Milk Fat Protein
State (no.) (lb) (%) (lb) (%) (lb) Reporting
Alabama 1 14,495 3.79 549 3.34 484 100
Arizona 20 18,481 3.86 713 3.20 591 100
Arkansas 7 17,127 4.37 749 3.29 563 100
California 397 18,682 4.33 808 3.34 638 89
Connecticut 52 16,973 4.39 744 3.30 560 100
Delaware 1 18,573 4.51 837 3.19 593 100
Florida 5 18,449 4.14 763 3.10 572 100
Georgia 7 15,721 3.58 564 3.26 513 100
Idaho 22 15,590 4.32 674 3.31 515 100
Illinois 164 17,749 4.38 778 3.16 561 100
Indiana 305 17,389 4.34 755 3.28 571 100
Iowa 558 18,770 4.41 829 3.26 612 100
Kansas 49 16,957 4.59 778 3.38 573 100
Kentucky 17 18,123 4.11 745 3.28 594 100
Louisiana 32 14,402 4.45 641 3.47 500 100
Maine 31 15,370 4.59 706 3.35 515 100
Maryland 328 16,865 4.52 763 3.31 559 100
Massachusetts 12 16,107 4.49 723 3.32 534 100
Michigan 24 15,670 4.06 636 3.10 487 100
Minnesota 377 15,415 4.47 689 3.25 501 100
Missouri 313 16,027 4.34 696 3.31 531 100
Nebraska 75 18,640 4.50 840 3.24 604 100
New Hampshire 9 15,523 4.44 690 3.31 513 100
New Jersey 3 20,285 4.76 966 3.26 660 100
New York 583 16,779 4.49 754 3.24 543 100
North Carolina 45 16,948 4.38 742 3.21 543 100
Ohio 304 17,226 4.48 771 3.33 573 100
Oklahoma 46 16,396 3.86 633 3.24 531 100
Oregon 336 18,425 4.41 812 3.27 602 100
Pennsylvania 710 16,650 4.37 728 3.24 540 100
South Carolina 50 14,943 4.49 671 3.25 485 100
South Dakota 45 12,698 4.47 567 3.23 410 100
Tennessee 98 17,158 4.23 725 3.19 547 100
Texas 116 16,432 4.03 663 3.21 527 100
Utah 2 18,330 4.15 762 3.18 582 100
Vermont 155 15,568 4.49 699 3.28 510 100
Virginia 97 16,262 4.46 726 3.24 527 100
Washington 111 16,364 4.60 753 3.40 556 100
West Virginia 11 15,794 4.67 738 3.53 558 100
Wisconsin 1,730 17,458 4.47 781 3.26 569 100
US 7,248 17,154 4.42 758 3.27 561 99 

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DHI Lactation Averages for Holstein  
Table 4. Holstein State and National Standardized Lactation Averages for Cows Calving in 2005 With Records
Used in National Genetic Evaluations.

  Records Milk Fat Protein
State (no.) (lb) (%) (lb) (%) (lb) Reporting
Alabama 929 22,203 3.32 738 2.99 665 100
Arizona 19,492 24,972 3.44 859 2.98 743 100
Arkansas 1,517 22,132 3.48 769 3.01 667 100
California 361561 26,406 3.61 953 3.06 808 89
Colorado