Brief Summary of Minutes of Annual Meeting

ANNUAL REPORT OF COOPERATIVE REGIONAL RESEARCH PROJECT: S-1008, Genetic Selection and Crossbreeding to Enhance Reproduction and Survival of Dairy Cattle Period Covered: 10-2004 to 10-2005 Date of Report: 22-Dec-2005 Annual Meeting Dates: 16-Oct-2005 to 17-Oct-2005 PROGRESS OF WORK AND PRINCIPAL ACCOMPLISHMENTS: Objective 1: Develop selection tools to enhance reproduction and survival using field data. Wisconsin demonstrated that important genetic variation exists in dairy cattle for Mycobacterium paratuberculosis infection susceptibility from estimates of heritability ranging from 0.081 to 0.141. DHI data, a management survey and maximum daily temperature on the day of insemination from Holstein cows on large commercial dairies revealed that the five most important explanatory variables affecting pregnancy status at 150 days were milk yield, body condition score and number of cows per pen played a significant role in predicting conception rate at first service. A detailed examination of body condition score (BCS) prior to and at different stages postpartum in these herds revealed that the probability of pregnancy by 150 d postpartum was 0.80 in herds with <15% BCS faults (i.e. falling below a predetermined threshold) and 0.53 in herds with >45% BCS faults. Days open data from Spanish Holstein herds were analyzed with standard linear models and with two alternative methodologies that account for censoring and showed strong agreement of sire rankings between models that take censoring into account. The Censored Linear Model predicted daughter fertility more accurately than either of the standard linear models. Producer-recorded clinical mastitis data from 77,791 cows in 418 herds were used to determine the potential for genetic improvement of mastitis resistance using data from on-farm management software programs. It appears that at least two segments need to be recorded each lactation, because mastitis in early lactation is lowly correlated with mastitis in mid or late lactation. Overall, this study shows that farmer-recorded clinical mastitis data can make a valuable contribution to genetic selection programs. Survival analysis in a Weibull proportional hazards model was used to evaluate the impact of somatic cell count (SCC) on the involuntary culling rate of US Holstein and Jersey cows with first calvings from 1990 to 2000. The risk of culling for Holstein and Jersey cows with lactation average SCC >700,000 cells/ml was 3.4 and 4.0, 2.7 and 2.9, or 2.3 and 2.2 times greater, respectively, than that of Holstein and Jersey cows with SCC of 200,000-250,000 cells/ml in herds with low, medium, or high average SCC.

Tennessee conducted research to quantify on-farm death rates in cows in the Southeastern US and to identify risk factors for on-farm cow deaths in Southeastern US herds. To date using 2004 and 2005 DHIA data from the DRMS in Raleigh, NC, death rates in Tennessee DHIA herds were found to be approximately 7 to 8% annually and on-farm death is now the leading cause of cows leaving the herds in Southeastern states including Tennessee.

Nebraska conducted a study of test-day records to compare test day (TD) models and a compound symmetry (CS) error covariance structure with autoregressive covariance structures (AR) for the estimation of genetic and environmental components of variance for milk, fat and protein yields and somatic cell score (SCS) in Holstein cows. The AR covariance structure among TD residual effects may help to prevent bias in heritability estimates for milk, fat and protein yields and SCS. In another study using the same data set, genetic evaluations from three test day (TD) models with different assumptions about the environmental covariance structure for test day records were compared with genetic evaluations from 305-d lactation records for dairy cows. The largest average estimates of accuracy of predicted breeding values were obtained with the test day ARs model and the smallest were with the 305-d model. More genetic improvement can be achieved by using TD models to select for animals for higher milk, fat and protein yields and lower SCS than by using models with 305-d lactation records.

North Carolina is examining dairy cow records via DRMS from several states in the South plus Indiana and Vermont to determine if there are differences in fertility of cow families that may be useful in future selection programs. Contemporary standard deviation (SD) differences from herd means will be used to establish an index for each cow that takes into account relative production and reproduction across multiple lactations and multiple generations within cow families.

The Animal Improvement Programs Laboratory (AIPL) of USDA at Beltsville, MD began publishing calving ease evaluations for Brown Swiss bulls in February 2005 and submitted these to Interbull for their September 2005 test run. Assuming favorable results, Interbull evaluations might be expected for Brown Swiss in Feb. 2006. Studies have been initiated in cooperation with the Holstein Association and the American Jersey Cattle Association to see if single nucleotide polymorphisms (SNP) can be more effective than blood typing and micro-satellites in parentage verification. Research is underway to determine how the 5 million calf livability scores currently in the NAAB calving ease database, most on Holstein calvings, might best be used in a genetic evaluation program to reduce the substantial economic loss associated with stillbirths. Development of a routine genetic evaluation for stillbirth would allow the U.S. to participate in the Interbull evaluation for stillbirth, as well as include it in Net Merit.

Iowa reported estimates of genetic parameters obtained for dystocia (DYS), perinatal mortality (PM), birth weight (BW), and gestation length (GL) from calving records from the Iowa State University dairy research farm, Ankeny, IA; 1968 to 2005 (n = 5794). Heritability estimates for direct additive and maternal effects were higher when estimated in a multi-trait model than by using a single-trait model.

Illinois continues cooperation with Iowa State on perinatal survival. A bimodal pattern of inheritance for calf survival was identified in sons of Holstein bulls from the National Association of Animal Breeders (NAAB) calving ease database using first parity daughter records. One explanation of this pattern of inheritance is an allele effect for bulls heterozygous for a quantitative trait loci affecting calf survival. Allele effects ranged from .29 percent change in calf survival to .41 with average allele effect of .35 (standard error of .03). Variation is sufficient to allow selection to move the average percent calf survival. Unfortunately, the bimodal bulls are younger than most of the other bulls suggesting that calf survival may be declining.

Georgia analyzed insemination records from GA and NY over 2000-2004 to gain insight into reasons for declining fertility in Holsteins. The conception rate was 0.2 at 50 DIM but increased to about 0.5 at 150 DIM. Natural service bulls showed about 0.15 higher conception rate overall, with a bigger difference in summer in GA. Holsteins may have been indirectly selected for longer lactations and for lower fertility shortly after calving. In a study of the genetic effect of heat stress, the 100 most and least heat tolerant Holstein sires were identified. Most heat tolerant sires were much lower in fluid milk and dairy form, lower in fat and protein, higher in udder score, DPR and PL, and were slightly above the average for TPI. Selection for fluid milk decreases heat tolerance, but not TPI.

Virginia investigated alternative definitions of productive life to replace the original measure of productive life as it gives credits to only the first 305 d of lactations up to 84 months of age of the cow. The alternatives explored included lactations either with a limit of 12 months per lactation or unlimited in length with no age limit. The majority of the cows were still in milk beyond 305 days, but more than 90 per cent of the lactations were less than 500 days of length. Heritability estimate of lactation curve based productive life (0.07) was higher than those of the 12 month, unlimited, and unlimited with calf credits options (0.069, 0.067, and 0.068, respectively), however, was lower than the original definition (0.073). Genetic properties of productive life improved with the increase in censoring age.

Pennsylvania obtained daily body weight measures, body weight change and body condition score (BCS) to describe genetic and phenotypic relationships among them. Electronic body weights were captured on all cows exiting the milking parlor in the Penn State dairy herd with the AfiFarm system. Body weight and BCS change in the first 30 days in milk (DIM) were merged with disease records. The correlation between body weight change and was less than expected (0.17) but the partial correlation was higher after adjustment for lactation number and season of calving (0.34). Weight change was more strongly correlated with all diseases than body condition change with the exception of BCS at calving and dystocia. The frequency of a disease incident during the first 30d was 0.48. A metabolic, ketosis or displaced abomasum incident had the greatest odds of occurring in the first 30 DIM. New York (Cornell), collaborating with Swedish researchers, investigated a population of SLB dairy cows that had an identified sire, a production at peak-test-day of at least 10 kg of milk, an age between 18 and 42 mo at first calving, reproduction information and health status in a collaborative study with Swedish scientists, All diseases occurring before 45 days, except ketosis and ovary dysfunction, had significant lengthening effects on interval from calving to first insemination (CFI). For diseases occurring after 45 days, Metritis, Foot and Leg Problems, and Other Diseases lengthened CFI median with 1-2 days. Cows treated for Ketosis, Mastitis, and Ovary Dysfunction had shorter CFI than untreated cows. For ovary dysfunction, this might be due to the favorable effect of the treatment itself. Among diseases occurring after first insemination, only Metritis had a significant lengthening effect on FLI while cows treated for Ketosis, Mastitis, Foot and Leg Problems, and Other Diseases had a shorter FLI. The number of days needed to become pregnant after calving (DO) increased in cows affected by diseases (except Mastitis) in the first 45 d after calving. Cows treated for Metritis and Ovary Dysfunction after 45 d had severely prolonged DO median, by 24 and 16 d, respectively. All diseases occurring either before or after day 45 lowered pregnancy rate at first insemination (PFI). Dystocia, Metritis and Ovary Dysfunction had the largest effects (decreased PFI by 10-14 percentage units). Objective 2: Explore the impact of crossbreeding on lifetime performance of cows Holstein cows in the St. Paul and Morris dairy herds in Minnesota and their daughters were mated over three years to either Holstein, Jersey or Montebeliarde sires with the goal of maintaining one-third of the cows in the two herds as purebred Holstein, and the remaining two-thirds of cows being various crosses of Jersey, Montbeliarde, and Holstein. A full complement of growth, reproduction, production and survival traits will be recorded on all animals. Minnesota is collaborating with seven California commercial dairies that have mated Holstein heifers and cows with imported semen of A.I. sires of Normande and Montbeliarde breeds from France, as well as the Swedish Red (SRB) and Norwegian Red (NRF) breeds, (collectively regarded as Scandinavian Red for this study). Some cows in the seven dairies continued to be pure Holstein. The Scandinavian Red-Holstein crossbreds (-2.2%) were not significantly different from the pure Holsteins for fat (lb) plus protein (lb) (1405 lb vs. 1436 lb); while the Montbeliarde-Holstein crossbreds (-3.8%) and the Normande-Holstein crossbreds (-8.6%) were significantly lower. Pure Holsteins had significantly higher milk (lb) and protein (lb) than all crossbred groups, but were not significantly different than Scandinavian Red-Holstein crossbreds for fat (lb) (763.3 lb vs. 749.6 lb.). Lactation curves were similar for the breed groups during first lactations. Averages of somatic cell score (as an indicator of mastitis) during first lactation were uniformly low compared to the entire USA, and crossbred groups did not differ significantly from pure Holsteins. Calving difficulty and stillbirths were also recorded. Both are traits of the sire as well as the dam. Scandinavian Red sires had significantly less calving difficulty and stillbirth than Holstein sires when dams of calves were first-calf pure Holsteins. Cows calving for the 2nd to 5th time had less calving difficulty and fewer stillbirths than first-calf heifers. Furthermore, significantly more Holstein-sired calves were stillborn than calves sired by bulls of other breeds. All births were analyzed for effect of breed of dam were for crossbred calves. Scandinavian Red-Holstein crossbreds (3.7%) had significantly less calving difficulty than pure Holsteins (17.7%) at first calving. Stillbirth rates tended to follow the averages for calving difficulty respective to breed group of dam, and Scandinavian Red-Holstein and Montbeliarde-Holstein dams had significantly lower stillbirth rates than pure Holstein dams at first calving. First-lactation cows that calved in the seven California dairies were compared for survival to 30 days, 150 days, and 305 days postpartum. Pure Holsteins left these dairies sooner than crossbreds, with 86% surviving to 305 days postpartum compared to 92% to 93% of crossbreds. A lower percentage of pure Holsteins also calved a second time within 20 months of first calving, 66% of pure Holsteins compared to 82% of Normande-Holstein crossbreds. Fertility, measured as actual days open for cows that had a subsequent calving or had pregnancy status confirmed by a veterinarian, indicated 38% of the pure Holsteins had 35 to 99 days open versus 52% of the Normande-Holstein crossbreds, 43% of the Montbeliarde-Holstein crossbreds, and 44% of the Scandinavian Red-Holstein crossbreds. The pure Holsteins had average days open of 150 days during first lactation while all crossbred groups had significantly fewer days open than the pure Holsteins with the Normande-Holstein crossbreds having the least at 123 days open. All three crossbred groups had significantly higher first service conception rates than the pure Holsteins.

In Virginia matings to create four breed groups, Holstein x Holstein (HH), Holstein x Jersey (HJ), Jersey x Holstein (JH), and Jersey x Jersey (JJ), continued through 2005 in the joint project at Kentucky and Virginia Tech. Hormonal regulation of the onset of puberty was the first study completed using crossbred project animals. Age at puberty by detection of progesterone in weekly blood samples was 40 weeks for JJ (n=11), 42.5 weeks for JH (n=10), 43.4 weeks for HJ (n=11), and 48.3 weeks for HH (n=18) heifers. Additive effects favoring Jersey were significant but maternal and heterosis effects were not for earlier age at puberty. These data will be merged with similar information currently being collected at the University of Kentucky. Preliminary results on dystocia and stillbirths in over 400 births at the two stations have been obtained. Somewhat surprisingly, maternal effects favored the Holstein dam over Jersey dams for both less dystocia and fewer stillbirths. Analysis of dystocia and stillbirths by logistics analysis showed Holstein genes to be 40 times more likely to cause dystocia through additive gene action, but only 30% as likely to cause dystocia through maternal gene action. For stillbirths, the odds ratios showed Holstein genes were nearly six times as likely to cause stillbirths through additive gene action, but only 30% as likely to cause stillbirths through maternal gene action.

Results from the Kentucky part of the joint project with Virginia Tech were available for births, perinatal mortality, birth weight, growth through 8 weeks and various measures of immune function. As expected, the breed groups differed in birth weight with HH being the largest but not significantly larger than HJ and JJ being the smallest. JH birth weights were similar to JJ. A significant additive effect favored Holstein but a significant maternal effect favored Jersey for birth weight. Gain from birth to either 42 d or 56 d favored JJ the least with no significant differences among HH, HJ or JH. Dry matter intake through 8 wk also favored all groups other than JJ. For the growth traits the additive genetic effects favored Holstein over Jersey while the opposite was true for maternal effects. There was significant heterosis for gain to 56 d as percent of birth weight. Various measures of immune function showed differences among the breed groups. HH were the highest and JJ the lowest for peripheral blood granulocytes which represent phagocytic number. JH had the highest antibody producing cells and JJ the highest total T-cells. While serum proteins did not differ among breed groups, the total immune globulin concentration was higher for the HJ and JH groups compared to HH and JJ. Fecal score, done daily from birth through 56 d, were averaged weekly and revealed a possible maternal effect which favored Jersey. A phagocytosis assay was also used to assess immune function of the different breed groups and the underlying genetic effects. Including both adhered and engulfed cells, HJ had the greatest phagocytic activity while the breed groups did not differ in phagocytic + killing activity and hence there was no evidence for any of the genetic effects. However, there was evidence for heterosis for phagocytosis. When only engulfed cells were measured, there were no differences among the breed groups for phagocytic + killing activity but the HJ and JJ groups had the highest phagocytic activity. There was a significant maternal effect favoring Jersey for phagocytic activity.

In North Carolina a planned crossbreeding trial using Jersey and Holsteins in a 2-breed criss-cross program has been in progress in a seasonal breeding, pasture-based dairy herd. In preliminary data, crossbred cows are intermediate in production with slight indications of heterosis but fertility of crossbred lactating cows is at least numerically higher than the average of the pure breeds. Dystocia in first parity animals has not been a major problem but numerically, it appears that Holstein heifers delivering pure bred Holstein calves have more difficult calvings than other breed combinations.

Considerable progress has been made at Maryland (AIPL) on crossbreeding evaluation issues this year. Many of the genetic evaluation programs have been modified and a multi-breed evaluation has been tested.

The objectives of this Tennessee study are to evaluate crosses of Swedish Red sires on Holstein, Jersey and crossbred cows in the Southeastern US. Nine commercial herds in Tennessee have used approximately 750 units of semen from available Swedish Red sires. Holstein, Jersey and some crossbred cows were serviced with the Swedish Red semen and contemporary Holstein and Jersey semen during 2003 and 2004. The oldest heifers from these matings are near breeding age. Approximately 100 female Swedish Red sired calves have been born in this study. Nearly 50% of the dairy farms in Tennessee are using at least some crossbreeding.

A Wisconsin project is evaluating birth weight, dystocia, fecal consistency score, respiratory disease score, and serum protein and immunoglobulin G levels in 33 F1 Jersey x Holstein calves and 106 backcross (Jersey x Holstein) x Holstein calves. Aforementioned data were also collected on 341 Holstein calves from the same experimental and commercial farms to serve as a population control to assess the effects of heterosis and calf management on these traits. Least squares means for birth weight of F1 and backcross calves were 5.0 and 1.0 kg lower, respectively, than for Holstein calves. Likewise, the odds ratio probability of requiring calving assistance was 2.26 times more likely for births involving Holstein calves versus F1 or backcross calves. Mean serum protein and immunoglobulin G levels at 0  72 hr of age were significantly higher (P < 0.05) in crossbred calves, relative to their Holstein contemporaries. Mean and maximum fecal scores during the first week of life and from birth to weaning as well as number of days with scours tended to be higher (P < 0.10) in Holstein calves compared with crossbred calves. Results suggest a higher incidence and greater severity of scours in Holstein calves than in crossbred calves. Respiratory disease scores did not differ between Holstein and crossbred calves.

Pennsylvania has initiated a project with 11 herds milking Brown Swiss x Holstein cows to compare the performance of Brown Swiss x Holstein cows with purebred Brown Swiss and Holstein cows and estimate heterosis for milk, fat and protein yield. Total milk, fat and protein yields and days in milk (DIM) were obtained for all herds for lactations 1 through 5 and average daily yields were calculated. Daily fat and protein yields were not different among the genetic groups. Daily milk yield was not different among Brown Swiss x Holstein crossbreds and ¾ Holstein or purebred Holstein cows. Purebred Holsteins and the Brown Swiss x Holstein crossbred had significantly greater daily milk yield than the 25% Holstein crossbreds and the purebred Brown Swiss. Objective 3: Develop breeding goals and appropriate indexes for optimum improvement of health, survival, reproduction and production

Minnesota reported that cows and heifers in the 1964 control line will be maintained into the future with approximately 30 lactating cows at the Morris station which has a low-input system of dairying, with heavy reliance on grazing, spring calving, and minimum shelter for cows. Control cows and heifers will be compared to pure Holstein cows and heifers as well as crossbred cows and heifers, which have contemporary genetics. Semen was collected in the early 1990s from about 3 sons of each of the original 20 control bulls to perpetuate the control line into the future. The study at Crookston continues with divergent selection for body size of cows. Rolling DHI averages for October 2005 were: Large line 47.6 cows 25,948 3.72% 966F 3.08% 799P Small line 67.3 cows 23,482 3.77% 885F 3.13% 734P Active AI sires are ranked annually from genetic evaluations, and only sires in the top 50% for PTAs of protein plus fat yield and with Reliabilities of 80% or higher are considered. Three sires are then selected for extremely large size and three for extremely small size using the Body Size Composite of the Holstein Association USA. The Swedish Red breed recently revised its Total Merit Index (TMI) eliminating growth rate of young sires, stature, and temperament while increasing the relative emphasis placed on daughter fertility, udder health, and udder conformation. The TMI for Swedish Red has a 34.2% weight on production, which still provides for a substantial positive response for production. The Swedish TMI and U.S. Net Merit have essentially equivalent components, except Sweden has Other Disease, which could be included with longevity. The comparable constituent traits and weights are (U.S. Net Merit followed by Swedish TMI):Production 55%, 34.2%; Daughter Fertility 7%, 14.9%, Sire Calving Ease 2%, 3.5%; Mat. Calving Ease 2%, 4.5%; Udder Health 9%,14.9%; Body Size 3% 0; Udder 7%, 14.3%; Feet & Legs 4%, 6.9% and Productive Life 11%, 7.0%.

Maryland (AIPL) has been cooperating with Virginia Tech to redefine Productive Life. Various alternatives have been considered, and the use of standard lactation curves to assign credits for longer lactations may be the preferred option.

Virginia conducted a comparison of Holstein with Brown Swissor Jersey cows in the same herd for age at first calving, first calving interval and true herd life up to five years in seven regions of the United States. The study showed that Jerseys calved in younger than Holsteins and had shorter first calving intervals. Brown Swiss calved in older than Holsteins, but with no difference in first calving interval. Geographic effects on Jerseys were less than for Holsteins, suggesting heat stress resistance. When cows of two breeds were housed together, breed differences were less than for cows of different breeds housed separately. Management expectations affected breed differences. A companion study of longevity of these three breeds, examined several survival-related traits using 60-month herdlife opportunity. Breed by region interaction was usually significant, with more consistent results for the southern regions. Jersey started productive life at a younger age than the other two breeds and proceeded to calve more frequently. Data for Brown Swiss were limited and results for that breed were often inconsistent. The breed usually had shorter herd-lives and fewer days in milk to 60 months of age than Jerseys or Holsteins. However, probability to survive to five years of age was greater for Brown Swiss than Holstein or Jersey. Lifetime production data were used to examine the effect of including lactations initiated prior to 5, 6, 7, 8, 9, and 10 years of age based either on complete (c) lactations or 305d (305) lactations on Relative Net Income (RNI) and Relative Net Income adjusted for Opportunity Cost (RNIOC). Herd length opportunity defines the maximum time that was included in the measure, while adjusting for opportunity cost account for premature or delayed culling. Regression measures showed that measures of RNIc for years 5-9 underestimate the 10 year value significantly more than for RNIOCc; however, the R2 values for both variables are almost identical. Results of regression analysis relating variables based on 305d showed that for these Holstein cows, Lifetime Profit based on 305d records is much less accurate than using complete lactation data. The change in R2 was proportional for both lifetime measures; however, the maximum R2 for 10 year opportunity was substantially reduced. Simple regression results demonstrated the impact of adjusting for opportunity cost on the relationship between the sires PTA for traits in Net Merit and the alternative measures of lifetime profit. All regressions were reduced in absolute value after correcting for opportunity cost.

Iowa examined realized response to sire selection for PTA fat plus protein using mature equivalent protein yield of cows in the long-term sire selection experiment at Iowa State University to determine if perceived enhancements in SAS PROC MIXED could be used in analyses involving repeated records of mature equivalent protein yield in the two selection lines. Users of SAS PROC MIXED should be encouraged to try the Kenward-Rogers method for test-of-significant for fixed effects in complex linear models. The results also confirmed that sire selection for PTA fat plus protein yield can increase protein yield.

Indiana (Purdue) has initiated a selection experiment with two divergent selection lines for dairy form. Dairy form, a conformation trait that combines strength, body condition, and body depth, has increased (thinner, deeper cows) over time, likely as a correlated response to selection for yield. Cows were assigned to either a high or low selection line for Dairy Form and will be mated to bulls with low Standardized Transmitting Ability (STA) for Dairy Form or to bulls with high STA for Dairy Form as evaluated by Holstein Association USA. Female offspring subsequently will be mated with other bulls from the same line. An attempt will be made to maintain approximately 60 cows per line in first and subsequent generations. In the first year, three bulls were selected and mated to cows in each group. Bulls in the low dairy form group averaged -1.87 STA for dairy form, compared to +3.80 STA for the high dairy form group in the first year, 1.97 vs. 3.97 for the chosen bulls in the second year, and -1.84 vs. 3.41. For this years bulls, daughters of bulls in the low dairy form group are expected to produce a modest 244 fewer pounds of milk per lactation, but are expected to stay in the herd longer, have less mastitis, and have a higher conception rate than daughters of bulls in the high dairy form group. Blood samples of foundation females have been collected and stored at Iowa State University for future genetic analyses.

Wisconsin used data are from the New York Milk Quality Promotion Services to examine the relationship between intramammary infection (IMI) status and somatic cell score. Whole farm samplings conducted from 1992 to 2004 were provided. In total, 79,308 cows were available for statistical analysis; 12.5% were contagious infections, 26.3% were environmental infections, and 61.2% were non-infected. DHI somatic cell scores (SCS) were from the same month as the bacteriological sample. Regrettably pedigree data were not available, so only a phenotypic study was possible. Significant factors in the logistic regression analysis included SCS, year, lactation number, stage of lactation, and production system. Regression lines for the three pathogen categories\ showed that one point increases in SCS were associated with about 5% increases in IMI probabilities for the environmental and contagious pathogens and 10% increase in the combined pathogen groups. The regression of IMI status on somatic cell score could provide information useful in determining selection index weights for SCS. Pennsylvania sought to evaluate the effectiveness of using simple regression techniques to estimate heritabilities for individual herds and determine the effect of adjusting records for herd heritability on the accuracy of genetic evaluations. Mature equivalent yields for milk, fat and protein and SCS from states representing four regions (Northeast, Southeast, Midwest, and West) were analyzed. Four samples of data were drawn across regions. A subset representing the 10 largest herds from the Northeast, Southeast, and Midwest and the15 largest herds from the West was assembled. Heritability was estimated for all samples using daughter-dam regression (h2DD), daughter-sire PTA regression (h2DS) and the average of the two (h2¼). Heritability was also estimated in the large herd subset (h2R) and generated individually for large herds. For yield traits, h2DD, h2DS and h2¼ were moderately correlated with h2R (range 0.43 to 0.67). Correlations for SCS were not as strong (range 0.23 to 0.43). Estimated breeding values generated before and after adjusting data for herd heritability were correlated with PTA from national genetic evaluations (Official PTA). Adjusting yield traits for h2DS, h2R and h2¼ generally increased the correlation with Official PTA while adjusting for h2DD tended to decrease the correlation. Adjusting SCS for h2R and h2¼ increased the correlation with Official PTA.