@article{clay_mcdaniel_brown_2004, title={Variances of and correlations among progeny tests for reproductive traits of cows sired by AI bulls}, volume={87}, ISSN={["0022-0302"]}, DOI={10.3168/jds.S0022-0302(04)70052-1}, abstractNote={Estimates of daughter fertility were computed using first artificial insemination (AI) breedings reported to the US Dairy Herd Improvement Association (DHIA) from 1995 through 1997. An animal model was used to compute estimated breeding values (EBV) of daughter groups with fixed effects of herd-year-month bred and classes of early lactation energy-corrected milk, days in milk (DIM) when bred, and parity. Standard deviations and ranges of bull EBV for daughter fertility for DIM were 9.1 and -31 to 18; standard deviations and ranges of bull EBV for daughter fertility for nonreturn were 3.8 and -11 to 10. Correlations were computed for EBV for daughter fertility with EBV for mating bull fertility and with predicted transmitting abilities (PTA) for milk, somatic cell score (SCS), and productive life for bulls (213) with minimums of 200 matings and 100 progeny with reproductive traits. None of the correlations among EBV for reproductive traits differed from 0.0. Correlations of EBV for daughter fertility with PTA for productive life were significantly positive. PTA for yield traits were not correlated with EBV for daughter differences in nonreturn or DIM. Very low correlations of EBV for daughter reproductive traits with PTA for yield indicate that, in order to improve daughter fertility, fertility must be incorporated in sire selection decisions.}, number={7}, journal={JOURNAL OF DAIRY SCIENCE}, author={Clay, JS and McDaniel, BT and Brown, CH}, year={2004}, month={Jul}, pages={2307–2313} }
 @article{abdallah_mcdaniel_2002, title={Heritability of changes in genetic evaluations of dairy bulls from first to later records of daughters}, volume={85}, ISSN={["0022-0302"]}, DOI={10.3168/jds.S0022-0302(02)74154-4}, abstractNote={Objectives of this study were to investigate changes in predicted transmitting abilities (PTA) of yields from evaluations based on first records to evaluations based on first and later records of daughters and determine whether these changes are heritable. Data were USDA sire evaluations of July 1989 through May 2000 on Holstein bulls in standard progeny testing programs. Changes in PTA for milk, fat, and protein from evaluations based on first records of daughters to evaluations on first and second were obtained on 2001 bulls. These were divided into two sets: subset 1 (n = 889) included bulls first evaluated before 1995 and subset 2 (n = 1112) included bulls first evaluated in 1995 and later. Changes in PTA from first-record evaluation to most recent evaluation (May 2000) were obtained on 2524 bulls first evaluated in 1995 or later. Mean changes in PTA for bulls first evaluated in 1995 and later were smaller than mean changes for bulls evaluated earlier but standard deviations were similar. Regressions of changes in PTA on changes in parent average showed that a change of 1.0 kg in parent average resulted in 1.1 to 1.2 kg change in PTA. Heritabilities estimated with animal model ranged from 0.14 to 0.23 for changes from first-record evaluation to evaluation on first and second, and 0.27 to 0.35 for changes from first-record evaluation to most recent evaluation. Heritabilities of this magnitude allow for identifying bulls that decrease in PTA.}, number={4}, journal={JOURNAL OF DAIRY SCIENCE}, author={Abdallah, JM and McDaniel, BT}, year={2002}, month={Apr}, pages={951–957} }
 @article{abdallah_mcdaniel_2002, title={Prediction of most recent evaluations of Holstein bulls from first available pedigree information}, volume={85}, ISSN={["0022-0302"]}, DOI={10.3168/jds.s0022-0302(02)74122-2}, abstractNote={The objectives of this study were to predict most recent evaluations of young bulls entering artificial insemination (AI) sampling programs from pedigree information available at time of sampling and investigate whether prediction equations differ among AI organizations. Data were pedigree information and most recent USDA evaluations on bulls entering AI sampling programs from 1989 through 1994. Pedigree information included earliest available parent average, predicted transmitting abilities (PTA) of sire, dam, and maternal grand sire. Most recent evaluations were from May 2000 evaluations and included PTA and daughter yield deviations for milk, fat, and protein. Regression coefficients on PTA of sire and PTA of dam were less than the expected coefficient of 0.50. Accuracy of prediction as determined by R-square values was less than 12%. Inclusion of PTA of maternal grand sire after PTA of sire and dam increased the accuracy of prediction by less than 1%, but regression coefficients on PTA of maternal grand sire differed from 0. Regressions on parent average were not different among AI organizations for prediction of PTA and daughter yield deviations. Partial regression coefficients on PTA of sire differed among AI organizations for prediction of fat and protein but did not differ for milk. Coefficients on PTA of dam did not differ among organizations. These results indicate that AI organizations put different emphasis on PTA of sire in selection of sons for fat and protein.}, number={3}, journal={JOURNAL OF DAIRY SCIENCE}, author={Abdallah, JM and McDaniel, BT}, year={2002}, month={Mar}, pages={670–676} }
 @article{abdallah_mcdaniel_2002, title={Proven and young Holstein: Bulls compared for daughter yields, productive life, somatic cell score, and inbreeding}, volume={85}, ISSN={["0022-0302"]}, DOI={10.3168/jds.s0022-0302(02)74121-0}, abstractNote={The objective of this study was to compare daughters of proven (progeny-tested) and young sampling bulls available for use at the same time for yield traits, productive life, somatic cell score, and inbreeding. Data were from USDA sire evaluations of July 1989 through July 1994. Proven bulls used between 1989 and 1994 were identified based on the change in number of daughters. Young bulls were identified based on age and date a bull first entered artificial insemination. Young bulls were classified into two categories: one included all young bulls available in one year and the other included the top 50% on parent average for milk. Daughter deviations for yields, productive life and somatic cell scores, and average inbreeding were obtained from May 2000 evaluation. Daughter deviation milk was not different between proven and top 50% young bulls but was lower for all young bulls. Young bulls (all and top 50%) exceeded proven bulls in daughter deviation fat and protein. Progeny of proven bulls had favorably higher productive life in most years but unfavorably higher somatic cell score than progeny of young bulls. Inbreeding was consistently higher for daughters of young bulls than for those of proven bulls. Results indicate that young bulls were competitive with proven bulls. Use of young bulls from among the top 50% should result in equal or higher genetic progress in yields compared to contemporaries by proven bulls.}, number={3}, journal={JOURNAL OF DAIRY SCIENCE}, author={Abdallah, JM and McDaniel, BT}, year={2002}, month={Mar}, pages={665–669} }
 @article{abdallah_mcdaniel_tabbaa_2002, title={Relationships of productive life evaluations with changes in evaluations for yields}, volume={85}, ISSN={["0022-0302"]}, DOI={10.3168/jds.s0022-0302(02)74123-4}, abstractNote={The objective of this work was to investigate the relationships of productive life with changes in bull evaluations for yield traits. Two datasets were analyzed. In the first, predicted differences for change in milk yield from first to second lactation of daughters of artificial insemination (AI) Holstein bulls used widely in the southeastern United States were available from a previous study. These were correlated with predicted transmitting abilities (PTA) of productive life from May 2000 USDA sire evaluations. Based on bulls with at least 10 daughters (n = 560) the correlation of PTA productive life with predicted differences for the change in milk yield was 0.30. The correlation increased to 0.36 for bulls with at least 50 daughters (n = 319) and to 0.40 for bulls with at least 75 daughters (n = 284). The second analysis included data on 1831 AI sampled Holstein bulls evaluated by USDA between July 1989 and May 2000. Changes in PTA yields were calculated as PTA from evaluations based on first and second records of daughters minus those from first-record evaluations. Correlation analyses showed that PTA yields from first-record evaluation and changes in PTA yields were positively associated with productive life. Regression coefficients on changes in PTA yields were all positive indicating that increases in PTA for yield traits as daughters aged corresponded with longer productive life. Using changes in AI bull evaluations for yields could improve prediction of productive life for little cost.}, number={3}, journal={JOURNAL OF DAIRY SCIENCE}, author={Abdallah, JM and McDaniel, BT and Tabbaa, MJ}, year={2002}, month={Mar}, pages={677–681} }
 @article{washburn_silvia_brown_mcdaniel_mcallister_2002, title={Trends in reproductive performance in Southeastern Holstein and Jersey DHI herds}, volume={85}, ISSN={["0022-0302"]}, DOI={10.3168/jds.S0022-0302(02)74073-3}, abstractNote={Trends in average days open and services per conception from 1976 to 1999 were examined in 532 Holstein and 29 Jersey herds from 10 Southeastern states. Three-year averages for eight intervals (time) were calculated (first: 1976 to 1978; eighth: 1997 to 1999). Milk, fat, fat-corrected milk, and number of cows increased across time. Herds of both breeds had linear, quadratic, and cubic effects of time on days open and services per conception. For 1976 to 1978, respective averages of days open and services per conception were 122 +/- 2.8 d and 1.91 +/- 0.08 for Jerseys, 124 +/- 0.7 d and 1.91 +/- 0.02 for Holsteins. Days open increased nonlinearly to 152 +/- 2.8 d for Jerseys and 168 +/- 0.7 d for Holsteins by 1997 to 1999, resulting in a breed x time interaction. Services per conception also increased nonlinearly, reaching 2.94 +/- 0.04 services for both breeds in 1994 to 1996, changing only slightly after 1996. Fat-corrected milk and number of cows had small but significant effects. Five subregions (one to three states) differed in mean days open and services per conception, but changes in those measures across time among subregions were similar. Days to first service increased by 16 (Holsteins) and 18 d (Jerseys) during the last five 3-yr periods, associated with increasing days open. Estrus detection rates generally declined from 1985 to 1999, associated inversely with services per conception. Reduced reproductive performance in Southeastern dairy herds is of concern. Multiple strategies are needed to attenuate further declines.}, number={1}, journal={JOURNAL OF DAIRY SCIENCE}, author={Washburn, SP and Silvia, WJ and Brown, CH and McDaniel, BT and McAllister, AJ}, year={2002}, month={Jan}, pages={244–251} }
 @article{clay_mcdaniel_2001, title={Computing mating bull fertility from DHI nonreturn data}, volume={84}, ISSN={["0022-0302"]}, DOI={10.3168/jds.S0022-0302(01)74585-7}, abstractNote={Animal model methodology was used to compute yearly measures of relative fertility of Holstein AI mating bulls based upon 70-d nonreturn of first breedings as reported to U.S. DHIA from 1988 through 1997. Estimated Relative Conception Rates (ERCR) were computed for bulls with a minimum of 50 first breedings in a single year using variance ratios 45.5 for mating bull, 45.5 for animal genetic effects, and 31 for permanent environment. The model assumed repeatability across lactations of 0.05 and included fixed effects of herd-year-month bred and classes of parity, early lactation energy-corrected milk and days open when bred. Estimates of fertility were greater for breedings to cows that were young, had low early lactation production, and were in late stages of lactation. ERCR were expressed as difference in nonreturn from the average AI mating bull of herdmates. Values ranged from -18 to +13. For ERCR computed from a minimum of 1000 breedings, 90% were within four units of zero. Early ERCR computed from a few breedings in a single year were tested for ability to predict later ERCR computed from a minimum of 1000 different breedings. Early ERCR computed from 300 or more matings accurately predicted later independent ERCR. For yearly estimates each based upon a minimum of 1000 breedings, 8% changed more than three units, and 4% declined more than three units. Correlations between ERCR and predicted transmitting abilities protein and type production index were significant but accounted for little variance. Correlations between ERCR and other traits were not significant.}, number={5}, journal={JOURNAL OF DAIRY SCIENCE}, author={Clay, JS and McDaniel, BT}, year={2001}, month={May}, pages={1238–1245} }
 @article{mcdaniel_2001, title={Uncontrolled inbreeding}, volume={84}, ISBN={0022-0302}, DOI={10.3168/jds.s0022-0302(01)70214-7}, abstractNote={The main objective of this review is provide a general overview of the current inbreeding status in major livestock types and to remind all animal breeders that increasing accuracy and intensity of selection are not the only considerations in a genetic improvement program.A second objective is to set the stage for detailed reviews of the situations in some individual species in this symposium.Intense selection in livestock without careful mating and large effective population size has led to uncontrolled inbreeding in many species.Modern and likely future genetic techniques will probably increase this trend unless steps to alleviate it are taken.Without control of inbreeding, deterioration in lowly heritable but economically important traits such as reproductive efficiency and survival is likely.All breeds and breeders in all species should take steps to reduce uncontrolled inbreeding to maintain genetic variation and improve competitiveness with other food protein sources.}, journal={Journal of Dairy Science}, author={McDaniel, B. T.}, year={2001}, pages={185} }
 @article{abdallah_mcdaniel_2000, title={Genetic change in milk, fat, days open, and body weight after calving based on three methods of sire selection}, volume={83}, ISSN={["0022-0302"]}, DOI={10.3168/jds.S0022-0302(00)75003-X}, abstractNote={Three Holstein lines, were compared, based on different methods of sire selection, for genetic change in 3.7% FCM, fat yield, days open, and predicted body weight after calving. The three lines were 1) evaluated sires selected only for 3.7% FCM (milk line), 2) evaluated sires selected on an index that included 3.7% FCM and type traits (index line), and 3) young bulls selected on pedigree for 3.7% FCM (young line). Cows from these lines were born in 1971 through 1993 in five experimental herds owned by the State Farm Division of North Carolina Department of Agriculture. Breeding values of cows in each line computed with a repeatability model were averaged by and regressed on birth year to estimate genetic change. Genetic gains in 3.7% FCM were 81 kg/yr for the milk line, 61 kg/yr for the line selected on index, and 68 kg/yr for the young sire line. Estimates of genetic gain in fat yield were 2.99, 2.16, and 2.54 kg/ yr in the three lines, respectively. Genetic gains in 3.7% FCM and fat yield in the milk line were significantly different from the index and young sire lines, but the index and young sire lines were not significantly different. Estimates of genetic change in days open were 0.71, 0.57, and 0.63 d/yr in the milk, index, and young sire lines, respectively. These estimates were not significantly different. Average breeding values for body weight decreased for births from 1971 to 1981 then rapidly increased for later births in all lines.}, number={6}, journal={JOURNAL OF DAIRY SCIENCE}, author={Abdallah, JM and McDaniel, BT}, year={2000}, month={Jun}, pages={1359–1363} }
 @article{abdallah_mcdaniel_2000, title={Genetic parameters and trends of milk, fat, days open, and body weight after calving in North Carolina experimental herds}, volume={83}, ISSN={["0022-0302"]}, DOI={10.3168/jds.S0022-0302(00)75004-1}, abstractNote={The main objective of this study was to estimate genetic trends for 3.7% FCM, fat yield, days open, and predicted body weight after calving in six experimental dairy herds owned by the State Farm Division of the North Carolina Department of Agriculture. Body weights were predicted from heart girths measured at or before the first test day after calving. Data analyzed were 23,052 records from 8575 cows, daughters of 681 bulls. Heritabilities and breeding values were estimated using the multiple-trait, derivative-free REML programs and a single-trait repeatability model. Breeding values of cows were averaged by and regressed on birth year to estimate genetic trends. Genetic correlations between traits were estimated by correlating breeding values. Estimates of heritability were 0.25 for 3.7% FCM, 0.28 for fat yield, 0.03 for days open, and 0.17 for predicted body weight. Unfavorable genetic relationships were found between yields and days open and between yields and body weight. Genetically, cows that were heavier after calving produced less milk and fat but conceived earlier than smaller cows. Genetic changes in yields and days open were greater for cows born after 1970, but the greatest genetic changes were after 1980 (FCM, 94.7 kg/yr; fat yield, 3.46 kg/yr; days open, 1.1 d/yr). Breeding values for body weight increased for cows born from 1950 to 1970, decreased until 1980, and increased for later parities. The results of our study suggest that AI organizations may need to include fertility traits in progeny testing and relax the emphasis on increased body weight.}, number={6}, journal={JOURNAL OF DAIRY SCIENCE}, author={Abdallah, JM and McDaniel, BT}, year={2000}, month={Jun}, pages={1364–1370} }
 @article{wu_smith_freeman_beitz_mcdaniel_lindberg_2000, title={Sequence heteroplasmy of D-loop and rRNA coding regions in mitochondrial DNA from Holstein cows of independent maternal lineages}, volume={38}, ISSN={["0006-2928"]}, DOI={10.1023/A:1002061101697}, abstractNote={A mitochondrial DNA (mtDNA) fragment containing the D-loop, phenylalanine tRNA, valine tRNA, and 12S and 16 rRNA genes was cloned and sequenced from 36 cows of 18 maternal lineages to identify the polymorphic sites within those regions and to detect the existence of heteroplasmic mtDNA in cows. Seventeen variable sites were observed within the D-loop and rRNA coding regions of bovine mtDNA within a 2.5-kb span. The hypervariable sites in the D-loop and rRNA coding regions were identified at nucleotide positions 169, 216, and 1594. Heteroplasmic mtDNA (variable mtDNA within a tissue) existed extensively in cows and was detected within the above regions in 11 of 36 cows sequenced. The insertion, deletion, and nucleotide transversion polymorphisms were found only in homopolymer regions. Heteroplasmy was observed frequently and seemingly is persistent in cattle. Though heteroplasmy was demonstrated, most lineages and mtDNA sites showed no heteroplasmy.}, number={9-10}, journal={BIOCHEMICAL GENETICS}, author={Wu, JM and Smith, RK and Freeman, AE and Beitz, DC and McDaniel, BT and Lindberg, GL}, year={2000}, month={Oct}, pages={323–335} }
 @article{mcdaniel_1995, title={Experience in using scores on feet and legs in selection of dairy cattle / Erfahrungen mit Merkmalen von Klauen und Gliedmassen bei der Selektion von Milchkuen}, volume={67}, number={6}, journal={Zuchtungskunde}, author={McDaniel, B. T.}, year={1995}, pages={449} }
 @article{mcdaniel_bell_1992, title={Experimental comparison of systems of selecting Holstein bulls}, volume={75}, journal={Journal of Dairy Science}, author={McDaniel, B. T. and Bell, W. E.}, year={1992}, pages={150} }
 @article{mcdaniel_fetrow_harrington_bell_rehman_1990, title={Factors affecting response to recombinant bovine somatotropin}, volume={73}, journal={Journal of Dairy Science}, author={McDaniel, B. T. and Fetrow, J. and Harrington, B. D. and Bell, W. E. and Rehman, J. D.}, year={1990}, pages={159} }
 @article{mcdaniel_bell_fetrow_harrington_rehman_1990, title={Survival rates and reasons for removal of cows injected with rBST}, volume={73}, journal={Journal of Dairy Science}, author={McDaniel, B. T. and Bell, W. E. and Fetrow, J. and Harrington, B. D. and Rehman, J. D.}, year={1990}, pages={159} }
 @article{mcdaniel_bell_1989, title={Genetic gain in milk yield from three systems of sire selection}, volume={72}, journal={Journal of Dairy Science}, author={McDaniel, B. T. and Bell, W. E.}, year={1989}, pages={68} }
 @article{mcdaniel_gallant_fetrow_harrington_bell_hayes_rehman_1989, title={Lactational, reproductive and health responses to recombinant bovine somatrotropin under field conditions}, volume={72}, journal={Journal of Dairy Science}, author={McDaniel, B. T. and Gallant, D. M. and Fetrow, J. and Harrington, B. and Bell, W. E. and Hayes, P. and Rehman, J. D.}, year={1989}, pages={429} }
 @article{mcdaniel_cassell_1981, title={EFFECTS OF EMBRYO TRANSFER ON GENETIC CHANGE IN DAIRY-CATTLE}, volume={64}, ISSN={["0022-0302"]}, DOI={10.3168/jds.S0022-0302(81)82873-1}, abstractNote={Impact of embryo transfer on rate of genetic gain was examined for a) development of bulls for progeny test, b) development of replacement females, and c) progeny testing of dams of bulls and replacement females. Increased selection intensity by embryo transfer potentially could improve genetic merit of bull dams by 17% when applied to production of sires for progeny test. Additional benefits would arise from increased availability of sisters to such bulls. Genetic merit of dams of replacement females increases more than genetic merit of dams of bulls with embryo transfer. However, current costs of embryo transfer limit its application to production of replacement females when increased yield is the sole source of added income. Increases in generation interval offset improvement in rate of genetic gain per generation from progeny testing females. Therefore, mass selection on own performance and pedigree produce a higher rate of genetic gain per year than progeny testing females. Application of embryo transfer to selection schemes for multiple traits may prove beneficial.}, number={12}, journal={JOURNAL OF DAIRY SCIENCE}, author={MCDANIEL, BT and CASSELL, BG}, year={1981}, pages={2484–2492} }
 @article{mcdaniel_1974, title={WHY NEW SIRE SUMMARIES ARE NEEDED}, volume={57}, ISSN={["0022-0302"]}, DOI={10.3168/jds.s0022-0302(74)84991-x}, abstractNote={Abstract Assumptions underlying the herdmate comparison now used in the United States and evidence on their validity under current conditions were reviewed. The main conclusion was that changes to account more adequately for genetic variation in herdmates of different progeny groups would do most to improve accuracy of the herdmate comparison method of evaluating sires. Changes in procedures so that comparisons are based more on cows of similar ages when possible would reduce dependence on assumptions concerning adjustment factors for age. Including information on bulls’ parentage also might be useful when limited progeny data are available. Herd-mate comparisons as now used in the United States are useful indicators of genetic merit, but they should be made more accurate by refinements listed above. When more sophisticated sire evaluation methods replace herdmate comparisons, they should be designed to have minimum dependence on adjustment factors for age and underlying assumptions.}, number={8}, journal={JOURNAL OF DAIRY SCIENCE}, author={MCDANIEL, BT}, year={1974}, pages={951–955} }