@article{knauer_stalder_serenius_baas_berger_karriker_goodwin_johnson_mabry_miller_et al._2010, title={Factors associated with sow stayability in 6 genotypes}, volume={88}, ISSN={["1525-3163"]}, DOI={10.2527/jas.2009-2319}, abstractNote={The purpose of this study was to determine the association of production factors with stayability to parity 4 (STAY4) under controlled experimental conditions. Data were from 2,293 female pigs, sampled from 6 genetic lines that were entered into the National Pork Producers Council Maternal Line National Genetic Evaluation Program. Genetic lines evaluated included Newsham (NH), National Swine Registry (NSR), American Diamond Swine Genetics (ADSG), Danbred (DAN), and 2 Dekalb-Monsanto lines (DK44 and GPK347). Stepwise logistic regression was utilized in the analysis of STAY4. All effects were nested within genetic line. Categorical effects in the model were arrival date to the wean-to-finish unit (entry date) and breed-gestation-farrowing facility (farm). Continuous effects in the model were gilt backfat, LM depth, ADG, age at puberty, age at first farrowing, and traits recorded before the last litter of the sow (prefarrow backfat, number born alive, number weaned, litter weaning weight, lactation feed intake, lactation backfat loss, and lactation length). Factors significant for STAY4 included farm, entry date, age at first farrowing, ADG, gilt backfat, and lactation before removal effects, as well as feed intake, number born alive, and lactation length. Age at first farrowing and lactation feed intake affected all genetic lines. Regression coefficients for STAY4 on age at first farrowing were -0.014, -0.022, -0.017, -0.016, -0.011, and -0.021 (all P < 0.05), respectively, for NH, NSR, ADSG, DK44, GPK347, and DAN genetic lines. Regression coefficients for STAY4 on lactation feed intake were 0.043, 0.049, 0.051, 0.061, 0.120, and 0.097 (all P < 0.05), respectively, for NH, NSR, ADSG, DK44, GPK347, and DAN females. Age at puberty, age at first farrowing, and lactation feed intake had the greatest effect on STAY4.}, number={11}, journal={JOURNAL OF ANIMAL SCIENCE}, author={Knauer, M. and Stalder, K. J. and Serenius, T. and Baas, T. J. and Berger, P. J. and Karriker, L. and Goodwin, R. N. and Johnson, R. K. and Mabry, J. W. and Miller, R. K. and et al.}, year={2010}, month={Nov}, pages={3486–3492} }
 @misc{baas_robison_tokach_goodwin_mabry_henry_johnson_clark_berger_2008, title={Untitled}, volume={86}, ISSN={["0021-8812"]}, DOI={10.2527/jas.2007-0360}, abstractNote={This letter is in response to the Letter to the Editor by Neil DeBuse published in this issue of the Journal of Animal Science regarding journal paper “Design and standards for genetic evaluation of seedstock populations” (81:2409–2418, 2003). The NPPC Genetic Programs Committee (GPC) and the authors of this journal paper recognize Newsham Hybrids as a reputable genetics company and a credible source of information to the swine industry. As a result, we have no reason to doubt their initial pedigree information and stand by the evaluation of the original Newsham Hybrids entry that was made by the GPC at the time the terminal line program was conducted. If N. DeBuse, a former Newsham Hybrids employee, believes that Newsham Hybrids deceived the National Pork Producers Council (Des Moines, IA) by misrepresenting their entry to the terminal line program, he should take that up with Newsham Hybrids officials. Until we receive official notification from Newsham Hybrids that the information concerning the Newsham Hybrids population provided to the GPC was inaccurate, we have no reason to report anything different.}, number={2}, journal={JOURNAL OF ANIMAL SCIENCE}, author={Baas, Tom J. and Robison, Odis W. and Tokach, Mike D. and Goodwin, Rodney and Mabry, John W. and Henry, Steve and Johnson, Rodger K. and Clark, L. Kirk and Berger, P. Jeffrey}, year={2008}, month={Feb}, pages={240–240} }
 @article{blowe_boyette_ashwell_eisen_robison_cassady_2006, title={Characterization of a line of pigs previously selected for increased litter size for RBP4 and follistatin}, volume={123}, ISSN={["1439-0388"]}, DOI={10.1111/j.1439-0388.2006.00620.x}, abstractNote={Summary}, number={6}, journal={JOURNAL OF ANIMAL BREEDING AND GENETICS}, author={Blowe, C. D. and Boyette, K. E. and Ashwell, M. S. and Eisen, E. J. and Robison, O. W. and Cassady, J. P.}, year={2006}, month={Dec}, pages={389–395} }
 @article{serenius_stalder_baas_mabry_goodwin_johnson_robison_tokach_millerll_2006, title={National pork producers council maternal line national genetic evaluation program: A comparison of sow longevity and trait associations with sow longevity}, volume={84}, ISSN={["0021-8812"]}, DOI={10.2527/jas.2005-499}, abstractNote={Data from the National Pork Producers Council Maternal Line National Genetic Evaluation Program were used to compare longevity of sows from 6 commercial genetic lines and to estimate the phenotypic associations of sow longevity with gilt backfat thickness, ADG, age at first farrowing, litter size at first farrowing, litter weight at first farrowing, average feed intake during lactation, and average backfat loss during lactation. The lines evaluated were American Diamond Genetics, Danbred North America, Dekalb-Monsanto DK44, Dekalb-Monsanto GPK347, Newsham Hybrids, and National Swine Registry. The data set contained information from 3,251 gilts, of which 17% had censored longevity records (sows lived longer than 6 parities). The line comparison was carried out by analyzing all lines simultaneously. Because the survival distribution functions differed among genetic lines, later analyses were carried out separately for each genetic line. All analyses were based on the non-parametric proportional hazard (Cox model). Dekalb-Monsanto GPK347 sows had a lower risk of being culled than sows from the other lines. Moreover, the shape of the survival distribution function of the Delkab-Monsanto GPK347 line was different from the other 5 lines. The Dekalb-Monsanto 347 line had lower culling rates because they had lower gilt reproductive failure before the first parity than gilts from the other lines. Within line, sows with lower feed intake and greater backfat loss during lactation had a shorter productive lifetime. Thus, producers should implement management practices having positive effects on sow lactation feed intake. Additionally, the swine genetics industry is challenged to simultaneously improve efficiency of gain of their terminal market pigs and to obtain high feed intake during lactation of their maternal lines for future improvement of sow longevity. Recording sow feed intake and backfat loss during lactation in nucleus and multiplication breeding herds should be considered. Between-line differences in this study indicate that it is possible to select for sow longevity, but more research is needed to determine the most efficient selection methods to improve sow longevity.}, number={9}, journal={JOURNAL OF ANIMAL SCIENCE}, author={Serenius, T. and Stalder, K. J. and Baas, T. J. and Mabry, J. W. and Goodwin, R. N. and Johnson, R. K. and Robison, O. W. and Tokach, M. and Millerll, R. K.}, year={2006}, pages={2590–2595} }
 @misc{johnson_berg_goodwin_mabry_miller_robison_sellers_tokach_2005, title={Critique of "Evaluation of procedures to predict fat-free lean in swine carcasses" - Authors' response to the Letter to the Editor by Schinckel}, volume={83}, DOI={10.2527/2005.83122721x}, abstractNote={In this letter, we provide responses to the issues raised by A. P. Schinckel in his Letter to the Editor regarding the manuscript by Johnson et al. (2004), “Evaluation of procedures to predict fat-free lean in swine carcasses,” J. Anim. Sci. 82:2428–2441. General responses to Schinckel's letter are made first, followed by specific responses to each issue raised. Schinckel cited several references to support his positions. The Boland et al. (1995) paper, addressing effects of operator error on variation in optical probe measurements, is work initiated by E. P. Berg, a coauthor of our paper, as a side project to his Ph.D. dissertation research. We are well aware of this source of variation. Except for Neter et al. (1996), a statistics text, and St-Pierre (2003), who addressed bias in predicting N flow in the duodenum of dairy cows, the papers cited by Schinckel are interpreted strictly from his perspective. Three of the papers referenced in Schinckel's letter were cited in our paper (Gu et al., 1992; Wagner et al., 1999; Schinckel et al., 2001), indicating our knowledge of this work. The other paper Schinckel references is a Purdue Swine Day Report (Schinckel et al., 2000) that we were not aware of, but we do not believe that it warranted citation in our paper.}, number={12}, journal={Journal of Animal Science}, author={Johnson, R. K. and Berg, E. P. and Goodwin, R. and Mabry, J. W. and Miller, R. K. and Robison, O. W. and Sellers, H. and Tokach, M. D.}, year={2005}, pages={2721–2722} }
 @article{walker_robison_whisnant_cassady_2004, title={Effect of divergent selection for testosterone production on testicular morphology and daily sperm production in boars}, volume={82}, DOI={10.2527/2004.8282259x}, abstractNote={The objective of this study was to characterize correlated responses in testicular morphology and daily sperm production to divergent selection for testosterone production. Duroc boars from high and low lines (HTL and LTL, respectively) divergently selected over 10 generations for testosterone production in response to a GnRH challenge followed by random selection were used. Testicular tissues were sampled from all available males of generation 20 (HTL, n = 46; and LTL, n = 13). Volume densities for Leydig cells, seminiferous tubules, and Sertoli cells were estimated along with sperm production. The HTL boars had greater volume densities of Leydig cells than did LTL (P < 0.01). Volume density of seminiferous tubules tended to differ between lines (P < 0.07), but Sertoli cell volume densities did not differ (P < 0.27). Sperm production traits, adjusted for age, did not differ significantly between lines. Body, testicular, and epididymal weights were recorded for boars from HTL (n = 82) and LTL (n = 44) from generations 20 and 21. After adjustment for BW, average paired testicular weights for HTL and LTL were 417 and 457 g (P < 0.01), respectively. Epididymal weights, adjusted for BW, were heavier for HTL (P < 0.01) than for LTL. To demonstrate that the selection lines still differed for testosterone production, lines were evaluated in generation 21. Endogenous testosterone production of the HTL (n = 54) and LTL (n = 44) testosterone production line averaged 49.0 ng/mL and 27.8 ng/mL (P < 0.01), respectively. Plasma FSH concentrations did not differ between lines (P < 0.30). Selection for testosterone production in response to a GnRH challenge was an effective method of changing testosterone concentrations, testicular size, epididymal weight, and volume density of Leydig cells. However, daily sperm production per gram of testes was unchanged. Based on the results of this study, selection for testosterone production is not recommended as a method of increasing sperm production in pigs.}, number={8}, journal={Journal of Animal Science}, author={Walker, S. and Robison, O. W. and Whisnant, C. S. and Cassady, J. P.}, year={2004}, pages={2259–2263} }
 @article{johnson_berg_goodwin_mabry_miller_robison_sellers_tokach_2004, title={Evaluation of procedures to predict fat-free lean in swine carcasses}, volume={82}, DOI={10.2527/2004.8282428x}, abstractNote={The objectives were to develop equations for predicting fat-free lean in swine carcasses and to estimate the prediction bias that was due to genetic group, sex, and dietary lysine level. Barrows and gilts (n = 1,024) from four projects conducted by the National Pork Board were evaluated by six procedures, and their carcass fat-free lean was determined. Pigs of 16 genetic groups were fed within weight groups one of four dietary regimens that differed by 0.45% in lysine content and slaughtered at weights between 89 and 163 kg. Variables in equations included carcass weight and measures of backfat depth and LM. Fat-free lean was predicted from measures of fat and muscle depth measured with the Fat-O-Meater (FOM), Automated Ultrasonic System (AUS), and Ultrafom (UFOM) instruments, carcass 10th-rib backfat and LM area (C10R), carcass last-rib backfat (CLR), and live animal scan of backfat depth and LM area with an Aloka 500 instrument (SCAN). Equations for C10R (residual standard deviation, RSD = 2.93 kg) and SCAN (RSD = 3.06 kg) were the most precise. The RSD for AUS, FOM, and UFOM equations were 3.46, 3.57, and 3.62 kg, respectively. The least precise equation was CLR, for which the RSD was 4.04 kg. All procedures produced biased predictions for some genetic groups (P < 0.01). Fat-free lean tended to be overestimated in fatter groups and underestimated in leaner ones. The CLR, FOM, and AUS procedures overestimated fat-free lean in barrows and underestimated it in gilts (P < 0.01), but other procedures were not biased by sex. Bias due to dietary lysine level was assessed for the C10R, CLR, FOM, and SCAN procedures, and fat-free lean in pigs fed the lowlysine dietary regimen was overestimated by CLR, FOM, and SCAN (P < 0.05). Positive regressions of residuals (measured fat-free lean minus predicted fat-free lean) on measured fat-free lean were found for each procedure, ranging from 0.204+/-0.013 kg/kg for C10R to 0.605+/-0.049 kg/kg for UFOM, indicating that all procedures overestimated fat-free lean in fat pigs and underestimated it in lean pigs. The pigs evaluated represent the range of variation in pigs delivered to packing plants, and thus the prediction equations should have broad application within the industry. Buying systems that base fat-free lean predictions on measures of carcass fat depth and muscle depth or area will overvalue fat pigs and undervalue lean pigs.}, number={8}, journal={Journal of Animal Science}, author={Johnson, R. K. and Berg, E. P. and Goodwin, R. and Mabry, J. W. and Miller, R. K. and Robison, O. W. and Sellers, H. and Tokach, M. D.}, year={2004}, pages={2428–2441} }
 @article{cassady_robison_johnson_mabry_christian_tokach_miller_goodwin_2004, title={National fork producers council maternal line genetic evaluation: A comparison of growth and carcass traits in terminal progeny}, volume={82}, DOI={10.2527/2004.82123482x}, abstractNote={The objective of this study was to compare growth and carcass traits of 1,252 progeny of six commercially available dam lines included in the National Pork Producers Council Maternal Line Evaluation Project. Lines compared included one maternal line supplied by each of American Diamond Swine Genetics (ADSG), Danbred NA (DB), two lines supplied by Monsanto Choice Genetics (DK and GPK347), Newsham Hybrids (NH), and Landrace x Large White females supplied by the National Swine Registry (NSR). All females were mated to DB, Duroc-Hampshire terminal sires. Traits analyzed were ADG from 56 to 115 kg live weight, days to 115 kg, backfat thickness measured at the 10th rib, carcass length, dressing percent, and 10th-rib LM area. Carcass traits were adjusted to a carcass weight of 85 kg. The statistical model included fixed effects of maternal line, sex, farrowing group, and finishing unit (farm). All two-way interactions among main effects were tested and removed from final models because they were not significant. In addition, because they were not significant, effects of farm and farrowing group were removed from models for carcass length and 10th-rib backfat thickness, and farm was removed from the model for LM area. Least squares means for ADG ranged from 0.74 to 0.79 kg/d. The GPK347 line had lower ADG and greater days to 115 kg than all other lines (P < 0.05). The ADSG (P < 0.05) and NH (P < 0.01) progeny had lower ADG than DK progeny. The DK line had the fewest days to 115 kg (P < 0.05). Progeny for the DB and NH lines had the least 10th-rib backfat, differing from ADSG, DK, and GPK347 (P < 0.05). Pigs from DB females had the greatest dressing percent, differing from ADSG, DK, GPK347, and NH (P < 0.05). The GPK347 had a lower dressing percent than all other lines (P < 0.05). Progeny of DB females had the greatest LM area, differing from ADSG, DK, GPK347, and NSR (P < 0.05). Offspring from ADSG and GPK347 had the smallest LM area; however, GPK347 and NSR did not differ. Differences in carcass length were statistically significant; however, actual differences were small. Economic weights for these traits relative to reproductive traits must be considered in integrated economic analyses to properly compare differences among lines in net economic value for specific markets.}, number={12}, journal={Journal of Animal Science}, author={Cassady, J. P. and Robison, O. W. and Johnson, R. K. and Mabry, J. W. and Christian, L. L. and Tokach, M. D. and Miller, R. K. and Goodwin, R. N.}, year={2004}, pages={3482–3485} }
 @article{moeller_goodwin_johnson_mabry_baas_robison_2004, title={The  National Pork Producers Council Maternal Line Mational Genetic Evaluation Program: A comparison of six maternal genetic lines for female productivity measures over four parities}, volume={82}, DOI={10.2527/2004.82141x}, abstractNote={Litter (n = 8,424) and female performance records were collected in two breed-to-wean production units in order to evaluate genetic line differences for sow longevity and maternal performance over four parities. Lines evaluated were American Diamond Genetics, Danbred North America, Dekalb-Monsanto DK44, Dekalb-Monsanto GPK347, Newsham Hybrids, and National Swine Registry. Females within a line were derived from a minimum of 65 sires, 197 dams (three dams per sire), and a maximum of three daughters per dam, except in the GPK347, which were produced using semen from 12 Nebraska Index boars mated with Dekalb-Monsanto Line 34 females. All lines expressed 100% maternal heterosis. Mixed model statistical procedures were used with fixed effects including genetic line, parity, production unit, and two-way interactions. Random effects included a contemporary week of production and female for repeated records. Lactation length (average 15 d) was included as a linear covariate where appropriate. In total, 3,599 females entered as early-weaned pigs, 3,283 entered the breeding herd, 2,592 farrowed at least a single litter, and 1,656 and completed four parities. Line (P < 0.001) and parity (P < 0.001) effects were observed for virtually all traits measured. Ranges of genetic line differences averaged across parities were 1.76 pigs for total born, 1.45 pigs born alive, and 0.31 stillborn pigs per litter. Ranges of line differences in total and live litter weight were 1.4 and 1.3 kg, respectively. Ranges among lines, within Parities 1 through 4, for litter size at weaning were 0.56, 1.08, 0.91, and 0.64 pigs per litter, respectively. Line differences for weight (33.8 kg) and backfat depth (6.4 mm) at farrowing, lactation feed intake (8.7 kg), weight loss (5.0 kg), and backfat loss (0.87 mm) were observed. Extended wean-to-estrus interval was related to variation in weight, feed intake, and backfat loss in all lines except the GPK347. The GPK347 females farrowed and weaned the largest number of pigs, ate less feed in lactation, and lost more backfat and weight during lactation, yet they had the largest litters and the shortest wean-to-estrus intervals. Line x parity interactions existed for many traits due to small rank changes, but in general, the high- and low-ranked lines did not change. Genetic line differences in reproductive efficiency through four parities exist and must be recognized when choosing a female line.}, number={1}, journal={Journal of Animal Science}, author={Moeller, S. J. and Goodwin, R. N. and Johnson, R. K. and Mabry, J. W. and Baas, T. J. and Robison, O. W.}, year={2004}, pages={41–53} }
 @article{baas_goodwin_christian_johnson_robison_mabry_clark_tokach_henry_berger_2003, title={Design and standards for genetic evaluation of swine seedstock populations}, volume={81}, DOI={10.2527/2003.81102409x}, abstractNote={The purpose of this article is to describe a program for evaluation of seedstock populations in the swine industry. Differences among seedstock populations for economically important traits must be identified in order for pork producers to efficiently use available genetic resources. National genetic evaluation programs have the potential to identify the important differences among populations and to increase the rate of genetic improvement in a population. Program results provide performance benchmarks that stimulate testing and selection procedures by seedstock suppliers that further increase the rate of genetic improvement. A Terminal Sire Line Genetic Evaluation Program was designed and conducted in the United States by the National Pork Producers Council (Des Moines, IA) to compare seedstock populations for use in crossbreeding systems. High levels of statistical accuracy for program results were established; the ability to detect differences of 0.25 SD per trait, a power of test of 75%, and a 5% significance level were selected. Pure breeds and breeding company sire lines were nominated for the program. Semen was collected from nominated boars and distributed to cooperating commercial producers during eight 1-wk breeding periods. Pigs were produced in 136 commercial herds and transported to testing facilities at 8 to 23 d of age. Nine of the 11 sire lines originally entered in the program completed the sampling requirements for statistical analysis. High levels of statistical accuracy and a large, representative sample of boars with restrictions on genetic relationships ensured that the program results included unbiased, highly accurate sire line data for growth, carcass, meat quality, and eating quality traits of economic importance. This program has shown commercial producers that they have several choices of sire lines for changing their crossbreeding programs in desired trait areas. Commercial product evaluation must be an ongoing process, and this program serves as a model for future testing and evaluation of diverse genetic seedstock populations.}, number={10}, journal={Journal of Animal Science}, author={Baas, T. J. and Goodwin, R. N. and Christian, L. L. and Johnson, R. K. and Robison, O. W. and Mabry, J. W. and Clark, K. and Tokach, M. and Henry, S. and Berger, P. J.}, year={2003}, pages={2409–2418} }
 @article{holl_robison_2003, title={Results from nine generations of selection for increased litter size in swine}, volume={81}, DOI={10.2527/2003.813624x}, abstractNote={Direct selection for increased litter size was done for nine generations. The select line consisted of approximately 15 sires and 60 dams per generation, and selection was based on estimated breeding values for number of live pigs. A control line of approximately 10 sires and 30 dams was maintained with stabilizing selection. Heritabilities estimated in the select line using restricted maximal likelihood procedures, daughter-dam regression within sires, and half-sib analysis were 0.01, 0.04, and 0.00 for number of pigs born alive (NBA) and 0.02, 0.16, and 0.00 for total born per litter (TB). Corresponding estimates for the control line were 0.01, 0.06, and 0.23 and 0.02, 0.07, and 0.09 for NBA and TB, respectively. Realized heritabilities for NBA from multiple regression were 0.09 +/- 0.08 in the select line and 0.11 +/- 0.166 in the control line. Heritability estimated from regression of differences in response between lines on differences in cumulative selection differentials was 0.13 +/- 0.07. At Generation 9, litter sizes, estimated breeding values, and cumulative selection differentials were 0.86 (P < 0.05), 0.63 (P < 0.01), and 9.05 (P < 0.01) pigs larger for the select line than for the control line. Phenotypic differences between lines for TB, adjusted backfat (BF), and days to 104 kg (DAYS) were not significant. Genetic trends in the select line were 0.053 +/- 0.002 pigs/yr for NBA, 0.054 +/- 0.013 mm/yr for BF, and 0.398 +/- 0.110 d/yr for DAYS. Corresponding phenotypic trends were 0.145 +/- 0.051 pigs/yr, -0.012 +/- 0.089 mm per yr, and 0.307 +/- 0.278 d/yr, respectively. Genetic trends in the control line were -0.026 +/- 0.004 pigs/yr for NBA, 0.026 +/- 0.022 mm/yr for BF, and -0.532 +/- 0.182 d/yr for DAYS. Corresponding phenotypic trends were 0.001 +/- 0.085 pigs/yr, -0.043 +/- 0.147 mm/yr, and -0.519 +/- 0.462 d/yr, respectively. Litter size can be increased by direct selection using breeding values estimated from an animal model, in conjunction with rearing selected gilts in litters of 10 pigs or less.}, number={3}, journal={Journal of Animal Science}, author={Holl, J. W. and Robison, O. W.}, year={2003}, pages={624–629} }
 @article{crocker_robison_2002, title={Genetic and nutritional effects on swine excreta}, volume={80}, DOI={10.2527/2002.80112809x}, abstractNote={The objective of this study was to investigate genetic and nutritional effects on swine excreta. Two studies were used. Study I was a 3 x 2 x 2 factorial design with three genetic groups, two diets, and two sexes. Genetic groups were a maternal line (WL), paternal line (BL) and their F1 progeny. Corn-soybean meal diets with either 18 or 14% CP, differing only by substitution of soybean meal for corn, were used in both studies. Study II was a 2 x 2 factorial design with two genetic groups and two diets. High testosterone (D2) and low testosterone (D1) Duroc lines were used. Solid and liquid wastes were collected for 3 d. A total of 108 pens in Study I and 50 pens in Study II were sampled twice. Total excreta were measured and samples collected for chemical analysis of N, NH3N, P, Ca, Cu, K, Zn, and Fe. Measures were adjusted for pig weight and feed disappearance. Maternal-line pigs excreted significantly less P, Ca, Cu, Zn, and Fe than F1 or BL pigs and numerically smaller quantities of all nutrients than BL pigs. In study II, differences were found between lines ofthe same breed. Line D2 pigs had greater output of P, Ca, and Cu (P< 0.05) than D1 pigs and numerically larger quantities of all other nutrients except NH3N and Fe. Pigs fed 14% CP excreted less N, NH3N, and K (P < 0.01) in both studies and excreted significantly less P in Study I. Pigs on a 14% CP diet excreted numerically smaller amounts of all nutrients in both studies except Ca in Study II. In Study I, gilts excreted smaller (P < 0.05) amounts of all nutrients than barrows. Genetic, nutritional, and gender differences influenced waste output.}, number={11}, journal={Journal of Animal Science}, author={Crocker, A. W. and Robison, O. W.}, year={2002}, pages={2809–2816} }
 @article{pala_robison_mccraw_2000, title={Evaluation of crossbred calf and cow types for the coastal plain of North Carolina}, volume={78}, DOI={10.2527/2000.7892253x}, abstractNote={Data in this experiment consisted of 418 lactation records, and weaning and birth weight records from 600 crossbred calves. The traits evaluated included birth weight, weaning weight, weaning weight per cow exposed, weaning weight per weight of cow, weaning weight per weight of cow exposed, and predicted milk yield. Angus, Brangus, and Gelbvieh sires were mated to purebred Hereford cows. Yearling and 2-yr-old Angus-Hereford, Brangus-Hereford, and Gelbvieh-Hereford daughters then were bred to Polled Hereford bulls (Data Set 2). Later-parity Angus-Hereford, Brangus-Hereford, and Gelbvieh-Hereford daughters were mated to Salers or Simmental sires (Data Set 3). Differences between Gelbvieh- and Brangus-sired calves or Gelbvieh-Hereford and Brangus-Hereford daughters were never significant for weaning weight, birth weight, or milk yield. Angus crosses had the lowest weaning weight, birth weight, and milk yield, but the highest kilograms of calf weaned per cow exposed in all data sets. Angus-Hereford and Brangus-Hereford dams had higher weaning weight per weight of cow exposed than Gelbvieh-Hereford dams (P < .01) in Data Set 3. There were no other significant differences related to cow weight.}, number={9}, journal={Journal of Animal Science}, author={Pala, A. and Robison, O. W. and McCraw, R. L.}, year={2000}, pages={2253–2256} }
 @article{robison_lubritz_johnson_1994, title={REALIZED HERITABILITY ESTIMATES IN BOARS DIVERGENTLY SELECTED FOR TESTOSTERONE LEVELS}, volume={111}, ISSN={["0931-2668"]}, DOI={10.1111/j.1439-0388.1994.tb00435.x}, abstractNote={SummaryData were collected from 1982 through 1992 from 100 sires and 891 Duroc boars. Testosterone production was measured from peripheral blood samples before (PRE) and after (POST) GnRH challenge. Additionally, data were collected on testes volume at 168 d (TVOL), days to 104 kg (DAYS104), number born alive (NBA) and backfat adjusted to 104 kg body weight (FAT). Realized heritabilities were estimated from the regression of response on cumulative selection differentials. Heritabilities for POST were .15 ± .18 and .24 ± .08 in the low and high lines, respectively. This compares with the estimate of .26 ± .21 from son‐sire regressions. The regression of other traits on cumulative selection differentials can be viewed as realized correlated responses to selection. After 10 generations, the high line was approximately three times greater than the low line for both PRE and POST levels of testosterone. Although not significant, high line pigs required fewer days to reach 104 kg, had more backfat and larger testes than low line pigs. Litter size was significantly larger for high line than for low line.}, number={1}, journal={JOURNAL OF ANIMAL BREEDING AND GENETICS-ZEITSCHRIFT FUR TIERZUCHTUNG UND ZUCHTUNGSBIOLOGIE}, author={ROBISON, OW and LUBRITZ, D and JOHNSON, B}, year={1994}, month={Mar}, pages={35–42} }
 @article{robison_luempert_1984, title={GENETIC-VARIATION IN WEIGHT AND SURVIVAL OF BROOK TROUT (SALVELINUS-FONTINALIS)}, volume={38}, ISSN={["1873-5622"]}, DOI={10.1016/0044-8486(84)90227-8}, abstractNote={Data were from brook trout (Salvelinus fontinalis) where four males were mated to four females in a diallel mating scheme, replicated eight times. Heritabilities computed from the sire component were 0.08 for 144 day weight and 0.60 for 243 day weight while those from the dam component were 0.34 and 0.37, respectively. Maternal variance decreased from 6% of total variance at 144 days to −6% at 243 days. Non-additive genetic variance was high at both ages. Heritabilities were estimated for cumulative survival at eight developmental stages. Heritabilities based on the sire component were low at early stages and decreased with time. Heritabilities based on the dam component were higher but followed the same pattern. Maternal variance accounted for approximately 11% of total variance at all stages except fertilization. Non-additive genetic variance was of considerable importance for all stages except fertilization. Heritabilities for survival between 144 days and 243 days were moderate (0.16 to 0.51). Low positive genetic correlations of 144 day weight with survival were obtained. Negative correlations between 243 day weight and survival suggest that selection for increased 243 day weight would indirectly select against survival. However, a moderate correlation between egg weight and 243 day survival, and a low, but positive correlation between egg weight and 243 day weight suggests that selecting heavier eggs would improve both weight and survival.}, number={2}, journal={AQUACULTURE}, author={ROBISON, OW and LUEMPERT, LG}, year={1984}, pages={155–170} }
 @article{robison_mcdaniel_rincon_1981, title={ESTIMATION OF DIRECT AND MATERNAL ADDITIVE AND HETEROTIC EFFECTS FROM CROSSBREEDING EXPERIMENTS IN ANIMALS}, volume={52}, ISSN={["0021-8812"]}, DOI={10.2527/jas1981.52144x}, abstractNote={A model is proposed for the estimation of genetic effects from crossbreeding data. Analyses of variance and appropriate F-tests allow estimation of the importance of various effects. Deviations from the model provide evidence about the existence of epistasis and(or) linkage effects. This procedure has three advantages over conventional analyses of crossbreeding data: (1) It is a less complex statistical procedure; (2) It provides a clearer understanding of the genetic components; (3) It allows prediction of breed crosses that were not included in the data set. This model was applied to data from the long-term dairy crossbreeding project conducted at the Beltsville Agricultural Research Center. Breed additive genetic superiorities of Holsteins over Ayrshires and Brown Swiss were 759 and 857 kg for milk yield (P<.01), 555 and 556 kg for fat-corrected milk yield (P<.05) and —.30 and —.44 for fat percentage (P<.01), respectively. Differences between Brown Swiss and Ayrshires were small. The nonadditive genetic effects measured by regression on the expected percentage of heterozygotic loci were important for Brown Swiss × Holstein and Ayrshire × Holstein crosses. Complete Brown Swiss × Holstein heterozygosity resulted in increases of 341 kg in milk (P<.05), 16.2 kg in milk fat (P<.01) and 378 kg in fat-corrected milk (P<.05). For Ayrshire × Holstein crosses, the heterosis contributions for milk fat and fat-corrected milk (P<.05) were 13.6 and 299 kg, respectively. Holstein maternal contributions for production traits exceeded those for Ayrshires and Brown Swiss by 607 (P<.01) and 476 kg (P<.01) for milk yield, 16.9 (P<.05) and 12.1 kg (NS) for fat yield and 494 (P<.01) and 375 kg (P<.05) for fat-corrected milk yield, but were .17 (P<.05) and .15% (NS) lower for fat percentage. There was no evidence that epistasis and linkage contributed significantly to differences among breed groups.}, number={1}, journal={JOURNAL OF ANIMAL SCIENCE}, author={ROBISON, OW and MCDANIEL, BT and RINCON, EJ}, year={1981}, pages={44–50} }
 @misc{robison_1981, title={THE INFLUENCE OF MATERNAL EFFECTS ON THE EFFICIENCY OF SELECTION - A REVIEW}, volume={8}, ISSN={["0301-6226"]}, DOI={10.1016/0301-6226(81)90016-6}, abstractNote={The experimental evidence concerning the existence and importance of maternal effects in beef cattle, dairy cattle and swine is reviewed. It is clear that maternal effects are important in all three species. Unless management programs and selection methods take maternal effects into consideration, selection efficiency will be reduced. Some suggestions are given for altering management programs to increase production and selection efficiency. On passe en revue les faits expérimentaux concernant l'existence et l'importance des effets maternels chez les bovins, les ovins et les pores. Il est clair que ces effets sont importants dans les trois espèces. Si les programmes de conduite des animaux et les méthodes de sélection ne les prennent pas en compte, l'efficacité de la sélection sera diminuée. On propose quelques modifications des programmes de conduite des animaux afin d'accroître l'efficacité de la production et de la sélection. Es wird über das experimentelle Ergebnis bezüglich des Vorhandenseins und der Bedeutung maternaler Effekte bei Fleisch- und Milchrindern und Schweinen berichtet. Es ist eindeutig, dass die maternalen Effekte für alle drei Tierarten bedeutsam sind. Wenn Managementprogramme und Selektionsmethoden die maternalen Effekte unberücksichtigt lassen, wird der Selektionserfolg reduziert sein. Es werden einige Anregungen für veränderte Managementprogramme gegeben mit dem Ziel, Produktion und Selektionserfolg zu erhöhen.}, number={2}, journal={LIVESTOCK PRODUCTION SCIENCE}, author={ROBISON, OW}, year={1981}, pages={121–137} }
 @article{robison_kelly_mcdaniel_mcdowell_1980, title={GENETIC-PARAMETERS OF BODY SIZE IN PUREBRED AND CROSSBRED DAIRY-CATTLE}, volume={63}, ISSN={["0022-0302"]}, DOI={10.3168/jds.S0022-0302(80)83156-0}, abstractNote={Breed additive, breed maternal, and heterozygotic effects on body weight, height at withers, depth of fore-chest, girth of fore-chest, length from withers to pins, length from withers to hips, and length from hips to pins at 6, 12, 18, and 30 mo of age were estimated from linear regression analyses. Data were available on 87 purebred Ayrshire, Brown Swiss, Holstein, and 213 two-way, three-way, and five-eights crosses. Birth year, birth month, and age of dam were significant environmental effects. Ayrshire additive effects were smaller than Holstein for all traits at all ages except length from hips to pins at 6 and 12 mo of age. Additive effects for Brown Swiss were smaller than for Holstein for body weight at 12 mo, height at withers at all ages, depth of fore-chest and girth of fore-chest at 6, 12, and 18 mo, length from withers to pins and length from withers to hips at 12 and 30 mo, and length from hips to pins at 18 mo. Breed maternal effects were not significant for any trait at any age. Means of crossbreds generally exceeded means of parental breeds, especially body weight. Average heterosis for body weight was 3.0% at 6 mo, 4.6% at 12 mo, 5.0% at 18 mo, and 3.5% at 30 mo of age. Heterosis for weight increased with age through 18 mo and declined by 30 mo of age. Heterosis for other traits was generally 1 to 2% with no trend with age.}, number={11}, journal={JOURNAL OF DAIRY SCIENCE}, author={ROBISON, OW and KELLY, MG and MCDANIEL, BT and MCDOWELL, RE}, year={1980}, pages={1887–1899} }
 @article{robison_yusuff_dillard_1978, title={MILK-PRODUCTION IN HEREFORD COWS .1. MEANS AND CORRELATIONS}, volume={47}, ISSN={["1525-3163"]}, DOI={10.2527/jas1978.471131x}, number={1}, journal={JOURNAL OF ANIMAL SCIENCE}, author={ROBISON, OW and YUSUFF, MKM and DILLARD, EU}, year={1978}, pages={131–136} }
 @article{robison_1976, title={GROWTH-PATTERNS IN SWINE}, volume={42}, ISSN={["1525-3163"]}, DOI={10.2527/jas1976.4241024x}, abstractNote={Postweaning rate of growth appears to be linear, or nearly so, for the ages and weights likely to be utilized in the near future. Furthermore, rate of growth is highly correlated with feed efficiency. Since maternal maintenance costs are restricted by limit feeding of the breeding herd, high mature weights are not realized and are of little concern to swine programs. Therefore, rate of growth is of major interest in swine breeding programs. Backfat, fat and protein depositions in the carcass are nearly linearly associated with increases in weight or age. Since fat increases more rapidly than protein, there is a gradual, constant change in their relative proportions. The decrease in feed efficiency with increasing weights is primarily due to increased maintenance costs and not to increased fat deposition.}, number={4}, journal={JOURNAL OF ANIMAL SCIENCE}, author={ROBISON, OW}, year={1976}, pages={1024–1035} }
 @article{robison_berruecos_1973, title={FEED EFFICIENCY IN SWINE .2. PREDICTION OF EFFICIENCY AND GENETIC CORRELATIONS WITH CARCASS TRAITS}, volume={37}, ISSN={["1525-3163"]}, DOI={10.2527/jas1973.373650x}, abstractNote={Data for this study were collected from 321 individually fed barrows, representing 62 sires. These results suggest that tests of 42 days in length and, perhaps, certain 28-day tests would adequately characterize pigs for growth and efficiency. Addition of percent lean cuts or carcass backfat did not significantly increase the accuracy of ADG or efficiencies from parts of the total test in predicting F/G or ADG for the total test. Indexes using ADG on test or lifetime ADG and live backfat probe would be 112% and 85%, respectively, as effective in selecting for F/G as direct selection for F/G. The genetic correlations between efficiency and carcass traits suggest that selection for increased efficiency would be expected to produce negative effects in Longissimus muscle area, free moisture, color and pH. However, percent lean cuts, backfat and marbling should be improved. On the other hand, the only undesirable changes expected when selection is applied for ADG is in live backfat and Longissimus muscle area, with no appreciable change in carcass quality.}, number={3}, journal={JOURNAL OF ANIMAL SCIENCE}, author={ROBISON, OW and BERRUECOS, JM}, year={1973}, pages={650–657} }
 @article{robison_berruecos_1973, title={Feed efficiency in swine. I. A comparison of measurement periods and methods of expressing feed efficiency}, volume={37}, DOI={10.2527/jas1973.373643x}, abstractNote={The objective of this study was to evaluate different methods of measuring feed efficiency. The data were collected from 321 individually fed barrows, representing 62 sires. Gain and feed consumption were measured during age (76 days) to weight (93.5 kg) (AW), weight (45.5 kg) to weight (93.5 kg) (WW) and age (83 days) to age (130 days) (AA) periods. Feed/gain (F/G), gain/feed (G/F) and average daily gain (ADG) were evaluated for the three periods. Heritability estimates for F/G in AA, WW and AW intervals (0.52±.28, 0.77±.25 and 0.61±.25, respectively) were higher than those for G/F in the same intervals (0.00, 0.08 and 0.55, respectively). Further, the coefficients of variation were much smaller for F/G in the AA and WW periods. For the AW interval, the coefficient of variation for F/G was similar to that for G/F. Thus, the smaller values of the coefficient of variation and the larger estimates of heritability indicate that F/G is a more satisfactory measure of efficiency.}, number={3}, journal={Journal of Animal Science}, author={Robison, O. W. and Berruecos, J. M.}, year={1973}, pages={643} }