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- Pigs (4)
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- Growth Traits (2)
- Litter Size (2)
- Ovulation (2)
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- Calcium (1)
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- Covariance Estimation (1)
- Dystocia (1)
- Embryonic Mortality (1)
- Expected Progeny Differences (1)
- Genetic Correlation (1)
- Genetic Groups (1)
- Genetic Parameters (1)
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Articles 1 - 19 of 19
Full-Text Articles in Life Sciences
Animal Model Estimation Of Genetic Parameters And Response To Selection For Litter Size And Weight, Growth, And Backfat In Closed Seedstock Populations Of Large White And Landrace Swine, Jose Bento S. Ferraz, Rodger K. Johnson
Animal Model Estimation Of Genetic Parameters And Response To Selection For Litter Size And Weight, Growth, And Backfat In Closed Seedstock Populations Of Large White And Landrace Swine, Jose Bento S. Ferraz, Rodger K. Johnson
Department of Animal Science: Faculty Publications
Records from 2,495 litters and 14,605 Landrace and Large White pigs from two farms, but established from the same base population and run as replicated selection lines, were analyzed. Selection within herd was on estimated breeding values weighted by economic values. Animal models and REML procedures were used to estimate genetic, phenotypic, and environmental parameters for the number of pigs born alive (NBA), litter weight at 21 d (LW), average daily gain from approximately 30 to 104 kg (AD GI, and backfat thickness adjusted to 104 kg (BF). Random animal genetic effects ( 01, permanent (NBA and LW) or litter …
Changes In Ovulation Rate, Uterine Capacity, Uterine Dimensions, And Parity Effects With Selection For Litter Size In Swine, Luis L. T. Gama, R. K. Johnson
Changes In Ovulation Rate, Uterine Capacity, Uterine Dimensions, And Parity Effects With Selection For Litter Size In Swine, Luis L. T. Gama, R. K. Johnson
Department of Animal Science: Faculty Publications
This study was conducted with random samples of pigs of a line (LS) selected for eight generations for litter size and a randomly selected control line (RS) in the Nebraska Gene Pool population and of crosses of these lines with a Large White- Landrace composite line (I) that was selected for an index of ovulation rate and embryonic survival to 50 d of gestation. Two experiments were done to obtain information on ovulation rate, uterine dimensions, and uterine capacity. In Exp. 1, 103 gilts were slaughtered 9 to 16 d after their second estrus to obtain reproductive tracts for evaluation …
Estimation Of The Parameters Involved In A First-Order Autoregressive Process For Contemporary Groups, K. M. Wade, R. L. Quaas, L. Dale Van Vleck
Estimation Of The Parameters Involved In A First-Order Autoregressive Process For Contemporary Groups, K. M. Wade, R. L. Quaas, L. Dale Van Vleck
Department of Animal Science: Faculty Publications
A methodology was developed for estimating the parameters involved in a first-order autoregressive process; these parameters comprise a variance component associated with the random effect, a correlation coefficient, p, and a residual variance. These parameters were estimated using REML with an expectation maximization algorithm. For two single trait analyses (milk and fat production being the dependent variable), the example chosen for the analyses was year-month -- treated as random and following a first-order autoregressive process within fixed herd. Initially, estimates failed to converge, possibly because of a time trend in the data, which was not accounted for by the model. …
Correlations For Genetic Expression For Growth Of Calves Of Hereford And Angus Dams Using A Multivariate Animal Model, R. Nunez-Dominguez, L. Dale Van Vleck, K. G. Boldman, Larry V. Cundiff
Correlations For Genetic Expression For Growth Of Calves Of Hereford And Angus Dams Using A Multivariate Animal Model, R. Nunez-Dominguez, L. Dale Van Vleck, K. G. Boldman, Larry V. Cundiff
Department of Animal Science: Faculty Publications
The purpose of this study was to estimate the correlation between the expression of genes from sires in purebred and crossbred progeny (rPC) and in Hereford and Angus F1 calves (rHA). Performance traits were weights at birth, 200 d, and 365 d. Progeny from Hereford, Polled Hereford, and Angus bulls mated to Hereford or Angus cows were used to estimate rpc. Progeny from Charolais, Shorthorn, Simmental, Limousin, Maine-Anjou, Chianina, Gelbvieh, Tarentaise, and Salers bulls mated to Hereford or Angus cows were used to estimate rm. Performances in purebreds (P) and crosses (C) or in Hereford …
Pregnancy Rate Is Greater When The Corpus Luteum Is Present During The Period Of Progestin Treatment To Synchronize Time Of Estrus In Cows And Heifers, T. Sanchez, M. E. Wehrman, E. G. M. Bergfeld, K. E. Peters, F. N. Kojima, Andrea S. Cupp, V. Mariscal, Roger J. Kittok, Richard J. Rasby, J. E. Kinder
Pregnancy Rate Is Greater When The Corpus Luteum Is Present During The Period Of Progestin Treatment To Synchronize Time Of Estrus In Cows And Heifers, T. Sanchez, M. E. Wehrman, E. G. M. Bergfeld, K. E. Peters, F. N. Kojima, Andrea S. Cupp, V. Mariscal, Roger J. Kittok, Richard J. Rasby, J. E. Kinder
Department of Animal Science: Faculty Publications
Our hypothesis was that conception in bovine females would be enhanced if the corpus luteum was present during the period of progestin treatment to synchronize estrus. In this study, 67 heifers (one replicate) and 124 cows (two replicates) were randomly assigned to one of two treatment groups. Seven days after estrus (Day 0), all animals were implanted with norgestomet and the implant remained in place for 10 days. All implants were removed on Day 17. Cows and heifers in one group received prostaglandin F2α (PGF2α) on Day 7 of the estrous cycle (PG 7; norgestomet without corpus …
Estimation Of Nonadditive Genetic Variances For A Total-Merit Model Including Maternal Effects, L. Dale Van Vleck
Estimation Of Nonadditive Genetic Variances For A Total-Merit Model Including Maternal Effects, L. Dale Van Vleck
Department of Animal Science: Faculty Publications
Henderson described a method to reduce the number of mixed-model equations when estimating additive and nonadditive genetic variances or predicting additive and nonadditive genetic merits. The extension to a maternal effects model is straightforward. When maternal genetic effects are strictly additive, an algebraic identity was found that reduces by a factor of two the order of a matrix that must be inverted each round to account for the genetic covariances among direct and maternal genetic effects. An algorithm for derivative-free restricted maximum likelihood was developed based on Henderson's total-merit model that is the basis for a reduced number of equations. …
Breed Comparisons For Growth Traits Adjusted For Within-Breed Genetic Trend Using Expected Progeny Differences, R. Nunez-Dominguez, L. Dale Van Vleck, Larry V. Cundiff
Breed Comparisons For Growth Traits Adjusted For Within-Breed Genetic Trend Using Expected Progeny Differences, R. Nunez-Dominguez, L. Dale Van Vleck, Larry V. Cundiff
Department of Animal Science: Faculty Publications
Records (2,910) of birth (BWT), weaning (WW), and yearling weight (YW) of F1 calves produced in a top-cross experiment involving Angus, Hereford, Pooled Hereford, Charolais, Limousin, Simmental, Gelbvieh, Maine-Anjou, Chianina, Tarentaise, Shorthorn, and Salers bulls mated to Hereford and Angus cows and records (4,592) of WW on three-breed-cross calves out of 986 F1 females of the same breed crosses were used in this study. The purposes were to estimate how much of the EPD of the sires was realized in crossbred calves and to estimate sire breed effects for the traits adjusted for genetic trend and sire sampling. …
Bioavailability Of Calcium In Sun-Cured Alfalfa Meal And Effect Of Dietary Calcium Concentration On Bone And Plasma Characteristics During Two Phases Of Gestation In Gilt, G. L. Walker, D. M. Danielson, E. R. Peo, Jr., R. F. Mumm
Bioavailability Of Calcium In Sun-Cured Alfalfa Meal And Effect Of Dietary Calcium Concentration On Bone And Plasma Characteristics During Two Phases Of Gestation In Gilt, G. L. Walker, D. M. Danielson, E. R. Peo, Jr., R. F. Mumm
Department of Animal Science: Faculty Publications
A study was conducted with gravid gilts to determine the bioavailability of Ca in sun-cured alfalfa meal (AM) and the effect of dietary Ca concentration on bone and blood characteristics during two phases of gestation.
Effect Of Calcium Source, Dietary Calcium Concentration, And Gestation Phase On Various Bone Characteristics In Gestating Gilts, G. L. Walker, D. M. Danielson, E. R. Peo, Jr., R. F. Mumm
Effect Of Calcium Source, Dietary Calcium Concentration, And Gestation Phase On Various Bone Characteristics In Gestating Gilts, G. L. Walker, D. M. Danielson, E. R. Peo, Jr., R. F. Mumm
Department of Animal Science: Faculty Publications
Sixty gravid crossbred gilts were allotted to a 2 x 3 x 2 factorial arrangement of treatments: two Ca sources (sun-cured alfalfa meal and CaC03), three dietary concentrations of Ca (50, 75, and 100% of NRC requirements), and two phases of gestation (55 and 105 d). The objectives were to determine the effect of Ca source, dietary Ca concentration, and gestation phase on bone characteristics (bone breaking strength, bone ash percentage, bone density, and bone ash density in the rib, thoracic, and coccygeal bones), to correlate bone responses to determine relative bone activity, and to determine reliability of …
Effect Of Immunization Against Lhrh On Isoforms Of Lh In The Ovine Pituitary, D. D. Zalesky, B. D. Schanbacher, H. E. Grotjan
Effect Of Immunization Against Lhrh On Isoforms Of Lh In The Ovine Pituitary, D. D. Zalesky, B. D. Schanbacher, H. E. Grotjan
Department of Animal Science: Faculty Publications
The role of LHRH in modulating intrapituitary LH content as well as the distribution of LH among its isoforms was examined in sheep. Rams (n = 3) and wethers (n = 6) were actively immunized against an LHRH-humanserum globulin conjugate. Pituitaries collected from these animals plus pituitaries from corresponding numbers of nonimmunized rams and wethers were extracted with a buffered saline solution containing protease inhibitors. Immunization markedly reduced total amounts of immunoreactive LH in the pituitary. An aliquot of each pituitary extract was desalted by flow dialysis against water and chromatofocused on a pH 10.5-7.0 gradient. Concentrations of LH in …
Economical And Biological Efficiencies Of Beef Cattle Differing In Level Of Milk Production, M. Van Oijen, M. Montano-Bermudez, Merlyn K. Nielsen
Economical And Biological Efficiencies Of Beef Cattle Differing In Level Of Milk Production, M. Van Oijen, M. Montano-Bermudez, Merlyn K. Nielsen
Department of Animal Science: Faculty Publications
Economical and biological efficiencies of beef production to weaning and to slaughter were estimated in three groups, different in milk available (low, medium, and high) to the calves but with the same potential for growth. Data from different breed groups of cows (low [L] = Hereford x Angus, medium [M] = Red Poll x Angus, and high [H] = Milking Shorthorn x Angus) were used. Economical efficiency was the ratio of income to expenses and biological efficiency was the ratio of calf weight to total feed energy required. Income was derived from cull cows and calves at weaning or carcasses …
Alternative Methods Of Selection For Litter Size In Mice: Iii. Response To 21 Generations Of Selection, Yvonne Kochera Kirby, Merlyn K. Nielsen
Alternative Methods Of Selection For Litter Size In Mice: Iii. Response To 21 Generations Of Selection, Yvonne Kochera Kirby, Merlyn K. Nielsen
Department of Animal Science: Faculty Publications
Alternative methods of selection to increase litter size in mice have been practiced for 21 generations followed by six generations of relaxed selection. Three replicates were used with four selection criteria: index of components (IX: I = 1.21 x total ovulation rate + 9.05 x ova success), uterine capacity (UT), litter size (LS), and an unselected control (LC). In IX, ovulation rate and ova success were measured by number of corpora lutea and number of pups born/number of corpora lutea, respectively. In UT, uterine capacity was measured and defined as number of pups born to unilaterally ovariectomized (right ovary excised) …
Yearling Bulls Shorten The Duration Of Postpartum Anestrus In Beef Cows To The Same Extent As Do Mature Bulls, Andrea S. Cupp, M. S. Roberson, T. T. Stumpf, M. W. Wolfe, L. A. Werth, N. Kojima, Roger J. Kittok, J. E. Kinder
Yearling Bulls Shorten The Duration Of Postpartum Anestrus In Beef Cows To The Same Extent As Do Mature Bulls, Andrea S. Cupp, M. S. Roberson, T. T. Stumpf, M. W. Wolfe, L. A. Werth, N. Kojima, Roger J. Kittok, J. E. Kinder
Department of Animal Science: Faculty Publications
The objective of this study was to determine whether yearling bulls, when pastured with cows, reduced the duration of postpartum anestrus to the same extent as did mature bulls. This experiment was conducted over a 3-yr period. Cows were stratified by parity group to achieve 37% 2-yr-old and 63% mature (> 2-yr-old) cows within each treatment group (approximately 50 cows per treatment per year). Cows were assigned in the order in which they calved to one of three treatment groups: 1) isolated from bulls (NBE; n = 158); 2) exposed to mature bulls that were z 3 yr of age …
Increasing Exogenous Progesterone During Synchronization Of Estrus Decreases Endogenous 17Β-Estradiol And Increases Conception In Cows, M. E. Wehrman, M. S. Roberson, Andrea S. Cupp, F. N. Kojima, T. T. Stumpf, L. A. Werth, M. W. Wolfe, Roger J. Kittok, J. E. Kinder
Increasing Exogenous Progesterone During Synchronization Of Estrus Decreases Endogenous 17Β-Estradiol And Increases Conception In Cows, M. E. Wehrman, M. S. Roberson, Andrea S. Cupp, F. N. Kojima, T. T. Stumpf, L. A. Werth, M. W. Wolfe, Roger J. Kittok, J. E. Kinder
Department of Animal Science: Faculty Publications
The objectives of this study were to determine the effects of dose of exogenous progesterone (P4) prior to artificial insemination on concentrations of 17β-estradiol (E2) and on conception rates in bovine females. Heifers (n = 100) and cows (n = 100) received P4-releasing intravaginal devices (PRIDs) to produce two different circulating concentrations of P4. All animals received a single PRID 10 days before (Day -10) the start of the breeding season (Day 0). In animals that received the low dose of P4 (1 PRID, target concentration of 2-3 ng/ml of plasma), …
Effects Over Lambs On Muscle Time Of Feeding A Β-Adrenergic Agonist To Wether Animal Performance, Muscle Growth, Endogenous Proteinase Activities, And Meat Tenderness, T. D. Pringle, Chris R. Calkins, Mohammad Koohmaraie, Steven J. Jones
Effects Over Lambs On Muscle Time Of Feeding A Β-Adrenergic Agonist To Wether Animal Performance, Muscle Growth, Endogenous Proteinase Activities, And Meat Tenderness, T. D. Pringle, Chris R. Calkins, Mohammad Koohmaraie, Steven J. Jones
Department of Animal Science: Faculty Publications
Forty wether lambs were used in a 2 x 4 factorial arrangement to determine the response of animal performance, muscle growth, proteinase activity, and meat tenderness to 0-adrenergic agonist (BAA) supplementation. Lambs were fed a finishing diet with or without 4 ppm of L644,969 and slaughtered after 0, 2, 4, and 6 wk of treatment. The ADG was higher (P < .05) in the treated than in the control lambs after 2 wk and returned to control levels thereafter. Semitendinosus weight and calpastatin activity were higher and μ-calpain activity was lower in the treated than in the control lambs after 2, 4, and 6 wk. Cathepsin B activity was higher ( P < .0 1) and cystatin-like activity was lower ( P < .05) after 2 wk in treated than in control lambs but returned to control levels thereafter. Longissimus protein:DNA was higher after 4 ( P < .05) and 6 ( P < .01) wk in the treated lambs than in the controls. The concentration of RNA and RNA:DNA ratio were higher ( P < .0 1) in the longissimus and semitendinosus muscles in the treated lambs after 2 wk and remained higher throughout the study. Semitendinosus protein and RNA content were higher after 2, 4, and 6 wk and DNA content was higher after 2 and 6 wk in the treated than in the control lambs. Longissimus shearforce values were higher ( P < .001) in the treated than in the control lambs at all slaughter end points. These data indicate a rapid alteration of muscle growth, activity of the calpain-calpastatin system, and meat tenderness during BAA treatment. It also seems that the BAA-stimulated muscle growth is closely related to the activity of the calpain-calpastatin system.
Effect Of Genetic Groups On Estimates Of Additive Genetic Variance, C. Pieramati, L. Dale Van Vleck
Effect Of Genetic Groups On Estimates Of Additive Genetic Variance, C. Pieramati, L. Dale Van Vleck
Department of Animal Science: Faculty Publications
This study examined the effect of genetic grouping on REML estimates of additive genetic variance with an animal model with selected base populations. A simulated population of 40 animals (20 males and 20 females) was followed under selection or random mating conditions for 10 generations. Each population was replicated 20 or 50 times. Genetic grouping reduced estimates of additive genetic variance in populations with selected base animals, whereas grouping had little effect on the estimate in unselected populations. The effect of genetic grouping varied according to the quantity and kind of information that was missing (percentage of deleted data and …
Sequential Transformation For Multiple Traits For Estimation Of (Co)Variance Components With A Derivative-Free Algorithm For Restricted Maximum Likelihood, L. Dale Van Vleck, K. G. Boldman
Sequential Transformation For Multiple Traits For Estimation Of (Co)Variance Components With A Derivative-Free Algorithm For Restricted Maximum Likelihood, L. Dale Van Vleck, K. G. Boldman
Department of Animal Science: Faculty Publications
Transformation of multiple-trait records that undergo sequential selection can be used with derivative-free algorithms to maximize the restricted likelihood in estimation of covariance matrices as with derivative methods. Data transformation with appropriate parts of the Choleski decomposition of the current estimate of the residual covariance matrix results in mixed-model equations that are easily modified from round to round for calculation of the logarithm of the likelihood. The residual sum of squares is the same for transformed and untransformed analyses. Most importantly, the logarithm of the determinant of the untransformed coefficient matrix is an easily determined function of the Choleski decomposition …
Environmental Effects On Neonatal Mortality Of Beef Calves, S. M. Azzam, J. E. Kinder, Merlyn K. Nielsen, L. A. Werth, K. E. Gregory, Larry V. Cundiff, R. M. Koch
Environmental Effects On Neonatal Mortality Of Beef Calves, S. M. Azzam, J. E. Kinder, Merlyn K. Nielsen, L. A. Werth, K. E. Gregory, Larry V. Cundiff, R. M. Koch
Department of Animal Science: Faculty Publications
Calving records from 1969 to 1989 from the Roman L. Hruska U.S. Meat Animal Research Center were used to investigate how climatic conditions, in addition to dystocia, age of dam, size of calf, and sex affect calf survival from birth to 1 wk of age. Data were analyzed separately for cows calving with (n = 11,094) or without (n = 72,187) dystocia. Neonatal mortality was described by a logit model and parameters were estimated by maximum-likelihood procedures. Calves born to cows with dystocia were five times as likely to die neonatally than calves born without assistance. Of all calves that …
Estimates Of Variances Due To Direct And Maternal Effects For Growth Traits Of Romanov Sheep, G. A. Maria, K. G. Boldman, L. Dale Van Vleck
Estimates Of Variances Due To Direct And Maternal Effects For Growth Traits Of Romanov Sheep, G. A. Maria, K. G. Boldman, L. Dale Van Vleck
Department of Animal Science: Faculty Publications
Records of growth traits of 2,086 Romanov lambs were used to estimate variance components for an animal model and genetic correlations between growth traits. Traits analyzed were birth weight (BWT), weaning weight (WW), 90-d weight (W90), and daily gain for the periods birth to weaning (DG1) and weaning to 90 d (DG2). Weaning was at approximately 40 d. Variance components were estimated using restricted maximum likelihood with an animal model including fixed effects for year x season, sex, rearing type, and litter size and random effects for the direct genetic effect of the animal (with relative variance h2), …