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- Selection (5)
- Litter Size (4)
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- Simulation (2)
- Uterus (2)
- Boar (1)
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- Ruminal escape protein (1)
Articles 1 - 16 of 16
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Calculation Of Breed Direct And Maternal Genetic Fractions And Breed Specific Direct And Maternal Heterozygosity For Crossbreeding Data, L. Dale Van Vleck
Calculation Of Breed Direct And Maternal Genetic Fractions And Breed Specific Direct And Maternal Heterozygosity For Crossbreeding Data, L. Dale Van Vleck
Department of Animal Science: Faculty Publications
Teaching, research, and herd breeding applications may require calculation of breed additive contributions for direct and maternal genetic effects and fractions of heterozygosity associated with breed specific direct and maternal heterosis effects. These coefficients can be obtained from the first NB rows of a pseudo numerator relationship matrix where the first NB rows represent fractional contributions by breed to each animal or group representing a specific breed cross. The table begins with an NB x NB identity matrix representing pure breeds. Initial animals or representative crosses must be purebreds or two-breed crosses. Parents of initial purebreds are represented by the …
Influence Of Dominance Relationships On The Estimation Of Dominance Variance With Sire-Dam Subclass Effects, N. Gengler, L. Dale Van Vleck, M. D. Macneil, I. Misztal, F. A. Pariacote
Influence Of Dominance Relationships On The Estimation Of Dominance Variance With Sire-Dam Subclass Effects, N. Gengler, L. Dale Van Vleck, M. D. Macneil, I. Misztal, F. A. Pariacote
Department of Animal Science: Faculty Publications
Two data sets from the USDA Livestock and Range Research Laboratory were analyzed to study dominance variance and the influence of dominance relationships. The first consisted of 4,155 birth weight (3,884 weaning weight) records of inbred USDA Line 1 Herefords. The second consisted of 8,065 birth weight (7,380 weaning weight) records from a line-cross experiment with five lines. Two models were used. Both included fixed effects of year-sex of calf and age of dam, and covariates for calving date, inbreeding of animal, and inbreeding of dam. For the second set, additional covariates were line composition and heterozygosity coefficients. Random effects …
Relationships Between In Situ Protein Degradability And Grass Developmental Morphology, R. B. Mitchell, D. D. Redfearn, Lowell E. Moser, R. J. Grant, K. J. Moore, B. H. Kirch
Relationships Between In Situ Protein Degradability And Grass Developmental Morphology, R. B. Mitchell, D. D. Redfearn, Lowell E. Moser, R. J. Grant, K. J. Moore, B. H. Kirch
Department of Animal Science: Faculty Publications
The objective of this research was to determine the relationships between the morphological development and in situ ruminally degradable protein (RDP), ruminally undegradable protein (RUP), and microbial protein of two cool season grasses (intermediate wheatgrass and smooth bromegrass) and two warm season grasses (switchgrass and big bluestem). The initial growth of grass tillers grown near Mead, Nebraska was clipped at ground level six times during the 1992 growing season and morphologically classified. Mean stage was calculated. Forage was ground to pass a 2-mm screen and was incubated in ruminally fistulated steers for 16 h. The RUP was adjusted for microbial …
Evidence For Quantitative Trait Loci Affecting Ovulation Rate In Pigs, Thomas A. Rathje, G. A. Rohrer, R. K. Johnson
Evidence For Quantitative Trait Loci Affecting Ovulation Rate In Pigs, Thomas A. Rathje, G. A. Rohrer, R. K. Johnson
Department of Animal Science: Faculty Publications
Fifty-five microsatellite markers were scored in an F2 population of pigs (n = 114 females) developed at the University of Nebraska. The population was produced by crossing a line previously selected for 10 generations using an index of ovulation rate and embryonal survival and a line selected at random. The lines were from a common base population and differed by 6.7 ovulations and 3.1 fetuses at 50 d of gestation. Ovulation rate and number of fully formed and mummified pigs were recorded for each female. Data were analyzed with regression models that included random animal effects. Likelihood-ratio tests were …
Genetic And Environmental Parameters For Ovulation Rate, Twinning Rate, And Weight Traits In A Cattle Population Selected For Twinning, K. E. Gregory, G. L. Bennett, L. Dale Van Vleck, S. E. Echternkamp, Larry V. Cundiff
Genetic And Environmental Parameters For Ovulation Rate, Twinning Rate, And Weight Traits In A Cattle Population Selected For Twinning, K. E. Gregory, G. L. Bennett, L. Dale Van Vleck, S. E. Echternkamp, Larry V. Cundiff
Department of Animal Science: Faculty Publications
A project was implemented in 1981 with the objective of increasing twinning rate in cattle. Daughters of foundation sires had twin calves at a frequency of from 8 to 13%, and foundation females had twin calves at an average frequency of 50%. Data were analyzed on twinning rate, ovulation rate, and weight traits. The h2 of ovulation rate increased from .11 to .38 for a single estrous cycle to the mean of eight estrous cycles. From all data, h2 for single observation of ovulation rate and twinning rate were .10 and .09, respectively. The rg between them …
Role Of Basic-Helix-Loop-Helix Transcription Factors In Sertoli Cell Differentiation: Identification Of An E-Box Response Element In The Transferrin Promoter, Jaideep Chaudhary, Andrea S. Cupp, Michael K. Skinner
Role Of Basic-Helix-Loop-Helix Transcription Factors In Sertoli Cell Differentiation: Identification Of An E-Box Response Element In The Transferrin Promoter, Jaideep Chaudhary, Andrea S. Cupp, Michael K. Skinner
Department of Animal Science: Faculty Publications
Sertoli cells are critical for testicular function and maintenance of the spermatogenic process. The induction of Sertoli cell differentiation in the embryo promotes testicular development and male sex determination. The progression of Sertoli cell differentiation during puberty promotes the onset of spermatogenesis. The maintenance of optimal Sertoli cell differentiation in the adult is required for spermatogenesis to proceed. The current study was designed to investigate the transcriptional regulation of Sertoli cell differentiation through the analysis of a previously identified marker of differentiation, transferrin gene expression. Sertoli cells produce transferrin to transport iron to developing spermatogenic cells sequestered within the blood-testis …
Variability In Metabolic Rate, Feed Intake And Fatness Among Selection And Inbred Lines Of Mice, D. E. Moody, Daniel Pomp, Merlyn K. Nielsen
Variability In Metabolic Rate, Feed Intake And Fatness Among Selection And Inbred Lines Of Mice, D. E. Moody, Daniel Pomp, Merlyn K. Nielsen
Department of Animal Science: Faculty Publications
Mouse populations differing in metabolic rate have been developed through selection for high (MH) and low (ML) heat loss (HLOSS), along with randomly selected controls (MC). Objectives of this study were to (a) compare MH, ML and MC lines for HLOSS and correlated traits of feed intake, body composition and organ weights; (b) compare three widely used inbred mouse lines with MH, ML and MC for the same traits ; and (c) investigate potential genotype by diet interaction resulting from feeding diets differing in fat percentage. Heat loss (kcal/day) of MH and ML mice differed by 37% of the mean …
A Simulation Model Including Ovulation Rate, Potential Embryonic Viability, And Uterine Capacity To Explain Litter Size In Mice: Ii. Responses To Alternative Criteria Of Selection, E. L. De A. Ribeiro, Merlyn K. Nielsen, Kreg A. Leymaster, Gary Bennett
A Simulation Model Including Ovulation Rate, Potential Embryonic Viability, And Uterine Capacity To Explain Litter Size In Mice: Ii. Responses To Alternative Criteria Of Selection, E. L. De A. Ribeiro, Merlyn K. Nielsen, Kreg A. Leymaster, Gary Bennett
Department of Animal Science: Faculty Publications
Direct selection for litter size was compared with selection for ovulation rate, ova success, or uterine capacity and for indexes of ovulation rate with ova success or uterine capacity. Selection was simulated for 10 generations in a mouse population based on a model integrating ovulation rate, potential embryonic viability, and uterine capacity. Two indexes including ovulation rate (OR) and ova success (OS) were I = .291 x OR + 2.19 x OS and I = .165 x OR + .736 x OS. Heritabilities for ovulation rate and ova success, assumed in the simulation and to derive the indexes, were .25 …
A Simulation Model Including Ovulation Rate, Potential Embryonic Viability, And Uterine Capacity To Explain Litter Size In Mice: I. Model Development And Implementation, E. L. De A. Ribeiro, Merlyn K. Nielsen, Gary Bennett, Kreg A. Leymaster
A Simulation Model Including Ovulation Rate, Potential Embryonic Viability, And Uterine Capacity To Explain Litter Size In Mice: I. Model Development And Implementation, E. L. De A. Ribeiro, Merlyn K. Nielsen, Gary Bennett, Kreg A. Leymaster
Department of Animal Science: Faculty Publications
Litter size in mice was studied using a model including ovulation rate, potential embryonic viability, and uterine capacity. Simulated results were compared with experimental results from a selection experiment with mice. The four criteria of selection were selection on number born (LS), selection on an index of ovulation rate and ova success (IX), selection on number born to unilaterally ovariectomized females (UT), and unselected control (LC). Comparisons were made to statistics of the base generation and to responses after 13 generations of selection. Phenotypic and genetic statistics for uterine capacity were generated so that simulations produced the experimental means, standard …
Effects Of Sire, Dam Traits, Calf Traits, And Environment On Dystocia And Subsequent Reproduction Of Two-Year-Old Heifers, D. J. Colburn, Gene H. Deutscher, Merlyn K. Nielsen, Don C. Adams
Effects Of Sire, Dam Traits, Calf Traits, And Environment On Dystocia And Subsequent Reproduction Of Two-Year-Old Heifers, D. J. Colburn, Gene H. Deutscher, Merlyn K. Nielsen, Don C. Adams
Department of Animal Science: Faculty Publications
A study was conducted over 3 yr to evaluate effects of sire birth weight EPD, calf birth weight and shape, and heifer pelvic area and weight, individually and in combination, on dystocia and subsequent rebreeding of 2-yr-old heifers. Heifers (n = 550), MARC II yearlings, were assigned for breeding to one of four Angus sires with birth weight EPD of -.95, -.82, +2.9, and +2.7 kg. At calving, heifers were assisted as needed. A gauge attached to the calf puller recorded applied traction pressure. Analysis of traction pressure detected only slightly larger amounts of variation (2 to 3%) affecting dystocia …
Limiting Amino Acids In Meat And Bone And Poultry By-Product Meals, M. J. Klemesrud, Terry Klopfenstein, Austin Lewis, D. H. Shain, D. Herold
Limiting Amino Acids In Meat And Bone And Poultry By-Product Meals, M. J. Klemesrud, Terry Klopfenstein, Austin Lewis, D. H. Shain, D. Herold
Department of Animal Science: Faculty Publications
In situ, digestion, and growth studies were conducted to evaluate four meat and bone meals and six poultry by-product meals as sources of escape protein and to predict the first-limiting amino acid for growing calves. Escape protein values, determined by 12-h in situ incubation, ranged from 41.7 to 51.0% of CP for meat and bone meals; poultry by-product meals ranged from 32.0 to 39.8%. True protein digestion in the gastrointestinal tract of lambs differed among protein sources ( P < .05), ranging from 79 to 95%. In each of three growth trials, 60 steers (258 ± 24, 241 ± 23, and 230 ± 16 kg for Trials 1, 2, and 3, respectively) were supplemented with 4 of the 10 protein sources along with a urea supplement. Protein sources were fed at 30, 40, 50, and 60% of the supplemental CP, with urea supplying the remainder. Protein efficiency differed among treatments ( P < .10), ranging from .61 to 1.55. Amino acid composition was determined for each protein source, and the individual metabolizable amino acids were regressed on the protein efficiency values. Escape protein values were correlated (R2 = .75) with protein efficiency but had a negative slope. Metabolizable methionine was the only amino acid moderately correlated (R …
Influence Of Sample Orientation On Prediction Of Fresh Ham Lean Content By Electromagnetic Scanning, N. L. Meseck, B. L. Gwartney, Chris R. Calkins, Phillip Miller
Influence Of Sample Orientation On Prediction Of Fresh Ham Lean Content By Electromagnetic Scanning, N. L. Meseck, B. L. Gwartney, Chris R. Calkins, Phillip Miller
Department of Animal Science: Faculty Publications
To evaluate the effect of orientation of hams during electromagnetic scanning on the estimation of dissected lean content, hams were scanned horizontally, posterior first (POS) or dorsal first (DOR), and vertically, medial side (aitchbone) first (MED; standing on the butt face). Weight and percentage of dissected lean were estimated using scan peak for each orientation, ham weight, and fat thickness. The mean scan peak for the MED orientation was approximately twice as great as peaks for the POS and DOR orientations, which suggests that this orientation may offer greater predictive accuracy by reducing the signal to noise ratio. Results, however, …
Development Of Gilts And Boars For Efficient Reproduction, Donald G. Levis, Vernon D. Leibbrandt, Dale W. Rozeboom
Development Of Gilts And Boars For Efficient Reproduction, Donald G. Levis, Vernon D. Leibbrandt, Dale W. Rozeboom
Department of Animal Science: Faculty Publications
Successful introduction of replacement gilts and boars into the breeding herd is an important aspect of breeding herd efficiency. To attain herd efficiency, females must ovulate adequate numbers of viable ova, express estrus, show willingness to mate, and conceive in a regular manner. Males must produce adequate numbers of fertile spermatozoa, possess ability and show willingness to mate, and produce high-conception rates. If these qualities are properly developed, pregnancy rate and litter size will be maximized.
Divergent Selection For Heat Loss In Mice: I. Selection Applied And Direct Response Through Fifteen Generations, Merlyn K. Nielsen, L. D. Jones, B. A. Freking, J. A. Deshazer
Divergent Selection For Heat Loss In Mice: I. Selection Applied And Direct Response Through Fifteen Generations, Merlyn K. Nielsen, L. D. Jones, B. A. Freking, J. A. Deshazer
Department of Animal Science: Faculty Publications
Divergent selection for heat production/ loss (kcal•kg-.75•d-1) , measured in 9- to 11-wk-old male mice, was conducted for 15 generations. Heat loss was measured for 15 h on individual animals placed overnight in direct, gradient-layer calorimeters. Selection for high (MH) and low (ML) heat loss and unselected control (MC) occurred in each of three replicates for a total of nine unique lines. Repeatability of the heat loss measurement was .45 and the CV was 10.5%. Cumulative realized selection differentials, averaged for the three replicates, were 145.1 and -105.0 (kcal•kg-.75•d-1) and ranged from …
Divergent Selection For Heat Loss In Mice: Ii. Correlated Responses In Feed Intake, Body Mass, Body Composition, And Number Born Through Fifteen Generations, Merlyn K. Nielsen, B. A. Freking, L. D. Jones, S. M. Nelson, T. L. Vorderstrasse, B. A. Hussey
Divergent Selection For Heat Loss In Mice: Ii. Correlated Responses In Feed Intake, Body Mass, Body Composition, And Number Born Through Fifteen Generations, Merlyn K. Nielsen, B. A. Freking, L. D. Jones, S. M. Nelson, T. L. Vorderstrasse, B. A. Hussey
Department of Animal Science: Faculty Publications
Divergent selection for heat loss (kcal•kg-.75•d-1) , measured in 9- to 11-wk-old male mice, was conducted for 15 generations. Selection for high (MH) and low (ML) heat loss and unselected control (MC) occurred in each of three replicates for a total of nine unique lines. Feed intake in males was measured during Generations 9 through 15. Body mass at commencement of mating in females and at time of measurement of heat loss in males was recorded. Body fat percentage at 12 wk for animals of Generations 6, 10, and 14 was predicted as a function of …
Comparison Of Usda Quality Grade With Tendertec For The Assessment Of Beef Palatability, M. H. George, J.D. Tatum, H. G. Dolezal, J. B. Morgan, J. M. Wise, Chris R. Calkins, T. Gordon, J. O. Reagan, G. C. Smith
Comparison Of Usda Quality Grade With Tendertec For The Assessment Of Beef Palatability, M. H. George, J.D. Tatum, H. G. Dolezal, J. B. Morgan, J. M. Wise, Chris R. Calkins, T. Gordon, J. O. Reagan, G. C. Smith
Department of Animal Science: Faculty Publications
Carcasses (n = 265) selected to differ in USDA yield grade were evaluated by expert graders and assessed for tenderness with the Tendertec Mark III Beef Grading Instrument. Tendertec measurements were collected on longissimus lumborum muscles in both sides of each carcass. During fabrication of each left carcass side, a rib section (later converted into three steaks) was removed for aging and subsequent sensory panel evaluation at 14 d and for Warner-Bratzler shear force measurements at 14 and 28 d. Correlation coefficients for repeatability of Tendertec output variables, between left and right carcass sides, were .57, .44, .70, and .65 …