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- Growth (9)
- Beef Cattle (8)
- Selection (8)
- Carcass (4)
- Pigs (4)
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- Reproduction (4)
- Carcass composition (3)
- Heritability (3)
- Pig (3)
- Sheep (3)
- Ambient Temperature (2)
- Cattle (2)
- Computed tomography (2)
- Corn Gluten Feed (2)
- Crossbreeding (2)
- Differential Display Polymerase Chain Reaction (2)
- Estrogen (2)
- Finishing Cattle (2)
- Forage (2)
- Line Evaluation (2)
- Litter Size (2)
- Longevity (2)
- Mice (2)
- Microarray (2)
- Ovulation Rate (2)
- Adjustment factors (1)
- Beef cattle (1)
- Birth weight; Weaning weight; Fleece weight; Litter size (1)
- Body Composition (1)
- Body Lean Mass (1)
Articles 1 - 30 of 44
Full-Text Articles in Animal Sciences
Follicular Development And Maturation In Gilts Selected For An Index Of High Ovulation Rate And High Prenatal Survival, H.-W. Yen, J. J. Ford, D. R. Zimmerman, R. K. Johnson
Follicular Development And Maturation In Gilts Selected For An Index Of High Ovulation Rate And High Prenatal Survival, H.-W. Yen, J. J. Ford, D. R. Zimmerman, R. K. Johnson
Department of Animal Science: Faculty Publications
Seventy-one 10th-generation gilts from White Line-1 (WL-1 = randomly selected control line) and White Line-2 (WL-2 = selected for an index of ovulation rate and prenatal survival rate) were used to compare the pattern of follicular development and atresia during the follicular phase of the estrous cycle. Gilts were treated with PGF2α on d 13 of the estrous cycle (d 0 of induced follicular development) to induce luteolysis and assigned randomly within line and sire for ovary recovery on d 0, 2, 3, 4, 5, and the day after estrus. Ovaries were evaluated for numbers of corpora albicantia and …
Microarray Profiling For Differential Gene Expression In Ovaries And Ovarian, A. R. Caetano, R. K. Johnson, J. J. Ford, Daniel Pomp
Microarray Profiling For Differential Gene Expression In Ovaries And Ovarian, A. R. Caetano, R. K. Johnson, J. J. Ford, Daniel Pomp
Department of Animal Science: Faculty Publications
A unique index line of pigs created by long-term selection ovulates on average 6.7 more ova than its randomly selected control line. Expression profiling experiments were conducted to identify differentially expressed genes in ovarian tissues of the index and control lines during days 2–6 of the follicular phase of the estrous cycle. Fluorescently labeled cDNAs derived from ovary and follicle RNA were cohybridized on microarray slides (n = 90) containing 4608 follicle-derived probes printed in duplicate. Statistical analysis of the resulting ~1.6 million data points with a mixed-model approach identified 88 and 74 unique probes, representing 71 and 59 …
A Large-Sample Qtl Study In Mice: Iii. Reproduction, Joao L. Rocha, Eugene J. Eisen, Frank Siewerdt, L. Dale Van Vleck, Daniel Pomp
A Large-Sample Qtl Study In Mice: Iii. Reproduction, Joao L. Rocha, Eugene J. Eisen, Frank Siewerdt, L. Dale Van Vleck, Daniel Pomp
Department of Animal Science: Faculty Publications
Using lines of mice having undergone long-term selection for high and low growth, a large-sample (n ≈ 1000 F2) experiment was conducted to gain further understanding of the genetic architecture of complex polygenic traits. Composite interval mapping on data from 10-week-old F2 females (n = 439) detected 15 quantitative trait loci (QTLs) on 5 chromosomes that influence reproduction traits characterized at day 16 of gestation. These QTL are broadly categorized into two groups: those where effects on the number of live fetuses (LF) were accompanied by parallel effects on the number of dead fetuses (DF), and those free …
A Genome Scan For Quantitative Trait Loci And Imprinted Regions Affecting Reproduction In Pigs, J. W. Holl, J. P. Cassady, D. Pomp, R. K. Johnson
A Genome Scan For Quantitative Trait Loci And Imprinted Regions Affecting Reproduction In Pigs, J. W. Holl, J. P. Cassady, D. Pomp, R. K. Johnson
Department of Animal Science: Faculty Publications
Quantitative trait loci for reproductive traits in a three-generation resource population of a cross between low-indexing pigs from a control line and high-indexing pigs from a line selected 10 generations for increased index of ovulation rate and embryonic survival are reported. Phenotypic data were collected in F2 females for birth weight (BWT, n = 428), weaning weight (WWT, n = 405), age at puberty (AP, n = 295), ovulation rate (OR, n = 423), number of fully formed pigs (FF, n = 370), number of pigs born alive (NBA, n = 370), number of mummified pigs (MUM, n = 370), …
National Pork Producers Council Maternal Line Genetic Evaluation: A Comparison Of Growth And Carcass Traits In Terminal Progeny, J. P. Cassidy, O. W. Robison, R. K. Johnson, J. W. Mabry, L. L. Christian, M. D. Tokach, R. K. Miller, R. N. Goodwin
National Pork Producers Council Maternal Line Genetic Evaluation: A Comparison Of Growth And Carcass Traits In Terminal Progeny, J. P. Cassidy, O. W. Robison, R. K. Johnson, J. W. Mabry, L. L. Christian, M. D. Tokach, R. K. Miller, R. N. Goodwin
Department of Animal Science: Faculty Publications
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 × 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, …
Heterosis For Grain Yield And Other Agronomic Traits In Foxtail Millet, M. M. Siles, William K. Russell, Lenis Alton Nelson, David D. Baltensperger, Blaine Johnson, L. Dale Van Vleck, Stanley G. Jensen, Gary L. Hein
Heterosis For Grain Yield And Other Agronomic Traits In Foxtail Millet, M. M. Siles, William K. Russell, Lenis Alton Nelson, David D. Baltensperger, Blaine Johnson, L. Dale Van Vleck, Stanley G. Jensen, Gary L. Hein
Department of Animal Science: Faculty Publications
Foxtail millet [Setaria italica (L.) P. Beauv.] is a largely self-pollinating species that is used as a warm-season annual in the USA. Nearly all cultivars of this species grown in the USA are selections from land races. This research was undertaken to determine whether sufficient high-parent heterosis is expressed in foxtail millet for grain yield and other key traits to justify the development and use of varietal crosses. Seven diverse parents and 21 F2s and 21 F3s produced from biparental crosses were evaluated in five environments in 1996. Genotype x environment interaction was highly significant …
Evaluation Of Gene Expression In Pigs Selected For Enhanced Reproduction Using Differential Display Pcr And Human Microarrays: I. Ovarian Follicles, C. D. Gladney, G. R. Bertani, R. K. Johnson, Daniel Pomp
Evaluation Of Gene Expression In Pigs Selected For Enhanced Reproduction Using Differential Display Pcr And Human Microarrays: I. Ovarian Follicles, C. D. Gladney, G. R. Bertani, R. K. Johnson, Daniel Pomp
Department of Animal Science: Faculty Publications
Differential display PCR (ddPCR) and complementary DNA microarray analyses were used to evaluate gene expression differences in porcine ovarian follicles between a line of pigs selected for an index of ovulation rate and embryo survival (Line I) and its randomly selected control line (Line C). Follicles (4.0 to 7.0 mm) were dissected from ovaries of multiparous sows (n = 27) at either 2 or 4 d following PGF2α analog injection on d 12 to 14 of the estrous cycle. Using ddPCR, differentially expressed bands (n = 282) were excised from gels and 107 were sequenced, yielding 84 unique porcine follicle …
Comparison Of Models Including Cytoplasmic Effects For Traits Of Rambouillet Sheep, G. D. Snowder, K. J. Hanford, L. Dale Van Vleck
Comparison Of Models Including Cytoplasmic Effects For Traits Of Rambouillet Sheep, G. D. Snowder, K. J. Hanford, L. Dale Van Vleck
Department of Animal Science: Faculty Publications
The objective was to determine appropriate analytical models considering cytoplasmic inheritance for birth weight (BWT, n = 35,604), weaning weight (WWT, n = 34,114), fleece weight (FWT, n = 38,113) and number born (NB, n = 39,029) for Rambouillet sheep. For BWT, models that included dam by year, dam by number born, and sire by dam effects, in addition to direct and maternal effects, were significantly better than the basic maternal effects model. For WWT, variances due to direct, maternal, and maternal permanent environmental effects (0.05 of variance) were not zero. For FWT, heritability was 0.55 for all models, but …
Heritability Estimates For Carcass Traits Of Cattle: A Review, Angel Rios Utrera, L. Dale Van Vleck
Heritability Estimates For Carcass Traits Of Cattle: A Review, Angel Rios Utrera, L. Dale Van Vleck
Department of Animal Science: Faculty Publications
We present estimates of heritability for carcass traits of cattle published in the scientific literature. Seventy-two papers published form 1962 to 2004, which reported estimates of heritability for carcass traits, were reviewed. The unweighted means of estimates of heritability for 14 carcass traits by slaughter end point (age, weight, and fat depth) were calculated. Among the three end points, carcass weight, backfat thickness, longissimus muscle area, and marbling score were the carcass traits with the most estimates of heritability (56≤n≤66). The averages for these traits indicate that they are similarly and moderately heritable (0.40, 0.36, 0.40, and 0.37, respectively). However, …
Effects Of Sire Misidentification On Estimates Of Genetic Parameters For Birth And Weaning Weights In Hereford Cattle, S. L. Senneke, M. D. Macneil, L. Dale Van Vleck
Effects Of Sire Misidentification On Estimates Of Genetic Parameters For Birth And Weaning Weights In Hereford Cattle, S. L. Senneke, M. D. Macneil, L. Dale Van Vleck
Department of Animal Science: Faculty Publications
Birth weights (4,155) and weaning weights (3,884) of Line 1 Herefords collected at the Fort Keogh Livestock and Range Research Laboratory in Miles City, MT, between the years of 1935 to 1989 were available. To study the effect of misidentification on estimates of genetic parameters, the sire identification of calf was randomly replaced by the identification of another sire based on the fraction of progeny each sire contributed to a yearly calf crop. Misidentification rates ranged from 5 to 50% with increments of 5%. For each rate of misidentification, 100 replicates were obtained and analyzed with single-trait and two-trait analyses …
Genetic Parameters For Six Measures Of Length Of Productive Life And Three Measures Of Lifetime Production By 6 Yr After First Calving For Hereford Cows, R. M. Koch, L. V. Cundiff, K. E. Gregory, L. Dale Van Vleck
Genetic Parameters For Six Measures Of Length Of Productive Life And Three Measures Of Lifetime Production By 6 Yr After First Calving For Hereford Cows, R. M. Koch, L. V. Cundiff, K. E. Gregory, L. Dale Van Vleck
Department of Animal Science: Faculty Publications
Genetic parameters for length of productive life given the opportunity (LPL|O), measured as days between first calving and disposal conditioned on one of six opportunity groups, L1 through L6 (e.g., L2 is length of productive life in days given the opportunity to live 2 yr after first calving), and lifetime production (LP), measured as the number of calves born (NB), number of calves weaned (NW), and cumulative weaning weight (CW) by 6 yr after first calving, were estimated using records of 1,886 Hereford cows from a selection experiment with three selected lines and a control line. Weaning weights were adjusted …
Responses To 19 Generations Of Litter Size Selection In The Ne Index Line. Ii. Growth And Carcass Responses Estimated In Pure Line And Crossbred Litters, D. B. Petry, J. W. Holl, R. K. Johnson
Responses To 19 Generations Of Litter Size Selection In The Ne Index Line. Ii. Growth And Carcass Responses Estimated In Pure Line And Crossbred Litters, D. B. Petry, J. W. Holl, R. K. Johnson
Department of Animal Science: Faculty Publications
Our objective was to estimate responses in growth and carcass traits in the NE Index line (I) that was selected for 19 generations for increased litter size. Differences between Line I and the randomly selected control line (C) were estimated in pure line litters and in F1 and three-way cross litters produced by mating I and C females with males of unrelated lines. Contrasts of means were used to estimate the genetic difference between I and C and interactions of line differences with mating type. In Exp 1, 694 gilts that were retained for breeding, including 538 I and …
Number Of Calves Born, Number Of Calves Weaned, And Cumulative Weaning Weight As Measures Of Lifetime Production For Hereford Cows, G. E. Martinez, R. M. Koch, L. V. Cundiff, K. E. Gregory, L. Dale Van Vleck
Number Of Calves Born, Number Of Calves Weaned, And Cumulative Weaning Weight As Measures Of Lifetime Production For Hereford Cows, G. E. Martinez, R. M. Koch, L. V. Cundiff, K. E. Gregory, L. Dale Van Vleck
Department of Animal Science: Faculty Publications
Genetic parameters for lifetime production for cows with the opportunity to produce from 2 through 7 yr of age, as measured by the number of calves born (NB2, …, NB7), the number of calves weaned (NW2, …, NW7), and cumulative weaning weight (CW2,…, CW7), were estimated using data from 3,064 Hereford cows from a selection experiment with a control line (CTL) and three lines selected for weaning weight (WWL), yearling weight (YWL), and an index of yearling weight and muscle score (IXL). Weaning weights were adjusted to 200 d of age and for sex and age of dam. Estimates of …
Responses To 19 Generations Of Litter Size Selection In The Nebraska Index Line. I. Reproductive Responses Estimated In Pure Line And Crossbred Litters, D. B. Petry, Rodger K. Johnson
Responses To 19 Generations Of Litter Size Selection In The Nebraska Index Line. I. Reproductive Responses Estimated In Pure Line And Crossbred Litters, D. B. Petry, Rodger K. Johnson
Department of Animal Science: Faculty Publications
Our objective was to estimate responses in reproductive traits in the Nebraska Index line (I) after 19 generations of selection for increased litter size. Responses were estimated in dams producing pure line, F1, and three-way cross litters. A total of 850 litters were produced over six year-seasons, including 224 pure line litters, 393 F1 litters produced from I and C females mated with DanbredNALandrace (L) or Duroc- Hampshire (T) boars, and 233 litters by F1 L x I and L x C females mated with T boars. Contrasts of means were used to estimate the genetic …
Age-Of-Dam Adjustment Factors For Birth And Weaning Weight Records Of Beef Cattle: A Review, Janice M. Rumpf, L. Dale Van Vleck
Age-Of-Dam Adjustment Factors For Birth And Weaning Weight Records Of Beef Cattle: A Review, Janice M. Rumpf, L. Dale Van Vleck
Department of Animal Science: Faculty Publications
Age-of-dam adjustment factors are used to pre-adjust birth and weaning weight data for national beef cattle genetic evaluations. Adjustments are used in order to make the means of the different age-of-dam subclasses similar so that a fair comparison of animals can be performed. A review was made of various research studies that have estimated age-of-dam adjustment factors for birth weight and weaning weight of beef cattle. In general, birth weight age-of-dam adjustment factors are the same across the sexes, but weaning weight age-of-darn adjustment factors differ across the sexes, with heifer calves receiving smaller adjustments than their male counterparts. Additionally, …
Genetic Relationships Between Sex-Specific Traits In Beef Cattle: Mature Weight, Weight Adjusted For Body Condition Score, Height And Body Condition Score Of Cows, And Carcass Traits Of Their Steer Relatives, K. A. Nephawe, L. V. Cundiff, M. E. Dikeman, J. D. Crouse, L. Dale Van Vleck
Genetic Relationships Between Sex-Specific Traits In Beef Cattle: Mature Weight, Weight Adjusted For Body Condition Score, Height And Body Condition Score Of Cows, And Carcass Traits Of Their Steer Relatives, K. A. Nephawe, L. V. Cundiff, M. E. Dikeman, J. D. Crouse, L. Dale Van Vleck
Department of Animal Science: Faculty Publications
Data from the first four cycles of the Germplasm Evaluation Program at the U.S. Meat Animal Research Center (USMARC) were used to investigate genetic relationships between mature weight (MW, n = 37,710), mature weight adjusted for body condition score (AMW, n = 37,676), mature height (HT, n = 37,123), and BCS (n = 37,676) from 4- to 8-yr old cows (n = 1,800) and carcass traits (n = 4,027) measured on their crossbred paternal half-sib steers. Covariance components among traits were estimated using REML. Carcass traits were adjusted for age at slaughter. Estimates of heritability for hot carcass weight (HCWT); …
Genetic Response To Selection For Weaning Weight Or Yearling Weight Or Yearling Weight And Muscle Score In Hereford Cattle: Efficiency Of Gain, Growth, And Carcass Characteristics, R. M. Koch, L. V. Cundiff, K. E. Gregory, L. Dale Van Vleck
Genetic Response To Selection For Weaning Weight Or Yearling Weight Or Yearling Weight And Muscle Score In Hereford Cattle: Efficiency Of Gain, Growth, And Carcass Characteristics, R. M. Koch, L. V. Cundiff, K. E. Gregory, L. Dale Van Vleck
Department of Animal Science: Faculty Publications
An experiment involving crosses among selection and control lines was conducted to partition direct and maternal additive genetic response to 20 yr of selection for 1) weaning weight, 2) yearling weight, and 3) index of yearling weight and muscle score. Selection response was evaluated for efficiency of gain, growth from birth through market weight, and carcass characteristics. Heritability and genetic correlations among traits were estimated using animal model analyses. Over a time-constant interval, selected lines were heavier, gained more weight, consumed more ME, and had more gain/ME than the control. Over a weight-constant interval, selected lines required fewer days, consumed …
A Large-Sample Qtl Study In Mice: Ii. Body Composition, Joao L. Rocha, Eugene J. Eisen, L. Dale Van Vleck, Daniel Pomp
A Large-Sample Qtl Study In Mice: Ii. Body Composition, Joao L. Rocha, Eugene J. Eisen, L. Dale Van Vleck, Daniel Pomp
Department of Animal Science: Faculty Publications
Using lines of mice having undergone long-term selection for high and low growth, a large-sample (n = ~1,000 F2) experiment was conducted to gain further understanding of the genetic architecture of complex polygenic traits. Composite interval mapping on data from male F2 mice (n = 552) detected 50 QTL on 15 chromosomes impacting weights of various organ and adipose subcomponents of growth, including heart, liver, kidney, spleen, testis, and subcutaneous and epididymal fat depots. Nearly all aggregate growth QTL could be interpreted in terms of the organ and fat subcomponents measured. More than 25% of QTL detected map …
A Large-Sample Qtl Study In Mice: I. Growth, Joao L. Rocha, Eugene J. Eisen, L. Dale Van Vleck, Daniel Pomp
A Large-Sample Qtl Study In Mice: I. Growth, Joao L. Rocha, Eugene J. Eisen, L. Dale Van Vleck, Daniel Pomp
Department of Animal Science: Faculty Publications
By use of long-term selection lines for high and low growth, a large-sample (n = ~1,000 F2) experiment was conducted in mice to further understand the genetic architecture of complex polygenic traits. In combination with previous work, we conclude that QTL analysis has reinforced classic polygenic paradigms put in place prior to molecular analysis. Composite interval mapping revealed large numbers of QTL for growth traits with an exponential distribution of magnitudes of effects and validated theoretical expectations regarding gene action. Of particular significance, large effects were detected on Chromosome (Chr) 2. Regions on Chrs 1, 3, 6, 10, …
Effect Of Organic Matter Addition To The Pen Surface And Pen Cleaning Frequency On Nitrogen Mass Balance In Open Feedlots, J. R. Adams, T. B. Farran, Galen Erickson, Terry Klopfenstein, C. N. Macken, C. B. Wilson
Effect Of Organic Matter Addition To The Pen Surface And Pen Cleaning Frequency On Nitrogen Mass Balance In Open Feedlots, J. R. Adams, T. B. Farran, Galen Erickson, Terry Klopfenstein, C. N. Macken, C. B. Wilson
Department of Animal Science: Faculty Publications
Three finishing trials were conducted to determine the effects of dietary manipulation and management on N losses from open feedlots. In each experiment, 96 steers were assigned randomly to 12 nutrient balance pens. In Trial 1, calves were fed for 180 d during the winter/spring months; in Trial 2, yearlings were fed for 132 d in the summer. In Trials 1 and 2, N losses from pens were compared directly by adding OM to the pen surface or indirectly by feeding digestible ingredients designed to increase OM excretion. The dietary treatment (BRAN) included 30% corn bran (DM basis) replacing dry-rolled …
Effects Of Concentration And Composition Of Wet Corn Gluten Feed In Steam-Flaked Corn-Based Finishing Diets, C. N. Macken, Galen E. Erickson, Terry Klopfenstein, Rick Stock
Effects Of Concentration And Composition Of Wet Corn Gluten Feed In Steam-Flaked Corn-Based Finishing Diets, C. N. Macken, Galen E. Erickson, Terry Klopfenstein, Rick Stock
Department of Animal Science: Faculty Publications
Two finishing experiments were conducted to determine the effects of concentration (Exp. 1) and composition of wet corn gluten feed (Exp. 2) in steam-flaked corn-based diets on feedlot steer performance. In Exp. 1, 192 English × Continental crossbred steer calves (299 ± 0.6 kg) were used in a completely randomized design with six dietary treatments (four pens per treatment). Treatments were six concentrations of wet corn gluten feed (Sweet Bran, Cargill Inc., Blair, NE; 0, 10, 20, 25, 30, and 35%) replacing steam-flaked corn (DM basis). All diets contained 10% corn silage, 5% supplement, and 3.5% tallow (DM basis). Gain …
Fat Supplementation And Reproduction In Beef Females, Richard N. Funston
Fat Supplementation And Reproduction In Beef Females, Richard N. Funston
Department of Animal Science: Faculty Publications
Inadequate dietary energy intake and poor body condition can negatively affect reproductive function. Supplemental lipids have been used to increase energy density of the diet and may also have direct positive effects on reproduction in beef cattle. Several fatty acid sources have been studied as they relate to reproductive function. Common sources include sunflower, safflower, cottonseed, rice bran, soybeans, fishmeal, animal tallow, and calcium salts of fatty acids. Fats have been fed before and after calving, during the breeding season, and during heifer development. Response to fat has been investigated through measuring body weight and body condition score, age at …
Effects Of Food Quality On Growth And Carcass Composition In Lambs Of Two Breeds And Their Cross, R. M. Lewis, J. M. Macfarlane, G. Simm, G. C. Emmans
Effects Of Food Quality On Growth And Carcass Composition In Lambs Of Two Breeds And Their Cross, R. M. Lewis, J. M. Macfarlane, G. Simm, G. C. Emmans
Department of Animal Science: Faculty Publications
The effects offood quality, breed type and sex (ram and ewe) on Iamb growth and carcass composition, and their changes throughout growth, were measured. The three breed typeswereScottish Blackface (B; no. = 24), Suffolk (S; no. = 28) and their reciprocal crosses (X; no. 33). The lambs had free access to a nutritionally non-limiting food, H, or a bulky food, L. Each lamb was scanned using X-ray computed tomography to measure the weights offat, lean and bone in the carcass at three degrees of maturity (0·30, 0·45 and 0·65) in live weight. Live weight and food intake data were recorded …
Effects Of Index Selection On The Performance And Carcass Composition Of Sheep Given Foods Of Different Protein Concentrations Ad Libitum., R. M. Lewis, G. C. Emmans, G. Simm
Effects Of Index Selection On The Performance And Carcass Composition Of Sheep Given Foods Of Different Protein Concentrations Ad Libitum., R. M. Lewis, G. C. Emmans, G. Simm
Department of Animal Science: Faculty Publications
Sheep of a line selected on an index to increase carcass lean content at 150 days of age (selected (S); no. = 90), and an unselected control line (control (C); no. = 90), were given ad libitum foods of three different protein concentrations (192, 141 and 120 g/kg dry matter). Growth was measured from about 21 to 114 kg live weight. The carcasses of each line were analysed for lean, fat and bone at three widely varying weights in both males and females. Level of protein did not affect the extent to tohidi S was superior to C in the …
Predicting Population Gene Frequency From Sample Data, R. M. Lewis, B. Grundy, L. A. Kuehn
Predicting Population Gene Frequency From Sample Data, R. M. Lewis, B. Grundy, L. A. Kuehn
Department of Animal Science: Faculty Publications
With an increase in the number of candidate genes for important traits in livestock, effective strategies for incorporating such genes into selection programmes are increasingly important. Those strategies in part depend on the frequency of a favoured allele in a population. Since comprehensive genotyping of a population is seldom possible, we investigate the consequences of sampling strategies on the reliability of the gene frequency estimate for a bi-allelic locus. Even within a subpopulation or line, often only a proportion of individuals will be genotype tested. However, through segregation analysis, probable genotypes can be assigned to individuals that themselves were not …
Exogenous Estrogen Boosts Circulating Estradiol Concentrations And Calcium Uptake By Duodenal Tissue In Heat-Stressed Hens, K.K. Hansen, M.M. Beck, S.E. Scheideler, Erin E. Blankenship
Exogenous Estrogen Boosts Circulating Estradiol Concentrations And Calcium Uptake By Duodenal Tissue In Heat-Stressed Hens, K.K. Hansen, M.M. Beck, S.E. Scheideler, Erin E. Blankenship
Department of Animal Science: Faculty Publications
In the hen, heat stress (HS) disrupts shell calcification and reproductive processes, including hormone synthesis and egg production. Two studies were conducted to investigate palliative effects of exogenous estrogen or dietary vitamin D3 on Ca homeostasis and reproductive physiology during HS. Study 1: Hy-Line W36 hens were randomly assigned to thermoneutral (TN) or HS treatments and to 1 of 7 estrogen treatments: zero (control) or one Compudose 200 implant given 1, 2, 3, 8, 9, or 10 d before onset of HS. With no implant, HS reduced plasma estradiol (E2) and total Ca absorbed (CaT) by duodenal cells (P < 0.05). In TN hens with implants, plasma E2 tripled within 24 h (P < 0.05) and remained elevated (P < 0.05) through d 9. In HS hens with implants, plasma E2 rose 6-fold (P < 0.05) to equal TN+E2 concentrations and remained elevated through d 10. In TN and HS hens with implants, the rate of Ca absorption (CaTR) and CaT increased dramatically; the responses were quadratic and essentially identical. Study 2: Hy-Line W36 hens were provided diets formulated either according to NRC requirements (NRC, 1994), or with the addition of 22,000 IU/kg vitamin D3 (+VD hens). A 24-h HS episode was imposed 2 wk after initiation of the dietary regimen. Duodenal samples were collected for Ca absorption assays after the 24-h HS episode. Both CaTR and CaT in +VD hens were approximately 3-fold higher than in hens in the NVD group (P = 0.102). The results lead to the conclusion that exogenous estrogen, high levels of dietary vitamin D, or both, before a HS episode, are efficacious in alleviating at least some of the effects of HS and should be further investigated.
Review: Re-Evaluation Of Phosphorus Requirements And Phosphorus Retention Of Feedlot Cattle, H. C. Block, G. E. Erickson, T. J. Klopfenstein
Review: Re-Evaluation Of Phosphorus Requirements And Phosphorus Retention Of Feedlot Cattle, H. C. Block, G. E. Erickson, T. J. Klopfenstein
Department of Animal Science: Faculty Publications
Phosphorus requirement recommendations for cattle are important for preventing over-feeding of P and excessive P excretion. Improved precision in managing P nutrition can reduce feedlot waste management concerns. Current beef recommendations (NRC, 1996) fail to account for absorption coefficient variation related to P source, whereas dairy recommendations (NRC, 2001) change absorption coefficients with P source. Maintenance and BW gain requirements for absorbed P do not represent underlying relationships. Maintenance P requirements reflect endogenous P loss arising from failure to reabsorb salivary P. Basing maintenance requirements on saliva P secretion and re-absorption rates should improve precision of maintenance requirement estimates. Gain …
Comparisons Of Angus, Charolais, Galloway, Hereford, Longhorn, Nellore, Piedmontese, Salers, And Shorthorn Breeds For Weight, Weight Adjusted For Condition Score, Height, And Condition Score Of Cows, Jesus Arango, L. V. Cundiff, L. Dale Van Vleck
Comparisons Of Angus, Charolais, Galloway, Hereford, Longhorn, Nellore, Piedmontese, Salers, And Shorthorn Breeds For Weight, Weight Adjusted For Condition Score, Height, And Condition Score Of Cows, Jesus Arango, L. V. Cundiff, L. Dale Van Vleck
Department of Animal Science: Faculty Publications
Breed differences for weight (CW), height (CH), and condition score (CS) were estimated from records (n &#;&#;12,188) of 2- to 6-yr-old cows (n &#; 744) from Cycle IV of the U.S. Meat Animal Research Center’s Germplasm Evaluation (GPE) Program. Cows were produced from mating Angus and Hereford dams to Angus, Hereford, Charolais, Shorthorn, Galloway, Longhorn, Nellore, Piedmontese, and Salers sires. Samples of Angus and Hereford sires were 1) reference sires born from 1962 through 1970 and 2) 1980s sires born in 1980 through 1987. The mixed model included cow age, season of measurement and their interactions, year of birth, pregnancy-lactation …
Covariance Functions And Random Regression Models For Cow Weight In Beef Cattle, Jesus Arango, L. V. Cundiff, L. Dale Van Vleck
Covariance Functions And Random Regression Models For Cow Weight In Beef Cattle, Jesus Arango, L. V. Cundiff, L. Dale Van Vleck
Department of Animal Science: Faculty Publications
Data from the first four cycles of the Germplasm Evaluation program at the U.S. Meat Animal Research Center were used to evaluate weights of Angus, Hereford, and F1 cows produced by crosses of 22 sire and 2 dam (Angus and Hereford) breeds. Four weights per year were available for cows from 2 through 8 yr of age (AY) with age in months (AM). Weights (n &#;&#;61,798) were analyzed with REML using covariance function-random regression models (CF-RRM), with regression on orthogonal (Legendre) polynomials of AM. Models included fixed regression on AM and effects of cow line, age in years, season of …
Phosphorus Fractionation In Manure From Swine Fed Traditional And Low-Phytate Corn Diets, Brian J. Wienhold, Phillip S. Miller
Phosphorus Fractionation In Manure From Swine Fed Traditional And Low-Phytate Corn Diets, Brian J. Wienhold, Phillip S. Miller
Department of Animal Science: Faculty Publications
Traditional corn (Zea mays L.) (TC), the primary grain used in swine (Sus scrofa) diets, stores a majority of its P as phytate, which is largely unavailable for digestion by nonruminant animals. Low- phytate corn (LPC) contains similar amounts of total P but a smaller percentage of P as phytate. When fed to swine, LPC increases P utilization and reduces P content of manure. While differences in P content between manure from animals fed TC and LPC diets have been documented, solubility and lability of manure P have not been compared. Manure P was characterized in manure …