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Renesting Decisions And Annual Fecundity Of Female Dickcissels (Spiza Americana) In Illinois, Jeffery Walk, Kevin Wentworth, Eric Kershner, Eric Bollinger, Richard Warner Jan 2004

Renesting Decisions And Annual Fecundity Of Female Dickcissels (Spiza Americana) In Illinois, Jeffery Walk, Kevin Wentworth, Eric Kershner, Eric Bollinger, Richard Warner

Faculty Research & Creative Activity

T.-Renesting decisions and annual fecundity are crucial for interpreting other demographic information, yet are infrequently reported. We used radiotelemetry to monitor female Dickcissels (Spiza americana) throughout the 1999 and 2000 breeding seasons in south- eastern Illinois. Overall fecundity (regardless of whether females remained in the study area throughout the breeding season) was 0.61 ? 0.13 female fledglings per year. Of females that re- mained within the study area, 94% fledged young (1.25 ? 0.15 female fledglings per year). Most females (62%) that experienced nest failure emigrated from the study area (moved >10 km) in 2.8 ? 0.6 days; others (36%) …


Breed Comparisons Of Weight, Weight Adjusted For Condition Score, Height, And Condition Score Of Beef Cows, J. A. Arango, L. V. Cundiff, L. D. Van Vleck Jan 2004

Breed Comparisons Of Weight, Weight Adjusted For Condition Score, Height, And Condition Score Of Beef Cows, J. A. Arango, L. V. Cundiff, L. D. Van Vleck

Roman L. Hruska U.S. Meat Animal Research Center: Reports

Breeds were compared for differences in BW (n = 56,731), heights (n = 51,407) and body condition scores (BCS, n = 56,371) of 2- to 8-yr-old cows from four cycles of the Germplasm Evaluation (GPE) Program at the U. S. Meat Animal Research Center (U.S. Meat Animal Research Center). Angus, Hereford, and topcross cows from 22 breeds of sires were produced. The mixed model for repeated measures of BW, height, and BCS included random additive genetic and permanent environmental effects of the cow. Differences among crosses were significant for all traits. In general, BW, …


Duck Nesting On Rotational And Continuous Grazed Pastures In North Dakota, Robert K. Murphy, Darrell J. Schindler, Richard D. Crawford Jan 2004

Duck Nesting On Rotational And Continuous Grazed Pastures In North Dakota, Robert K. Murphy, Darrell J. Schindler, Richard D. Crawford

United States Fish and Wildlife Service: Publications

To improve the economic viability of grazed prairie and thus conserve it as wildlife habitat, the Prairie Pothole Joint Venture (PPJV) cost-shares establishment of rotational cattle grazing on privately owned, native rangeland. During 1996 and 1997 we evaluated duck nest density, nest success, and nesting habitat on six PPJV rotational grazed pastures on the Missouri Coteau landform in central and northwestern North Dakota. Each rotational pasture was paired with a traditional, continuous grazed pasture for comparison. We located 444 nests of eight duck species. We detected no differences (P > 0.1) between rotational and continuous grazed pastures in apparent nest density …


High Abundance Of Nesting Long-Eared Owls In North Dakota, Robert K. Murphy, Laura J. Rosenfield, Robert N. Rosenfield, Melvin P. Nenneman Jan 2004

High Abundance Of Nesting Long-Eared Owls In North Dakota, Robert K. Murphy, Laura J. Rosenfield, Robert N. Rosenfield, Melvin P. Nenneman

United States Fish and Wildlife Service: Publications

The long-eared owl (Asio otus) is a secretive, poorly understood species in the Great Plains of the United States and Canada. In North Dakota the long-eared owl has been considered a species of special concern (Petersen 1991), due mainly to lack of information on its occurrence and nesting status. We discovered 39 long-eared owl nests while searching for Cooper's hawk (Accipiter cooperii) nests in northwestern and north central North Dakota during April and May 2000. Long-eared owl nests mainly were observed at J. Clark Salyer and Des Lacs National Wildlife Refuges (NWRs) in the Souris River …


Non-Native Species Monitoring And Control In The Upper San Juan River, New Mexico 2004, Jason E. Davis Jan 2004

Non-Native Species Monitoring And Control In The Upper San Juan River, New Mexico 2004, Jason E. Davis

United States Fish and Wildlife Service: Publications

Intensive non-native removal in 2004 on the upper San Juan River marked the fourth year of such efforts. A total of 6,925 channel catfish Ictalurus punctatus and 1,216 common carp Cyprinus carpio were removed from RM’s 166.6 – 147.9 during 10 removal trips. Of the 10 trips, 6 were conducted from PNM Weir to Hogback Diversion (RM’s 166.6 – 159.0) and four from Hogback Diversion to Shiprock Bridge, New Mexico (RM’s 158.8 – 147.9). In addition to intensive removal efforts, opportunistic removal during riverwide monitoring trips continued in 2004.

PNM Weir to Hogback Diversion - SECTION 1

Channel catfish CPUE …


Environmental Contaminants Associated With A Swine Concentrated Animal Feeding Operation And Implications For Mcmurtrey National Wildlife Refuge, Matthew S. Schwarz, Kathy R. Echols, Mark J. Wolcott, Karen J. Nelson Jan 2004

Environmental Contaminants Associated With A Swine Concentrated Animal Feeding Operation And Implications For Mcmurtrey National Wildlife Refuge, Matthew S. Schwarz, Kathy R. Echols, Mark J. Wolcott, Karen J. Nelson

United States Fish and Wildlife Service: Publications

Waste generated by concentrated animal feeding operations (CAFOs) may contain a variety of contaminants including nutrients, pathogens, trace elements, antibiotics, and hormones. In 2000, the U.S. Fish and Wildlife Service began to characterize CAFO contaminants in lagoons, canals, and created wetlands operated by Hastings Pork, a large swine CAFO adjacent to McMurtrey National Wildlife Refuge (McMurtrey) in Clay County, Nebraska. The created wetlands were designed to attract waterfowl; therefore, the primary purpose of this research was to evaluate whether migratory waterfowl were likely exposed to CAFO contaminants. A secondary research objective was to determine if created wetland water was suitable …


The Jackrabbit Dairy Review, Vikram Mistry Jan 2004

The Jackrabbit Dairy Review, Vikram Mistry

The Jackrabbit Dairy & Food Review

No abstract provided.


Dairy Digest 2004, South Dakota State University Dairy Club Jan 2004

Dairy Digest 2004, South Dakota State University Dairy Club

Dairy Digest

No abstract provided.


Curassows, Guans And Chacalacas: Status Survey And Conservation Action Plan (2000-2004), Stuart D. Strahl, Daniel M. Brooks Jan 2004

Curassows, Guans And Chacalacas: Status Survey And Conservation Action Plan (2000-2004), Stuart D. Strahl, Daniel M. Brooks

Galliformes Specialist Group and Affiliated Societies: Reports and Other Materials

Executive Summary

Introduction

  • Scope, structure, and objectives of the plan
  • Rationale for the action plan
  • Relevance of the action plan to general biodiversity conservation
  • Cracid Specialist Group activities, strategy, and history
  • Symposia and workshops
  • Cracid Specialist Group publications
  • Other activities related to cracid conservation
  • Cracid natural history
  • Evolution and ecology
  • Biogeography, distribution, and habitat association
  • The role of cracids in ecosystems
  • Cracids as biological indicators of ecosystem health
  • Socio-economic importance of cracids
  • Sustainable use
  • Potential for ecotourism
  • Taxonomic definitions used in this action plan
  • Threats to cracids
  • Hunting pressure
  • Habitat destruction
  • Lack of knowledge
  • Action needed to secure the future …


Demographics And The Ecological Role Of The Channel Catfish (Ictalurus Punctatus) In Commercially Exploited And Unexploited Reaches Of The Wabash River With Implications For The Flathead Catfish (Pylodictis Olivaris), Robert E. Colombo Jan 2004

Demographics And The Ecological Role Of The Channel Catfish (Ictalurus Punctatus) In Commercially Exploited And Unexploited Reaches Of The Wabash River With Implications For The Flathead Catfish (Pylodictis Olivaris), Robert E. Colombo

Faculty Research & Creative Activity

Catfish are a major component of the Wabash River fish assemblage and are commercially fished below river kilometer (Rkm) 500. From Rkm 322 through 499 the commercial fishery is subjected only to Indiana fishing regulations. In this reach of river, there is a 254-mm minimum total length limit on both sport and commercially harvested catfish. Below RM 322, the Wabash River forms the state boundary of Indiana and Illinois. In this region of river there are two different length limits on commercially harvested catfish with Indiana having a 254-mm length limit and Illinois having a 381-mm length limit. There is …


Dairies And Local Economic Development, Alvaro Garcia, Kenneth Kalscheur Jan 2004

Dairies And Local Economic Development, Alvaro Garcia, Kenneth Kalscheur

SDSU Extension Fact Sheets

This fact sheet is one in a series intended to answer — with science-based land-grant university research — questions frequently asked by the public about issues and needs affecting agricultural growth, urban expansion, and rural community development in South Dakota. During 2002, the year with latest available USDA figures, livestock production in South Dakota represented 50.7% of total agricultural cash receipts, followed by 42.4% for crops and 6.9% for government payments. Dairy products, at $178,176,000, were fifth of all agricultural cash receipts and were a highly significant portion of the state’s economy. In light of possible dairy expansion in the …


The Natural History And Morphology Of The Eastern Cricket Frog, Acris Crepitans Crepitans, In West Virginia, Kimberly Ann Bayne Jan 2004

The Natural History And Morphology Of The Eastern Cricket Frog, Acris Crepitans Crepitans, In West Virginia, Kimberly Ann Bayne

Theses, Dissertations and Capstones

Two subspecies of cricket frogs, Acris crepitans blanchardi and Acris crepitans crepitans, historically have occurred in West Virginia. The range of Acris c. blanchardi, Blanchard’s Cricket Frog, begins along the Ohio River extending into West Virginia. The Eastern Cricket Frog, Acris c. crepitans, is found in counties located in the eastern panhandle. The Eastern Cricket Frog is a species of great concern. Two sites where Acris c. crepitans historically occurred, two sites that never contained A. c. crepitans, one historical site that currently has A. c. crepitans, and two new sites that have A. c. crepitans were studied by auditory …


Use Of An Artificial Pond And Marshes By Amphibians And Reptiles In West Virginia, Vanessa A. Dozeman Jan 2004

Use Of An Artificial Pond And Marshes By Amphibians And Reptiles In West Virginia, Vanessa A. Dozeman

Theses, Dissertations and Capstones

A farm pond approximately 40 years old located in Wayne County, West Virginia was studied to determine the ingress and egress of amphibians and reptiles. In addition to the pond, 2 small marshes were also examined. The study extended from February 2003 to November 2003. The pond is approximately 36 m long and 38 m wide and is located on a south-facing hillside at 202 m in elevation. A drift fence composed of landscaping cloth was constructed to completely encircle the site. At every 5.15 m, funnel traps were positioned on both sides of the fence. Traps were checked daily …


Update On Omega-3 Fatty Acids And Litter Size In Swine, Duane Reese Jan 2004

Update On Omega-3 Fatty Acids And Litter Size In Swine, Duane Reese

Nebraska Swine Reports

A literature review was conducted to examine the role that dietary omega- 3 fatty acids may have in improving litter size in swine. Omega-3 fatty acids are not normally present to any great extent in practical swine diets, but they are increasingly believed to be important in human and pet health. In all but one of the studies reviewed the number of pigs born alive improved (0.2 to 0.7 pigs litter) when sows were provided diets that contained more omega-3 fatty acids. In all the studies that reported litter size at weaning, positive responses were observed (0.3 to 1.3 pigs/litter) …


Different Biological Responses Of Pigs Of Two Genetic Populations To Prrsv Challenge Suggests Underlying Genetic Variation In Susceptibility/Resistance To Prrsv, Derek B. Petry, Justin W. Holl, John Weber, Rodger K. Johnson, Alan R. Doster, Fernando Osario Jan 2004

Different Biological Responses Of Pigs Of Two Genetic Populations To Prrsv Challenge Suggests Underlying Genetic Variation In Susceptibility/Resistance To Prrsv, Derek B. Petry, Justin W. Holl, John Weber, Rodger K. Johnson, Alan R. Doster, Fernando Osario

Nebraska Swine Reports

The objective was to determine whether genetic variation in susceptibility to Porcine Respiratory and Reproductive Syndrome virus (PRRSV) exists. One hundred pigs from each of two distinctly different populations (NE Index Line, I, and Duroc-Hampshire cross pigs, DH) were challenged with PRRSV at 26 days old. A littermate to each challenged pig was included in the experiment without PRRSV challenge to serve as a control. Body weight and temperature were recorded and blood samples were drawn from all pigs on the day of challenge and 4, 7 and 14 days post-challenge. All pigs were sacrificed and a necropsy was performed …


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 Jan 2004

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 …


Effects Of Two Dried Forages, And A Choice Between Them, On Intake, Growth And Carcass Composition In Lambs Of Two Breeds And Their Cross, R. M. Lewis, J. M. Macfarlane, G. C. Emmans Jan 2004

Effects Of Two Dried Forages, And A Choice Between Them, On Intake, Growth And Carcass Composition In Lambs Of Two Breeds And Their Cross, R. M. Lewis, J. M. Macfarlane, G. C. Emmans

Department of Animal Science: Faculty Publications

The effects of for age type, breed type and sex on lamb growth and carcass composition, and their changes throughout growth, were measured. The three breed types were Scottish Blackface (no. =31), Suffolk (no. =28) and their reciprocal cross (no. =30). The lambs were given ad libitum a pelleted rye grass alone, pelleted lucerne alone or a choice of both. Each lamb was scanned using X-ray computed tomography to measure the weights of fat, lean and bone in the carcass at three proportions of mature body weight (0-30, 0·45 and 0·65). Live weights and food intake data were recorded weekly. …


Distribution, Habitat Use, Growth, And Condition Of A Native And An Introduced Catfish Species In The Hudson River Estuary, Stephen M. Jordan, Robert M. Neumann, Eric T. Schultz Jan 2004

Distribution, Habitat Use, Growth, And Condition Of A Native And An Introduced Catfish Species In The Hudson River Estuary, Stephen M. Jordan, Robert M. Neumann, Eric T. Schultz

EEB Articles

White catfish (Ameiurus catus) is native to the Hudson River and is now coexisting with the recently established channel catfish (Ictalurus punctatus). These species were sampled from four freshwater reaches and four habitat types of the Hudson River estuary to assess whether the two species overlapped in their habitat use, and whether any impact on the native species was evident. Catfishes were sampled in 1998 and 1999 using baited hoop nets (N = 708 net nights). Catch-per-unit-effort (CPUE, number of fish per net night; total catch = 368) of white catfish was significantly different among reaches …


The Impact Of Social Interactions On Torpor Use In Hummingbirds, Donald R. Powers Jan 2004

The Impact Of Social Interactions On Torpor Use In Hummingbirds, Donald R. Powers

Faculty Publications - Department of Biological & Molecular Science

Measurements of metabolic rate and fat deposition were made on a three-species hummingbird guild in southeastern Arizona to determine if the energetic advantage gained by a dominant territorial species (Lampornis clemenciae) over subordinate competitors (Archilochus alexandri and Eugenes fulgens) resulted in less frequent use of torpor. Results showed that L. clemenciae was able to store enough fat during the day to avoid nocturnal torpor. Restricted access to food limited fat storage in both competitors, resulting in frequent torpor use. Avoidance of torpor by L. clemenciae supports the notion that use of nocturnal torpor by hummingbirds comes with a cost, and …


Conjugated Linoleic Acid Metabolism And Body Fat Loss In Mice, Kim Hargrave, Brett Meyer, Jess L. Miner Jan 2004

Conjugated Linoleic Acid Metabolism And Body Fat Loss In Mice, Kim Hargrave, Brett Meyer, Jess L. Miner

Nebraska Beef Cattle Reports

Mice were fed conjugated linoleic acid (CLA) with or without fish oil or aspirin, which deplete tissue arachidonic acid and block arachidonic acid metabolism, respectively. Mice fed fish oil did not lose body fat when supplemented with CLA but mice fed soy oil did. Aspirin did not alter CLA-induced body fat loss. CLA may be metabolized to an isomer of arachidonic acid to induce a loss of body fat. However, this body fat loss is apparently not mediated via alteration of prostaglandin synthesis. Understanding the regulation of body fat by CLA may offer insight into the mechanisms of body fat …


Hydrogen Sulfide Concentration In Vicinity Of Beef Cattle Feedlots, Richard K. Koelsch, Bryan L. Woodbury, David E. Stenberg, Daniel N. Miller, Dennis D. Schulte Jan 2004

Hydrogen Sulfide Concentration In Vicinity Of Beef Cattle Feedlots, Richard K. Koelsch, Bryan L. Woodbury, David E. Stenberg, Daniel N. Miller, Dennis D. Schulte

Nebraska Beef Cattle Reports

A field survey of Total Reduced Sulfur (TRS) concentrations in the vicinity of beef cattle feedlots was conducted to compare field observations against current regulatory thresholds. It was observed that TRS levels in the vicinity of beef cattle feedlots are not likely to exceed current regulatory thresholds used by Nebraska. It was further noted concentration of TRS varies with air temperature and time of day. However, wet feedlot surface conditions had almost no impact upon observed TRS concentrations. Feedlots typically do not contribute significant hydrogen sulfide emissions and are unlikely to produce concentrations in excess of current Nebraska Department of …


Performance Of Mouse Lines Divergently Selected For Heat Loss When Exposed To Different Environmental Temperatures. I. Reproductive Performance, Pup Survival, And Metabolic Hormones, P. M. Kgwatalala, J. L. Deroin, Merlyn K. Nielsen Jan 2004

Performance Of Mouse Lines Divergently Selected For Heat Loss When Exposed To Different Environmental Temperatures. I. Reproductive Performance, Pup Survival, And Metabolic Hormones, P. M. Kgwatalala, J. L. Deroin, 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, along with the unselected controls (MC). Objectives of the study were to compare the MH, ML, and MC lines for reproductive performance, pup survival, and metabolic hormones when reared at 12, 22, and 31°C, and to search for line × environment interactions. Conception and litter size were recorded on the parent generation mice introduced to the environments at 11 wk of age and bred after a 3-wk acclimatization period. Survival of pups (pre-weaning to 3 wk; post-weaning from 3 to 9 …


Hatching Asynchrony, Survival, And The Fitness Of Alternative Adult Morphs In Ambystoma Talpoideum, Travis J. Ryan Jan 2004

Hatching Asynchrony, Survival, And The Fitness Of Alternative Adult Morphs In Ambystoma Talpoideum, Travis J. Ryan

Scholarship and Professional Work - LAS

The mole salamander, Ambystoma talpoideum, exhibits both aquatic (gilled) and terrestrial (metamorphosed) adult morphologies. Previous studies have shown the existence of body-size advantages associated with the terrestrial morph in A. talpoideum and other polymorphic salamanders (e.g., A. tigrinum). However, aquatic adult A. talpoideum mature at a younger age and often breed earlier than terrestrial adults. We tested the hypothesis that early maturation and reproduction in aquatic adults increase fitness (irrespective of body size). We reared larval A. talpoideum in mesocosms and varied the timing of hatching, with early-hatching larvae representing the offspring from early-breeding aquatic adults, and late-hatching larvae representing …


Investigation Into The Use Of Bait Stations For The Control Of The European Wild Rabbit (Oryctolagus Cuniculus) In The Urban Bushland Reserve Of Bold Park, Perth, Western Australia, Malin Kordes Jan 2004

Investigation Into The Use Of Bait Stations For The Control Of The European Wild Rabbit (Oryctolagus Cuniculus) In The Urban Bushland Reserve Of Bold Park, Perth, Western Australia, Malin Kordes

Theses : Honours

European rabbits in Australia have a significant impact on the environment and the economy. It is therefore necessary to implement control programs. In rural areas a number of methods including warren ripping and poisoning are frequently used. In urban areas though, rabbit control is not as easily accomplished because the use of many control methods is not appropriate. For example, the poison 1080 often cannot be used due to public health concerns and warren ripping cannot be used in conservation areas. Poisoning with pindone, an anticoagulant, is therefore one of few options available to the managers of urban reserves. However, …


Animal Science Alumni Newsletter, Winter 2004 Jan 2004

Animal Science Alumni Newsletter, Winter 2004

Department of Animal Science: Departmental News

Contents:

Four Animal Science Faculty Awarded Omtvedt lnnovation Awards
Animal Science Leadership Academy
From the Department Head’s Desk
New Faculty
Animal Science Leadership Academy
Alum Earns First Degree in Culinary
Middle School Science Teacher Learns about Research First Hand
Sahs Exhibition Hall Named After Former Director
Former Department Head to Retire From University of Wisconsin
Animal Science Graduate Student Association (ASGSA)
Bud Britton Golf Classic
ASGSA Activities
Ambassador Activities
Equestrian Team Successful Again
Sixth Annual Block and Bridle Steak Fry
Recent Department Awards and Recognitions
Nold Receives Distinguished Specialist Award
Wolverton 2004 4-H Hero's Award
Notable Undergraduate
Beef Top 40 …


Predicting Population Gene Frequency From Sample Data, R. M. Lewis, B. Grundy, L. A. Kuehn Jan 2004

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 …


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 Jan 2004

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 …


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 Jan 2004

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.


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 Jan 2004

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 Jan 2004

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 …