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Technical Note: Collection And Preparation Techniques Change Nutrient Composition Of Masticate Collected From Esophageally Fistulated Cattle, Jacqueline A. Musgrave, J. V. Judy, K. H. Jenkins, T. J. Klopfenstein, L. A. Stalker

Department of Animal Science: Faculty Publications

Two experiments determined effects of collection and preparation techniques on nutrient composition of masticate samples from esophageally fistulated cattle. In Exp. 1, 12 esophageally fistulated cattle were maintained on 2 precollection diets, high CP (24% CP; n = 6) or low CP (7.7% CP; n = 6), for 8 d. On d 9, the esophageal plug was removed, screen bottom bags were attached, and each cow was offered fresh grass. Immediately after fresh grass sample collection was complete, dry grass (hay) was offered and a sample was collected. Blood samples were collected and analyzed for serum urea nitrogen concentration. Masticate …

2015 Beef Cattle Report (Complete)

Nebraska Beef Cattle Reports

Table of Contents

Cow/Calf

Impact of Heifer Development System on Subsequent Gain and Reproduction 5

Genetic Parameter Estimates for Calving Difficulty and Birth Weight in a Multibreed Population 8

Estimation of British- and Continental-Specific Heterosis Effects for Birth, Weaning, and Yearling Weight in Cattle 10

Using Sugar Beet Pulp to Replace Wheat Straw when Limit Feeding Late Gestation Beef Cows 12

Supplementing Cow-Calf Pairs Grazing Smooth Bromegrass 14

Effects of Calf Age at Weaning on Cow and Calf Performance and Feed Utilization in an Intensive Production System 16

An Economic Analysis of Conventional and Alternative Cow-Calf Production Systems 19

Effect …

Effect Of Corn Plant Maturity On Yield And Nutrient Quality Of Corn Plants, Cassandra A. Row, Adam L. Shreck, Robert G. Bondurant Bondurant, Curtis J. Bittner, Jana L. Harding, James C. Macdonald, Terry J. Klopfenstein, Galen E. Erickson

Nebraska Beef Cattle Reports

Two corn plots (short season, 102-day, and normal season, 111-day corn) were serially harvested to evaluate nutrient, digestibility, and yield change over the duration from half-milk line through black layer. Digestibility of the corn plant decreased as corn plant maturity and NDF content increased. The lower leaf in the normal season plot decreased in digestibility, but did not change in the short season plot. Little change was observed in the digestibility of the internodes across time. The NDF content of the upper plant increased in both plots. The internodes increased in NDF content across time in both plots. The results …

Effects Of Dietary Fat Source And Monensin On Methane Emissions, Vfa Profile, And Performance Of Finishing Steers, Anna C. Pesta, Andrea K. Watson, Robert G. Bondurant Bondurant, Samodha C. Fernando, Galen E. Erickson

Nebraska Beef Cattle Reports

A finishing study was conducted to evaluate the effects of dietary fat source and presence or absence of monensin on performance, methane (CH4) emissions, and ruminal VFA profile of cattle. No effects on performance or VFA profile were observed. Inclusion of modified distillers grain plus solubles (MDGS) in the diet tended to increase measures of CH4 production when compared to other fat sources (corn oil or tallow), while inclusion of monensin in the finishing diet was not significant for CH4 production.

Impact Of Heifer Development System On Subsequent Gain And Reproduction, Hazy R. Nielson, John D. Harms, Adam F. Summers Summers, Rebecca A. Vraspir, Rick N. Funston

Nebraska Beef Cattle Reports

Replacement heifers from 2 different calving herds (March and May) were fed ad libitum hay and 4 lb of supplement/day, or were allowed to graze meadow and received 1 lb of supplement/day from mid-January to mid-April prior to both breeding seasons. Heifers from both calving herds that received hay had a greater average daily gain during the treatment period compared with meadow grazing heifers. However, heifers grazing meadow experiencedcompensatory gain during their respective breeding season, resulting in similar body weights at pregnancy diagnosis for March-calving heifers. The proportion of heifers that attained pubertybefore breeding and became pregnant was similar between …

Evaluation Of Changes In Nutritional Quality Of Corn Residue Over Time, Mandi Jones, James C. Macdonald, Terry J. Klopfenstein Klopfenstein, Galen E. Erickson, Keith Glewen, Andrea K. Watson

Nebraska Beef Cattle Reports

Irrigated corn residue was sampled across time in order to determine changes in quality and proportion of corn residue as the plant dried and was exposed to effects of weathering. Corn plants from two hybrids were planted on two different planting dates and harvested at periodic intervals from August 2012 to December 2012. Proportions of stem, blade/sheath, husk/shank, and cob made up smaller components of total plant DM as it matured, with the largest relative reduction occurring in the blade/sheath or stem. Hybrid impacted TDN values primarily because the 119 day hybrid was less mature at the early sampling dates.

Impact Of Algae Supplemented Diets Combined With Antioxidants On The Nutritional Profile, Quality Attributes, And Storage Stability Of Chicken Breast Meat, Rebecca G. Norcross

Theses and Dissertations--Animal and Food Sciences

Consumers’ demands for ω-3 polyunsaturated fatty acids (PUFAs) are at all-time high. Algae, a common source of PUFAs, and antioxidants are both used as supplements in livestock feeds, are known to affect the overall quality of meat. To implement PUFA deposits into broiler meat, this study evaluated combining antioxidants and algae in broiler feed to enhance the breast meat quality. Broilers were fed diets supplemented with 50 IU Vitamin E or 200 g/ton EconomasE (EcoE, an antioxidant pack) plus 10 IU Vitamin E, with or without 0.5% algae extract (SP-1). The feed oil was partially oxidized soybean oil (POV: 86 …

Case Study: Producer Concerns And Perceptions Regarding The Effect Of Methane On Cattle Production And The Environment: A Survey Of Nebraska Producers, B. M. Boyd, A. Jones, Lisa Franzen-Castle, K. Jenkins, Richard J. Rasby, Matt K. Luebbe, Richard R. Stowell, Samodha C. Fernando, Galen E. Erickson

Department of Animal Science: Faculty Publications

Enteric methane production from cattle and its effect on climate change has been a topic of debate. Multiple studies have explored methods to reduce cattle enteric methane production while simultaneously improving performance. However, most strategies developed have not been widely implemented by cattle producers. Knowledge of producer concerns and perceptions on methane production from cattle and its effect on the environment may be limited. Therefore, the objectives of this survey were to determine what Nebraska producers know about methane production by cattle and how it affects performance and to determine whether different age groups, regions of Nebraska, and production size …

Optimizing The Use Of Fibrous Residues In Beef And Dairy Diets, James C. Macdonald, G. E. Erickson, P. J. Kononoff, T. J. Klopfenstein

Department of Animal Science: Faculty Publications

Increased corn prices over the past decade have altered land use away from traditional forage in favor of corn. Accordingly, beef and dairy producers have had to adopt non-traditional forage resources into their production systems, many of which have become available as a result of increased corn production. Byproducts of the wet and dry milling industries have been used to replace both corn and forage in beef and dairy diets. Byproducts containing corn bran have large amounts of readily digestible hemicellulose. The use of byproducts may increase milk production, ADG, and G:F in dairy, beef growing, and beef finishing diets, …

Sheep Updates 2015 - Moora, Bruce Mullen, Kate Pritchett, Kimbal Curtis, Daniel Real, Jaq Pearson, Lynne Bradshaw, Geoff Lindon, Katherine Davies, Kevin Hepworth, Stephen Lee, Dawson Bradford, Lucy Anderton, Jackie Jarvis, Ben Patrick

Sheep Updates

This session covers thirteen papers from different authors:

1. The Sheep Industry Business Innovation project, Bruce Mullan, Sheep Industry Development Director, Department of Agriculture and Food, Western Australia

2. Western Australian sheep stocktake, Kate Pritchett and Kimbal Curtis, Research Officers, Department of Agriculture and Food, Western Australia

3. Tedera - a perenial forage legume to reduce your supplementary feeding in summer and autumn, Dr. Daniel Real, Senior Plant Breeder, Department of Agriculture and Food, Western Australia

4. National Livestock Identification System (NLIS) for sheep and goats - what is the NLIS database? Jac Pearson, Biosecurity Officer, Department of Agriculture and …

Sheep Updates 2015 - Katanning, Bruce Mullan, Kate Pritchett, Kimbal Curtis, Chris Wilcox, Mike Hyder, Leigh Sonnerman, Lynne Bradshaw, Geoff Lindon, Katherine Davies, Joe Young, Stephen Lee, Ian Robertson, Lucy Anderton, Hayley Norman, Ed Barrett-Lennard, Jackie Jarvis, Ben Patrick

Sheep Updates

This session covers fourteen papers from different authors:

1. The Sheep Industry Business Innovation project, Bruce Mullan, Sheep Industry Development Director, Department of Agriculture and Food, Western Australia

2. Western Australian sheep stocktake, Kate Pritchett and Kimbal Curtis, Research Officers, Department of Agriculture and Food, Western Australia

3. Wool demand and supply - short term volatility, long term opportunities, Chris Wilcox, Principal of Poimena Analysis

4. Lifetime management for maternal ewes, Mike Hyder, Research Officer, Department of Agriculture and Food, Western Australia

5. National Livestock Identification System (NLIS) for sheep and goats - what is the NLIS database? Leigh Sonnermann, …

A Cooperative Study On The Standardized Total-Tract Digestible Phosphorus Requirement Of Twenty-Kilogram Pigs, O. Adeola, M. J. Azain, S. D. Carter, T. D. Crenshaw, M. J. Estienne, B. J. Kerr, M. D. Lindemann, C. V. Maxwell, P. S. Miller, M. C. Shannon, E. Van Heugten

Department of Animal Science: Faculty Publications

A cooperative study comprising growth performance, bone mineralization, and nutrient balance experiments was conducted at 11 stations to determine the standardized total-tract digestible (STTD) P requirement of 20-kg pigs using broken-line regression analysis. Monocalcium phosphate and limestone were added to a corn–soybean meal–based diet at the expense of cornstarch to establish 6 concentrations of STTD P from 1.54 to 5.15 g/kg in increments of 0.62 g/kg at a constant Ca:total P of 1.52:1.0. Diets were fed to 936 pigs (average initial BW of 19 kg) in 240 pens for 20 replicate pens of barrows and 20 replicate pens of gilts …

Yield And Forage Value Of A Dual-Purpose Bmr-12 Sorghum Hybrid, Melinda K. Yerka, Andrea K. Pederson, J. J. Toy, Galen E. Erickson, Jeffrey F. Pedersen, Rob B. Mitchell

Department of Animal Science: Faculty Publications

Grain sorghum [Sorghum bicolor (L.) Moench] is an important crop for rainfed production systems with 2.7 million ha grown in the United States in 2013. The brown-midrib (bmr) mutations, especially bmr-12, have resulted in low stover lignin and high fiber digestibility without reducing grain yield in some sorghum lines. However, the effect of the bmr trait on beef cattle (Bos taurus) performance when grazing crop residue is unknown. Our objectives were to validate previous small-plot results reporting no grain yield difference between near-isogenic bmr-12 (BMR) and wild-type control (CON) A Wheatland × R

Tx430 …

The Effects Of Technology Use In Feedlot Production Systems On Feedlot Performance And Carcass Characteristics, C. L. Maxwell, B. C. Wilson, C. F. O'Neill, B. K. Wilson, C. G. Hixon, C. L. Haviland, A. N. Grimes, M. S. Calvo-Lorenzo, D. L. Vanoverbeke, G. G. Mafi, C. J. Richards, D. L. Step, B. P. Holland, C. R. Krehbiel

Department of Animal Science: Faculty Publications

The objectives of this study were to examine the effects of feedlot production systems with and without the use of a β-adrenergic agonist compared to an all-natural production program on feedlot performance and carcass characteristics. Crossbred beef steers (n = 336; initial BW = 379 ± 8 kg) were randomized to 1 of 3 treatments in a randomized complete block design (RCBD; 14 steers/pen; 8 pens/treatment). Treatments consisted of an all-natural treatment (NAT), a conventional treatment (CONV), and a conventional treatment with a β-agonist (CONV-Z). All treatments were fed the same basal diet with NAT cattle receiving no growth promoting …

Energy Status Of Steers Dictates Effectiveness Of Glycerol Inclusion In High-Roughage And High-Concentrate Feedlot Diets, Erin M. Rife

Electronic Theses and Dissertations

The objective of this research was to determine how to use glycerol as an effective source of energy in ruminant diets. Steer calves were used in a 56 d backgrounding study (n=128; Initial BW=340 ± 15 kg) and 105 d finishing study (n=120; Initial BW=420 ± 20 kg). Dietary treatments during backgrounding included 0, 8, 16, and 24% glycerol replacing corn silage in corn silage-based diets. Steers continued on within relative levels of dietary glycerol with finishing diets consisting of 0, 5, 10, and 15% glycerol replacing corn. Cumulative DMI, ADG, and G:F increased linearly (P

Population Ecology Of Rocky Mountain Elk In The Black Hills, South Dakota And Wyoming, Benjamin D. Simpson

Electronic Theses and Dissertations

We conducted a 2-year (2012–2013) study of survival and cause–specific mortality using individually marked adult cow and neonate elk (Cervus elaphus) occupying the southwestern region of the Black Hills. We used known-fate analysis in Program MARK for survival analysis of adult cows and calves. We estimated survival and cause-specific mortality of 49 adult female elk over the 2 years of the study. Annual adult cow survival was 0.85 (95% CI = 0.72–0.87). We documented 12 mortalities with harvest (58.3%) and predation (16.6%) accounting for the majority of known mortalities. We captured and fit 71 neonates < 10 days of age with expandable Very High Frequency (VHF) radiocollars during summer 2012 (n = 37) and 2013 (n = 34). Annual (12 month) survival of elk calves was 0.75 (95% CI = 0.61–0.84) while summer (20 weeks; 15 May–25 September) survival was 0.79 (95% CI = 0.68–0.88). Predation accounted for 87.5% of mortalities; remaining mortalities were from starvation (6.3%) and unknown (6. 3%) causes. We used Global Positioning System (GPS) collars to collect 167,707 locations to determine home range, movement ecology, and macroscale resource selection of 48 adult cow elk. We documented elk using a variety of migration strategies (obligate migrator, resident, conditional migrator, disperser); the majority of the population (58%) was migratory. Spring migration distance travelled ranged from 2.45 km – 74.44 km (n = 42); fall migration distances ranged from 6.41km – 153.95 km (n = 46). We used 99% Brownian Bridge Movement Models to create seasonal and overall home ranges of adult cow elk. Mean overall home range size for conditional migrators was 249.28 km2 (SE = 28.60, n = 7, range = 233.75), for obligate migrant elk it was 227.18 km2 (SE = 13.94, n = 29, range = 346.83), and for resident elk it was 175.65 km2 (SE = 22.75, n = 11, range = 216.04). We used discrete choice models to determine resource selection at the macro-habitat scale of collared adult elk using ArcMap 10.1 data. Adult cow elk selected for open grassland/herbaceous areas and early successional forest areas close to forested edges at higher elevations. Our study showed that elk populations have the ability to thrive within an ecosystem with healthy predator populations.

Contents, Discovery Editors

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

No abstract provided.

Discovery: The Student Journal Of Dale Bumpers College Of Agricultural, Food And Life Sciences - Volume 16 2015, Several Authors

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

No abstract provided.

Evaluation Of L-Methionine Bioavailability In Nursery Pigs, Jina Lim

Theses and Dissertations--Animal and Food Sciences

DL-Methionine (Met) has been conventionally used in swine diets with assumption of similar bioefficacy with L-Met. However, because L-Met is the form that is utilized by animals for protein synthesis, L-Met could, theoretically, be more available. Four experiments were conducted to evaluate L-Met bioavailability in nursery pigs with 21-day growth trials. A total of 105,105,112 and 84 crossbred pigs were used in Exp. 1, 2, 3 and 4, respectively. Each experiment had a low Met basal diet and 3 levels of the Met sources (DL-Met and L-Met). In addition to the basal diet, supplementation levels were 0.053%, 0.107% and 0.160% …

Fertilizers In Aquaculture, Bartholomew Green

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Pond fertilization is an important component of semi-intensive to intensive aquaculture pond management that supports successful production of the culture organism. Semi-intensive and intensive aquaculture pond management fall along the extensive to hyper-intensive management continuum and are characterized by high stocking rate of the culture animal, limited use of fertilizers, use of compound or complete feeds, and water quality monitoring and management, including use of mechanical aeration. Fertilization contributes to establishing and maintaining a pond environment that allows the culture organism to utilize efficiently the compound or complete feeds offered. This chapter presents information on pond food webs, sources and …

Female Breakfast Skippers Display A Disrupted Cortisol Rhythm And Levated Blood Pressure, Megan Witbracht, Nancy L. Keim, Shavawn Forester, Adrianne Widaman, Kevin D. Laugero

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Chronic stress and over-activity in the hypothalamic–pituitary–adrenal (HPA) axis may link breakfast skipping and poor cardiometabolic health. Missing the first major meal of the day in rodents prolongs elevated circulating corticosterone at a time when it's normally decreasing. To extend these findings to humans, we hypothesized that habitual breakfast skippers would display a similar pattern of circulating cortisol and alterations in meal and stress-induced cortisol reactions. Normal weight to obese women aged 18–45 years old who were strictly defined as either breakfast skippers (n = 30) or breakfast eaters (n = 35) were invited to participate in our …

Hypoxia Affects Performance Traits And Body Composition Of Juvenile Hybrid Striped Bass (Morone Chrysops X M. Saxatilis), Bartholomew W. Green, Steven D. Rawles, Sidney A. Fuller, Benjamin H. Beck, Matthew E. Mcentire

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Performance traits and body composition of juvenile hybrid striped bass (Morone chrysops x M. saxatilis) in response to hypoxia were evaluated in replicate tanks maintained at constant dissolved oxygen concentrations that averaged 23.0 ± 2.3%, 39.7 ± 3.0%, and 105.5 ± 9.5% dissolved oxygen saturation. Fish were fed a commercially formulated feed daily to apparent satiation. Total feed intake and fish growth and yield increased linearly in response to increased dissolved oxygen concentration. Nutrient utilization was reduced significantly only at the greatest level of hypoxia. With the exception of whole-body protein content, whole body compositional indices and nutrient …

Investigating The Amino Acid Digestibility Of Alternative Protein Sources And Determining The Impact Of Dietary Fiber On Energy, Nitrogen, And Amino Acid Digestibility In Growing Pigs, Bradley M. Cotten

Open Access Theses

Three experiments were designed to quantify the nitrogen (N) and amino acid (AA) digestibility of various protein sources fed to growing pigs. The protein ingredients were sunflower meal, cottonseed meal, canola meal, camelina meal, egg albumen, casein, blood meal, plasma meal, potato protein concentrate, soy protein concentrate, soy protein isolate, and linseed meal, which were fed as the sole source of amino acids for the animals and were included in semi-purified, corn starch-based diets. A semi-purified, nitrogen-free diet (NFD) was used to estimate endogenous losses of AA. In each experiment, pigs were surgically fitted with a simple T-cannula at the …

Management Effects On The Environmental Footprint Of Swine Production, Aaron M. Jones

Open Access Theses

Livestock production in general is a very small contributor to GHG emissions. However, swine producers will continually be faced with a series of challenges to minimize the environmental impact of swine production. The main objectives of the the studies in this thesis were to evaluate the effects of reducing dietary CP with the supplementation of synthetic AA and the effects of feeding diets with or without antibiotics on manure generation and excretion of N and C. In Exp. 1, thirty-two barrows were used in a metabolism study to evaluate the effect of feeding reduced CP, amino acid (AA) supplemented diets …

Relationships Between Behavioral Measures And Productivity In Growing Beef Cattle, Kelsey Bruno

Theses and Dissertations--Animal and Food Sciences

The relationships between behavioral measures, growth performance, and immunocompetence in receiving beef steers were explored in three experiments. Specifically, exit velocity (EV) and objective chute score (OCS) were examined as temperament measures. In experiment 1, no main effects or interactions with degradable intake protein (DIP) or interactions between temperament measures were observed (P ≥ 0.11); however, high OCS steers had greater intake and gain:feed (P < 0.10) and slow EV steers had higher intake and gain (P < 0.10) than their counterparts. In experiment 2, during week two of social observations, dominance hierarchy rankings were dependent on OCS and EV (P < 0.05); slow EV steers also had increased antibody responses and gain (P < 0.10) and high OCS steers had increased gain (P < 0.10). In experiment 3, subjective chute scores and OCS were positively correlated (P < 0.01) and both EV and OCS treatments changed over time (P < 0.10); intake, vaccine titer response, and gain:feed responses to monensin were dependent on OCS treatment (P < 0.10). The studies suggest that temperament, measured by EV and OCS, affects growth performance and health related measures and is related to social dominance behavior in receiving beef steers.

An Evaluation Of Precision Dairy Farming Technology Adoption, Perception, Effectiveness, And Use, Matthew Richard Borchers

Theses and Dissertations--Animal and Food Sciences

Precision dairy farming technologies provide a variety of functions to dairy farmers. Little is known about dairy producer perception of these technologies. A study was performed to understand dairy producer perception of parameters monitored by precision dairy farming technologies. Calving has potential to be predicted using these same parameters and technologies. A second study was performed using two commercially marketed technologies in calving prediction. In order for these technologies to generate accurate and useful information for dairy farm use, they must accurately quantify these parameters. The final study evaluated the accuracy of five commercially marketed technologies in monitoring feeding, rumination, …

Effects Of Post-Hatch Holding Time And Early Nutrition Strategies On Growth Performance, Carcass And Skeletal Characteristics Of Young Chickens, Marquisha A. Paul

Theses and Dissertations--Animal and Food Sciences

The study objectives of this thesis were to evaluate the effects of delayed feeding and specific aspects of the Programmed Nutrition (PN) feeding strategy (Alltech, Inc.) on growth performance, carcass characteristics, and skeletal characteristics of commercial broiler chicks through market age, as well as investigate the effects of breed and the PN feeding strategy on early growth and development. When commercial broiler chicks were fed reduced nutrient diets, delayed feeding decreased early growth performance and carcass yield (P<0.05), whereas post-hatch PN conditioning for 72 hours improved early growth performance and alleviated the negative effects of delayed feeding on carcass yield (P<0.05). Through market age, delayed feeding improved Gain: Feed (P<0.05), while PN had the opposite effect. Interactive effects and main effects of delayed feeding and PN were observed for tissue mineral concentration (P<0.05). PN lowered bone ash % (P<0.05) and increased meat oxidation of broiler chicks during storage (P<0.05). PN also had negative effects on early growth performance and bone breaking strength (P<0.05) of various meat-type breeds, but especially for non-commercial, moderate-growing or fast-growing breeds. In conclusion, PN may be suitable for commercial broiler chicks that experience delayed feeding and are fed reduced nutrient diets.

Algae Or Yeast Supplementation For Lactating Dairy Cows, Maegan E. Weatherly

Theses and Dissertations--Animal and Food Sciences

The objective of the first study was to quantify the effects of feeding Schizochytrium sp. microalgae (SP-1, Alltech, Inc., Nicholasville, KY) on milk fat and DHA content. Eight cows were fed: 0, 100, 300, or 600 g of algae per day. Fat percentage was greater (P < 0.05) for cows on treatments 0 g and 100 g than for cows on treatments 300 g and 600 g (P < 0.05). Docosahexaenoic acid in milk was greater for cows on treatment 300 and 600 than for cows on treatment 0 and 100 (P < 0.05).

The objective of the second study was to assess yeast supplementation effects on high and low forage dairy cow diets. Four cows were assigned to 1 of 4 treatments: 1) low forage (LF), 2) low forage with 10 g/d yeast (Yea-Sacc®; Alltech Inc., Nicholasville, KY; LFY), 3) high …

Using The Indicator Amino Acid Oxidation Technique To Study Threonine Requirements In Horses Fed Different Feed Compositions, Chanhee Mok

Theses and Dissertations--Animal and Food Sciences

Threonine has been reported to be the second limiting amino acid in typical equine diets, but its actual requirement has not been determined in horses. The indicator amino acid oxidation (IAAO) method has been successfully used for evaluating amino acid metabolism and requirements in animals and humans. The objective of this research was to use the IAAO method to estimate threonine requirements in mature horses fed two different feed compositions. In the first study, 6 Thoroughbred mares (4 – 16 years old) received each of 6 levels of threonine intake in a high concentrate diet, in a randomly determined order. …

Across-Ecoregion Analysis Suggests A Hierarchy Of Ecological Filters That Regulate Recruitment Of A Globally Invasive Fish, Przemek G. Bajer, Timothy K. Cross, Joseph D. Lechelt, Christopher J. Chizinski, Michael J. Weber, Peter W. Sorensen

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Aim -- Even successful invaders are abundant only in a fraction of locales they inhabit. One of the main challenges in invasion ecology is explaining processes that drive these patterns. We investigated recruitment of a globally invasive fish, common carp (Cyprinus carpio), across three ecoregions to determine the role of environmental characteristics, predatory communities and propagule pressure on the invasion process at coarse and fine spatial scales.

Location -- Lakes across Northern Forest, Temperate Forest and Great Plains ecoregions of North America.

Methods -- We used data from 567 lakes to model presence or absence of carp recruitment …