Large or Food Animal and Equine Medicine Commons^™

Timed Insemination Vs. Modified Estrus Detection In Beef Heifers, Benjamin T. Tibbitts, Tonya L. Meyer, Dan J. Kelly Kelly, Richard N. Funston

Nebraska Beef Cattle Reports

Th e objective of this study was to compare a modified estrus detection and fixed time AI vs. no estrus detection and fixed time AI on subsequent pregnancy rates. Yearling heifers were estrus synchronized and AI at 72 ± 2 h after prostaglandin injection. In one group estrus was not detected and all heifers received gonadotropin releasing hormone at the fixed- time AI; in the other group estrus was detected at 58 ± 2 and 70 ± 2 h after prostaglandin and inseminated in the following order at 72 ± 2 h: heifers in estrus at 58 h, heifers in …

Growth And Reproductive Performance Of Yearling Beef Heifers Implanted With Revalor G In The Nebraska Sandhills, Benjamin T. Tibbitts, Hazy Rae Nielson, K. H. Ramsay Ramsay, Richard N. Funston

Nebraska Beef Cattle Reports

Th is study evaluated effects of a single stocker implant (Revalor G) on growth and reproductive performance of yearling beef heifers in the Nebraska Sandhills. Crossbred heifers, grazing native Sandhills range, were randomly assigned to either be implanted 82 ± 2 days prior to estrus synchronization, or not implanted, to determine the effects of growth implants on heifer performance. Heifers were bred via artificial insemination followed with clean- up bulls. Implanted heifers gained more and were heavier at the end of the trial, but had a reduced pregnancy rate than non- implanted heifers. Implanted heifers also had a lower pregnancy …

Impact Of Heifer Development System In Two Different Breeding Seasons, Shelby A. Springman, Hazy Rae Nielson, Jacqueline A. Musgrave Musgrave, John Nollette, Andy Applegarth, Richard N. Funston

Nebraska Beef Cattle Reports

Replacement heifers from March and May calving herds were offered ad libitum meadow hay and 4 lb/d supplement or grazed meadow and offered 1 lb/d supplement from mid- January to mid- April. Heifers fed hay gained more during the treatment; however, heifers grazing meadow experienced compensatory gain, resulting in similar body weight at pregnancy diagnosis in both calving herds. Pregnancy rates were similar between treatment groups in March and May heifers. A reduced input winter management system is a viable option to maintain pregnancy rates in early and late summer breeding seasons.

Effects Of Distillers Grains Or Fiber On Enterohemorrhagic Escherichia Coli In Steers, Liesel G. Schneider, Curtis J. Bittner, Jordan E. Burhoop Burhoop, F. Henry Hilscher, Galen E. Erickson, Terry J. Klopfenstein, Rodney A. Moxley, David R. Smith

Nebraska Beef Cattle Reports

Increased probability for fecal shedding and colonization by Escherichia coli O157:H7 has been observed in previous studies when steers are fed increased inclusions of distillers grains. A feeding study was conducted to determine if distillers grains or fiber from distillers grains in the finishing ration of feedlot steers affected fecal shedding prevalence of seven serogroups of enterohemorrhagic Escherichia coli (EHEC- 7). For EHEC O45 and EHEC O103, the greatest prevalence of shedding occurred when steers were fed increased distillers grains For all EHECs except for O111, fecal shedding prevalence was similar between the corn control and either of the corn …

Effect Of Long- Term Corn Residue Grazing On Soil Properties, Manbir K. Rakkar, Humberto Blanco, Mary E. Drewnoski Drewnoski, Jim C. Macdonald, Terry J. Klopfenstein

Nebraska Beef Cattle Reports

An experiment was conducted to evaluate the effect of long- term (16 years) corn residue grazing with cattle on soil compaction, soil structure, soil organic matter, and nutrients. Three treatments: 1) fall grazing (November through January; 1.8 to 2.5 AUM/ac), 2) spring grazing (February to middle April; 2.3 to 3.1 AUM/ac), and 3) control (no grazing) under a no- till irrigated corn- soybean system in eastern Nebraska were studied. Crop yields were increased and soil bulk density and cone index (parameters of soil compaction), wet soil aggregate stability (parameter of soil structural quality), and organic matter content were not affected …

Effect Of Increasing Supplemental Rumen Undegradable Protein (Rup) On Performance Of Calves Fed A Silage Growing Diet, Colton R. Oney, F. Henry Hilscher, Robert G. Bondurant Bondurant, Andrea K. Watson, Galen E. Erickson, Terry J. Klopfenstein

Nebraska Beef Cattle Reports

A growing study evaluated the effects of increasing supplemental rumen undegradable protein (RUP) on performance of calves fed an 85% corn silage diet. Five levels of supplementation were evaluated with 12 individually fed steers per level of supplement. Supplement levels consisted of 0, 3.25, 6.5, 9.75 and 13% supplemental RUP (% of diet DM) fed as a blend of 60% Soypass and 40% Empyreal. Increasing supplemental RUP in the diet increased ending body weight and average daily gain linearly, and decreased F:G linearly while DMI remained constant among treatments. As cattle grew from 600 to 730 lb, F:G was improved …

2017 Nebraska Beef Cattle Report (Complete)

Nebraska Beef Cattle Reports

Contents

Cow/Calf: Effect of Heifer Development System on Reproduction and Subsequent Gain as a Pregnant Heifer • Impact of Heifer Development System in Two Breeding Seasons • Timed Insemination vs. Modifi ed Estrus Detection in Beef Heifers • Growth and Reproductive Performance of Yearling Beef Heifers Implanted with Revalor G in the Nebraska Sandhills • Development of Terminal and Maternal Economic Selection Indices in Beefmaster Cattle • Effects of Wintering System on Cow and Calf Performance in a Summer- Calving Intensive Production System • Methods to Increase Productivity of Spring Calving Production Systems in the Nebraska Sandhills

Growing: Effect of …

In Situ Digestibility Of Residue Parts Of Corn Planted In Different Populations And Row Widths, Viviane B. Ferrari, Janessa J. Updike, Jana Harding Harding, Keith Glewen, Terry J. Klopfenstein, Jim C. Macdonald

Nebraska Beef Cattle Reports

Plant density can be changed by altering row width and/or number of plants within a row. The use of narrower rows at seeding may increase yield and reduce plant-toplant competition. Corn seeds were planted at 2 row widths (15 and 30- inch rows) and 3 plant populations (25,200, 35,000 and 54,000 seeds / acre). Samples of corn residue were collected 4 dates (October 8, October 24, November 5 and November 19) postharvest and separated into cob, stem, leaf and husk to determine changes in quality over time. Th e greatest plant population increased the NDF content and NDF digestibility of …

Role Of Skeletal Paracrine Signals In The Proliferation And Chondrogenic Differentiation Of Interzone Cells, Parvathy Thampi

Theses and Dissertations--Veterinary Science

Articular cartilage in mammals has a limited intrinsic capacity to repair structural injuries and defects, a fact that contributes to the chronic and progressive nature of osteoarthritis. Current treatment modalities do not enable articular cartilage to achieve a complete and permanent restoration of normal structure and function with large or partial thickness lesions. In contrast to mammals, Mexican axolotl salamanders (Ambystoma mexicanum) have demonstrated the remarkable ability to spontaneously and completely repair even large joint cartilage lesions, an intrinsic healing process that involves interzone cells in the intraarticular space. Further, when interzone tissue is transplanted into critical sized …

Biology And Detection Of Pregnanes During Late Gestation In The Mare, Michelle Arelia Ann Wynn

Theses and Dissertations--Veterinary Science

Progesterone in the mare declines to almost undetectable concentrations in late gestation. It’s metabolized into several pregnanes, some circulating at very high concentrations. Although the function of many pregnanes remains unclear, 5α-dihydroprogesterone and allopregnanolone are bioactive. Measurements of pregnanes in late gestation are typically by immunoassay, although results are confounded by cross-reactivity with related pregnanes. Conversely, liquid chromatography tandem mass spectrometry (LC-MS/MS) allows differentiation of individual pregnanes. The purposes of these studies were: 1) to evaluate the ability of a 5α-reductase inhibitor, dutasteride, to alter pregnane metabolism and pregnancy outcome, 2) to evaluate changes in target pregnanes in late gestation …

Physiological Changes Associated With Pregnant Or Nonpregnant Mares Grazing Pastures Of Orchardgrass-Bluegrass, Kentucky 31 Tall Fescue Infected With Epichloë Coenophiala, Or Kyfa9821 Tall Fescue Infected With The Novel Endophyte Ar584, Victoria A. Taylor

Theses and Dissertations--Veterinary Science

Kentucky 31 tall fescue (KY31) infected with the common toxic endophyte strains of Epichloё coenophiala produces toxic alkaloids that improve plant vigor, but cause numerous adverse effects in grazing animals. Researchers developed a variety of KY31 containing an alternative strain of E. coenophiala, termed novel endophyte (NE). Adverse health effects in mares have not been evaluated.

Experiments in this thesis tested the hypothesis that the NE pasture does not cause adverse effects typically associated with KY31. Specific aims were to: 1) compare forage ergovaline concentrations between KY31 vs NE pastures; 2) evaluate palmar artery diameters in mares grazing KY31, …

Effect Of Harvest Method And Ammoniation On Digestibility And Intake Of Corn Residue, Ashley C. Conway, Tasha M. King, Melissa L. Jolly-Breithaupt Breithaupt, Jim C. Macdonald, Terry J. Klopfenstein, Mary E. Drewnoski

Nebraska Beef Cattle Reports

The effects of three harvest methods, both with and without ammonia treatment, on the in vivo digestibility and intake of baled corn residue were assessed in a digestion trial with lambs. Treatments included three corn residue harvest methods (conventional rake and bale, New Holland Cornrower™ with eight rows or with two rows of corn stalks chopped into the windrow containing the tailings [leaf, husk and upper stalk] from eight harvested rows) and the effects of ammoniation at 5.5% of DM compared to no ammoniation of the residue. Th e 2- Row baled residue (51.7%) had greater dry matter digestibility than …

Methods To Increase Productivity Of Spring Calving Production Systems In The Nebraska Sandhills, Devin Broadhead, L. A. Stalker, Jacki A. Musgrave Musgrave, Rick N. Funston

Nebraska Beef Cattle Reports

Feeding supplement to cattle grazing dormant winter range increased cow BW and BCS and calf performance, but not pregnancy rate. Using a CIDR to shorten the post-partum interval in a cow herd with existing acceptable reproductive performance did not improve pregnancy rate. Feeding creep feed to calves increased weaning BW but should be considered within the context of a cost/benefit analysis. Additional years of data collection may be necessary to draw definitive conclusions.

Predicting Feedlot Growth Performance Over The Feeding Period Utilizing Steer Age And Body Weight, Curtis J. Bittner, Andrea K. Watson, Jim C. Macdonald Donald, Galen E. Erickson

Nebraska Beef Cattle Reports

A pooled- analysis of UNL feedlot pens examined the effects of steer age and body weight on feedlot growth performance. For data analysis, pens were divided into 3 subclasses based on steer age (calf- fed, short yearling, or long yearling) and, grouped based upon initial body weight (500 to 1200 lb, in 100 lb increments) within each age class. As initial body weight increased, DMI (lb/d) for the whole feeding period increased quadratically in calf-fed steers and increased linearly in short and long yearlings. A quadratic increase in ADG was observed in calf- feds as initial body weight increased. No …

Acknowledgements

Nebraska Beef Cattle Reports

Appreciation is expressed to the following firms, associations, or agencies who provided grant support for research in the beef cattle program.

Agriculture and Food Research Initiative Competitive Grant/ USDA/NIFA Foundation Program: Animal Reproduction

The Beef Checkoff , Centennial, Colo

Cargill Corn Milling, Blair, Neb.

CSIRO, Commonwealth Scientific and Industrial Research Organization, Dickson, ACT, Australia

Elanco Animal Health, Indianapolis, Ind.

Huvepharma Inc. Peachtree City, GA

Dr. Kenneth and Caroline McDonald Eng Foundation San Antonio, Tex.

Lallemand Animal Nutrition. Montreal, Quebec, Canada

Merck Animal Health, Madison, NJ

National Cattlemen’s Beef Association, Centennial, Colo.

Effect Of Harvest Method On Digestibility Of Corn Residue, Tasha M. King, Melissa L. Jolly-Breithaupt, Jana L. Gramkow Gramkow, Terry J. Klopfenstein, Jim C. Macdonald

Nebraska Beef Cattle Reports

Corn residues can be an economical forage source for producers and advanced harvest methods have increased the quality of baled residue. A digestion study was conducted to evaluate the effects of harvest method of corn residues (low- stem, highstem, and conventional) on digestibility in lambs. Samples from total fecal collection were dried 1 of 3 ways to determine effects on digestibility estimates. Corn residue containing low- stem had greatest overall digestibility with high- stem residue being intermediate and conventional harvesting having the lowest digestibility. Drying method had no effect on digestibility estimates.

Comparison Of Titanium® 5 Ph- M Versus Titanium® 5 Plus Nuplura® Ph With The Presence Or Absence Of Monensin On Health And Performance Of Newly Received Feedlot Calves Fed Ramp®, Robert M. Jones, Curtis J. Bittner, F. Henry Hilscher Hilscher, Mallorie F. Wilken, Rick Stock, Galen E. Erickson

Nebraska Beef Cattle Reports

A receiving study was conducted to evaluate the effects of RAMP® with Rumensin® concentration (0 or 25.0 g/ton) given with one of two viral vaccinations (Titanium® 5 PH- M or Titanium® 5 plus NUPLURA® PH) on steer growth performance and morbidity. There were no significant vaccine by diet interactions observed. Neither vaccine treatment nor Rumensin® level affected intake, gain, or feed conversion. Vaccine type did not affect first pull (P = 0.19) or second pull morbidity rates (P = 0.52). These findings suggest that neither vaccine type nor Rumensin® concentration had any effect on steer growth performance or morbidity rate.

Evaluation Of 0 Or 300 Mg Of Optaflexx® On Growth Performance And Carcass Characteristics Of Steers Fed To Different Degrees Of Finish, Robert M. Jones, Curtis J. Bittner, F. Henry Hilscher Hilscher, Mallorie F. Wilken, Galen E. Erickson

Nebraska Beef Cattle Reports

A feedlot study evaluated the effects of ractopamine hydrochloride (Optaflexx®) dosage (0 or 300 mg/steer daily) and days on feed (118, 139, 160, 174 DOF) as a 2 × 3 + 1 factorial (steers fed 174 d were not fed Optaflexx) on performance of big yearlings. No interaction was observed between Optaflexx and days on feed. Feeding Optaflexx improved live final BW, carcass- adjusted ADG, carcass- adjusted feed conversion, and calculated yield grade. Increasing days on feed linearly increased live final BW, carcass-adjusted feed conversion, HCW, dressing percent, and marbling score but not ADG. Furthermore, a quadratic increase in LM …

Corn Residue Quality Throughout The Grazing Season, Shelby E. Gardine, Gavin L. Harsh, Robert G. Bondurant Bondurant, Jana L. Gramkow, Andrea K. Watson, Terry J. Klopfenstein

Nebraska Beef Cattle Reports

Changes in in vitro organic matter digestibility and digestible organic matter of corn residue were evaluated throughout the fall grazing and spring grazing seasons. In vitro organic matter digestibility and digestible organic matter were greatest at the beginning of fall grazing and declined over time. Slight weathering resulted in lower quality corn residue available at the beginning of spring grazing compared to the beginning of fall grazing. The in vitro organic matter digestibility of available residue declined 21% over the fall grazing season and 51% throughout the spring grazing season. As the availability of nutrients declines over time, adjustments in …

Perceptions Of Crop Consultants And Producers On Grazing Corn Residue In Nebraska, Jordan L. Cox, Kristen M. Ulmer, Manir Rakkar Rakkar, Lisa Franzen-Castle, Humberto Blanco-Canqui, Mary Drewnoski, Jim C. Macdonald, Richard J. Rasby

Nebraska Beef Cattle Reports

A survey was conducted to explore factors influencing corn residue grazing recommendations by crop consultants and producer practices in Nebraska. Approximately 80% of consultants recommended grazing corn residue, while 63% of producers allowed grazing. Of producers who did not graze, about 50% cited concerns related to soil compaction, inconvenience (lack of water, fencing, and land/equipment damage), and lack of access to livestock. Producers who allowed and consultants who recommended grazing were more likely to perceive that grazing residue increased subsequent grain yields. Most consultants (56.0%) and producers (43.8%) reported making decisions in regards to grazing based on their own observation. …

Pooled Gain Analysis Of Steers Grazing Corn Residue And Supplemented With Distillers Grains, Cody A. Welchons, Jim C. Macdonald

Nebraska Beef Cattle Reports

A pooled analysis combined data from three trials in which steer calves grazing corn residue were supplemented with distillers grains at varying amounts as a percent of BW. A regression equation was calculated in order to provide an accurate estimate of gain for calves fed distillers grains at various rates. Steers supplemented with distillers grains in a range from 0.3 to 1.1% of BW (1.5 to 6.5 lb / steer daily) had estimated gains that ranged from 1.07 to 1.94 lb / d. Th is prediction equation provides an estimate of gain for calves supplemented with distillers grains at various …

Effect Of Feeding Field Peas On Fresh Beef Quality, Hope R. Voegele, Katherine I. Domenech, Emery K. Kunze Kunze, Felipe A. Ribeiro, Karla H. Jenkins, Jim C. Macdonald, Chris R. Calkins

Nebraska Beef Cattle Reports

Th is study was conducted over two years to evaluate the use of field peas during two phases of production (grazing and finishing) on overall fresh beef quality. The backgrounding treatments included: no supplement, field peas, or dry- rolled corn and finishing treatments included the presence or absence of field peas. Loin samples (n = 232) were aged for 14 d and placed under retail display conditions for 7 d. Dietary treatments had no effect on tenderness (WBSF or SSF) or visual discoloration and minimal effects on objective color, lipid oxidation and fatty acid composition. These data indicate field peas …

Nutrient Content Of Summer-Planted Oats After Corn Harvest And Grazing Performance, Kristen M. Ulmer, Robert G. Bondurant, Jana L. Gramkow Gramkow, Mary E. Drewnoski, James C. Macdonald

Nebraska Beef Cattle Reports

Annual forages provide producers with an alternative grazing source in the fall. A cover crop grazing study was conducted following corn harvest to evaluate the steer ADG and yield of summer sown oats and turnips planted after either high moisture corn or corn silage production. Th e gain of steers grazing oats aft er silage was 1.29 lb/day, while the gain of steers grazing corn residue and oats aft er high moisture corn was 0.72 lb/day. Average oat forage production aft er silage harvest was 2857 lb/acre, while oat production following corn harvest was 523 lb/ acre. Fall forage production …

Statistics Used In The Nebraska Beef Report And Their Purpose

Nebraska Beef Cattle Reports

The purpose of beef cattle and beef product research at UNL is to provide reference information that represents the various populations (cows, calves, heifers, feeders, carcasses, retail products, etc) of beef production. Obviously, the researcher cannot apply treatments to every member of a population; therefore he/ she must sample the population. The use of statistics allows the researcher and readers of the Nebraska Beef report the opportunity to evaluate separation of random (chance) occurrences and real biological effects of a treatment. Following is a brief description of the major statistics used in the beef report. For a more detailed description …

Effect Of Heifer Development System On Reproduction And Subsequent Gain As A Pregnant Heifer, Shelby A. Springman, Hazy Rae Nielson, Tonya L. Meyer, Mike Kirby, Jim Teichert, Richard N. Funston

Nebraska Beef Cattle Reports

Weaned heifers grazed corn residue, upland range, or were fed 1 of 2 drylot diets differing in energy. Heifer development diets did not impact their resulting AI or final pregnancy rates. Cost per pregnant heifer was similar among treatments. A subset of AI- pregnant heifers was placed in a Calan Broadbent individual feeding system during late gestation. As a pregnant heifer, feed efficiency was not impacted by development system. These results indicate producers may utilize their most readily available and/or cost- effective feed resources with no detriment to pregnancy rates or feed efficiency as first- calf heifers.

Effect Of Three Initial Implant Programs With A Common Terminal Revalor®- 200 On Feedlot Performance And Carcass Traits Of Weaned Steers, Colton R. Oney, Galen E. Erickson, Andrea K. Watson Watson, Marshall N. Streeter, Robert J. Cooper, Bill D. Dicke, D. J. Jordon, Tony L. Scott

Nebraska Beef Cattle Reports

A commercial feedlot study utilizing 1,350 calf- fed steers (initial BW = 623 lb; ±23 lb) compared three initial implant strategies: Revalor®- IS (day 1), Revalor®- IS (day 1) and Revalor®- 200 (day 67), or Revalor®- XS (day 1). Each initial implant strategy was followed by a terminal Revalor®- 200 implant (day 133) to determine effects on performance and carcass traits. No differences in final body weight, intake, gain, or feed conversion were observed on either a live, or carcass adjusted basis. Th ere were also no differences in hot carcass weight, USDA quality grade, or USDA yield grade. Results …

Allelic Variation In Cxcl16 Determines Cd3+ T Lymphocyte Susceptibility To Equine Arteritis Virus Infection And Establishment Of Long-Term Carrier State In The Stallion, Sanjay Sarkar, Ernest Bailey, Yun Young Go, R. Frank Cook, Ted Kalbfleisch, John E. Eberth, R. Lakshman Chelvarajan, Kathleen M. Shuck, Sergey Artiushin, Peter J. Timoney, Udeni B. R. Balasuriya

Maxwell H. Gluck Equine Research Center Faculty Publications

Equine arteritis virus (EAV) is the causative agent of equine viral arteritis (EVA), a respiratory, systemic, and reproductive disease of horses and other equid species. Following natural infection, 10–70% of the infected stallions can become persistently infected and continue to shed EAV in their semen for periods ranging from several months to life. Recently, we reported that some stallions possess a subpopulation(s) of CD3⁺ T lymphocytes that are susceptible to in vitro EAV infection and that this phenotypic trait is associated with long-term carrier status following exposure to the virus. In contrast, stallions not possessing the CD3⁺ T …

Enhanced Bovine Colostrum Supplementation Shortens The Duration Of Respiratory Disease In Thoroughbred Yearlings, Clara K. Fenger, Thomas Tobin, Patrick J. Casey, Edward A. Roualdes, John L. Langemeier, Ruel Cowles, Deborah M. Haines

Maxwell H. Gluck Equine Research Center Faculty Publications

Bovine colostrum (BC) is used in humans as a nutritional supplement for immune support and has been shown to reduce Respiratory disease (RD). Other nutritional supplements, minerals and vitamins including mannan oligosaccharides (MOS), zinc and vitamins A, C and E have also been used for immune support. The aim of this prospective blinded randomized clinical trial was to evaluate the effects of a BC, MOS, zinc and vitamin based enhanced bovine colostrum supplement (BCS) on incidence and duration of RD occurring in yearling horses. 109 yearlings on two Thoroughbred farms in Central Kentucky were randomly assigned to treatment or placebo …

Large Deletions At The Shox Locus In The Pseudoautosomal Region Are Associated With Skeletal Atavism In Shetland Ponies, Nima Rafati, Lisa S. Andersson, Sofia Mikko, Chungang Feng, Terje Raudsepp, Jessica Pettersson, Jan Janecka, Ove Wattle, Adam Ameur, Gunilla Thyreen, John E. Eberth, John Huddleston, Maika Malig, Ernest Bailey, Evan E. Eichler, Göran Dalin, Bhanu Chowdary, Leif Andersson, Gabriella Lindgren, Carl-Johan Rubin

Maxwell H. Gluck Equine Research Center Faculty Publications

Skeletal atavism in Shetland ponies is a heritable disorder characterized by abnormal growth of the ulna and fibula that extend the carpal and tarsal joints, respectively. This causes abnormal skeletal structure and impaired movements, and affected foals are usually killed. In order to identify the causal mutation we subjected six confirmed Swedish cases and a DNA pool consisting of 21 control individuals to whole genome resequencing. We screened for polymorphisms where the cases and the control pool were fixed for opposite alleles and observed this signature for only 25 SNPs, most of which were scattered on genome assembly unassigned scaffolds. …

Impacts From The Use Of Antibiotics In Livestock: Methods Of Transmission Of Antibiotic Resistance From Livestock To Humans, Kristin M. Walden

Biology: Student Scholarship & Creative Works

Antibiotic use in livestock production has been around since the 1950s. Antibiotic feed is used in livestock and other meat producing animals for three reasons: illness prevention, illness treatment, and growth promotion. Unfortunately, since the time that antibiotics were first invented, antibiotic resistant bacteria have become a threat to public health. There are many studies showing methods of transmission of antibiotic resistance from livestock to humans. Antibiotic resistance can spread from livestock to soil, water, insects, and food, which ultimately comes into contact with humans. A proposed study to measure antibiotic resistance when eliminating antibiotic feed will provide a hypothesis …