Life Sciences Commons^™

The Effect Of Design And Dose Level Choice On Estimatlng The Optimal Dose In A Quantitative Dose-Response Experiment, Henry R. Rolka, George A. Milliken, James R. Schwenke, Marta Remmenga

Conference on Applied Statistics in Agriculture

D-optimality is a commonly used criterion to evaluate a design with respect to parameter estimation. The variance of the optimal dose estimate is another criterion for evaluating a design. The quantitative dose-response experiment involves fitting a model to data and estimating an optimal dose. Two techniques for estimating an optimal dose and three models are used to compare the variances of optimal dose estimates over nine equally spaced balanced designs and five fixed unequally spaced six-point designs. The results show that a design which is more D-optimal than another design does not necessarily produce optimal dose estimates with less variance.

Analysis Of Genotype X Environment Interaction By Graphical Techniques, George C.J. Fernandez

Conference on Applied Statistics in Agriculture

Genotype x Environment interactions results from the changes in the magnitude of differences among genotypes (non-crossover or quantitative interactions) or changes in the relative ranking of the genotypes (crossover or qualitative interactions) in different environments. Non-crossover interactions are usually associated with variance heterogeneity and non-additivity. The analysis of variance combined with joint regression analysis failed to differentiate between the crossover and non-crossover interactions. Tedious computations are necessary in comparisons of all possible pairs of genotypes in all possible pairs of environments in the crossover detection tests. Therefore, differentiating the non-crossover interaction caused by variance heterogeneity and non-additivity from crossover interaction …

Analysis Of The Spatial Distribution Of Sugarbeet Plants, Stephen D. Kachman, John A. Smith

Conference on Applied Statistics in Agriculture

The spatial distribution of emerged sugarbeet plants is an important aspect of the performance of sugarbeet planters. Three major components influencing the spatial distribution are the ability to drop a single seed at a time, the ability to drop the seeds a fixed distance apart, and the ability of the seed to emerge. A model has been developed to describe the distribution of the spacing between emerged sugarbeet plants. The model consists of a mixture of normal and gamma distributions. The spatial data consists of the distance between neighboring emerged plants. Spatial data was collected on 7 planters operated at …

Evaluation Of Four Covariate Types Used For Adjustment Of Spatial Variability, Paul N. Hinz, John P. Lagus

Conference on Applied Statistics in Agriculture

Four types of covariates are used to account for spatial variability in data from a field experiment for evaluating 620 soybean varieties for iron chlorosis. The covariates are calculated as the average of 4 and of 14 neighboring residuals and of 4 and of 14 neighboring observations. The residual mean square from the analysis of covariance was smaller' when residuals were used in calculation of the covariates than when observations were used. Moreover, use of 14 neighbors resulted in smaller residual mean squares than did use of 4 neighbors. Differences among 4 covariate types were small and not practically important. …

Multi-Product Dry Milling Yields Prediction When Products Are Not Independent, Aziz Bouzaher, Alicia L. Carriquiry

Conference on Applied Statistics in Agriculture

The yield of products in the dry milling industry is largely determined by the physical properties of the corn kernel. The main objective of this paper is to investigate several statistical models of dry milling yield prediction based on physical characteristics of corn. Data consisting of one hundred corn samples representing a range of genetic traits and quality differences are used. For each corn sample, sixteen physical and chemical properties together with six dry milling product yields were measured, in a controlled laboratory environment .

For each corn sample, we consider a vector of dry milling product yields, and a …

Messy Experimental Designs, Dallas E. Johnson

Conference on Applied Statistics in Agriculture

This paper describes the statistical analysis of an agricultural experiment that was conducted in a very complex, but somewhat reasonable, experimental design. A correct analysis of data collected from the experimental design used requires the estimation of 8 error terms.

A Statistical Analysis Of The Performance Of Milking System Vacuum Regulators, Linda J. Young, Gerald R. Bodman, Eugene C. Boilesen, Walter W. Stroup

Conference on Applied Statistics in Agriculture

Milking machine vacuum regulators were tested at dairies across the United States over a period of twelve years. The drop in vacuum level with increasing air flow for each regulator tested was modeled using segmented regression. Three measures of regulator performance were considered: the slope of the line in the first phase, the variability about the first line, and the join point (after which vacuum pressure began to drop rapidly). The distribution of the join point was estimated based on an accelerated failure time model with censoring, Weibull errors, a model effect, and a linear effect of set point vacuum. …

Evaluation Of Methane Gas Production In A Simultaneous Regression System, Mark W. Jenner, Jon Maatta, Dennis M. Sievers

Conference on Applied Statistics in Agriculture

Methane gas production is a function of volatile solids activity in anaerobic digesters. Increasing the solids retention time of the swine manure digester system without increasing the hydraulic retention time would theoretically increase the methane gas production efficiency. Coagulation treatments were performed on the effluent of the second digester in a system of two digesters in series .

The objective of this paper is to describe mathematically the relationship of the Coagulation treatments in the second digester to biogas production and volatile solids retention. An initial, single equation, ordinary least squares regression produced statistically significant parameter estimates, but failed to …

A Reevaluation Of The Growth Decline In Pine In Georgia, And In Georgia-Alabama Combined, Z. Ouyang, H. T. Schreuder, J. Li

Conference on Applied Statistics in Agriculture

Using an improved testing procedure based on bootstrap and weighted jack-knife confidence intervals with the same model as used in Bechtold et al. (1991) and Ruark et al. (1991), analysis in this paper generally confirm the results of a significant decrease in growth rate in pine in Georgia and Alabama for 1972 - 1982 (5th cycle) relative to 1961 - 1972 (4th cycle) discussed in these papers.

Shrinkage In Ternary Mixes Of Container Media, Silvia Bures, Franklin A. Pokorny, Glenn O. Ware

Conference on Applied Statistics in Agriculture

Based on functional relationships established for binary mixes of container media, a mathematical model is proposed for ternary component mixtures. Shrinkage values are generated for three-component mixtures based on mathematical equations. Empirically observed shrinkage values for corresponding three-component mixtures are determined and used as the basis for assessing the reliability of the proposed mathematical model for characterizing shrinkage in mixtures of container media. . Regression equations were developed and compared for both theoretical and empirical results.

Nonlinear Estimation Of Growth Curve Models For Germination Data Analysis, Bahman Shafii, William J. Price, Jerry B. Swensen, Glen A. Murray

Conference on Applied Statistics in Agriculture

Logistic, Gompertz, Richards and Weibull growth curves were evaluated for their suitability as mathematical and empirical models to represent cumulative germination. By avoiding the limitations associated with the method of moments and single-value germination indices, the fitted models provided superior description of the time course of germination. The four-parameter Weibull model gave the best fit across a relatively wide range of seed species and germination conditions, and the resulting parameter estimates reflected identifiable aspects of the germination process. The nonlinear estimation of the germination response included a parameter summary, together with their asymptotic standard errors and correlation matrix, along with …

Straight Line Regression When Both Variables Are Subject To Error, Norman R. Draper

Conference on Applied Statistics in Agriculture

This expository note discusses the problem of fitting a straight line when both variables are subject to error. A brief review of the literature is undertaken, and one fitting method, the geometric mean functional relationship, is spotlighted and illustrated with two sets of example data. The emphasis is on providing practical advice. All methods have drawbacks, but the geometric mean functional relationship method appears to provide a sensible course of action in many practical problems, and could benefit from further investigation.

Editor's Preface, Table Of Contents, And List Of Attendees, George A. Milliken

Conference on Applied Statistics in Agriculture

These proceedings contain papers presented at the third annual Kansas State University Conference on Applied Statistics in Agriculture, held in Manhattan, Kansas, April 28 through 30, 1991.

Comparison Of Protein Sources For Phase Ii Starter Diets (1991), J A. Hansen, Michael D. Tokach, Robert D. Goodband, Jim L. Nelssen

Kansas Agricultural Experiment Station Research Reports

A total of 432 weanling pigs (initially 15.3 lb and 21 d of age) was used in a growth trial to compare various protein sources in the Phase II starter diet. During Phase I (0 to 7 d post-weaning), all pigs were fed a common high nutrient density diet containing 1.5% lysine, 10% porcine plasma, 10% lactose, and 20% dried whey. During Phase II (7 to 28 d post-weaning), pigs were fed one of six experimental diets. All Phase II diets contained 10% dried whey and were formulated to 1.18% lysine. The positive control diet contained 4% menhaden fish meal …

Seasonal Performance Of Finishing Heifers (1991), Michael R. Langemeier, J. Mintert, Ted C. Schroeder

Kansas Agricultural Experiment Station Research Reports

This study examined the impact of date of feedlot placement on feed conversion, daily gain, and death loss. Results indicated that heifers placed on feed from September to December required more feed per pound of gain, had lower daily gains and higher death loss, and generally exhibited more variation in feeding performance than heifers placed during the rest of the year. Cattle feeders should take these performance variations into account when developing budgets and calculating breakeven sale prices for heifers.

Performance Of Holstein Calves From Three To Twelve Months Of Age (1991), J. Velazco, J. L. Morrill, Robert T. Brandt Jr., R. Schalles

Kansas Agricultural Experiment Station Research Reports

Sixty-four Holstein steers were used to study the effect of season and age on performance. Animals beginning the trial in spring were heavier (P.05) among seasons in average daily gain and feed conversion after 6 mo of age. Rate of growth was reduced after 9 mo of age for all seasons.; Dairy Day, 1991, Kansas State University, Manhattan, KS, 1991;

Leukocyte Function And Health Status Of Calves Supplemented With Vitamins A And E (1991), S. D. Eicher-Pruiett, J. L. Morrill, Frank Blecha, C. G. Chitko-Mckown

Kansas Agricultural Experiment Station Research Reports

Forty-four Holstein calves were fed milk replacers with varied concentrations of vitamins A and E from 3 to 45 d of age to determine their effects on concentrations of plasma vitamin A (retinol and retinyl palmitate) and vitamin E (a- tocopherol), lymphocyte and neutrophil functions, and health of calves. Plasma a-tocopherol was unaffected by increased vitamin A supplementation. Fecal scores, and eye and nose membrane responses were improved with increased vitamin A and lower vitamin E concentration, whereas the same treatment tended to reduce neutrophil cytotoxic and bactericidal activity by 6 wk of age. Increased supplemental vitamin E tended to …

Producing Hogs Under Contract (1991), Michael R. Langemeier

Kansas Agricultural Experiment Station Research Reports

Recently, there has been a renewed interest in contract hog production. Contractors are looking for an effective means to expand production or utilize excess feed production capacity. Producers enter contracts to minimize input cost and market risks or to obtain financing for buildings and equipment. Provisions vary from contract to contract. Producers that are making the decision whether to produce hogs under contract should calculate expected returns for a range of production and cost scenarios. Whatever the contract provisions, producers and contractors should make sure that the contract rewards them for what they do best.; Swine Day, Manhattan, KS, November …

Space Requirements Of Finishing Pigs Fed To A Heavier Weight (Removed Individually) (1991), G E. Fitzner, David A. Nichols, Joe D. Hancock, Robert H. Hines

Kansas Agricultural Experiment Station Research Reports

Space allowances of 6, 8, 10, and 12 ft2 were evaluated for pigs fed from 120 to 250 lb. The management system used was to remove pigs individually as they reached 250 lb, which provided increasing space per pig. Using this management system, average daily gain, average daily feed intake, and feed efficiency improved linearly with increasing space allowance. Pigs allowed 6ft2 gained slower, ate less, and required more feed per lb of gain compared to pigs allowed 8, 10, and 12 ft2. Pigs permitted 8, 10, and 12 ft2 were similar in rate of gain, feed consumption, and feed …

Extrusion Of Sorghum, Soybean Meal, And Whole Soybeans Improves Growth Performance And Nutrient Digestibility In Finishing Pigs (1991), Terry L. Gugle, Robert H. Hines, Joe D. Hancock

Kansas Agricultural Experiment Station Research Reports

One hundred forty-four finishing pigs (124 lb avg initial wt) were used to determine the effects of extruding sorghum, soybean meal (SBM), and whole soybeans on growth performance and nutrient digestibility. Treatments were: 1) control diet with ground sorghum, SBM, and soybean oil; 2) diet 1 with the ground sorghum, SBM, and soybean oil blended and extruded; 3) sorghum and whole soybeans extruded separately and blended; and 4) sorghum and extruded soybeans blended and extruded together. Extrusion was in an Insta-Pro extruder. All diets were formulated to be equal in concentrations of metabolizable energy (ME) and lysine. Pigs fed diets …

Effect Of Replacing Milk Proteins With Wheat Gluten And Soybean Products On Digestibility Of Nutrients And Growth Performance In Nursery Pigs (1991), B T. Richert, J L. Morrill, Joe D. Hancock

Kansas Agricultural Experiment Station Research Reports

Two experiments were conducted to evaluate the nutritional value of processed wheat gluten for early-weaned pigs. The first experiment involved 72 weanling pigs with an avg age of 20 d and avg wt of 9.2 lb. Six diets were fed to the pigs in individual metabolism cages. Protein sources were casein, flash-dried wheat gluten, spray-dried wheat gluten, two solubilized wheat glutens, and soybean meal. Response criteria were N digestibility, biological value, and N retention. Casein had greater N digestibility, biological value, and N retention than the other protein sources. The wheat gluten products had greater N digestibility than soybean meal. …

Effects Of Porcine Somatotropin Dosage And Lysine Level On Growth Performance Of Growing Pigs (1991), G E. Fitzner, T L. Weeden, B R. Schricker, Robert H. Hines, Jim L. Nelssen, Robert D. Goodband, Joe D. Hancock

Kansas Agricultural Experiment Station Research Reports

Eighty crossbred barrows initially weighing 70.5 lb were used in a 5 wk trial to determine the optimum dosage of porcine somatotropin (PST) required to promote maximum growth response in growing pigs fed diets containing either 1.0 or 2.0% lysine. Pigs received a daily injection of placebo or 2, 4, or 8 mg pST in combination with one of two experimental diets containing either 1.0 or 2.0% dietary lysine. Increasing the dosage of pST of pigs fed both diets resulted in an increase in average daily gain (ADG), a reduction in average daily feed intake (ADFI), and an improvement in …

The Effect Of Pre-Weaning Exposure To Soybean Meal On Subsequent Post-Weaning Growth Performance In The Early-Weaned Pig (1991), K G. Friesen, Frank Blecha, D N. Reddy, P G. Reddy, B T. Richert, Robert D. Goodband, Jim L. Nelssen

Kansas Agricultural Experiment Station Research Reports

Two hundred and forty pigs averaging 11.3 lb and 21 d of age were utilized to determine the effect of pre-weaning exposure to soybean meal on nursery performance. Pigs were derived from sows that were fed either a soybean meal based- or a corn gluten meal based-diet throughout gestation and lactation. Across sow treatments, pigs were stomach-infused with 6 g/d of soybean meal or placebo from d 5 to 9 of age. Treatment structuring prior to weaning allowed for comparisons between pigs immunologically sensitized to soy proteins and pigs nonsensitized to soy proteins. Nursery treatments allowed for a comparison between …

The Influence Of Dietary Threonine On Growth Performance And Carcass Characteristics Of Pst-Treated Finishing Pigs (1991), J L. Laurin, J A. Hansen, B R. Schricker, Robert D. Goodband, Jim L. Nelssen

Kansas Agricultural Experiment Station Research Reports

Eighty crossbred barrows (initial wt = 131 lb) were utilized to determine the dietary threonine requirement of finishing pigs injected with porcine somatotropin (PST). Barrows were injected daily in the extensor muscle of the neck with either 4 mg pST or a placebo and fed diets containing either .45, .55, .65, or .75% threonine. All other amino acids, vitamins, and minerals were calculated to be at least double current requirements for finishing pigs so as not to limit performance. Pigs were housed in an open-sided building with two pigs per pen and five replications of the eight treatments. Feed and …

Health Considerations For The Year 2000 (1991), J F. Connor

Kansas Agricultural Experiment Station Research Reports

As the swine industry matures, profit margins will decrease. Control of the major factors affecting feed cost will drive the system. Upgrading or maintaining health will be a major emphasis, because disease agents and complexes affect growing-finishing performance. Many diseases, such as pneumonia caused by Actinobacillus (llaemophilus) pleuropneumonia and swine dysentery, dramatically affect growing-finishing performance. Diseases decrease average daily feed intake (ADFI) and increase feed per gain ratio (FIG) in many instances. At the same time, they increase input costs via treatments, vaccines, and feed additives. Historically, our control methods may have been successful on individual farms, but not across …

Evaluation Of Revalor® Implants For Stocker-Finishing Steers (1991), Robert T. Brandt Jr., R.J. Grant, Ronald V. Pope

Kansas Agricultural Experiment Station Research Reports

Revalor® implants (containing trenbolone acetate plus estradiol) were evaluated in a grazing-finishing system using steers with a known previous implant history. Grazing gains were not improved by either Ralgro® or Revalor implants, suggesting that previously implanted steers may not respond to implants during a later growing phase. During the finishing phase, steers implanted with Revalor gained 5.4 to 8.0% faster (P<.05) than steers implanted with Synovex-S®. Gain efficiency in the finishing period was improved 4.8% (P<.10) for steers receiving no pasture implant and a Revalor implant during the finishing phase (0R), compared with steers receiving Ralgro/Synovex (RS) or Revalor/Revalor (RR) implants in the pasture/feedlot phases. Steers implanted with RR had larger (P<.05) ribeye areas than RS steers, with 0R steers intermediate. However, RR steers had a 20 percentage unit reduction (P<.05) in carcasses reaching the choice grade compared to RS steers. Revalor can improve steer feedlot performance, but multiple implantation may reduce quality grade.

Effects Of Hybrid And Maturity At Harvest On Agronomic Performance Of Corn For Silage (1991), R. Suazo, R.N. Sonon, L. Pfaff, J.T. Dickerson, K.K. Bolsen

Kansas Agricultural Experiment Station Research Reports

Twelve, commercial, corn hybrids were grown under irrigated conditions in 1990 and evaluated for agronomic and silage characteristics at three stages of maturities (1/2 milk line, black layer, and 7 days post-black layer). Time to mid-anthesis and mid-silk ranged from 62 to 68 and 65 to 70 days, respectively, and plant height ranged from 78 to 98 inches. Whole-plant dry matter (DM) content and whole-plant DM and grain yields for the 12 hybrids ranged from 23.6 to 53.7 %, 6.1 to 9.6 tons of DM per acre, and 60 to 170 bushels per acre, respectively, over the three maturities. Whole-plant …

Severe Flea Infestation In Dairy Calves (1991), Michael W. Dryden, A. B. Broce

Kansas Agricultural Experiment Station Research Reports

In June 1991, an investigation was conducted of a severe flea infestation in 23 Holstein dairy calves in South Central Kansas. Inspection of the dairy revealed massive numbers of fleas on calves and in the barn where they were housed. Analysis of blood samples from 10 calves revealed that nine of them had mild to severe anemia. A management program was initiated consisting of treatments of calves and premises with insecticide and insect growth regulator and removal of straw bedding from the barn. Inspection of the dairy 9 wk after this complete control program was initiated revealed that fleas were …

Beef Safety - Current Research And Summary Of Progress (1991), F. Cunningham, Melvin C. Hunt, Curtis L. Kastner, Donald H. Kropf, B. Larson, D. Schafer, D. Simms, S. Smith, M. Vanier, Daniel Y.C. Fung

Kansas Agricultural Experiment Station Research Reports

Beef and beef products are significant parts of a balanced diet in the U.S. and major parts of the Kansas economy. Therefore, these products must be carefully processed, handled, and monitored for microbial quality to ensure safety for the consumer. KSU Animal Sciences research is designed to accomplish this end and to enhance demand for beef. We have made a major commitment to beef safety research. Moreover, results with beef are generally applicable to other meats.

Influence Of Water Treatment On Digestion Dynamics Of Steers Consuming High- And Low-Forage Diets (1991), D.L. Harmon, A.D. Flood

Kansas Agricultural Experiment Station Research Reports

The influence of drinking water treatment (Oxion Inc., Hugoton, KS) on digestion and metabolism was evaluated in steers fed low- and high-forage diets. Water treatment did not influence digestibility of any nutrient measured nor did it influence the profile of ruminal metabolites. Water treatment did increase water consumption two- to threefold and also increased ruminal fractional water outflow (%/h) for steers fed the high forage, but not the high concentrate, diet. Increased water consumption could be a beneficial response, but it is not known if water consumption increases with management programs different than those used in the present study.