Linear and nonlinear mixed model analyses of growth performance of commercial U.S. dairy buck kids

2016 ◽  
Vol 136 ◽  
pp. 151-155
Author(s):  
T.W. Murphy ◽  
D.L. Thomas ◽  
T.L. Montgomery
Keyword(s):  
Growth Performance ◽  
Mixed Model ◽  
Nonlinear Mixed Model ◽  
Linear And Nonlinear

Comparing linear and nonlinear mixed model approaches to cosinor analysis

2003 ◽  
Vol 22 (20) ◽  
pp. 3195-3211 ◽  
Author(s):  
Susan K. Mikulich ◽  
Gary O. Zerbe ◽  
Richard H. Jones ◽  
Thomas J. Crowley
Keyword(s):  
Mixed Model ◽  
Nonlinear Mixed Model ◽  
Cosinor Analysis ◽  
Linear And Nonlinear

249 Increasing Structural Fiber Improves Growth Performance of Nursery Pigs

2021 ◽  
Vol 99 (Supplement_1) ◽  
pp. 93-93
Author(s):  
Sara Ebarb ◽  
Sabrina May ◽  
Mark D Newcomb
Keyword(s):  
Growth Performance ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Two Phase ◽  
Nursery Pigs ◽  
High Fiber ◽  
Rice Hulls ◽  
Fiber Treatment ◽  
Wheat Middlings

Abstract Fiber ingredients in swine diets have various components that affect the intestinal tract distinctively. The objective of this study was to determine the effect of structural fiber sources on growth performance of nursery pigs. A total of 1,760 weanling pigs (initial BW = 6.12 ± 0.3 kg, 16 reps/trt, 22 pigs/pen) were used in a study with 5 dietary treatments: 1) Complex nursery diet with no additional fiber (CON); 2) CON + 2% rice hulls; 3) CON + 4% rice hulls; 4) CON + 6% wheat middlings; 5) CON + 12% wheat middlings. Fiber ingredients were added at the expense of corn and some processed soybean meal to maintain similar dietary protein levels. Using an in vitro fermentation estimation of fermentation for rice hulls and wheat middlings, diets were constructed to add similar levels of structural (non-fermentable NDF) fiber between low and high additions of rice hulls and wheat middlings. Pens across two barns were randomly allotted independent of one another and within a location block to one of the five treatments on d 0 of a two-phase study (d 0–11 and d 11–20.5 post-weaning). Data were analyzed by general linear model in R. Mortality and removal data were analyzed as a generalized linear mixed model with a binomial distribution. Contrasts tested the effect of additional fiber (CON vs treatments 2–5), effect of medium vs high fiber (treatment 2/4 vs 3/5), effect of source of fiber (treatment 2/3 vs 4/5), and the interaction of level and source of fiber. Overall (Table 1), additional fiber resulted in increased ADFI (P < 0.05) and tended to increase ADG (P < 0.10). Probability of mortality and removal was reduced (P < 0.05) when additional fiber was included. In summary, increasing the level of structural fiber improved performance and livability of nursery pigs.

scholarly journals Skill Transference of a Probe-Tube Placement Training Simulator

2020 ◽  
Vol 31 (01) ◽  
pp. 040-049 ◽  
Author(s):  
Robert W. Koch ◽  
Hasan Saleh ◽  
Paula Folkeard ◽  
Sheila Moodie ◽  
Conner Janeteas ◽  
...  
Keyword(s):  
Mixed Model ◽  
Tracking System ◽  
Optical Tracking ◽  
Tube Placement ◽  
Control Group ◽  
Educational Settings ◽  
Training Simulator ◽  
Nonlinear Mixed Model ◽  
Optical Tracking System ◽  
Clinical Scenarios

AbstractProbe-tube placement is a necessary step in hearing aid verification which needs ample hands-on experience and confidence before performing in clinic. To improve the methods of training in probe-tube placement, a manikin-based training simulator was developed consisting of a 3D-printed head, a flexible silicone ear, and a mounted optical tracking system. The system is designed to provide feedback to the user on the depth and orientation of the probe tube, and the time required to finish the task. Although a previous validation study was performed to determine its realism and teachability with experts, further validation is required before implementation into educational settings.This study aimed to examine the skill transference of a newly updated probe-tube placement training simulator to determine if skills learned on this simulator successfully translate to clinical scenarios.All participants underwent a pretest in which they were evaluated while performing a probe-tube placement and real-ear-to-coupler difference (RECD) measurement on a volunteer. Participants were randomized into one of two groups: the simulator group or the control group. During a two-week training period, all participants practiced their probe-tube placement according to their randomly assigned group. After two weeks, each participant completed a probe-tube placement on the same volunteer as a posttest scenario.Twenty-five novice graduate-level student clinicians.Participants completed a self-efficacy questionnaire and an expert observer completed a questionnaire evaluating each participant’s performance during the pre- and posttest sessions. RECD measurements were taken after placing the probe tube and foam tip in the volunteer’s ear. Questionnaire results were analyzed through nonparametric t-tests and analysis of variance, whereas RECD results were analyzed using a nonlinear mixed model method.Results suggested students in the simulator group were less likely to contact the tympanic membrane when placing a probe tube, appeared more confident, and had better use of the occluding foam tip, resulting in more improved RECD measurements.The improved outcomes for trainees in the simulator group suggest that supplementing traditional training with the simulator provides useful benefits for the trainees, thereby encouraging its usage and implementation in educational settings.

scholarly journals 128 Effects of a Bacillus-based probiotic and prebiotics on nursery pig performance, fecal consistency, and fecal microflora

2019 ◽  
Vol 97 (Supplement_2) ◽  
pp. 75-76
Author(s):  
Mariana Boscato Menegat ◽  
Michaela B Braun ◽  
Joel M DeRouchey ◽  
Jason C Woodworth ◽  
Jim Bryte ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Growth Performance ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Experimental Unit ◽  
Bacillus Sp ◽  
Nursery Pigs ◽  
Fecal Microflora ◽  
Microbial Analysis ◽  
Diet Control

Abstract This study evaluated the progeny of sows fed a control or probiotic diet with Bacillus subtilis C-3102 (Calsporin®, Calpis Co. Ltd., Tokyo, Japan) at 500,000 and 1,000,000 CFU/g diet in gestation and lactation, respectively. A total of 358 weaned pigs (DNA 241 × 600) were used in a 42-d trial with 4–5 pigs/pen and 18–19 pens/treatment. Pens were allotted to treatments in a completely randomized design based on BW at weaning. Treatments were a 2×2 factorial with main effects of sow diet (control vs. probiotic) and nursery diet (control vs. probiotic). In the nursery probiotic diet, a product based on probiotic Bacillus subtilis C-3102 at 500,000 CFU/g diet and prebiotics β-glucans and mannan oligosaccharides was included at 0.05% (BacPack ABF™, Quality Technology International, Inc., Elgin, IL). Diets were corn-soybean meal-based. Growth performance and fecal consistency on a 1-to-5 scale were evaluated weekly. Fecal samples were collected for microbial analysis by culture method and bacterial quantification of Bacillus subtilis C-3102, total Bacillus sp., Lactobacillus sp., Clostridium perfringens, Salmonella spp., Enterococcus sp., Enterobacteriaceae, total aerobes, and total anaerobes. Data were analyzed using a linear mixed model (PROC GLIMMIX, SAS®) with pen as experimental unit. There was no evidence for effect of sow diet, nursery diet, or interactions (P > 0.10) on overall nursery growth performance and fecal consistency. However, growth performance from d 21 to 42 and final BW were greater (P < 0.05) in progeny of control-fed sows compared to probiotic-fed sows. Microbial analysis revealed an increase (P < 0.01) in Bacillus subtilis C-3102 and, consequently, total Bacillus sp. in fecal microflora of probiotic-fed pigs. In conclusion, probiotic inclusion to sow diets lowered growth performance of the progeny in late nursery. The probiotic diet provided to sows or nursery pigs did not influence fecal consistency, but altered the fecal microbial population in nursery pigs by increasing total Bacillus sp.

scholarly journals PSVII-9 Effects of a multi-species direct-fed microbial on growth performance and carcass characteristics of grow-finish pigs

2019 ◽  
Vol 97 (Supplement_2) ◽  
pp. 216-216
Author(s):  
Mariana Boscato Menegat ◽  
Joel M DeRouchey ◽  
Jason C Woodworth ◽  
Mike D Tokach ◽  
Steve S Dritz ◽  
...  
Keyword(s):  
Growth Performance ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Block Design ◽  
Control Diet ◽  
Random Effect ◽  
Carcass Characteristics ◽  
Experimental Unit ◽  
Feeding Duration ◽  
Corn Distillers

Abstract This study was conducted to determine the effects of a multi-species direct-fed microbial (DFM) product based on lactic acid bacteria and Bacillus subtilis on growth performance and carcass characteristics of grow-finish pigs. A total of 1,188 pigs (PIC 359 × 1050; initially 25.8 kg BW) were used in a 121-d growth trial with 27 pigs/pen and 22 pens/treatment. Pigs were allotted to treatments based on initial BW in a randomized complete block design. Treatments included a control diet and the control diet with added DFM (BiOWiSH Technologies Inc., Cincinnati, OH) included at 0.055% of the diet at the expense of corn. Diets were based on corn, distillers dried grains with solubles, and soybean meal and fed in four dietary phases. Data were analyzed using a linear mixed model (PROC GLIMMIX, SAS®) with treatment as fixed effect, block as random effect, and pen as experimental unit. Overall (d 0 to 121), pigs fed the control diet had greater ADG (P < 0.05) and final BW (P < 0.001) compared to pigs fed the DFM diet (Table 1). There was no evidence for differences (P > 0.05) in ADFI or G:F between treatments. The difference in final BW resulted in heavier (P < 0.05) HCW in control pigs compared to DFM pigs, but no evidence for differences (P > 0.05) was observed in carcass yield, backfat, loin depth, and percentage lean between treatments. In conclusion, the inclusion of this multi-species DFM in growing-finishing diets reduced ADG in this commercial study. This response could be related to inclusion rate, feeding duration, or other factors not identified in this study, warranting further research to characterize the effects on pig performance.

scholarly journals Reaction rate coefficient k20 and temperature coefficient Θ in organic waste thermal disintegration

2018 ◽  
Vol 23 ◽  
pp. 00026
Author(s):  
Sylwia Myszograj
Keyword(s):  
Activated Sludge ◽  
Mixed Model ◽  
Heating Temperature ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Rate Of Change ◽  
Waste Activated Sludge ◽  
Nonlinear Mixed Model ◽  
The Difference ◽  
Reaction Speed

It was described the test of sewage sludge and organic fraction of municipal mixed solid waste thermal disintegration process. The waste activated sludge used during the tests was collected from the secondary settlement tank in a mechanical-biological wastewater treatment plant. The biowaste used in the studies was collected from an area of new buildings. It was noticed from means values of Soluble Chemical Oxygen Demand (SCOD) plot that both heating temperature and time, influence the amount of dissolved COD. The observations indicate that changes of SCOD can be described by an increasing, differentiable function of time and the rate of change of the soluble COD in the hydrolysates, in time is proportional to the difference of the maximum values of SCOD and its value in time, which leads to the relationship of the first-order ordinary differential equation. The process effectiveness depending on the temperature was described with the mathematical model including Van't Hoff-Arrhenius equation. Inspection of the data and some preliminary fits indicates, that for the description of changes in SCOD terms of time and temperature were adopted the form of nonlinear mixed model. Values of k20 indicator and Θ parameter depend on the substrate type. For waste activated sludge thermal disintegration, value of reaction speed indicator k20 was 0.028 h-1 (0,67 d-1), and value of temperature indicator equalled Θ = 1.024. For thermal disintegration of biological waste, value of reaction speed indicator k20 was 0.016 h-1 (0,38 d-1), and value of temperature indicator equalled Θ = 1.016.

scholarly journals Comparison of growth curves of two genotypes of dairy goats using nonlinear mixed models

2013 ◽  
Vol 152 (5) ◽  
pp. 829-842 ◽  
Author(s):  
J. G. L. REGADAS FILHO ◽  
L. O. TEDESCHI ◽  
M. T. RODRIGUES ◽  
L. F. BRITO ◽  
T. S. OLIVEIRA
Keyword(s):  
Random Effects ◽  
Growth Curve ◽  
Mixed Model ◽  
Growth Curves ◽  
Growth Patterns ◽  
Dairy Goat ◽  
Residual Variance ◽  
Nonlinear Mixed Model ◽  
Error Structure ◽  
Mixed Model Methodology

SUMMARYThe objective of the current study was to assess the use of nonlinear mixed model methodology to fit the growth curves (weightv.time) of two dairy goat genotypes (Alpine, +A and Saanen, +S). The nonlinear functions evaluated included Brody, Von Bertalanffy, Richards, Logistic and Gompertz. The growth curve adjustment was performed using two steps. First, random effectsu1,u2andu3were linked to the asymptotic body weight (β1), constant of integration (β2) and rate constant of growth (β3) parameters, respectively. In addition to a traditional fixed-effects model, four combinations of models were evaluated using random variables: all parameters associated with random effects (u1,u2andu3), onlyβ1andβ2(u1andu2), onlyβ1andβ3(u1andu3) and onlyβ1(u1). Second, the fit of the best adjusted model was refined by using the power variance and modelling the error structure. Residual variance ($\sigma _e^2 $) and the Akaike information criterion were used to evaluate the models. After the best fitting model was chosen, the genotype curve parameters were compared. The residual variance was reduced in all scenarios for which random effects were considered. The Richards (u1andu3) function had the best fit to the data. This model was reparameterized using two isotropic error structures for unequally spaced data, and the structure known in the literature as SP(MATERN) proved to be a better fit. The growth curve parameters differed between the two genotypes, with the exception of the constant that determines the proportion of the final size at which the inflection point occurs (β4). The nonlinear mixed model methodology is an efficient tool for evaluating growth curve features, and it is advisable to assign biologically significant parameters with random effects. Moreover, evaluating error structure modelling is recommended to account for possible correlated errors that may be present even when using random effects. Different Richard growth curve parameters should be used for the predominantly Alpine and Saanen genotypes because there are differences in their growth patterns.

scholarly journals PSVIII-10 Effects of enzyme supplementation in corn distiller’s dried grains with solubles (DDGS) diets on growth performance in broilers: a meta-analysis

2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 211-211
Author(s):  
Jae-Cheol Jang ◽  
Zhikai Zeng ◽  
Pedro E Urriola ◽  
Gerald C Shurson
Keyword(s):  
Growth Performance ◽  
Fixed Effects ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Meta Analysis ◽  
Growth Responses ◽  
Exogenous Enzymes ◽  
The Mean ◽  
Enzyme Supplementation ◽  
Mean Differences

Abstract The objective of this study was to conduct a meta-analysis to quantitatively summarize the growth responses of broilers fed cDDGS and the efficacy of various types of dietary enzyme supplementation. A total of 12 publications with 69 observations were included in the database. Individual observations were analyzed using a multivariable linear mixed model. The mean differences (MD) of BWG, FI, and gain efficiency (G/F) were calculated by subtracting either the enzyme response in corn-soybean meal (CSB) or CSB+cDDGS based diets to the control, and was expressed as a percentage (MD = (enzyme – control)/control ×100%). A type of exogenous enzymes (xylanase; protease; carbohydrases; cocktail = proteases + carbohydrases), and feeding phase (starter = d 0 to d 21; finisher = d 21 to d 42 or 49; overall = d 0 to d 42 or more) were included as fixed effects. Dietary enzyme inclusion showed significant improvement on BWG (3.19%, P &lt; 0.01) and G/F (5.69%, P &lt; 0.01) in broilers fed cDDGS diet. However, no significant enzyme responses were observed in broilers fed CSB diet on growth performance. Broilers fed cDDGS diet had increased (P &lt; 0.01) BWG with the addition of protease (3.32 %) and cocktail (3.27 %), whereas addition of xylanased improved (P &lt; 0.01) G/F by (3.56 %) and carbohydrases (1.90 %). Broilers fed cDDGS diet with enzyme supplementation showed greater improvement in BWG (3.71 %, P &lt; 0.01) and G/F (3.78 %, P &lt; 0.01) at finisher phase compared with starter phase. Likewise, Broilers fed CSB diet with enzyme supplementation increased BWG (9.40 %, P &lt; 0.01) and G/F (3.11 %, P &lt; 0.01) at finisher phase. In conclusion, supplementation of xylanase and carbohydrases in cDDGS diet improved G/F, and the enzyme response can be maximized when fed during the finisher phase diet compared with the starter phase diet.

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