Experiment of Feeding Factors for Cost-Effective Weight Gain in Tilapia By Amanda Adams and Brian Orleans STAT 231

Objective/Research Question  What type of feeding causes optimal growth in farmed tilapia?  Combination of Percent Protein and Feeding Regime  Most cost-effective way to maximize weight gain

Experimental Design  Completely Randomized Factorial Design (CRF)  Percent of Protein in the Diet  Fixed Effect with 4 levels  Feeding Regime (amount of food by body weight)  Fixed effect with 3 levels  Brood Stock (parents)  Random Effect with 3 levels  Experiment Unit: 1 tank of tilapia  Observational Unit: Individual fish weight after 8 weeks

Experimental Procedure  Duration: 8 weeks  36 tanks of fish  Brood Stock => 25 offspring =>20 fish weighed  Randomization  Selection of offspring can’t truly be randomized  Final fish chosen to be weighed is randomized

Analysis  Check Assumptions  Inspect ANOVA for interaction (What type)  Examine simple effects between percentage of protein and feeding regime  Cost analysis

Power Analysis  α =.05  Power =.85  Looking to detect 2σ (σ = 9.4g)  Between 3 factors, max. r value = 7  N = 252  Constructing σ  Range of weight (16.6g, 73.0g)  σ = 9.4g