Kerry W. Tudor

Substitution of Plant Proteins or Meat and Bone Meal for Fish Meal in Diets of Nile Tilapia

Abstract Five experimental diets containing plant proteins and synthetic amino acids with and without fish meal or meat and bone meal were fed to Nile tilapia Oreochromis niloticus averaging 13 g for 84 d in aquaria. Each experimental diet contained 20% corn gluten meal, 34–40% high-lysine corn, 29–36% soy grits, 0 or 6% fish meal or meat and bone meal, and supplemented with synthetic lysine, tryptophan, and threonine. There were no significant differences (P > 0.05) in weight gain, feed conversion ratio, and protein efficiency ratio for Nile tilapia fed the all plant protein diet, the fish meal diets with two levels of fat, the meat-and-bone-meal diets with two levels of fat, and the commercial diet containing fish meal and meat and bone meal. Thus, substitution of plant proteins or meat and bone meal for fish meal in Nile tilapia diets did not affect growth response.

Technical and economical feasibility of on-farm fish feed production using fishmeal analogs

Abstract Ten experimental diets and one control diet were fed to 720 tilapia (20 fish × 12 cages × three replicates) in a recirculating aquaculture system to determine the economic significance of replacing fishmeal with fishmeal analogs if the fishmeal analogs were processed on-site by the producer. All experimental diets were produced at Illinois State University using an Insta-Pro Model 600 Jr. extruder plus grinding, weighing and mixing equipment commonly found on commercial livestock operations. Primary diet protein sources included corn gluten meal, corn gluten feed and distillers dried grains. All diets were balanced for amino acid requirements of the fish, and both 32 and 36% crude protein diets were fed. There was no significant difference in feed conversion ratio (FCR) between diets with fishmeal and diets without fishmeal. There was no significant difference in FCR between 32 and 36% crude protein diets. An economic engineering model which included all equipment necessary for extruding and handling pelleted feed on-site was developed. Annualized investment and operating costs were estimated to determine the total cost of processing each of the 10 experimental diets. There was a significant difference in cost of gain among the 10 experimental diets and the control diet. Cost of production was highly sensitive to volume of feed extruded.

An analysis of risk management tools utilized by Illinois farmers

Purpose - – The purpose of this paper is to investigate the relationships among choice of risk management tools, perceived effectiveness of risk management tools, self-reported risk attitude, and farm and farmer characteristics. Design/methodology/approach - – A mail survey was used to collect information about utilization of risk management tools, perceived effectiveness of risk management tools, and factors that could influence choice of risk management tools by Illinois farmers. Cluster analysis, one-way ANOVA, Findings - – Multinomial logistic regression analysis revealed that age and gross farm income (GFI) were the strongest predictors of the risk management tool utilization group to which an individual would be assigned. The number of risk management tools utilized decreased with age but increased with GFI. Neither self-reported risk attitude nor education was a significant independent variable in the multinomial logistic regression model, but both were strongly impacted by age. Younger farmers with higher GFI were the most likely users of hedging. Research limitations/implications - – The results of this study provide support for the idea that farmers who are better able to generate revenue are better able to manage risk, but the direction of causality was not investigated. Practical implications - – Risk management service providers could benefit from this study as a benchmark for understanding their current and potential farmer clients’ risk management strategies. Originality/value - – This study used cluster analysis and multinomial logistic regression to address the complexity of decisions regarding multiple risk management tools. The number of tools utilized by individuals was investigated.

Growth Response of Tilapia Fed Diets Rich in High-Lysine Corn and Corn Gluten

Abstract The purpose of this study was to find out if fish meal is necessary in tilapia diet for good growth response. Five experimental diets (32% protein) containing 46-51% high-lysine corn, 20% corn gluten meal, supplemented with soy grits and synthetic amino acids, with and without fish meal were formulated. The diets were fed to tilapia with average initial weight of 13 g for 70 days in aquaria. Weight gain expressed as percentage increase after 70 days or as grams/day, feed conversion ratio, and protein efficiency ratio were equal (P > 0.05) to a commercial feed (36% protein) for all experimental diets. It appears that 32% protein diets with 46-51% high-lysine corn and 20% corn gluten meal were adequate for tilapia based on weight gain, feed conversion ratio, and protein efficiency ratio, and that fish meal is not necessary for tilapia feed to obtain good growth response.

THE NORTH CENTRAL AQUACULTURE REGION AS A POTENTIAL MARKET FOR FARM-RAISED HYBRID STRIPED BASS

Seafood restaurant chefs/managers, single-unit supermarket buyers, and supermarket chain buyers in the North Central Aquaculture Region were surveyed. Based upon familiarity with farm-raised hybrid striped bass and offer prices quoted, it appeared that seafood restaurants were the most promising retail outlet for the fish. However, only 41.7% of restaurant respondents knew that farmers raised hybrid striped bass as a food fish, and only 25.8% of the dollars spent on finfish and finfish products by restaurants went toward purchases of farm-raised fish. Results of the study suggested that successful large-scale marketing of farm-raised hybrid striped bass in the North Central Region would depend upon extensive product promotion and education of consumers and retailers, especially restaurateurs.