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United States Department of Agriculture

Agricultural Research Service

Research Project: INTEGRATION OF NUTRITIONAL, GENETIC AND PHYSIOLOGICAL APPROACHES TO IMPROVE PRODUCTION EFFICIENCY OF RAINBOW TROUT

Location: Small Grains and Potato Germplasm Research

2007 Annual Report


1a.Objectives (from AD-416)
Objective of this research are; 1)Develop a series of trout feeds that replace fish meal and fish oil with novel and traditional plant-derived ingredients. .
2)Determine optimal supplementation levels of vitamins and limiting amino acids for plant-based feeds. .
3)Identify and evaluate genetic, biochemical and physiological responses of trout fed grain-based feeds. .
4)Identify rainbow trout families with improved phenotypes for growth and utilization of an alternative plant-protein fish feed through a genetic selection program. New funds will be used to expand objective one of the project plan: 1) Objective 1 of the project consists of developing trout feeds formulated with traditional plant-derived ingredients in place of fish meal and fish oil. Within this area of research the experimental diets are to be tested to determine the optimal supplementation level of vitamins and limiting amino acids necessary to obtain maximal growth. The financial increase to the project will aid in developing ingredient enhancement through the development of biological and mechanical concentration methods for the formulation of nutrient complete feeds.

New funds will be used to expand Objective One of the research project plan: 1) Develop a series of trout feeds that replace fishmeal and fish oil with traditional and enhanced plant-derived ingredients. The focus should be on ingredient enhancement through biological and mechanical concentration of required nutrients for complete feed development. Expedite expanded capacity to increase select cultivars in trout feeding trials. This includes expanding strains being developed at Leetown, WV. Dr. Keshun Liu: Objectives include;.
1)evaluate current methods of dry and wet fractionization for ways to improve performance or reduce cost of production;.
2)evaluate chemical and enzymatic treatments for effectiveness and production costs,.
3)evaluate nutritional quality of protein concentrates, and.
4)develop improved analytical methods for some key grain nutrients, such as beta-glucan, protein, to assist breeding screen for improved grain quality. Dr. Frederic Barrows Objectives;.
1)identify the most effective organism and blend of grains to result in a high protein low carbohydrate ingredient, 2) identify optimal processing and incubating conditions, 3) evaluate digestibility and palatability of each ingredients with in-vivo testing, 4) evaluate effect of long term feeding of experimental ingredient on growth, and product quality. Dr. Kenneth Overturf Objectives: .
1)installation of 10 heath tray incubators for hatching and isolating individual families, 80- 4'x15" troughs for rearing fry, and 25- 5' circular for holding individual families and mixed tagged families. Also included with this is the necessary infrastructure such as securing adequate water to the tanks and electrical and lighting for rearing and handling of the fish.


1b.Approach (from AD-416)
This research will benefit fish farmers, grain farmers and assist in protecting the environment by reducing nutrients in hatchery effluents, and reducing exploitation of ocean fisheries. A series of plant-based feeds will be eveloped, replacing fish meal, and containing the proper balance of essential nutrients. New cultivars of barley and oats will be evaluated as a fish feed ingredient along with alternate crops such as flax, sunflower and safflower. A breeding program will be used to develop new strains of rainbow trout that are better able to utilize plant-based feeds, grow faster and more efficiently and have improved product quality characteristics. Traditional methodologies to determine metabolic scope for a given nutrient or ingredient will be used to evaluate the relative contribution and metabolic efficacy of nutrients supplied in plant-based feeds. Information developed concerning the genetic, biochemical, and physiological responses of rainbow trout to consumption of various plant-derived ingredients will be used as a basis for developing future feed formulations and to develop improved selection parameters for trout breeding programs. Dr. Keshun Liu: Use 4 approaches to address this problem. .
1)evaluate and further process protein-rich by-products of current ethanol or beta-glucan production,.
2)develop modified and novel methods to fractionate grain proteins for trout feed ingredients,.
3)evaluate and process current improved cultivars of barley and oats, such as low-phyate cultivars for making fish feed ingredients, and.
4)select and breed new cultivars of barleys and oats with enhanced composition through collaborating with plant scientist at the ARS, Aberdeen ID (Project # 5366-21000-024-00D). Dr. Frederic Barrows: Solid substrate culture (SSC) has been proven to be an effective method for fungal production on a commercial scale. The effectiveness of this approach is due to the relatively low capital costs and low energy costs. This approach has not been used for the development of animal feeds before, but preliminary studies are quite promising. Utilizing different organisms and different blends of grains, a variety of products will be produced. Dr. Kenneth Overturf: Genetic selection programs for trout have been initiated at the NCCCWA and at the HFCES (through Aberdeen). The goal of the HFCES program is to select fish with an enhanced ability to utilize a plant based feed more efficiently. The goal of the NCCCWA is to select trout for superior growth performance. Improved strains will be reared and analyzed in Idaho.

FY99 Program Increase $225,000 Add 1 SY for research on cereal grains & fish FY03 Program Increase $223,537 Add 1 SY FY04 Program Increase $241,566 Add 1 SY FY04 Program Increase $584,232 Add 1 SY FY05 Program Increase $111,600 Replaces 5366-21310-002-00D (12/04). FY06 Program Increase $89,100


4.Accomplishments
Analysis of Protein Degradation in Rainbow Trout

The expression of genes and protein enzymatic activity of the three main degradation pathways in fish muscle was assessed and correlated with varying planes of nutrition. Understanding the genetic components of muscle accretion is important in determining the specific energy potential of alternative feed material in diets and selected rainbow trout. At the Hagerman Fish Culture Experiment Station in Hagerman, Idaho tissue samples were obtained from rainbow trout that were fully fed, starved for several weeks, or starved and then refed for several days and analyzed for the expression of degradation genes and for enzymatic activity. The development of markers for improved degradation profiles in fish has the potential to select for fish with significantly improved growth rates. These studies address the NP106 components of genetic improvement, Problem C. Genomic Resources and were conducted at the Hagerman Fish culture Experiment Station in collaboration with the University of Idaho.

Genetic mapping of low-phytate mutations in barley.

Phytate is the major storage form of phosphorus in grains but it is not digestible for monogastric animals including poultry, pigs, and fish which can result in a source of water polution. Phytate also binds other minerals such as iron and reduces the availability of minerals to animals. A better understanding the genetic mechanism of phytate biosynthesis will eventually improve the nutritional value of grains and reduce the impact of animal agriculture on the environment. To understand the phytate metabolic pathway, we mapped 17 additional low phytate mutations in barley. Our results indicate that at least 6 genetic loci are involved in the barley low phytate mutant collection. This research not only provides insight into the genetic study of phytate in plants, but also makes barley a better model system. These studies address the NP106 components of Growth, Development and Nutrition, Problem C, Sustainable Source of Nutrients.

Dry fractionation methods to enrich cereal grain protein

Several methods of dry fractionation were compared to determine which method or combinations of methods were best for separating barley into high protein fractions with an acceptable production yield. We found that milling followed by sieving separated fractions with varying protein contents. Yet, the method of milling significantly affected the efficiency of protein enrichment and the protein content in individual sized fractions. The abrasive milling produced sieve sized fractions with much higher variation in protein content than the impact milling. Yet, when the two methods of milling followed by sieving were compared with a single process of pearling (debranning), the later was found to be the best approach to produce barley fractions with highest protein content. Since fractions with high protein concentration tended to be low in mass, there is a need to make a balance between protein enrichment levels and mass recovery of resulting fractions. Based on data of pearled bran fractions and sieve sized fractions, it was possible to produce a combined fraction having a 50% increase in protein content with over 50% of total seed mass. These studies address the NP106 components of Growth, Development and Nutrition, Problem C, Sustainable Source of Nutrients.

Inability of methionine to preclude taurine supplementation in plant protein diets for rainbow trout.

Taurine has previously been identified as a potential limiting nutrient in plant-based diets for rainbow trout, although rainbow trout have some capacity for taurine biosynthesis from sulfur amino acid precursors. Methionine is the precursor sulfur amino acid that can economically be supplemented to animal feeds potentially more cost effectively than taurine. The experiment tested the efficacy of supplementing methionine and taurine separately and in combination on production performance of rainbow trout. Using metabolite profiling technologies this experiment determined that supplementing taurine was more efficacious in supplying taurine that the bioconversion of methionine to taurine. The impact of this research will be to further verify the need for taurine supplementation in plant-based diets for rainbow trout and continue to refine plant-based aquafeeds and reduce dependence on fish meals. These studies address the NP106 components of Growth, Development and Nutrition, Problem D. Nutrient Use and Feed Evaluation, and were conducted at the Hagerman Fish culture Experiment Station in collaboration with the University of Idaho.

Evaluation of NRC vitamin requirements in extruded trout diets based upon either fish meal or plant meal.

The recommended vitamin levels in trout diets by the NRC do not account for the effect of cooking extrusion or the primary protein source, fish meal versus plant meals. A 16 week feeding study identified vitamin E deficiency in fish meal based diets, and pantothenic acid in plant meal based diets, to be the first deficiency symptoms observed. Vitamin premixes should be adjusted for extrusion and a recommended premix was developed. This open-formula vitamin premix is being adopted in the place of outdated formulation produced by other government agencies, and its use will reduce feed costs and more adequately supply essential vitamins to rapidly growing fish. These studies address the NP106 components of Growth, Development and Nutrition, Problem D. Nutrient Use and Feed Evaluation, and were conducted at the Hagerman Fish culture Experiment Station in collaboration with the University of Idaho.


5.Significant Activities that Support Special Target Populations
none


6.Technology Transfer

Number of active CRADAs and MTAs2
Number of invention disclosures submitted1
Number of non-peer reviewed presentations and proceedings16

Review Publications
Liu, K., Peterson, K.L., Raboy, V. 2007. Comparison of the Phosphorus and Mineral Concentrations in Bran and Abraded Kernel Fractions of a Normal Barley (Hordeum vulgare) Cultivar versus Four Low Phytic Acid (lpa) Isolines. Journal of Agricultural and Food Chemistry. 55:4453-4460.

Gaylord, T.G., Teague, A.M., Barrows, F.T. 2006. Taurine supplementation of all-plant protein diets for rainbow trout oncorhynchus mykiss.. Journal of the World Aquaculture Society. 37:509-517.

Gaylord, T.G., Barrows, F., Teague, A.M., Johansen, K.A., Overturf, K.E., Shepherd, B.S. 2007. Supplementation of taurine and methionine to all-plant protein diets for rainbow trout (Omcorhynchus mykiss). Aquaculture 269:514-525.

Gatlin Iii, D., Barrows, F., Bellis, D., Brown, P., Campen, J., Dabrowski, K., Gaylord, T.G., Hardy, R.W., Herman, E.M., Hu, G., Krogdahl, A., Nelson, R., Overturf, K.E., Rust, M., Sealey, W., Skonberg, D., Souza, E.J., Stone, D., Wilson, R.F. 2007. Expanding the Utilization of Sustainable Plant Products in Aquafeeds – A Review. Aquaculture Research. 38:551-579.

Barrows, F., Stone, D.A., Hardy, R.W. 2007. The effects of extrusion conditions on the nutritional value of soybean meal for rainbow trout (Oncorhynchus mykiss. Aquaculture, Elsevier Science. v 265:244-252

Liu, K., Fu-Hung, H. 2007. Protein-Protein Interactions in high moisture-extruded meat analogs and heat-induce soy Protein Gels. Journal of the American Oil Chemists' Society. 84(8):741-748

Liu, K. 2007. Laboratory Methods to Remove Surface Layers from Cereal Grains Using a Seed Scarifier and comparison with a barley pearler.. Cereal Chemistry.84(4):407-414

Liu, K. A modified Laboratory Method to Remove Outer Layers from Cereal Grains Using a Barley Pearlier. 2007 Cereal Chemistry. 84(4):407-414.

Last Modified: 7/25/2014
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