|Overturf, Kenneth - Ken|
Submitted to: Book of Abstracts Aquaculture America
Publication Type: Abstract Only
Publication Acceptance Date: 1/7/2007
Publication Date: 2/26/2007
Citation: Sealey, W., Barrows, F., Smith, C., Herman, E.M., Overturf, K.E., Lapatra, S. 2007. Can Supplementing starter diets with probiotics increase soybean meal incorporation levels in practical grow-out diets for Rainbow Trout. Book of Abstracts Aquaculture America.p. 831 Interpretive Summary: Increased utilization of plant protein meals has been embraced as a sustainable alternative to fish meal, with soybean meal commonly used. However, inclusion rates of soybean meal in salmonid diets are currently kept low to minimize detrimental effects on growth, enteritis and immune response. Probiotics have been used to treat both infectious and noninfectious enteritis in humans and other terrestrial animals and similarly may represent a feasible method for increasing soy utilization in soy sensitive aquatic species. After feeding rainbow trout soybean diets with and without probiotics it was noticed that there was a significant depression in growth in fish fed soy diets with probiotics. Although probiotics appeared to improve soybeanmeal utilization by first feeding rainbow trout, they provided only limited benefits once feeding was discontinued.
Technical Abstract: This study was conducted to evaluate the ability of partially autolyzed yeast and Grobiotic™-A to improve immune response and disease resistance in rainbow trout. Three experimental diets were prepared by supplementing either partially autolyzed yeast or Grobiotic™-A at the manufacturer’s recommended level (2%) to a practical type control diet. Rainbow trout were cultured in 145-L fiberglass tanks in a fresh water flow through system and fed the test diets fed by hand to apparent satiation for nine weeks. At three and nine weeks post weighing, fish were sampled for determination of respiratory burst activity, plasma protein, total immunoglobulin and lysozyme and TNF-a expression. At the conclusion of the feeding trial, fish remaining after sampling were pooled by diet; one subsample was examined for their ability to respond humorally to infectious hematopoietic necrosis virus (IHNV) and another subsample was challenged by intraperitoneal injection with IHNV. Dietary inclusion of 2% partially autolyzed yeast or Grobiotic™-A had no negative impacts on health or growth of rainbow trout. In contrast, although substantial variability was observed for immune response parameters, striking beneficial effects of inclusion of 2% partially autolyzed yeast or Grobiotic™-A were noted on survival of rainbow trout following experimental challenge with IHNV.