|In recent years there has been increasing interest in the replacement of animal proteins with plant proteins in commercial feeds for the Pacific white shrimp, Litopenaeus vannamei. Primary reasons for this interest are to reduce cost by using a high quality but lower cost ingredient and to move towards ingredients that are from renewable resources for which production can be expanded. As with oil prices, the cost for many of our protein sources such as fish meal, poultry by-product meal, and other animal protein meals have increased over the years driving up feed costs. The idea of replacing animal protein meals with plant proteins in diets reduces the dependence on
the animal protein industry and provides alternative choices when formulating feeds.
Consequently, two growth trials were conducted to evaluate the potential of replacing poultry by-product meal with soybean meal in production diets for L. vannamei. For those trials, four iso-nitrogenous diets were formulated to evaluate the replacement of poultry by-product meal with a combination of soybean meal and corn gluten meal. Juvenile shrimp were stocked at 34 shrimp/m2 and were cultured in 0.1 hectare ponds under standardized production conditions. Feed inputs were pre-scheduled using feeding protocols that have a maximum feed input of 7.10 kg/ha/d. Additionally, these four diets, a fifth diet consisting of high plant protein content with substitution of fish oil with soybean oil, and a commercial reference diet were evaluated in a semi-enclosed recirculating system stocked with 30 juvenile L. vannamei per tank. Culture water was pumped from a production pond for six hours per day and was recirculated at a rate of 3 L/min within the tanks to mimic production pond conditions. Each diet had four replicates. Feed rates were predetermined by using a feed conversion ratio (FCR) of 1:1.2 and an average weekly growth of 1.5 g/wk.
At the conclusion of these studies, shrimp were harvested, final weights, population distribution, net yield, and feed utilization was determined. Final yields in the pond study averaged between 6,093-6,943 kg/ha. Average final weights varied between 22-24 g, survival was 80% and the FCR was 1.0. The 79-d tank culture produced average final weights between 19.4-20.5 g, survival varied between 94.2-96.7%, and the FCR was 1.1. There were no significant differences found between any of the poultry by-product meal replacement diets in either the pond or tank study.