2
CHANNEL CATFISH
T
An overview of nutritional requirements
by Herbert E. Quintero, PhD, Aquaculture/Fisheries Centre, University of Arkansas at Pine Bluff, USA
he catfish industry is one of the largest and best developed aquaculture segments in the United States. Commercial production of channel catfish started developing in the late 1950s and early 1960s, and since then feed formulation for catfish started to be tested (Hastings and Dupree, 1969). The main objective of providing minimal quantities of nutrients has not changed since those earlier studies, but the need for increasing production and optimizing resources has changed. Initially, channel catfish were raised in ponds at low stocking densities and fed low-cost, incomplete diets. That trend changed by introducing nutritional balanced diets that were developed based on the determination of nutrient requirements of this species starting in the early 1970s (Lovell, 1977). US catfish production increased rapidly from the early 1980s until 2003 when it reached 662 million pounds of catfish processed representing more than half of total aquaculture production. However that trend shifted and started declining with 300 million pounds of catfish processed in 2012, which represents approximately 55 percent decrease since 2003 (USDA, 2004, Hanson & Sites, 2013). In recent years, the industry has been striving to develop technological solutions to improve production, including implementing hybridization programs, and intensifying production with the introduction of new technologies such as
the split-pond system and the in-pond raceway system, both of them variations of the partitioned aquaculture system (Brown & Tucker, 2013; Brown et al. 2014). These technological solutions also require optimizing feed formulations and feeds, as well improved feed management practices to make the catfish industry economical and environmentally sustainable. Li et al. (2012) indicated “because feed is a major cost in catfish production, representing more than 50 percent of total variable costs, optimizing feeding rate and frequency would improve feeding efficiency, reduce feed cost, and improve profit�. Feed formulation is of paramount importance because aquafeeds are required to provide appropriate nutrient requirements for each stage of fish development (biological, and physiological features), and have strong effects on stress tolerance and health. Feed formulation has to overcome economical challenges derived from the variability in the cost of feed ingredients, needs to adjust to stringent availability of certain ingredients (especially fishmeal and fish oil), and environmental regulations related to effluents disposal (Boyd et al. 2003, Tacon & Metian, 2008). A more recent issue that is also affecting fish feed formulation is related to the quality of the final product from the marketing and the consumer perspective (human health), especially in regards to muscle fatty acid composition. Components in the fish diet include dietary protein and essential amino acids, which are considered the largest and most costly component (Trushenski et al. 2006). Historically, fishmeal has been the main source of protein in compound aquafeeds with
42 | January | February 2016 - International Aquafeed