Effects of dietary carbohydrate level on growth and body composition of juvenile tilapia, Oreochromis niloticusxO. aureus

Abstract

A growth trial was conducted to feed juvenile tilapia (initial weight,9.1 AE 0.1g), Oreochromis niloticus  O. aureus, isonitrogenous diets for 8 weeks. Six diets were formulated containing 29% crude protein from casein and gelatin, 10% crude fat from soybean oil and re¢ned soybean lecithin and varying levels of corn starch ranging from 6% to 46% at increments of 8%, with corresponding energy to protein (E/P) ratios of 35.6, 37.9, 40.2, 42.5, 44.8 and 47.1kJ g À1 . Weight gain (WG), speci¢c growth rate, feed e⁄ciency ratio and protein e⁄ciency ratio were signi¢cantly higher in ¢sh fed diets with starch ! 22% (or E/P ratio ! 40.2 kJ g À1 ) than in ¢sh fed diets with 6% or 14% starch (or E/P ratio of 35.6 or 37.9 kJ g À1 ).No further improvement was measured when dietary starch content increased beyond 22%. Body protein retention showed the same general pattern as WG, and was highest in ¢sh fed the 22% starch diet. Body composition was signi¢cantly a¡ected by dietary starch level. Fish fed diets with starch ! 30% had signi¢cantly higher lipid content than ¢sh fed diets with 6% or 14% starch. Ash content was negatively correlated with starch inclusion level, but moisture and protein contents did not show discernible trends among treatments. Results indicate that hybrid tilapia can utilize 46% dietary starch without growth retardation, while 22% starch in feed for juvenile tilapia containing 29% protein and 10% lipid, or an E/P ratio of 37.9 kJ g À1 is optimal. à Di¡erent superscripts within each column indicate signi¢cant (Po0.05) di¡erences between ¢sh fed di¡erent diets.Aquaculture Research, 2005 Dietary carbohydrate level in juvenile tilapia Y Wang et al.

Effects of dietary carbohydrate level on growth, biochemical composition and glucose metabolism of juvenile sea cucumber Apostichopus japonicus (Selenka)

“…Our results showed that specific growth rate and feed conversion efficiency increased with the elevating dietary carbohydrate levels from 25.61% to 45.31%, and then decreased with further elevation in carbohydrate levels from 45.31% to 66.09%, suggesting that excess carbohydrate level led to a poor growth of organisms, as reported by other studies (Li et al, 2013;Tan et al, 2009;Wang et al, 2005) EAA, essential amino acid; 2 FAA, flavor amino acid; 3 DAA, drug amino acid; TAA, total amino acid. Seo et al (2011a) with dietary carbohydrate levels from approximately 40% to 70%.…”

Effects of different dietary wheat starch levels on growth, feed efficiency and digestibility in grass carp (Ctenopharyngodon idella)

“…This indicated that excess digestible dietary carbohydrate in diets D40 and D 47 to some extent was converted to lipid in various tissues. These increments in tissue lipid due to high starch levels were also reported in previous studies (Rainbow trout, Oncorhynchus mykiss: Tekinay and Davies 2001; Hybrid tilapia, Oreochromis niloticus 9 O. aureus: Wang et al 2005). Moreover, the inclusion of excess energy in diets is known to produce fatty fish, reduce feed consumption and inhibit proper utilization of other feedstuffs (Takeda et al 1975;Shiau and Lin 1993;Ovie et al 2005).…”

Growth and metabolic responses in Nile tilapia (Oreochromis niloticus) subjected to varied starch and protein levels of diets

“…Part of challenges to be solved by the research on fish nutrition is to find mechanisms to diminish protein levels in diets by replacing them with cheaper non-protein energy sources like carbohydrates and lipids (Gao et al 2011). Although finfish do not require carbohydrates in their diet, absence of carbohydrates in diet significantly reduces growth and daily weight gain due to muscle mass loss (Perag on et al 1999) and the incorporation of complex carbohydrates in fish feeding has also been identified to decrease ammonia excretion, improve fish growth and spare protein in many fish species (Shiau & Cheng 1999;Peres & Oliva-Teles 2002;Wang et al 2005;Wu et al 2007). The ability of fish to use dietary carbohydrates differs among species (NRC 2011); diets with high levels of carbohydrates in carnivorous fish diminish consumption of food and their growth (Hemre et al 2002), whereas omnivorous fish are more tolerant to carbohydrates using them more efficiently as energy source and even storing them as lipids (Shiau 1997).…”