Minimum water exchange spares the requirement for dietary methionine for juvenile Litopenaeus vannamei reared under intensive outdoor conditions

Abstract

We examined if minimum water exchange could spare dietary methionine (Met) required for maximum growth performance of juvenile Litopenaeus vannamei reared in an intensive outdoor system. Shrimp of 1.98 ± 0.13 g were stocked at 70 animals/m2 and reared for 72 days in 50 tanks of 1 m3 under flow‐through (14.4% a day) and static (1.4%–2.9% a day) green‐water conditions at 32.0 ± 3.7 g/L salinity. Five diets with a minimum inclusion of fishmeal supplemented with a dipeptide, dl‐methionyl‐dl‐methionine, were formulated to contain increasing levels of Met, 4.8, 6.2, 7.2, 8.1 or 9.4 g/kg (on a dry matter basis). Each of the five diets were fed four times daily to five replicate groups. Dietary Met and water exchange significantly influenced shrimp survival, gained yield, apparent feed intake, food conversion ratio and final body weight (p < .05). Raising shrimp under limited water exchange, i.e., static versus flow‐through spared the dependence on higher levels of dietary Met to maximize shrimp body weight, from 9.4 g/kg to 8.0 g/kg (14.0 and 12.6 g/kg Met+Cys respectively). In an intensive rearing system, a reduction in water exchange is desirable as it leads to a lower need for supplemental dietary Met.

Crude protein in low‐fish meal diets for juvenile Litopenaeus vannamei can be reduced through a well‐balanced supplementation of essential amino acids

“…This was not reflected in feed intake data in our study. While dl ‐Methionyl‐ dl ‐Methionine is known to have less leaching in water and a high bioefficacy in whiteleg shrimp diets (Façanha et al, , ; Niu et al, ; J.‐J. Xie et al, ), other sources of feed‐grade CAAs are likely prone to leaching in water.…”

“…Determination of AA concentration in dietary ingredients and diets was carried out following procedures described in Figueiredo Minimum amounts of EAA targeted in the experimental diets, other than that of Met, were: 1.92% Lys, 1.31% Thr, 0.37% Trp, 2.07% Arg, 0.75% His, 1.07% Iso, 1.84% Leu, 1.21% Val, and 1.47% Phe. Recommendations for AAs other than Met were based on industry knowledge, data published in recent years (Huai et al, 2009;Jin, Liu, Liu, & Zhang, 2017;Li et al, 2015;Liu et al, 2014;NRC, 2011;Zhou et al, 2012;Zhou, Wang, Wang, & Tan, 2013) and also on our past experience (Façanha et al, 2016(Façanha et al, , 2018. To balance other dietary EAAs while reducing CP content, diets were also supplemented with L-Lysine, L-Arginine, L-Threonine, L-Tryptophan, L-Phenylalanine, and L-Histidine.…”

“…Four tanks were assigned for the CTL. The rearing system and water preparation were the same as that adopted by Nunes et al (2011) and Façanha et al (2016Façanha et al ( , 2018.…”

“…Our recent studies showed that Met required in practical diets for the maximum growth of juvenile whiteleg shrimp varied from 0.80 to 0.94% (1.26-1.40% methionine (Met) + cysteine) depending on the culture system (outdoor static versus flow-through system, 70 shrimp/m 2 ;Façanha, Sabry-Neto, Figueiredo-Silva, Oliveira-Neto, & Nunes, 2018) and from 0.72 to 0.81% (1.19-1.28% Met + Cys) depending on stocking density (50-75 shrimp/m 2 ; Façanha, Oliveira-Neto, Figueiredo-Silva, & Nunes, 2016). However, given that Met is the first limiting AA in shrimp feed, it is important to further strengthen our knowledge on this subject.…”

Feed preference and growth response of juvenile Litopenaeus vannamei to supplementation of marine chemoattractants in a fishmeal‐challenged diet

“…Shrimp of 0.99 ± 0.08 g ( n = 5,712) were stocked under 100 animals/m 2 and fed 10 times during daylight using an automatic feeding dispenser (Nunes, Sabry‐Neto, Silva, Oliveira‐Neto, & Masagounder, ). Shrimp were fed following a feeding table, according to the equation MM = 0.0931BW 0.6200 (Façanha, Sabry‐Neto, Figueiredo‐Silva, Oliveira‐Neto, & Nunes, ; Nunes et al, ; Nunes & Parsons, ), where MM is the maximum amount of feed (g) that can be eaten daily by one individual of a specific BW. To avoid excess feeding, feeding rates were reduced by 20% across all diets.…”