Economic analysis of overwinter feeding regimens for channel catfish (Ictalurus punctatus)

Abstract

Overwintering is a major source of uncertainty for US catfish farmers, particularly decisions on feeding. To address this issue, economic analysis was undertaken using results from pond experiments. Three overwintering strategies (full-feed, partial-feed, and no-feed) for two year classes of catfish were compared. Year 1 fingerlings were 22 g and year 2 fish were 420 g at stocking. Winter feeding was based on temperature and body weight percentages; (1) full-feeding followed the regime during the November to April period; (2) partial-fed treatments followed the temperature/body weight regimen only during the months of November, March and April, with no feeding during the coldest months of December to February; and (3) no-feeding treatments received no feed during the overwinter period. Cost and returns were estimated for each alternative and each alternative was assessed using: (1) overwinter period experimental results, (2) overwinter period experimental results extended through the grow-out period, (3) overwinter period experimental results extended to minimally acceptable fish sizes, and (4) adjusted estimates to reflect commercial-scale practices. Sensitivity analyses on feed conversion ratios, stocking rates and fish selling prices were also conducted on commercial-scale enterprises. Results consistently showed partial-fed overwinter practices to be most profitable. Secondly, year 1 fish always had higher returns than year 2 fish due largely to the additional overwintering period and associated variable and fixed costs incurred by the year 2 fish production practices. The data upon which this analysis was based

Assessment of compensatory growth in stunted fingerlings of Snubnose pompano, Trachinotus blochii (Lacepede, 1801), in marine conditions

“…Compensatory growth (CG) in fish is a phase of augmented growth when favourable conditions are restored after a period of TA B L E 2 Growth characteristics of stunted and normal fish during experiment 1 (30 days stunting) growth depression that may be categorized as over compensation, full compensation, partial compensation and no compensation based on the rate of recovery of the growth rate (Ali et al, 2003). The degree of compensation of growth in ration-restricted fish mainly depends on factors such as species studied (Bavcevic et al, 2010;Bhujel, Little, & Hossain, 2007;Cho & Cho, 2009;Hatch, Hansen, Kim, & Lovell, 1998;Santiago et al, 2004;Tian & Qin, 2003), duration of stunting (Das, Mishra, Mishra, & Jayasankar, 2016) and method of stunting (Ali et al, 2003). The present work was envisaged to determine the level of compensatory growth in T. blochii, an important species for mariculture, under different stunting durations, so as to get baseline data for developing strategies for its field level application.…”

Modelo explicativo de la rentabilidad de las empresas de piscicultura marina. Aplicación empírica a la cría de dorada (Sparus aurata) y lubina (Dicentrarchus labrax) en España

“…La revisión de la literatura científica sobre piscicultura ha permitido identificar un importante número de trabajos que utilizan la rentabilidad de la actividad como indicador del efecto económico del factor analizado, entre los que cabe destacar los que la utilizan para analizar: el rendimiento económico de diferentes tipos de alimentación (Urban Jr. y Pruder, 1991;Moñino et al, 2002;Sánchez Lozano et al, 2007;Petersen et al, 2011), la viabilidad económica de la explotación comercial de una especie o producto (Oca et al, 2002;Jeffs y Hooker, 2000;Keys et al, 2004;PootLópez y Gasca-Leyva, 2009;Shamshak y Anderson, 2009;García y García, 2010;Zúñiga, 2010), y el impacto que tienen las condiciones ambientales (Hatch et al, 1998;León et al, 2006;Hernández et al, 2007), el sistema de producción (Losordo y Westerman, 1994;Thongrak et al, 1997;Goode et al, 2002;Lever et al, 2004;Taylor et al, 2006;Liu;Sumaila, 2007y Buck et al, 2010 o la localización de la explotación (Moksness et al, 1998;Gasca-Leyva et al, 2002;Irz y McKenzie, 2003;Bozoglu y Ceyhan, 2009;Miao et al, 2009;Petersen y Phuong, 2010;Huang et al, 2011) sobre el resultado económico del proceso de cultivo.…”

Observations on impact of stunting on breeding performance of farmed rohu Labeo rohita (Hamilton, 1822)

“…Application of stunting followed by growth compensation has been exploited for enhancing production in several species of farmed fish. Compensatory growth pattern has been evaluated in several commercially important cultured fishes such as olive flounder (Cho and Cho, 2009), Nile tilapia (Bhujel et al, 2007), big head carp (Santiago et al, 2004), channel catfish (Hatch et al, 1998) and sun fish (Hayward et al, 1997) all over the globe.…”