Energy and protein demands for optimal egg production including maintenance requirements of female tilapiaOreochromis niloticus

Abstract

The daily requirements of a spawning tilapia female are quantified from the sum of the requirements for maintenance plus production of eggs. The protein and energy requirements for maintenance and the cost of depositing energy and protein towards growth or gonadal products were determined by supplying feed at increasing levels from zero to the maximum intake. Comparative body composition analyses of the females in addition to the amount and the content of eggs enabled us to quantify the total energy and protein channelled into weight gain or alternatively into egg production. The amount of eggs produced increased with increasing feeding levels and ranged between 0.7 and 1.1 g eggs per kg−1 fish day−1. Regardless of feed allowance, the composition of eggs was similar and contained 235 mg protein and 10.5 kJ g−1 wet weight. In contrast, the whole body of tilapia contained 167 mg protein and 6.7 kJ g−1 on average. The energy requirement for maintenance was calculated to be 59.46 kJ × BW (kg)0.80 and 0.98 g × BW (kg)0.70 for digestible protein. The partial efficiency of producing gonads was 0.67 and 0.59 for digestible energy and digestible protein respectively.

Effects of dietary methylmercury on the dopaminergic system of adult fathead minnows and their offspring

“…Mean muscle Hg concentrations were significantly higher in females (ANOVA df ¼ 1, F ¼ 55.23, p < 0.001) fed the Hg-spiked diet (0.804 AE 0.084 ppm Hg, n ¼ 8) than treated males (0.506 AE 0.039 ppm Hg, n ¼ 5). This may be a result of increased food consumption by females to meet the energetic demands of egg production because MeHg is generally found associated with proteins in the muscle of fish [47,48]. Mean wet weight muscle concentrations of control fish were not different between genders (0.084 AE 0.017 ppm Hg, n ¼ 13).…”

Growth of Nile tilapia post-larvae from broodstock fed diet with different levels of digestible protein and digestible energy

“…This lack of information about the specific broodstock nutritional requirements in fish (Bhujel et al, 2001;Lupatsch et al, 2010) has driven the recent development in research studies on both tilapia (El-Gamal et al, 2007;Sink & Lochman, 2008;Sink et al, 2010;Ng & Wang, 2011) and other commercial freshwater (Parra et al, 2008;Navarro et al, 2010) and marine (FernandezPalacios et al, 1995;Mazzorra et al, 2003) fish cultures.…”

Physiological and reproductive response to varying quantitative lipid inclusion in diets for Gulf killifishFundulus grandisBaird and Girard

“…; Zakeri et al . ; Lupatsch, Deshev & Magen ). Protein is vital as the other major component of egg yolk along with lipid and has important reproductive roles in hormones and enzymes (Brooks, Tyler & Sumpter ).…”

“…Diets were isonitrogenous and contained onlỹ 33% protein (Table 1), a relatively low level for broodfish. Many reproductive experiments in other species have used protein levels ranging from 40 to 60% (Schulz et al 2008;Zakeri et al 2009;Lupatsch, Deshev & Magen 2010). Protein is vital as the other major component of egg yolk along with lipid and has important reproductive roles in hormones and enzymes (Brooks, Tyler & Sumpter 1997).…”