Optimizing diets to decrease environmental impact of Nile tilapia (Oreochromis niloticus) production

Abstract

Aquaculture is one of the most thriving animal production sectors, and Nile tilapia (Oreochromis niloticus) farming represents 8% of total finfish culture. However, the industry sustainability depends on the development of cost‐effective and environmental friendly feeds. This study aimed to reduce dietary protein levels in diets for juvenile tilapia and to minimize diet environmental impact while maximizing biological efficiency. A growth trial was performed using five isoenergetic plant protein‐based diets with decreasing levels of crude protein: 360, 340, 320, 300 and 280 g/kg diet (D360, D340, D320, D300 and D280, respectively). Dietary protein utilization was assessed by metabolic trials using a radiolabelled amino acid mixture. Tilapia in all treatments showed similar growth performance and feed intake. Feed conversion ratio was significantly higher in fish fed the D280 than the D360 diet, while no differences were found for other treatments. Protein retention was significantly higher in tilapia fed the D300 than the D360 diet. Amino acid catabolism increased in fish fed the D360 diet, though without significant differences in muscle amino acid retention. This study demonstrates that dietary protein levels can be reduced to 300 g/kg diet without hindering tilapia growth and feed conversion ratio, while reducing environmental nitrogen losses.

Nitrogen retention, nutrient digestibility and growth efficiency of Nile tilapia ( Oreochromis niloticus ) fed dietary lysine and reared in fertilized ponds

“…In the present study, the LowL diet resulted in less (p < .05) growth than the BalL diet. This finding agrees with previous studies, which reported that the growth performance, feed intake and feed conversion ratio of Nile tilapia were optimal at a dietary lysine level of 28-36 g kg −1 CP (Teodósio et al, 2020); digestible protein (Furuya et al, 2012) and protein retention were significantly higher in tilapia fed 30 g kg −1 CP (Teodósio et al, 2020). It was also previously observed that daily weight gain was better in Nile tilapia (27.5 g kg −1 ) fed a diet containing 55.5 g lysine kg −1 CP, than in Nile tilapia fed a diet containing 43.9 g lysine kg −1 CP (Michelato et al, 2016).…”

Growth performance, robustness against stress, serum insulin, IGF‐1 and GLUT4 gene expression of red tilapia (Oreochromis sp.) fed diet containing graded levels of creatine

“…This condition was proved by a decline in blood protein value of 11.77%, which caused an increase in protein retention value of 33.03% compared to negative control (Table 4). Additionally, improved protein utilization will reduce oxidative deamination processes (Michelato et al., 2016; Subramanian, 2013; Teodósio et al., 2019), thus improving fish growth (Suprayudi et al., 2011; Suprayudi, 2018) and decreasing the nitrogen excretion out of the body (Zupa et al, 2015). Furthermore, it could also lead to less threat of fish physiological stress due to waste accumulation in the water.…”

Combination of lysine and histidine improves growth performance, expression of muscle growth‐related genes and fillet quality of grow‐out Nile tilapia

“…The present results confirmed compelling evidence for the importance of lysine and histidine supplementation in combination to optimize growth performance in grow-out Nile tilapia. Pereira et al, 2017;Teodósio et al, 2019;Trosvik et al, 2012). Previous researches have attributed the synergic effects of multiple amino acids supplementation on protein retention efficiency and consequently growth of grass carp, Ctenopharyngodon idella (Gan et al, 2012); Nile tilapia, (Nguyen et al, 2020) and rainbow trout, Oncorhynchus mykiss (Cheng et al, 2003).…”