Growth and hematology of pacu subjected to sustained swimming and fed different protein levels

Abstract

-The objective of this work was to evaluate the effect of sustained swimming and dietary protein levels on growth and hematological responses of juvenile pacu (Piaractus mesopotamicus). A completely randomized design was used in a 3x2 factorial arrangement, with three levels of dietary protein (24, 28, and 32% crude protein), two rearing conditions (sustained swimming or motionless water), and 15 replicates. Fish were subjected to sustained swimming at the velocity of two body lengths per second (2 BL s -1 ), for 45 days. The level of dietary protein and the swimming conditions affected the performance, growth, and hematological profile of pacu. Swimming conditions influenced nutritional factors, increasing daily weight gain, specific growth rate, number of erythrocytes, mean corpuscular volume, and mean corpuscular hemoglobin. Fish under sustained swimming and fed with 24% crude protein showed better growth performance, with higher specific growth rate (4.11±0.88) and higher daily weight gain (2.19±0.47 g per day). Sustained swimming can increase the productive performance of pacu and simultaneously reduce dietary protein levels.Index terms: Piaractus mesopotamicus, erythropoiesis, exercise, growth rate, weight gain. Crescimento e hematologia de pacu submetido a natação sustentada e alimentado com diferentes níveis proteicosResumo -O objetivo deste trabalho foi avaliar o efeito da natação sustentada e de níveis de proteína na dieta sobre o crescimento e a resposta hematológica de juvenis de pacu (Piaractus mesopotamicus). Utilizou-se o delineamento inteiramente casualizado, em arranjo fatorial 3x2, com três níveis de proteína na dieta (24, 28 e 32% de proteína bruta), duas condições de criação (natação sustentada ou água imóvel) e 15 repetições. Os peixes foram submetidos à natação sustentada na velocidade de duas vezes o comprimento corporal por segundo (2 CC s -1 ), por 45 dias. O nível de proteína da dieta e as condições de nado afetaram o desempenho, o crescimento e o perfil hematológico do pacu. As condições de nado influenciaram os fatores nutricionais, com aumento de ganho de peso diário, taxa de crescimento específico, número de eritrócitos, volume corpuscular médio e hemoglobina corpuscular média. Peixes sob natação sustentada e alimentados com 24% de proteína bruta apresentaram melhor desempenho de crescimento, com maior taxa de crescimento específico (4,11±0,88) e maior ganho em peso diário (2,19±0,47 g por dia). A natação sustentada pode aumentar o desempenho produtivo de pacus e ao mesmo tempo reduzir os níveis de proteína na dieta.Termos para indexação: Piaractus mesopotamicus, eritropoiese, exercício, taxa de crescimento, ganho em peso.

Influence of a Blend of Dietary Essential Amino Acids on Growth, Enzymatic Activity, and Intestinal Histology of Blue Discus

“…The increase in transaminase activity indicated liver damage. Changes in the content of these enzymes are indications of liver damage caused by an inadequate nutritional balance in the diet, such as excess protein (Nunes et al, 2013), and the effect of anti-nutritional factors or source of the nutrient (Ota et al, 2019). The increase in AST and ALT activities are considered to be a response of the organism to stressors and nutritional metabolism (Meng et al, 2018), which deserves attention because, for this species, longevity is required.…”

“…Proteases are enzymes responsible for the digestion of proteins, from which the AAs are converted to the body mass of the fish. Proteins are the main organic constituents of fish, accounting for from 65 to 75% of the total body dry matter and are associated with fish growth and/or yield (Nunes et al, 2013). The stimulation to produce enzymes by the presence of some specific food is associated with both the production and modulation of genetic expression in the hepatopancreas (Honorato et al, 2010).…”

Physiological Mechanism and Application of Fish Exercise Training in Aquaculture

“…Salmo trutta showed the highest rate of weight gain at a water flow rate of 1 BL/s [22]. In addition, some aerobic training also has a positive effect on the growth of non-salmon trout species such as Sparus aurata, Piaractus mesopotamicus and Oreochromis niloticus [23][24][25]. However, there are studies shown that aerobic exercise training has no significant or even negative effects on the growth of fish, such as Oncorhynchus tshawytscha, Procypris rabaudi, Chondwstoma nasus, Paralichthys olivaceus, Xiphophorus montezumae [26][27][28][29][30].…”

South American fish species suitable for aquaponics: a review

“…Pacu is valued as a table fish due to its high quality and tasty white meat and as game fish in view of its behaviour in continental sport fishing (David et al 2019a;Furuya et al 2008). Its production has been promoted by its being a rustic, omnivorous species with easy acceptance of formulated feed and intensive systems (David et al 2019a;Nunes et al 2013;Portella et al 2012). This allows production of fish of approximately 1.3 kg in the first 12 months (Urbinati and Gonçalves 2005).…”