Effect of Crowding Stress on Some Physiological Functions of Nile Tilapia, Oreochromis niloticus (L.) Fed Different Dietary Protein Levels

Lima

et al. 2013

Pesq. agropec. bras.

-The objective of this work was to evaluate the effect of feed deprivation and refeeding with diets containing different energy to protein ratios (E/P) on the performance and physiology of juvenile tambaqui (Colossoma macropomum). A 4x2 factorial arrangement with three replicates was used, with four E/P ratios (11.5, 10.5, 9.5, and 8.5 kcal g -1 digestible energy per protein) and two feeding regimens (with and without deprivation), during 60 days. Fish from the food-deprived group were fasted for 14 days and refed from the fifteenth to the sixtieth day, whereas the remaining fish were fed for 60 days. At the end of the experimental period, weight of fish subjected to food deprivation was lower than that of those continuously fed; however, this condition did not influence the physiological parameters analyzed. Tambaqui fed 11.5 kcal g -1 achieved lower final weight than those fed with the other diets, in both regimens. Among the physiological parameters, only plasma protein presented significant increase in fish fed 8.5 kcal g -1 , in both feeding regimens, probably due to the higher dietary protein concentration. These results indicate that fish show a partial compensatory growth, and that 10.5 kcal g -1 can be recommended for the diet of juvenile tambaqui.Index terms: Colossoma macropomum, blood parameters, energy/protein requirement, food restriction. Estratégias alimentares e relação entre energia e proteína sobre o desempenho e a fisiologia de tambaquiResumo -O objetivo deste trabalho foi avaliar o efeito da privação alimentar e da realimentação com dietas contendo diferentes relações entre energia e proteína (E/P) sobre o desempenho e a fisiologia de juvenis de tambaqui (Colossoma macropomum). Utilizou-se arranjo fatorial 4x2 com três repetições, com quatro relações E/P (11,5, 10,5, 9,5 e 8,5 kcal g -1 de energia digestível por proteína) e dois regimes alimentares (com e sem privação), durante 60 dias. Peixes do grupo com privação alimentar permaneceram em jejum por 14 dias e foram realimentados do décimo quinto ao sexagésimo dia, enquanto os demais foram alimentados por 60 dias. Ao final do período experimental, o peso dos peixes submetidos à privação alimentar foi menor do que o dos alimentados continuamente; entretanto, esta condição não influenciou os parâmetros fisiológicos avaliados. Tambaquis alimentados com 11,5 kcal g -1 obtiveram menor peso que os alimentados com as demais dietas, em ambos os regimes. Entre os parâmetros fisiológicos, apenas a proteína plasmática apresentou aumento significativo nos peixes alimentados com 8,5 kcal g -1 , em ambos os regimes alimentares, provavelmente em razão da maior concentração de proteína na dieta. Esses resultados mostram que os peixes apresentam crescimento compensatório parcial em todos os tratamentos, e que 10,5 kcal g -1 pode ser recomendada para a dieta de juvenis de tambaqui.Termos para indexação: Colossoma macropomum, parâmetros sanguíneos, exigência energia/proteína, restrição alimentar.

Section: Resultssupporting

confidence: 80%

Feeding strategies and energy to protein ratio on tambaqui performance and physiology

Lima

et al. 2013

Pesq. agropec. bras.

“…The Majalaya carp belongs to the Cyprinidae family and is an important fish to be cultured in Indonesia 10 . Though several research studies regarding stocking density in some fish have been conducted 2, 3, 11– 13 , the influence of different stocking densities on the growth, feed efficiency, and survival of the Majalaya common carp in hapa fish ponds has never been determined. Thus, the purpose of the research was to evaluate the growth statues, feed efficiency, and survival rate of the Majalaya common carp, reared at different socking density, viz: 50, 75, 100, and 125 fish m −3 in the hapa fish pond.…”

Section: Introductionmentioning

confidence: 99%

Influence of different stocking density on the growth, feed efficiency, and survival of Majalaya common carp (Cyprinus carpio Linnaeus 1758)

2018

Background: Stocking density is key to successful Majalaya common carp ( Cyprinus carpio Linnaeus 1758) culture which is a valuable fish culture in Indonesia. The aim of the present study was to evaluate the growth statues, feed utilization, and survival rate of Majalaya common carp (reared with different stocking density. Methods: In total, 1400 fish were randomly distributed into four replicates of four different groups of stocking density: 50, 75, 100, and 125 fish m −3. All fish were fed using a satiation method, three times per day with commercial diet for 12 weeks. At the end of the trial week, growth, feed utilization, and survival were determined. Water quality measures, such as dissolved oxygen (mg L -1), temperature (°C), pH, NH 3 (mg L -1), and NO 2 (mg L -1) were also measured once a week during the trial. Results: Similar weight gain and SGR were found in Majalaya common carp reared at stocking densities of 50 to 100 fish m 3. However, 125 fish m -3 density may reduce weight gain and SGR. The average weekly and daily weight gain of Majalaya common carp significantly increased when reared from 50 to 100 fish m -3 and remained constant at 125 fish m -3 density. Meanwhile, feed conversion ratio and survival of Majalaya common carp were not affected by any stocking density. Conclusions: A stocking density of 100 fish m -3 exhibited significantly higher growth of Majalaya common carp in hapa net ponds among the treatment. Temperature ranges of 29.20-33.38°C, pH 7.47-8.22, DO 4.76-7.55 (mg L -1), NH 3 0-0.5 mg L -1, and NO 2 0-1 mg L -1 were found to provide optimum condition to the fish.

“…Moreover, where land, water, manpower and other facilities are limiting it may be more profitable to adopt higher stocking densities [28]. On the contrary, reducing stocking densities ensures better fish growth [13]- [16] but may not always be favorable for commercial culture [11]. Proper management of stocking densities can therefore improve the growth, profitability, sustainability, health as well as reduce competition among fingerlings for food, space and other essentials of survival [29].…”

Section: Introductionmentioning

confidence: 99%

Lake-Based Nursery Rearing of Nile Tilapia (<i>Oreochromis niloticus</i>) Fingerlings in Nylon Hapas: Effects of Stocking Density on Growth, Survival and Profitability

Asase¹,

Nunoo²,

Attipoe³

2016

The inadequate supply of tilapia fingerling is a major limitation to cage culture development in Ghana. Lake-based hapa systems are very efficient in nursing fingerlings although the process can be tricky due to inherent effects of stocking densities and environmental factors. This study aimed at assessing the growth, survival and profitability of Nile tilapia (Oreochromis niloticus) fingerlings of the Akosombo strain reared in nine 1 m 3 Lake-based hapas at different densities. Each hapa was stocked with 2.12 ± 0.14 g sex-reversed tilapia fingerlings at varying stocking densities of 400 fish/m 3 , 800 fish/m 3 and 1200 fish/m 3 serving as treatments T1, T2 and T3 respectively. Each treatment was replicated thrice. Bi-weekly samplings were done and water quality parameters were measured. After the experiment, analysis of variance showed significant differences (p < 0.05) in the weight gained, specific growth rate, profit index and feed conversion ratio among treatments. The T1 fingerlings exhibited the highest specific growth rate (3.28 ± 0.10%/day) and FCR (1.42 ± 0.09) than others. Overall, profit index was affected by stocking density and varied significantly between treatments. Treatment T3 was found to be better for commercial fingerling production because survival rate (91.14 ± 3.23%) and profit index (3.96 ± 0.24) were the highest while treatment T1 recorded the least index of 1.31 ± 0.10. Survival rates ranged between 89% and 91% but no statistical differences were observed among treatments. It is concluded that the stocking densities used had significant effects on the specific growth rate, gain in weight and feed conversion ratio of fingerlings reared in Lake-based hapas. However, in fingerling production, not only profit but also rapid growth needs consideration, hence, T2 is highly recommended 661for nursery rearing of tilapia fingerlings in this system due to the relatively high profit index, growth rate and survival.