Effects of molasses yeast in diets of Nile tilapia

Este trabalho teve como objetivo avaliar o efeito da levedura desidratada de álcool (Saccharomyces cerevisae) como substituto do suplemento vitamínico, em dietas de tilápia-do-nilo (Oreochromis niloticus). Trezentos alevinos machos, sexualmente revertidos, com peso médio de 1,5 g, foram distribuídos igualmente em 20 aquários de fibra de vidro, equipados com filtro biológico. Cinco dietas isoprotéicas com 32% de proteína bruta na primeira fase (40 dias) e com 28% de proteína bruta na segunda fase (74 dias) foram fornecidas ad libitum, duas vezes ao dia. A dieta-controle não continha levedura, e as demais apresentavam 10% de levedura. O delineamento foi inteiramente casualizado, com cinco tratamentos e quatro repetições. Não houve influência significativa dos tratamentos sobre o ganho de peso e taxa de crescimento específico. Foi observada, nos peixes alimentados com dietas sem suplemento vitamínico, alta mortalidade. Os peixes que receberam levedura apresentaram menor conteúdo corporal de proteína, e maior, de lipídeos. A levedura desidratada de álcool pode ser usada como fonte de vitaminas hidrossolúveis em dietas para alevinos de tilápia-do-nilo.This study aimed to evaluate the effects of molasses yeast (Saccharomyces cerevisae) as replacement for vitamin premix in diets for Nile tilapia (Oreochromis niloticus). Three hundred sex-reversed, all-male fingerlings, averaging 1.5 g live weight, were stocked in 20 circular 270-L biofilter equipped fiberglass tanks (15 fish/tank). They were fed to satisfaction twice a day with a 32% crude protein diet for 40 days, followed by a 28% crude protein diet for 74 days. Test diets were prepared to contain at least 10% of yeast as replacement for the vitamin premix, and a diet without yeast was used as control. Five treatments were arranged in a completely randomized design with four replications. No significant differences were observed in regard to weight gain and specific growth rate. High mortality was observed on groups fed with diets without vitamin premix supplementation. Fish fed with yeast-containing diets presented reduced body protein and increased body lipids as compared to fish fed with the control diet. Molasses yeast is suited to replace water-dissolvable vitamins in diets of Nile tilapia fingerlings

Impacto ambiental e parâmetros zootécnicos da produção de tilápia do Nilo (Oreochromis niloticus) sob diferentes manejos alimentares

Male juveniles of Nile (Oreochromis niloticus) tilapia were stocked in 12 ponds of 300 m2, at a density of 1.7 fish/m2 to evaluate the effect of different food management on fish production and carcass characteristic. Four different treatments were studied as follows: natural foods and rations in pellets, extruded or minced. Completely randomized design with 4 treatments and 3 repetitions was used. The rations containing 30% crude protein and 3,000 kcal digestible energy were supplied twice daily, at a rate varying between 3 and 5% of total estimated biomassa. Chicken drops were used as natural food. Limnological variables monitored during the period were within acceptable levels required by the species. Total fish production was significantly different (P0,05) com maiores valores para os tratamentos com ração peletizada (5.996,83kg/ha) e extrusada (5.440,74kg/há). Os peixes arraçoados apresentaram maiores valores de gordura corporal (1,57 a 1,98%) e visceral (12,64 a 25,04%) quando comparados aos peixes não arraçoados, que apresentaram níveis de 0,17 e 0,00%, respectivamente. Os peixes que tiveram menor desempenho produtivo (tratamento alimento natural) apresentaram menores níveis de gordura corporal e, maior aceitação pelos provadores, enquanto os peixes com maior desempenho produtivo (tratamentos arraçoados) apresentaram maiores porcentagens de gordura visceral e alta rejeição pelos provadore

Efeito da utilização da levedura desidratada de álcool em dietas para tilápia-do-nilo

Este trabalho teve como objetivo avaliar o efeito da levedura desidratada de álcool (Saccharomyces cerevisae) como substituto do suplemento vitamínico, em dietas de tilápia-do-nilo (Oreochromis niloticus). Trezentos alevinos machos, sexualmente revertidos, com peso médio de 1,5 g, foram distribuídos igualmente em 20 aquários de fibra de vidro, equipados com filtro biológico. Cinco dietas isoprotéicas com 32% de proteína bruta na primeira fase (40 dias) e com 28% de proteína bruta na segunda fase (74 dias) foram fornecidas ad libitum, duas vezes ao dia. A dieta-controle não conti-nha levedura, e as demais apresentavam 10% de levedura. O delineamento foi inteiramente casualizado, com cinco tratamentos e quatro repetições. Não houve influência significativa dos tratamentos sobre o ganho de peso e taxa de crescimento específico. Foi observada, nos peixes alimentados com dietas sem suplemento vitamínico, alta mortalidade. Os peixes que receberam levedura apresentaram menor conteúdo corporal de proteína, e maior, de lipídeos. A levedura desidratada de álcool pode ser usada como fonte de vitaminas hidrossolúveis em dietas para alevinos de tilápia-do-nilo

Efeito da utilização da levedura desidratada de álcool em dietas para tilápia-do-nilo

Este trabalho teve como objetivo avaliar o efeito da levedura desidratada de álcool (Saccharomyces cerevisae) como substituto do suplemento vitamínico, em dietas de tilápia-do-nilo (Oreochromis niloticus). Trezentos alevinos machos, sexualmente revertidos, com peso médio de 1,5 g, foram distribuídos igualmente em 20 aquários de fibra de vidro, equipados com filtro biológico. Cinco dietas isoprotéicas com 32% de proteína bruta na primeira fase (40 dias) e com 28% de proteína bruta na segunda fase (74 dias) foram fornecidas ad libitum, duas vezes ao dia. A dieta-controle não conti-nha levedura, e as demais apresentavam 10% de levedura. O delineamento foi inteiramente casualizado, com cinco tratamentos e quatro repetições. Não houve influência significativa dos tratamentos sobre o ganho de peso e taxa de crescimento específico. Foi observada, nos peixes alimentados com dietas sem suplemento vitamínico, alta mortalidade. Os peixes que receberam levedura apresentaram menor conteúdo corporal de proteína, e maior, de lipídeos. A levedura desidratada de álcool pode ser usada como fonte de vitaminas hidrossolúveis em dietas para alevinos de tilápia-do-nilo.This study aimed to evaluate the effects of molasses yeast (Saccharomyces cerevisae) as replacement for vitamin premix in diets for Nile tilapia (Oreochromis niloticus). Three hundred sex-reversed, all-male fingerlings, averaging 1.5 g live weight, were stocked in 20 circular 270-L biofilter equipped fiberglass tanks (15 fish/tank). They were fed to satisfaction twice a day with a 32% crude protein diet for 40 days, followed by a 28% crude protein diet for 74 days. Test diets were prepared to contain at least 10% of yeast as replacement for the vitamin premix, and a diet without yeast was used as control. Five treatments were arranged in a completely randomized design with four replications. No significant differences were observed in regard to weight gain and specific growth rate. High mortality was observed on groups fed with diets without vitamin premix supplementation. Fish fed with yeast-containing diets presented reduced body protein and increased body lipids as compared to fish fed with the control diet. Molasses yeast is suited to replace water-dissolvable vitamins in diets of Nile tilapia fingerlings

Produtive performance of Nile tilapia in cages in a rural dam, Vale do Ribeira, SP, Brazil

This study aimed to evaluate the adequate fish stocking density for intensive rearing in fresh water cage system at Vale do Ribeira region. Present study was conducted in Pariquera-Açu municipalities, in the Pisciculture sector of Polo Regional do Vale do Ribeira of APTA (SAA, SP) from november of 2012 to april of 2013. Eighteen cages of 4 m3, arranged in three lines, with 50 m, in a rural reservoir of 2.7 hectares were installed. A production cycle was done using 10,800 Nile tilapia juveniles, Oreochromis niloticus, with initial average weight of 25 ± 3.0 g divided in three stocking densities of 100, 150 and 200 fish/m3, with six replication of each stocking density. Fish performance in each cage was evaluated, in each 30th days, by the achievement of daily weight gain, final weight gain, apparent food conversion, survival and final average biomass (4 m3). For water quality determination of the rural reservoir, it was marked five points of sampling: water supply, rearing area divided in three points at 10 cm depth and effluent. Related to final length, final weight, final weight gain and survival there was significant difference (P<0.05) between the smallest and the highest stocking density. However, in relation to feed conversion the highest density (200 fish/m3) had the better result. Water quality parameters were adequate to tropical fish rearing patterns and to CONAMA 357/05 resolution. Performance data of this research show the viability of cage system with density 150 fish/m3 in Vale do Ribeira region.This study aimed to evaluate the adequate fish stocking density for intensive rearing in fresh water cage system at Vale do Ribeira region. Present study was conducted in Pariquera-Açu municipalities, in the Pisciculture sector of Polo Regional do Vale do Ribeira of APTA (SAA, SP) from november of 2012 to april of 2013. Eighteen cages of 4 m3, arranged in three lines, with 50 m, in a rural reservoir of 2.7 hectares were installed. A production cycle was done using 10,800 Nile tilapia juveniles, Oreochromis niloticus, with initial average weight of 25 ± 3.0 g divided in three stocking densities of 100, 150 and 200 fish/m3, with six replication of each stocking density. Fish performance in each cage was evaluated, in each 30th days, by the achievement of daily weight gain, final weight gain, apparent food conversion, survival and final average biomass (4 m3). For water quality determination of the rural reservoir, it was marked five points of sampling: water supply, rearing area divided in three points at 10 cm depth and effluent. Related to final length, final weight, final weight gain and survival there was significant difference (P<0.05) between the smallest and the highest stocking density. However, in relation to feed conversion the highest density (200 fish/m3) had the better result. Water quality parameters were adequate to tropical fish rearing patterns and to CONAMA 357/05 resolution. Performance data of this research show the viability of cage system with density 150 fish/m3 in Vale do Ribeira region

Characterization and evaluation of the impact of feed management on the effluents of Nile tilapia (Oreochromis niloticus) culture

O objetivo deste trabalho foi avaliar o efeito da utilização de diferentes manejos alimentares: alimento natural, ração peletizada, extrusada ou farelada, sobre a qualidade da água dos efluentes gerados em uma criação de tilápia do Nilo (Oreochromis niloticus). O experimento foi desenvolvido durante 19 semanas em doze viveiros de 300 m², com renovação contínua de água, povoados com juvenis machos de tilápia do Nilo na densidade de 1,7 peixes m-2. As rações isoproteícas (30% de proteína bruta) e isoenergéticas (3.000kcal de energia digestível) foram fornecidas duas vezes ao dia. Quanto ao tratamento alimento natural, foi utilizado esterco de galinha poedeira. Semanalmente, foram aferidos na água de abastecimento e nos efluentes, temperatura, oxigênio dissolvido, pH, fósforo total, nitrogênio total, clorofila a e material em suspensão. de maneira geral, houve piora na qualidade da água dos efluentes de todos os tratamentos estudados, em comparação a água de abastecimento, evidenciando o impacto ambiental desta atividade produtiva, podendo levar a eutrofização dos corpos d'água receptores.The objective of this study was to evaluate the effect of different feed management on the quality of effluent water generated in Nile tilapia (Oreochromis niloticus) culture ponds. Feed was supplied as follows: natural food, and pelleted, extruded or minced ration. The study was conducted during 19 weeks in 12 continuous water exchange ponds of 300 m² each, with a population of male Nile tilapia juveniles, in a density equal to 1.7 fish m-2. Feeds contained 30% crude protein, 3,000 kcal digestible energy, and were supplied twice a day. Natural food consisted of chicken manure. Temperature, dissolved oxygen, pH, total phosphorus, total nitrogen, chlorophyll a and suspended solids were monitored weekly in the supplying and effluent water. Water residence time was also determined for the ponds. In general, effluent water quality decreased in all treatments.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Nile tilapia, Oreochromis niloticus, productive performance and carcass characteristics as related to food management

Male juveniles of Nile tilapia, Oreochromis niloticus, were stocked in 12, 300-m 2 ponds at a density of 1.7 fish/m 2 to evaluate the effects of different food management methods (natural foods and diets in pellet, floating or minced form) on fish production and carcass characteristics. Water quality variables monitored during the period were within acceptable levels for the species. Total fish production was significantly different (P < 0.05) and the highest values were obtained with diets in pellet (5,997 kg/ha) and floating (5,441 kg/ha) form. The fish fed diets had higher contents of body fat (1.57 to 1.98%) and visceral fat (12.64 to 25.04%) than fish fed natural food, which had levels between 0.17 and 0%, respectively. Natural food treatment yielded lower fish production and fish with lower body fat, while treatments that yielded higher fish production (rations) higher percentage of visceral fat. © 2004 by The Haworth Press, Inc. All rights reserved