Poultry by-product meal as dietary protein source for dourado, Salminus brasiliensis: an economic appraisal

The dourado, Salminus brasiliensis, a large, carnivorous, Neotropical, Characin, is highly regarded for fish farming and sport fishing alike. However, studies on the farming and husbandry of dourado are still scarce. This study evaluated the performance of dourado fed diets formulated so as to contain increasing levels of poultry by-product meal as a replacement for fish meal and aimed to identify the maximum level of replacement to maximize profit. The trial was set up in a closed recirculation system with controlled water quality (temperature 27 °C, dissolved oxygen 6.5 mg L–1, pH 7.4, and ammonia 0.25 mg L–1). Juvenile fish were stocked in tanks in a completely randomized design, acclimatized to system conditions and experimental diets, and then fed twice a day for 66 days with extruded, nutritionally complete diets (40 % digestible protein and 4020 kcal kg–1 digestible energy), formulated to contain 0, 20, 40, 60, 80 or 100 % poultry meal as a surrogate protein source for fish meal. Performance parameters – average weight gain, specific growth rate, feed consumption, feed conversion rate, protein efficiency rate, productive value of protein, energy retention rate, survival rate – did not differ (p > 0.05). To minimize the effects of influential data, the robust regression method was used and profit maximization analysis revealed that replacing 33.3 % of dietary fishmeal by poultry by-product meal maximizes profit in the farming of dourado

Factores no genéticos en el crecimiento predestete de corderos biotipo lana en el trópico de altura colombiano

The objective of this study was to evaluate the effect of non-genetic factors on the characteristics of pre-weaning growth in sheep under tropical conditions. The sex of the lamb, the type of birth (single, multiple) and parity number on the birth weight, weaning weight and preweaning daily gain of 52 wool biotype lambs were evaluated. The lambs were weighed weekly from birth to week 12 (weaning). The sex of lambs did not have a significant effect on the variables evaluated. Lambs from mothers of third lambing had a higher preweaning daily gain than lambs from mothers of first lambing (p<0.05). Singleborn were heavier at birth and at weaning than lambs born as twins (p<0.05). It is concluded that the type of birth is the factor that mainly affects the characteristics of preweaning growth and that the sex of the offspring and lambing number do not significantly affect the growth performance.El estudio tuvo como objetivo evaluar el efecto de factores no genéticos sobre las características del crecimiento predestete en ovinos bajo condiciones tropicales. Se evaluó el sexo de la cría, el tipo de nacimiento y el número de partos de la madre sobre los pesos al nacimiento, pesos al destete y la ganancia diaria predestete de 52 corderos biotipo lana. Las crías fueron pesadas semanalmente desde el nacimiento hasta la semana 12 (destete). El sexo de la cría no tuvo un efecto significativo sobre las variables evaluadas. Los corderos provenientes de madres de tercer parto presentaron una mayor ganancia diaria predestete que los corderos provenientes de ovejas de primer parto (p<0.05). Los corderos provenientes de partos simples fueron más pesados al nacimiento y al destete que corderos provenientes de partos múltiples (p<0.05). Se concluye que el tipo de nacimiento es el factor que principalmente afecta las características de crecimiento predestete y que el sexo de la cría y el número de partos no afectan significativamente las características en mención

Mathematical non linear growth models as tool for evaluation of the growth of nile red tilapia (Oreochromis spp.) and nile tilapia (Oreochromis niloticus var. Chitralada) fed pelleted feeds or extruded feeds

En este estudio se evaluó el crecimiento de tilapia nilótica y tilapia roja a lo largo de un ciclo productivo comercial en sistema cerrado intensivo. La valoración del desempeño productivo de estas especies, con suministro de dietas extruidas o peletizadas enmarcadas en un sistema de alimentación por fases, mostró un efecto favorable del alimento extruido sobre el alimento peletizado. Se modeló mediante funciones no lineales el crecimiento del peso corporal y los componentes corporales (agua, proteína, lípidos y cenizas), siendo más acertadas las predicciones cuando se empleó el modelo de Bertalanffy en tilapia nilótica y el de Michaelis-Menten en tilapia roja. Los resultados mostraron un canal de expresión común del crecimiento para los dos procesamientos evaluados. Los anteriores desarrollos permitieron el diseño y verificación de un modelo bioenergético de predicción de los requerimientos de energía digestible, la tasa de alimentación y la conversión alimenticia en las dos especies de tilapia. Un análisis de rendimiento en cortes comerciales (filete y canal) indicó un efecto del procesamiento del alimento sobre dichas variables, siendo el rendimiento en filete más alto con el alimento extruido en tilapia nilótica, mientras que el rendimiento en canal fue más alto en tilapia roja cuando se emplearon dietas paletizadas. El estudio mostró la utilidad del modelaje matemático como herramienta estratégica de análisis para el estudio del crecimiento de tilapia. / Abstract. This study evaluated growth of Nile tilapia and red tilapia during a commercial production cycle in a recirculating system. Effects of extrusion and pelleting of feed on the productive performance of the species were analyzed in a phase feeding system. Performance was improved when fish fed on extruded feed. Effects of feed processing on body composition were also examinated. Mathematical no linear functions were used to predict the body weight and carcass components (water, protein, fat and ash) for both species. Von Bertalanffy model was a better fit for Nile tilapia growth, whereas Michaellis-Mentel model allowed better estimation of growth of red tilapia. A common channel of expression for both feed processes was defined. These developments allowed designing and verification of a bioenergetic model for prediction of digestible energy requirements, feeding rate, and feed conversion rate for both species. Feed processing affected performances of fish: extruded feed tended to yield better filleting and pelleted feed elicited the best carcass yield. Mathematical modelling is a strategic tool to understand the growth of tilapia.Magíster en producción animal. Línea de investigación – Nutrición animalMaestrí

Mathematical modelling of the utilization efficiency of dietary energy and dietary protein by pacu (Piaractus mesopotamicus Holmberg, 1887)

Sistemas intensivos de produção de peixes demandam o uso de dietas completas e manejo alimentar e nutricional precisos. O principal objetivo da nutrição dos peixes é melhorar a eficiência da utilização da energia e dos nutrientes da ração. Alta eficiência, na realidade, significa maior retenção de nutrientes e energia, i.e., maior crescimento, com menor descarga de nutrientes nos corpos d\'água. O objetivo deste trabalho foi estudar a eficiência de utilização da energia e a proteína da ração para o pacu, Piaractus mesopotamicus. Em um primeiro ensaio foram caracterizadas as propriedades físicoquímicas e os coeficientes de digestibilidade aparente da proteína e da energia de 28 amostras de rações para peixes onívoros comercializadas na região de Piracicaba, estado de São Paulo. Os dados obtidos foram utilizados no ajuste de modelos de regressão linear múltipla para predizer os conteúdos de energia digestível (ED) e proteína digestível (PD) das rações comerciais para a espécie. Uum segundo grupo de ensaios foi dedicado ao estudo da eficiência metabólica da utilização da energia e da proteína. Utilizando-se a técnica de respirometria de fluxo intermitente, foi quantificada a taxa metabólica padrão em peixes de diferente tamanho (17 g - 1050 g) em cinco temperaturas (19, 23, 26, 29 e 33°C). O coeficiente oxi-calórico para oxidação de gordura (13,72 J mg-1 O2) foi utilizado para converter os dados de consumo de oxigênio em taxas de produção de calor. O coeficiente alométrico da produção de calor em jejum foi próximo a 0,8, valor usual para outras espécies de peixes. A partir da aplicação do método fatorial de análise foram estimadas as exigências de energia digestível e proteína digestível para mantença e para o crescimento do pacu e o efeito do nível de lipídeos dietéticos (alto - AL, ou baixo - BL) sobre as exigências nutricionais. O nível de lipídeos da ração não influenciou a estimativa de exigência de energia para mantença (26,57 kJ de ED kg-0,8 dia-1 e 0,076 g de PD kg-0,7 dia-1). A exigência de energia digestível para crescimento (kJ de ED por kJ de energia retida) foi maior para a ração BL (1,387) do que para a ração AL (1,285). A exigência em proteína digestível (g de PD por g de proteína depositada) foi maior para peixes alimentados com a ração BL do que com a ração AL (1,7015 vs. 1,583).Intensive fish farming systems entail the use of complete feeds and accurate feeding and nutrition management. The main objective of fish feeding and nutrition practices is the efficient use of feed energy and nutrients. High efficiency actually means increased retention of nutrients and energy, i.e., improved growth ratio and reduced discharge of nutrients in the water. This work aimed at studying the efficiency of use of feed energy and protein of pacu, Piaractus mesopotamicus. A first trial characterized physicochemical properties and apparent digestibility coefficients of protein and energy of 28 commercial, omnivorous fish feeds sampled in the region of Piracicaba, state of São Paulo. The data were used to set multiple linear regression models predicting the digestible energy (DE) and digestible protein (DP) contents of commercial, sampled feeds. A second group of trials studied the metabolic efficiency of use of energy and protein. The intermittent flow respirometry technique was used to quantify the standard metabolic rate of different fish size classes (17 g - 1050 g) at five temperatures (19, 23, 26, 29 and 33 ° C). The coefficient for oxy-caloric fat oxidation (13.72 J mg-1 O2) was used to convert the oxygen consumption data to heat production ratios. The allometric coefficient of heat production in fasting condition was 0.8, a typical value for other fish species. Digestible energy and digestible protein requirements for maintenance and growth and effects of dietary lipids (high - AL, or low - BL) contents on nutritional requirements of pacu were then studied with the aid of factorial analysis method. Dietary lipid contents did not affect energy requirements for maintenance (26.57 kJ DE kg-0.8 day-1 and 0.076 g DP kg-0.7 day-1). The digestible energy requirement for growth (kJ of ED per kJ of energy retained) was higher for BL feeds (1.387) than for AL feeds (1.285). The requirements of digestible protein (g DP per g of deposited protein) was higher for the BL than for the AL feed (1.7015 vs. 1.583)

Poultry by-product meal as dietary protein source for dourado, Salminus brasiliensis: an economic appraisal

ABSTRACT: The dourado, Salminus brasiliensis, a large, carnivorous, Neotropical, Characin, is highly regarded for fish farming and sport fishing alike. However, studies on the farming and husbandry of dourado are still scarce. This study evaluated the performance of dourado fed diets formulated so as to contain increasing levels of poultry by-product meal as a replacement for fish meal and aimed to identify the maximum level of replacement to maximize profit. The trial was set up in a closed recirculation system with controlled water quality (temperature 27 °C, dissolved oxygen 6.5 mg L−1, pH 7.4, and ammonia 0.25 mg L−1). Juvenile fish were stocked in tanks in a completely randomized design, acclimatized to system conditions and experimental diets, and then fed twice a day for 66 days with extruded, nutritionally complete diets (40 % digestible protein and 4020 kcal kg−1 digestible energy), formulated to contain 0, 20, 40, 60, 80 or 100 % poultry meal as a surrogate protein source for fish meal. Performance parameters – average weight gain, specific growth rate, feed consumption, feed conversion rate, protein efficiency rate, productive value of protein, energy retention rate, survival rate – did not differ (p > 0.05). To minimize the effects of influential data, the robust regression method was used and profit maximization analysis revealed that replacing 33.3 % of dietary fishmeal by poultry by-product meal maximizes profit in the farming of dourado

Partial substitution of fishmeal with soybean protein-based diets for dourado Salminus brasiliensis

Cost and environmental restrictions limit the use of fishmeal (FM) in aquafeeds and plant protein (PP) sources. Soybean by-products are important alternative; however, their antinutritional factors may reduce fish growth. This study evaluates the effect of FM substitution for PP (soybean meal and soy protein concentrate) in diets of dourado (Salminus brasiliensis), a promising species for fish farming and empirically considered highly tolerant to PP-based diets. A control diet was formulated to contain 20 % of fishmeal and 61 % of plant protein (SBM) and other five diets with decreasing FM graded levels (16 %, 12 %, 8 %, 4 %, 0 %), which were replaced by soybean protein concentrate (SPC), comprising six treatments and four replicates. Fifteen dourados (6.73 ± 0.2 g) were stocked into 200 L tanks in a recirculating system, fed with experimental diets three times a day to apparent satiation for 90 days. Growth performance, food conversion ratio, protein efficiency ratio and protein retention efficiency of fish were impaired when FM substitution exceeded 13.05 % (the broken line analysis method). Histological analysis of intestinal mucosa showed a decrease in villus height when fishmeal was totally replaced by PP, which probably impaired digestive functions of fish and reflected in a severe loss on growth performance