Evaluation of chemical silage on egg quality parameters in ISA Brown line laying hens (Gallus gallus domesticus) / Evaluación del ensilado químico sobre los parámetros de calidad del huevo en gallinas ponedoras de la línea ISA Brown (Gallus gallus domesticus)

ABSTRACT In this study we evaluated the inclusion of chemical silage from red tilapia viscera (Oreochromis sp.) in diets for ISA Brown line laying hens (Gallus gallus domesticus) and its influence on nutritional parameters and egg quality. A total of 56 16-week-old laying hens were randomly divided into two groups (one per diet), which in turn were subdivided into 7 groups, each with 4 birds. Eggs were collected during the first 13 weeks of laying. During this period the egg quality parameters were evaluated until week 11; the bromatological characterization of the egg was carried out in the 2nd and 4th week of laying. The results indicated that the inclusion of chemical silage in 17,18% dry matter does not result in statistically significant differences in egg quality parameters or in their bromatological composition, with respect to the control. This led to the conclusion that chemical silage can be used as an alternative to protein inputs such as fish meal and soybean cake in the diet of laying hens, without modifying the quality of the final product.

RESUMEN En este trabajo se evaluó la inclusion de ensilado químico de vísceras de tilapia roja (Oreochromis sp.) en dietas para gallinas ponedoras (Gallus gallus domesticus) de la raza Isa-Brown, y su influencia sobre parámetros nutricionales y la calidad del huevo. Se utilizó un total de 56 gallinas ponedoras de 16 semanas de edad divididas al azar en dos grupos (uno por dieta), los cuales a su vez se subdividieron en 7 grupos de 4 aves cada uno. Se les recolectó huevos durante las primeras 13 semanas de postura. Durante este periodo se realizó la evaluación de los parámetros de calidad del huevo hasta la semana 11. La caracterización bromatológica del huevo se realizo en las semanas 2 y 4, luego de haber sido puestos. Los resultados indicaron que la inclusion de ensilado químico en un 17,18% materia seca, no genera diferencias estadísticamente significativas (p < 0,05) en los parámetros de calidad del huevo ni en su composición bromatológica, con respecto al control. Esto permitió concluir que el ensilado químico puede ser usado como alternativa a insumos proteicos como harina de pescado y torta de soya en la alimentación de gallinas ponedoras, sin modificar la calidad del producto final.

Bromatological characteristics of fillet fish of Leporinus agassizi and Leporinus fasciatus (Pisces: Characidae) in its natural habitat / Características bromatológicas de filetes de Leporinus agassizy Leporinus fasciatus (Pisces: Characidae) en su hábitat natural

ABSTRACT Bromatological parameters in 39 Warakú verdadero (Leporinus agassizi) and 21 Warakú pinima (Leporinus fasciatus) fillets were analyzed at three different sites of the Vaupés River, Colombia sampled during a hydrobiological cycle. The bromatological parameters did not shown significant differences in relation to the sites and season of capture. At point 3 and during the descending water season Leporinus agassizi had the highest values for dry matter (25.24%), protein (19.82%) and ash (2.16%). The highest lipid value for this species was found in low waters at point 1 (2.93%). Leporinus fasciatus showed the highest levels of dry matter (25.19%) and ash (2.16%) at point 3 during ascendant and high waters, respectively. The bromatological parameters tends to vary regarding the time of year. It was possible to determined that these fish species have great potential for continental aquaculture thus constituting a healthy food model.

RESUMEN Se analizaron los parámetros bromatológicos de 39 filetes de Warakú verdadero (Leporinus agassizi) y 21 filetes de Warakú pinima (Leporinus fasciatus) muestreados durante un ciclo hidrológico en tres puntos diferentes del Rio Vaupés, Colombia. Los parámetros evaluados no presentaron diferencias significativas en relación al sitio y época de captura. En el punto 3 y durante la temporada de aguas descendentes Leporinus agassizi tuvo los valores más altos para materia seca (25,24%), proteína (19,82%) y cenizas (2,16%). Los mayores niveles de lípidos para esta especie fueron encontrados en aguas bajas del punto 1 (2,93%). Leporinus fasciatus presentó los niveles más altos de materia seca (25,19%) y cenizas (2,16%) en el punto 3 durante la temporada de aguas ascendentes y altas, respectivamente. Las variables bromatológicas tendieron a variar de acuerdo con la época del año. Fue posible determinar que estas especies de peces poseen un gran potencial para la acuicultura de aguas continentales constituyendo así un modelo de alimentación saludable.

Trophic structure of a floodplain fish assemblage in the upper Amazon basin, Bolivia / Estructura trófica de un ensamblaje de peces en la cuenca alto-Amazónica, Bolivia

Abstract Amazonian fish assemblages are typically high in species diversity and trophic complexity. Stable isotopes are valuable tools to describe the trophic structure of such assemblages, providing useful information for conservation and ecological management. This study aimed at estimating the relative contribution of the different basal carbon sources to the diet of primary consumer fishes (herbivores and detritivores), and determining the trophic position (TP) of the dominant fishes from each trophic guild (herbivores, detritivores, invertivores and piscivores). For this purpose we analyzed stable isotope ratios of carbon (δ13C) and nitrogen (δ15N) in potential food sources, and muscle tissue of fishes in five oxbow lakes located in the floodplain of River Ichilo, Bolivia. Terrestrial plants and C3 aquatic macrophytes were the major carbon source contributing to the diet of herbivorous fishes, whereas particulate organic matter (POM) contributed more to the diet of detritivore fishes. In general, C4 aquatic macrophytes contributed little to the diet of herbivores and detritivores. However, we found a relatively high contribution of C4 macrophytes (28 %) to the diet of the herbivores Mylossoma duriventre and Schizodon fasciatus. We found a good agreement between our estimated TP values and the trophic group assigned based on diet composition from literature. The herbivore M. duriventre was at the bottom of the food web, being the baseline organism (TP = 2). The remaining primary consumers (herbivores and algivore/detritivores) exhibited relatively high TP values (2.3-2.9), probably due to their opportunistic feeding behavior. Omnivore/invertivore species studied displayed TP values near the 3.0 value expected for secondary consumers. Piscivore fishes were at the top TP, with TP values varying from 3.3 (Serrasalmus spilopleura and Serrasalmus rhombeus) to 3.8 (Pseudoplatystoma fasciatum). The fact that detritivore fishes, the most abundant food source for piscivores, occupy relatively high TPs determines that food chains in these particular Amazonian floodplains are longer than previously thought. Rev. Biol. Trop. 66(3): 1258-1271. Epub 2018 September 01.

Resumen Los ensamblajes de peces amazónicos presentan alta diversidad y complejidad trófica. La descripción de su estructura trófica proporciona información útil para su manejo. Con el fin de estimar la contribución de las fuentes básicas de carbono en la dieta de los consumidores primarios, y determinar la posición trófica (PT) de las especies dominantes de peces de cada gremio, analizamos isótopos estables de carbono (δ13C) y nitrógeno (δ15N) en las fuentes de carbono y en músculo de peces, de la llanura de inundación del río Ichilo. Las plantas terrestres y las macrófitas C3 fueron las mayores fuentes de carbono en la dieta de los peces herbívoros, mientras que la materia orgánica particulada contribuyó más a la dieta de los detritívoros. Las macrófitas C4 contribuyeron poco a la dieta de herbívoros y detritívoros, excepto para Mylossoma duriventre y Schizodon fasciatus, en las que encontramos una contribución relativamente alta (28 %). Encontramos una buena relación entre los valores estimados de PT y el gremio trófico asignado en la literatura. El herbívoro M. duriventre estuvo en la base de la red trófica (PT = 2). Los restantes consumidores primarios mostraron valores de PT relativamente altos (2.3 - 2.9), probablemente debido a sus hábitos alimenticios oportunistas. Las especies omnívoras/invertívoras mostraron valores cercanos a 3. Los peces piscívoros estuvieron en la cima de la red trófica, con PT que variaron entre 3.3 (Serrasalmus spilopleura y Serrasalmus rhombeus) y 3.8 (Pseudoplatystoma fasciatum). Estos datos sugieren que las cadenas tróficas en llanuras de inundación amazónicas, son más largas de lo que se suponía.

Optimum dietary protein requirement for Amazonian Tambaqui, Colossoma macropomum Cuvier, 1818, fed fish meal free diets / Exigência protéica de juvenis de tambaqui, Colossoma macropomum Cuvier, 1818, alimentados com rações livres de farinha de peixe

Fish meal free diets were formulated to contain graded protein levels as 25% (diet 1), 30% (diet 2), 35% (diet 3) and 40% (diet 4). The diets were fed to tambaqui juveniles (Colossoma macropomum) (46.4 ± 6.3g) in randomly designed recirculating systems for 60 days, to determine the optimum protein requirement for the fish. The final weight of the fish, weight gain (28.1, 28.5, 32.2, 28.0g) and specific growth rate increased (P>0.05) consistently with increasing dietary protein up to treatment with 35% protein diet and then showed a declining trend. Feed intake followed the same trend resulting in best feed efficiency (62.5%) in fish fed diet with 35% protein. Similarly, the protein intake increased significantly with increasing dietary protein levels and reduced after the fish fed with 35% protein; while protein efficiency ratio (2.28, 1.99, 1.87, 1.74) decreased with increasing dietary protein levels. Carcass ash and protein had linear relationship with dietary protein levels while the lipid showed a decreasing trend. Ammonia content (0.68, 0.73, 0.81, 1.21 mg L-1) of the experimental waters also increased (P<0.05) with increasing protein levels while pH, dissolved oxygen and temperature remained fairly constant without any clear pattern of inclination. Broken-line estimation of the weight gain indicated 30% protein as the optimum requirement for the fish.

Foram formuladas quatro dietas sem a inclusão de farinha de peixes contendo os níveis crescentes de proteína de 25% (dieta 1), 30% (dieta 2), 35% (dieta 3) e 40% (dieta 4). As dietas foram fornecidas a juvenis de tambaqui (Colossoma macropomum) (46.4 ± 6.3g) distribuídos ao acaso em um sistema de recirculação durante 60 dias, para determinar o requerimento protéico ótimo para o peixe nesta faixa etária. O peso final dos peixes, o ganho de peso (28.1, 28.5, 32.2, 28.0g) e a taxa de crescimento específico tiveram um aumento não significativo (P>0,05) conforme aumentou o nível protéico das rações até o nível de 35% proteína e então uma tendência ao declínio. O consumo de alimento seguiu a mesma tendência resultando em melhor eficiência alimentar (62.5%) para os peixes alimentados com a dieta contendo 35% de proteína. Similarmente, o consume de proteína aumentou significativamente com o aumento crescente dos níveis protéicos dietários e reduziu após os peixes serem alimentados com a dieta com 35% de proteína, enquanto a taxa de eficiência protéica (2.28, 1.99, 1.87, 1.74) diminuiu com o aumento dos níveis protéicos dietários. A cinza e a proteína da carcaça apresentaram uma relação linear com os níveis protéicos dietários enquanto o lipídio mostrou uma tendência decrescente. O aumento do conteúdo da amônia (0.68, 0.73, 0.81, 1.21 mg L-1) da água dos tanques experimentais com a elevação dos níveis de proteína não foi significativo (P>0,05) enquanto o pH, oxigênio dissolvido e a temperatura permaneceram claramente constantes sem qualquer padrão claro de inclinação. O "ponto de virada" da curva de ganho de peso indicou 30% como o nível protéico ótimo para esta espécie de peixe, nesta fase de crescimento, nas condições deste experimento.