Se determinó el contenido de nutrientes y la digestibilidad in vitro (pepsina/pancreatina) en muestras de cuatro especies exóticas de peces de agua dulce: tilapia (T, Oreochromis niloticus), carpa plateada (CP, Arichthistys nobilis), carpa cabezona (CC, Hypophtaimichtys molitrix) y carpa herbívora (CH, Ctenopharingodon idella), de uso común en Cuba en sistemas de policultivo semiintensivo de peces. El nivel de PB (Nx6.25, % BS) de la CH fue significativamente superior (P0.001) al resto de las especies (64.6), con valores intermedios para T (60.7) y CC (59.2), que fueron semejantes entre sí, mientras que para CP se obtuvo la cifra inferior (49.6). La digestibilidad in vitro (pepsina/pancreatina) de la materia orgánica y el N fue consistentemente alta en todos las muestras examinadas. La digestibiliad in vitro de la materia orgánica y el N fueron significativamente inferiores (P0.01) en CP (71.4 y 59.8%) respectivamente) con respecto al resto de las otras especies. Los valores de uso digestivo de materia orgánica y N fueron intermedios para CC (84.6 y 86.3% respectivamente) y netamente superiores para CH y T (96.4 y 94.1; 93.6 y 93.0% respectivamente). Se confirmó a partir de estos resultados que las cuatro especies de peces de agua dulceestudiadas pueden constituir fuentes de alimento de alto valor nutricional en dietas para cerdos en diferentes categorías. | The nutrient content and in vitro digestibility of organic matter and nitrogen were studied in four fresh water fish species: tilapia (T, Oreochomis niloticus), silver carp (SC, Arichthistys nobilis), bighead carp (BC, ypophtaimichtys molitrix) and grass carp (GC, Ctenofaringodon idellum), raised in semi-intensive polyculture in Cuba. The crude protein content (Nx6.25, % DM) of GC was 64.6, significantly higher (P0.001) than T (60.7) and BC (59.26) whereas SC had the lowest values (49.6). In vitro digestibility of organic matter and nitrogen were high in all the examined samples. The in vitro digestibility of organic matter and nitrogen were significantly lower (P0.01) in SC (71.4 and 59.8% respectively) than in the other samples which intemediate values for BC (84.6 and 86.3% respectively) and highest values for GC and T (96.4 and 94.1; 93.6 and 93.0% respectively). It is suggested that the four fresh water fish species studied may be high nutritive feeds for pigs

The culture of the giant Malaysian prawn, Macrobrachium rosenbergii, has been recently introduced in Argentina where some tests are carried out, both by the public and private organization. The culture and rearing of the Macrobrachium rosenbergii consists of two phases: the obtainment of larvae from ovate females, and the development and fattening of these postlarvae until they reach a commercial size. Because the need of brackish water for the first phase, many culturists work only on the second phase, i.e., the final production. The complete cycle, from the ovate female to the final harvest, lasts between 6 and 8 months. The most important elements to be taken into account in the M. rosenbergii culture is water quality, controlling the pH, salitness, temperature, NH3 content, dissolved oxygen and turbidness. The processing depends on the requeriments of the chosen markets. They can be sold complete or only the tails, fresh, frozen or peeled. | El cultivo del camaron gigante de la Malasia, Macrobrachium rosenbergii, ha sido recientemente introducido en la Argentina donde se llevan a cabo experiencias a nivel estatal y privado. El cultivo y la cria de este crustaceo consta de 2 etapas: la obtencion de larvas a partir de madres ovadas, y el desarrollo y engorde de estas postlarvas hasta obtener un tamano comercial. Debido a la necesidad de agua salada para la 1ra etapa, muchas camaroneras se dedican a la realizacion de la 2da etapa solamente, es decir, a la produccion final. El ciclo completo desde la madre ovada hasta la cosecha final dura entre 6 a 8 meses. Dentro de los puntos criticos a controlar en el trabajo de una granja acuatica de cultivo de M. rosenbergii esta el cuidado de la calidad del agua, verificando el pH, la salinidad, temperatura, oxigeno disuelto, contenido de NH3 y turbidez. El procesado del camaron depende de la exigencia de los mercados elegidos. Se pueden vender enteros o solamente las colas, frescos, congelados o pelados.

An experiment was conducted to study the effect of dietary electrolytic balance (dEB) and addition of sodium bicarbonate to drinking water on carcass and meat quality of pigs. Sodium bicarbonate was used to adjust dEB to 140, 200 and 280 mEq/kg for T1, T2 and T, respectively. 144 Landrace*Duroc male pigs were allocated at 4 per pen and used until 105 kg liveweight. At the end pigs were kept in the same pens and diets for a week during which sodium bicarbonate rich water was supplied to a half of them. Therefore the experimental design was split in a factorial 2x3 and treated water was administered until slaughter. Forty-eight pigs were selected and sent to the slaughterhouse in order to evaluate the effect of experimental treatments on carcass and meat quality parameters. Enriched water significantly increase urine pH, hot and cold carcass weight and killing-out percentage (P<0.01). However did not affect fat or loin depth, lean meat percentage or chilling losses as well as meat quality parameters. pH of muscles Semimembranosus (SM) or Longissimus thoraccis (LT) measured at 45 min were not affected by dEB. However meat pH measured after 24 h statistically increased in both SM (P<0.01) and LT muscles (P<0.05). Pigs fed with low dEB showed a pH indicating meat with a tendency to become acid (5.5<pH<5.6) whereas meat from pigs of the other 2 groups has good ability to be consumed fresh or transformed. Electrical conductivity of SM muscle also indicated better meat quality of pigs fed medium and high dEB (P<0.05). Drip loss from the meat was also strongly reduced as a consequence of dEB (P<0.02). Meat from pigs fed low dEB lost the double of water than meat from pigs fed medium or high dEB. It can be concluded that dEB supplementation could positively affect meat quality parameters like pH 24h, electrical conductivity or drip losses. All these parameters were improved using finishing diets with a medium (200 mEq/kg) or high dEB (280 mEq/kg). Sodium bicarbonate in drinking water before slaughter did not seem to affect meat quality parameters. Nevertheless, it seems that it could improve carcass weight or killing-out percentage but those results need to be confirmed in other trials.

Se realizo un ensayo con terneros Aberdeen Angus, que consumian heno de Eragrostis curvula (5 p. 100 PB y 77,8 FND) y Medicago sativa (18 p. 100 PB y 47,3 FND) y agua de bebida con 1,75 g/L y 5,9 g/L de residuo seco de evaporacion. Los terneros recibian el mismo forraje, pero diferente calidad de agua. Se midio: consumo de materia seca (CMS, kg/kg sup (0,75)), consumo de agua (CH2O, L/kg sup (0,75)) y digestibilidad (DMS p. 100). Los resultados indican que para baja calidad de forraje el CMS (0,067 +- 0,013), CH2O (0,225 +- 0,047) y DMS (56,21 +- 9,8 p. 100) fueron superiores cuando se suministro agua de alta salinidad que para media salinidad de agua (CMS = 0,060 +- 0,011; CH2O = 0,203 +- 0,044; DMS = 48,16 +- 11,42 p. 100). Con el forraje de alta calidad la situacion es inversa, con alta salinidad del agua los valores de CMS (0,108 +- 0,024) y CH2O (0,453 +- 0,087) son menores que para media salinidad del agua (CMS = 0,114 +- 0,018; CH2O = 0,525 +- 0,162) y la digestibilidad es igual para ambos casos (DMS = 66,84 +- 8,41 p. 100; 66,55 +- 7,27 p. 100). Se concluye que en condiciones de baja calidad de forraje, agua con hasta 6 g de RSE/L es beneficiosa, al mejorar la digestibilidad y consumo del forraje, pero con forraje de alta calidad, se limita el consumo de esta y del forraje.