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With the objective of knowing the productive performance under the climatic conditions of Mayabeque province in the West of Cuba, six varieties of elephant grass, three of Pennisetum purpureum (Morado, king grass, and Cuba CT-169) and three hybrids of Pennisetum purpureum x Pennisetum glaucum (Cuba OM-22, H-1 and H-2). A random block design was used in five plots of 5x5 m² in a red ferralitic soil. Cuts belonging to dry season were made every 90 days, and those of rainy period were made every 60 days. Fertilization was applied at a rate of 250 kg of N/ha/year in the form of urea. During dry season, irrigation was applied every 15 days with a standard of 250 m³/ha. Production of DM/ha/year was 23.1-35.2 - 35.l - 34.4 - 38.8 and 14.1 tons of dry matter (DM)/ha/year for Morado, king grass, Cuba CT-169, Cuba OM-22, H-1 and H-2 respectively. Cuba OM-22 showed higher production and leaf proportion (16.6 t/DM/ha and 48.l %, respectively). Varieties with lower (P<0.005) yield of dry matter (Morado and H-2) had higher percentage of crude protein in the plant, but lower yield of CP/ha/year. Cuba OM-22 maintained a high percentage of CP with high yield of DM. Thermal sum was similar for both seasons and there was no direct relationship between the thermal sum and yields, and the age at cut had an influence on results. Yields were similar for the best studied varieties so there should be a focus on proportion of leaves among them and other qualities. [ABSTRACT FROM AUTHOR]

The change of chemical fertility of a ferrallitic red brown soil in the biomass bank technology of Pennisetum purpureum Cuba CT-115 was researched with different years of exploitation (6, 12 and 18 years, respectively). The pH indicators (in KCL), MO, N, P, K, Ca and Mg were researched. The data were subjected to variance analysis, according to simple classification model and the t-Student test was used in necessary cases. With the longer time of exploitation of 18 years, there was significant increase (P < 0.0001) of the OM (3.07 to 5.16 %), followed by the biomass bank with 12 years (3.04 to 3.71%), while the P content significantly decreased (P < 0.0056) in the biomass bank of 18 years (57.84 to 39.21 ppm), but did not varied in 12 years. The soil in the biomass bank of 6 years did not showed variation of the studied chemical indicators. The results indicated that there is an increase of the soil OM as it is higher the exploitation time of the biomass bank and P content decrease. It is recommended that, under similar soil conditions, the monitoring of the soil fertility state, mainly of the P assimilable content, from 6 years of uninterrupted exploitation with this technology. [ABSTRACT FROM AUTHOR]

A random block design with five replications and thirteen treatments was applied. Treatments consisted of three varieties of Pennisetum purpureum (king grass, Cuba CT-115 and Cuba CT-169) cut two (August and February), four (May, July, September and February) and five times a year (November, February, May, July and September) and two of Saccharum officinarum (Jaronú 60-5 and Villa Clara 21), cut one (February) and two (February and August) times a year for determining their influence on some forage quality indicators. The experiment was conducted in a red ferrallitic soil for four years with fertilization (100-60-80 kg/ha/year of N, P2O5 and K2O, respectively) and irrigation during the dry period. There were differences (P < 0.001) in the CP content of the varieties according to the cutting frequency. The highest values were registered in leaves, stems and the whole plant of the Pennisetum varieties with ranging values of 7.6-10, 4.2-5.9 and 5.1-7.3 %, respectively when cut five times a year. Crude fiber differed (P < 0.001) and the lowest values were recorded in the Pennisetum varieties with the highest cutting frequency. For in vitro organic matter digestibility there were differences (P < 0.001) favorable to the highest cutting frequency. Best results were attained when the Pennisetum varieties were cut five times per year. Cutting Saccharum two times per year propitiated the disappearance of Jaronú 60-5 at the end of the second year of study. The best balance of the studied indicators was obtained when Pennisetum and Saccharum varieties were cut five and once per year, respectively. There is available information that will allow improving the management of these varieties, for using them efficiently and attaining greater longevity of the plantation. [ABSTRACT FROM AUTHOR]

Se aplicó un diseño de bloques al azar con cinco réplicas y trece tratamientos, que consistieron en tres variedades de Pennisetum purpureum (king grass, Cuba CT-115 y Cuba CT-169), cortadas dos (agosto y febrero), cuatro (mayo, julio, septiembre y febrero) y cinco veces al año (noviembre, febrero, mayo, julio y septiembre), y dos de Saccharum officinarum (Jaronú 60-5 y Villa Clara 21), cortadas una (febrero) y dos (febrero y agosto) veces por año, para determinar su influencia en algunos indicadores de la calidad de los forrajes. El experimento se condujo en suelo ferralítico rojo durante cuatro años, con fertilización (100-60-80 kg/ha/año de N, P2O5 y KƻO, respectivamente) y riego durante el período poco lluvioso. Hubo diferencias (P < 0.001) en el tenor de PB de las variedades de acuerdo con la frecuencia de corte. Los mayores valores se registraron en las hojas, tallos y planta íntegra de las variedades de Pennisetum, con rango de valores de 7.6-10, 4.2-5.9 y 5.1-7.3 % respectivamente, cuando se cortaron cinco veces al año. La fibra cruda difirió (P < 0.001) y los menores valores se registraron en las variedades de Pennisetum con la mayor frecuencia de corte. Para la digestibilidad in vitro de la materia orgánica hubo diferencias (P < 0.001) favorables a la mayor frecuencia de corte. Los mejores resultados se alcanzaron cuando las variedades de Pennisetum se cortaron cinco veces al año. Cortar dos veces al año a Saccharum repercutió en que la Jaronú 60-5 desapareciera al finalizar el segundo año de estudio. El mejor balance de los indicadores estudiados se obtuvo cuando las variedades de Pennisetum y Saccharum se cortaron cinco y una vez al año, respectivamente. Se dispone de información que permite mejorar el manejo de estas variedades, utilizarlas eficientemente y lograr mayor longevidad de la plantación. [ABSTRACT FROM AUTHOR]

In order to assess the impact of the technology of biomass banks on milk production, the information of 27 indicators was recorded, obtained from nine dairy units of the Basic Unit of Cooperative Production (BUCP) "Desembarco del Granma", in Villa Clara province, from 2000 to the first semester of 2009. The combination semester-year-dairy unit allowed making a general matrix, with 169 cases. A total of 89 cases were analyzed in the first semester or dry period to facilitate the data interpretation, while in the second semester or rainy period, 80 cases were analyzed. The main components analysis (MCA) were used for the interpretation of the results. In the matrixes studied, four main components (MC) explained more than 70 % of the variability. The MC 1 in each matrix explained more than 35 % of the variance, and was highly correlated with indicators of productive importance, such as productivity per cow, production of milk/ha and total production per semester. Only this component was highly correlated with time and with the main technological changes, like paddocking and the percentage increase of Cuba CT-115 pasture. However, the relation was low with the sugarcane percentage and that of artificial pastures, replacement percentage of animals, stocking and birth. These indicators were not highly modified in time. The rotated matrices were used to determine the impact indexes in each scene, which changed their values, from negative to positive, with the years, and were, at the same time, an impact demonstration of this technology. The relation MC 1 allowed reliable regression equations in time, expressing the impact values of the biomass banks on the main productive indicators. Under the conditions of this BUCP, the organizational actions increased the milk production in 60 L/ha/year. The interval parturition-gestation decreased in 6.5 d/year. The milk/lactation increased in 73.3 L/year, the total milk production per dairy unit in 6252 L, and the liter per milking cow in 0.2/year. It is suggested that the BUCP considers a new cycle of developing the technologies and methods of animal management to increase the stocking rate, amount and quality of the feed for the dry season and favor the diminishing of the interval parturition-gestation. [ABSTRACT FROM AUTHOR]

Se estudió el desarrollo de los clones de hierba elefante, Cuba CT-169, king grass (Pennisetum purpureum) y Cuba OM -22 (Pennisetum híbrido), para medir en diferentes momentos de corte (cada 14 d) las variables altura, rendimiento verde y seco, relación hoja-tallo, porcentaje de materia seca, fibra, digestibilidad in vitro, proteína y cenizas. Se hicieron 13 cortes durante 182 d del período lluvioso para estudiar la relación entre la edad al corte y las variables estudiadas. Se presentan las curvas de acumulación de biomasa, las cuales se ajustaron al modelo de Gompertz. Hasta el corte 3 (42 d), los rendimientos acumulados fueron semejantes para las tres variedades, próximos a las 5 t de MS/ha. A partir de esta edad, Cuba CT 169 aventajó al resto de los clones en rendimiento acumulado. A las 26 semanas (corte 13), las variedades Cuba CT-169 y Cuba OM-22 acumularon 27 y 28 t MS/ha respectivamente, y el king grass 23 t MS/ha. El resto de las mediciones se ajustaron a modelos lineales. Los tres clones disminuyeron su calidad al aumentar la edad, mientras aumentó la acumulación de biomasa, por lo que el productor debe elegir entre más calidad o más biomasa entre 42 y 70 d. El clon Cuba OM-22 presentó mejor proporción de hojas, por lo que se recomienda su utilización en vacas altas productoras y cerdos. Otra de sus ventajas es que no presenta vellosidades en las hojas. Por su rápido crecimiento, productividad y buen contenido proteico, se sugiere la utilización del Cuba CT-169 para propósitos generales de producción de forrajes. [ABSTRACT FROM AUTHOR]

En un diseño de parcelas divididas con cinco replicas, se estudió el efecto de la distancia de plantación y dosis de fertilización química en la producción y calidad de la semilla vegetativa del pasto Pennisetum purpureum vc. Cuba CT-169, plantado a vuelta de arado. Las parcelas principales fueron la plantación a vuelta de arado a 90 y 180 cm entre surcos. Las subparcelas se correspondieron con la aplicación de 0 y 500 kg/ha de fórmula 8-6-10 en el primer corte. La altura (289.25 cm), el largo de los entrenudos (12.75 cm) y el número de yemas/tallo fueron mayores en la vuelta de arado a 180 cm, con fertilización. Sin embargo, las diferencias no fueron significativas en el segundo corte (octubre de 2006). El rendimiento de biomasa verde (148.269) en el primer corte se obtuvo con la vuelta de arado a 90 cm, con fertilización. En este corte, el rendimiento de tallos (123.7 t/ha) y la capacidad de multiplicación de los mismos (20.6) fue mayor (P < 0.001) con la plantación a vuelta de arado, con fertilización. En el segundo cote, el rendimiento de tallos vegetativos (45.7 t/ha) y la capacidad de multiplicación (7.6) se obtuvieron con la vuelta de arado a 180 cm, y no se afectó por la fertilización. El costo de plantación del CT-169 fue 127.66 pesos/ha menos con vuelta de arado a 180 cm. Se concluye que, para la producción de semilla vegetativa, el pasto Cuba CT-169 debe plantarse a 180 cm y fertilizarse con 500 kg/ha de fórmula completa, ya que constituye la mejor opción técnico-económica. No se debe descartar la posibilidad de utilizar el primer corte como semilla, en áreas donde se plante a 90 cm y se fertilice. [ABSTRACT FROM AUTHOR]

A systematic sampling design with five repetitions was used to characterize the dynamics of accumulation of biomass of Guinea grass Mombaza (Panicum maximum Jacq). In the first year, different regrowth ages (14, 28, 42, 56, 70, 84, 98, 112, 126, 140, and 154 d) were studied in the rainy season, and up to 168 d, in the dry season. For the rest of the years, they were studied up to 168 d in both seasons. The height and yield of dry matter were the growth indicators. The results were analyzed through the statistical software Infostat and SPSS and the models of best goodness of fit were tested considering the coefficient of determination, the mean square of the error, and the significance of each model. The logistic model was the one with the best fit to the agronomic indicators. It was identified that at about 56 d of regrowth there is an inflection point, time in which there is start of the growth of the Guinea grass Mombaza. In the conditions under study, the potential yield of dry matter from Mombaza was of 21.09 t/ha as average in the three years. The height attained was of 224 cm at 168 d of regorwth; whereas in the dry season it attained 74 cm at the same age. [ABSTRACT FROM AUTHOR]

Para caracterizar la dinámica de acumulación de biomasa de la guinea Mombaza (Panicum maximum Jacq) durante tres años, se utilizó un diseño de muestreo sistemático con cinco repeticiones. En el primer año, se estudiaron diferentes edades de rebrote (14, 28, 42, 56, 70, 84, 98, 112, 126, 140 y 154 d) para el período lluvioso, y hasta 168 d para el poco lluvioso. Para los dos años restantes se estudiaron hasta los 168 d en ambas épocas del año. La altura y el rendimiento de materia seca fueron los indicadores de crecimiento. Los resultados se analizaron mediante los paquetes estadísticos Infostat y SPSS y se probaron los modelos que mayor bondad de ajuste mostraron, teniendo en cuenta el coeficiente de determinación, el cuadrado medio del error y la significación de cada modelo. El modelo logístico fue el que mejor ajuste presentó para los indicadores agronómicos. Se identificó que aproximadamente a los 56 d de rebrote se encuentra el punto de inflexión, momento en el que se inicia el crecimiento de la guinea Mombaza. En las condiciones estudiadas, el rendimiento potencial de materia seca de la Mombaza fue de 21.09 t/ha como promedio en los tres años. La altura alcanzada fue de 224 cm a los 168 d de rebrote. Mientras que en el período seco alcanzó 74 cm a la misma edad. [ABSTRACT FROM AUTHOR]

Para caracterizar la dinámica de acumulación de biomasa de la Guinea Mombaza (Panicum maximum Jacq), se utilizó un diseño de muestreo sistemático con cinco repeticiones. Se estudiaron diferentes edades de rebrote (14, 28, 42, 56, 70, 84, 98, 112, 126, 140 y 154 d) para el período lluvioso y hasta 168 d para el poco lluvioso. En cada muestreo se tomaron 3 m2 del área de cada repetición. La altura y el rendimiento de materia seca fueron los indicadores de crecimiento. Los resultados se analizaron mediante los paquetes estadísticos Infostat y SPSS y se probaron los modelos que mostraron mayor bondad de ajuste, según el coeficiente de determinación, el cuadrado medio del error y la significación de cada modelo. Los modelos ajustados para los indicadores estudiados fueron el Cuadrático, el Exponencial y el Gompertz. Guinea Mombaza mostró una curva de crecimiento más prolongada que otras especies de pastos y manifestó un comportamiento promisorio en las condiciones edafoclimáticas estudiadas. [ABSTRACT FROM AUTHOR]

The article presents a study which aimed to point out some of the fundamental, new or adequately adjusted principles to apply a method of efficient and sustainable rotational grazing in the American subtropics without irrigation. The main finding is the proposal of the Efficient and Sustainable Rotational Grazing (ESRG) for the American subtropics without irrigation, as a result of its principles and benefits. This will allow more efficiency in the cattle system, especially for milk production in the American tropics without irrigation.

The article discusses research on the movement of certain chemical components during grazing and regrowth of the clone Pennisetum purpureum CUBA CT-115. A random black design with five replications in the dry season was used to determine the protein percentage and value of potassium in leaves. It was found that the substance movility in the development cycle of the plant was evident that it has a high capacity for biomass accumulation and production of fast regrowth.

Different regression models were adjusted to predict growth of Pennisetum purpureum cv. king grass in the rainy and dry periods in the Western region of Cuba through the accumulated dry matter yield. Information from experiments carried out by the Department of Pastures of the Institute of Animal was used. Data on biomass accumulation of the pasture at 13 regrowth ages in the rainy period and 10 in the dry one with 14 d of difference between ages were utilized. Five regression models (three linear and two non-linear) and five statistical criteria were evaluated. A sample obtained from the Bootstrap was used for selecting the best adjustment in the studied variable. The maximum growth rhythm, age at which was attained the inflection point and the appropriate moment for the exploitation of the forage area, were estimated. The model of best adjustment was the Gompertz. The highest value of biomass accumulation for the rainy period was of 23.82 t of DM ha-1 and in the rainy period of 7.31 t of DM ha-1. The period of highest forage growth speed was between 14 and 57 d. In yield terms, the exploitation of this variety under the studied conditions must be from 88 to 90 d in the rainy period and of 78 to 88 d in the dry period. It is recommended to evaluate the curve of biomass accumulation of Pennisetum purpureum cv. king grass until 140 d of age and to confirm results obtained under different environmental and soil conditions. [ABSTRACT FROM AUTHOR]

Se utilizaron diferentes modelos de regresión para estudiar la dinámica de crecimiento del Pennisetum purpureum vvc. Cuba CT-169 mediante las variables agronómicas rendimiento acumulado de materia seca, porcentaje de hojas y altura de la planta. Se utilizó información de experimentos realizados por el Departamento de Pastos del Instituto de Ciencia Animal. Cada 14 d, se tomaron datos de la acumulación de biomasa del pasto a doce edades de corte durante el período lluvioso, y a diez edades en el poco lluvioso, sin aplicar fertilización ni riego. Se ajustaron tres modelos lineales (simple, cuadrático y cúbico) y tres no lineales (logístico, Gompertz y exponencial). Se aplicaron cuatro criterios estadísticos para seleccionar los modelos de mejor bondad de ajuste. Los modelos propuestos explicaron la mayor parte de la variabilidad total, con coeficientes de determinación superiores a 89 %, varianza residual mínima, parámetros significativos y valores adecuados para el resto de los criterios evaluados. Los modelos de mejor ajuste en el período lluvioso fueron el de Gompertz, para el rendimiento acumulado de materia seca y la altura, y el exponencial para el porcentaje de hojas. En el poco lluvioso, el de mejor ajuste fue el logístico para el rendimiento acumulado de materia seca y la altura; y el lineal simple para el porcentaje de hojas. En las condiciones de este estudio, se recomienda cortar el forraje a la edad de 70 y 106 d en los períodos lluvioso y poco lluvioso, respectivamente. Se sugiere profundizar en el comportamiento de los indicadores bromatológicos y validar los modelos propuestos en investigaciones futuras para simular el comportamiento de este pasto en diferentes condiciones. [ABSTRACT FROM AUTHOR]

Different regression models were used to study the growth dynamics of Pennisetum purpureum cv. Cuba CT-169 through the agronomic variables accumulated yield of dry matter, percentage of leaves, and plant height. The data of the experiments were from the Pastures Department at the Institute of Animal Science. Every 14 d, data of the pasture biomass accumulation were collected at twelve cut ages during the rainy season, and at ten ages in the dry season, without fertilization or irrigation. Three linear models (one-way, quadratic, and cubic) and three non-linear (logistic, Gompertz, and exponential) were fitted. Four statistical criteria were applied to select the models of best goodness of fit. The models accounted for most of the total variability, with coefficients of determination superior to 89 %, minimum residual variance, significant parameters and adequate values for the rest of the criteria. The models of best fit in the rainy season were the Gompertz, for the accumulated yield of dry matter and the height, and the exponential, for the leaf percentage. In the dry season, that of best fit was the logistic, for the accumulated yield of dry matter and the height; and the one-way linear, for the leaf percentage. In the conditions of this study, the forage cut at 70 and 106 d of age is recommended in the rainy and dry seasons, respectively. Deepening into the performance of the bromatological indices is suggested, as well as validating the proposed models in further researches to simulate the response of this pasture to different conditions. [ABSTRACT FROM AUTHOR]

For predicting the productive performance of Pennisetum purpureum cv. king grass with different cutting frequencies and N fertilizer levels, a non-linear mixed regression model and another of categorical regression were adjusted. Data from a five-year experiment were taken in which the effect of cutting frequency and nitrogen dosage (N) on DM yield was evaluated. Literature data from the last 30 years were collected for selecting the variables of highest influence on DM yield. The Bootstrap re-sampling was used for generating a sample of 50 observations per cut. Five statistical criteria were assessed for selecting that of better adjustment in the variable studied. It was established that the non-linear mixed regression model was not adequate for predicting the performance of DM yield, since it showed coefficients of determination lower than 80%. The categorical regression achieved to predict DM yield with high precision in the adjustment, according to the established statistical criteria that allowed identifying the variables and effects of greater importance in the rainy and dry periods. The cutting frequency was the one of highest incidence in both periods. [ABSTRACT FROM AUTHOR]

Se condujo un experimento para caracterizar, desde el punto de vista botánico, los clones Cuba CT-16, Cuba CT-44, Cuba CT-74, Cuba CT-115 y Cuba CT-169 obtenidos a partir de cultivo de tejidos in vitro de ápices de king grass (Pennisetum purpureum Schum). Estos clones se seleccionaron aleatoriamente. Se tomaron medidas morfológicas en el tallo, la hoja, la inflorescencia, así como las características anatómicas de la epidermis y la cutícula para un total de 28 descriptores. Los clones difirieron entre sí (P < 0.01) para un grupo de descriptores medidos. El número de estomas fue de 12.7/campo visual en el Cuba CT-74. En los otros, el valor varió entre 2.3 y 3.4, sin diferir entre ellos. Los cuerpos silicios litiformes llegaron a 13.1 en el Cuba CT-115, y sólo a 5.3 en el Cuba CT-44. Hubo un resultado importante en la inflorescencia que tuvo 3 flores hermafroditas, solo en el king grass. Sin embargo, se observaron también entre 3 y 5 flores masculinas en el resto, además de las hermafroditas, cuyo valor varía de 1 a 3. El análisis global de los resultados indicó que los clones 44, 74 y 115 fueron diferentes de su progenitor en 54, 50 y 50 %, respectivamente, para los descriptores empleados. El Cuba CT-16 fue el más semejante al progenitor, igual que el Cuba CT-169 (38 % de caracteres diferentes). Se discute la validez del sistema taxonómico empleado, así como la susceptibilidad de variación de los caracteres vegetativos por influencias ambientales con relación a los reproductivos. [ABSTRACT FROM AUTHOR]

In a group of 70 patients of both sexes been treated with antiinflammatory drugs, affected by Rheumatoid Arthritis in activity, we have found the presence of lesions, erosions and gastroduodenal ulcers in 40% by endoscopic examination (26% erosions and 14% ulcers), without any relation with clinical symptoms. Those patients who received larger doses than 30mgr./kg./day of AAS suffered most frequently lesions (43.8%). These 28 patients with lesions have been studied prospectively in a double blind method, and treated twice a day with 150 mgs. doses of Ranitidine or Placebo, throughout a period of 5 weeks without discontinuing the treatment with anti-inflammatories (AAS, Indomethacin, steroids). At the end of the trial those patients who failed in healing their lesions were treated with Ranitidine in the same doses for another period of 5 weeks. The treatment with Ranitidine in doses of 300 mgr/day has resulted curative of the gastroduodenal lesions, although maintaining the aggressive drugs, in the 87% of the patients. We have observed that the treatment with Placebo is less effective and that difference has high statistical significance (p 0.005).