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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]

In order to evaluate the animal response of a ruminal protein activator in animals which intake a Tetrachne dregei summer grass, differed from autumn and ripe, with the purpose of improving the forages intake and the in vivo dry matter digestibility, two doses of a ruminal protein activator (200 and 400 g. head.d-1) and a control without the activator in 280 kg steers were studied in a metabolism shed. These animals received Tetrachne dregei controlled in a completely randomized design with three treatments, three repetitions and four sampling days for food intake and feces collection measurements. The average composition was of 5.7 and 40.6 % of crude protein, 73.1 and 32.5 % of neutral detergent fiber, for Tetrachne dregei and the ruminal protein activator, respectively. It was estimated 77.52 % of degradable protein in the activator. The control animals, only fed with Tetrachne dregei had lower total dry matter intake, forage dry matter intake and dry matter digestibility with respect to the treated groups(P <0.001), without significant differences. The total dry matter intake, dry matter digestibility and the digestible dry matter intake, was increased in 18.9, 9.3 and 33.6 % respectively, compared to that obtained in the treated animals, (P <0.001) and the forage dry matter intake in 14.5 % (P <0.002), but there were not significant differences between doses. The ruminal protein activator achieved high response to low doses, when increasing the intake of digestible organic matter and degradable protein significantly in 34 and 50 %, respectively (P <0.001). [ABSTRACT FROM AUTHOR]

To characterize morphoagronomical and quality indicators of Megathyrsus maximus cv. Likoni, Mombaza and Tanzania in the dry period, a random block design with five replications and three treatments which corresponding to the studied varieties was used. Plots of 5x7 m were sown and the cutting height was of 10 cm above soil level. The study was developed during two consecutive years. The determined indictors were: dry matter content of the whole plant, height, dry matter yield, morphological composition, length and width of leaves, number of tillers and number of plants/m2. The quality indicators of plants were also analyzed: crude protein, neutral detergent fiber and acid detergent fiber. Mombaza and Tanzania had the highest yields (P < 0.001) during the first year, with values of 3.84 and 3.94 t/ha, respectively, while Likoni and Tanzania showed the highest yields(P < 0.001) in the second year (2.49 and 2.46 t/ha, respectively). The Likoni variety showed the lower (P < 0.001) leaves percentage (65.42 % and 67.84 %) and higher (P < 0.001) of stems (34.58 % and 20.47 %) during the first and second year, respectively. The quality indicators: crude protein, EE, neutral detergent fiber, acid detergent fiber, lignin, cellulose, hemicelluloses and in vitro dry matter digestibility showed no differences between varieties. It is concluded that the plants studied had an adequate agroproductive performance under the edphoclimatic and management conditions in which the study was carried out. The Mombaza and Tanzania varieties are a good option to counteract the lack of food in the dry period because of its higher leaves proportion, which provides a higher quality to the food. [ABSTRACT FROM AUTHOR]

The plant Páramo grasslands ecosystem characterization was carried out by means of field expeditions to eight protected areas that Ecuador maintains through the Ministry of Environment. The expeditions were carried out every two months during three years, to evaluate in situ the botanical composition, frequency, density, height, basal cover and aerial cover. The observations were registered during two periods per year, at 60, 90, 120, 150 and 180 d, for a total of 36 evaluations in each study place. The soil pH varied between 5.0 and 8.5, it is volcanic, with sandy and loamy characteristics. The identified species in the Ecuadorians heathlands were: 169 plants with forage importance, 90 grasses, 14 legumes, 28 compounds and 37 belonging to Equitaceas, Oxalidaceas, Liliaceas, Scrophulariaceas, Rosaceas, Ciperaceas, Poligonaceas, Plantaginaceas, Arbustivas, Orchideaceas, Ranunculaceas and Gentianaceas. A total of eighteen species showed good performance, when locating, at least, in a place. Those of great persistence and adaptation were Agrostis breviculmis, Agrostis exigua, Arrhenatherum pratensis, Arrhenatherum elatius, Bromus lanatus, Bouteloua curtipendula, Calamagrostis bolanderi, Calamagrostis tarmensis, Digitaria floridona, Eragrostis curvula, Euchlaena mexicana, Festuca weberbaueri, Holcus lanatus, Paspalum plicatulum, Paspalum bomplandianum, Poa pratensis, Stipa plumeris and Stipa plumosa. For the production of green and dry forage, respectively, the best were Euchlaena mexicana, with 25.9 and 6.7 t/ha/cut, and Arrhenatherum elatius, with 24.4 and 6.9 t/ha/cut; also Arrhenatherum pratense, with 23.0 and 6.1 t/ha/cut and Stipa plumeris, with 21.9 and 6.8 t/ha/cut. There was great plants biodiversity that can be use for animal feeding, which is observed from other studies of chemical composition and management. [ABSTRACT FROM AUTHOR]

This research was carried out in the Ecuadorian Páramo grasslands, between 2900 and 4200 m o.s.l, in Loja, Zamora Chinchipe, Azuay, Cañar, Chimborazo, Bolívar, Tungurahua, Cotopaxi, Pichincha, Imbabura and Carchi provinces. For the identification and taxonomical classification of species there were taken herborized samples and identified by agrostologists. The Hitchcock, Gould, Lombardo and Tovar taxonomic keys were used for the identification. From the grasses family, in the eight study places, 90 species were identified, including 37 genus, being the mains, with higher number of species: Festuca (14), Paspalum (10), Agrostis (7), Calamagrostis (7), Bromus (6), Stipa (5), Poa (5), Agropirum (3), Arrhenatherum (2), Brisa (2) and Andropogon (2).The species that prevailed in the study places were: Agrostis breviculmis, Agrostis exigua, Bromus lanatus, Calamagrostis tarmensis, Festuca humilior, Festuca ortophylla, Festuca weberbaueri and Paspalum bomplandianum. The diversity indexes of the existent meadow species showed values from mean (0.72) to high (0.90), as for their uniformity. This allowed determining that the biodiversity is variable, according to the environmental conditions of the studied Páramo grassland ecosystems. Similar performance was obtained for trees grasses species. [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]