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San Juan de los Morros, Venezuela

Herrera A.M.,National Experimental University of Tachira | Martinez N.,Central University of Venezuela | Herrera P.,University Simon Rodriguez | Colmenares O.,University Romulo Gallegos | Birbe B.,University Simon Rodriguez
Zootecnia Tropical | Year: 2010

To evaluate the effect of the supplementation with multinutritional blocks (MB) on milk production, 20 dual purpose cows were used with breeding and 1 or 2 calving, in hilly area of the central plains of Venezuela. The experiment was carried with duration of 60 days of supplementation and 30 additional days of evaluation. A completely randomized design was used, with two groups: Control group (CG) (n=10): animals with ad libitum basal diet and Experimental group (EG) (n=10): animals with diet basal ad libitum plus MB. Sold milk and consumed by the calf were measured, and used to estimate total milk. As basal diet these animals were in paddocks with species like Cynodon nlemfuensis, Panicum maximun, Andropogon gayanus, Brachiaria arrecta and Dichanthium aristatum, and consumed milled hay of Cynodon nlemfuensis and crop residues of Sorghum bicolor in corrals. The chemical composition of the MB was: 29,6% of crude protein, 2,1% of ethereal extract, 16,9% of DNF, 9,9% of calcium and 2,5% of phosphorus. The average of MB intake was 67,92± 21,41 g.100 kg-1 live weight. The effect of treatment was significant in the milk consumed by the calf (P<0,01), with EG=1,17 ± 0,34 and CG= 0,75 ± 0,36 kg; sold and total milk did not show significant differences between treatments (P>0,05). A tendency exists to the increase in the milk production in supplemented cows with multinutritional blocks in these conditions, evidenced in the consumption of milk by the calf. Source

Rios Cabrera Maria M.,Libertador Experimental Pedagogical University | Magaly R.D.,University Romulo Gallegos | Ruben M.R.,Libertador Experimental Pedagogical University | Hugo G.,Libertador Experimental Pedagogical University
Revista Geografica Venezolana | Year: 2010

An exploratory study of the physical properties and organic matter of soils located in the Maracay River basin (Aragua State, Venezuela) was carried out to relate them to the susceptibility to produce the debris flows. Some physical properties were characterized by means of a univariant descriptive analysis and were compared taking as a reference their structure and its association with the cohesion and the adhesiveness. It was found that the soils located in the highest zone are homogenous in sand content, generally higher than 60% and shows variability with regard to the contents of silt and clay. The relationship between sand and clay is 10:1. According to the obtained limits of Atterberg, these soils are characterized by their low plasticity, susceptible to pass from the plastic to the liquid state when adding reduced portions of water, which magnifies the risk of occurrence of sliding of the materials, condition that can worsen with the anthropic intervention. Source

Olivo A.,Central University of Venezuela | Ojeda A.,Central University of Venezuela | Landinez J.,University Centroccidental Lisandro Alvarado | Pizzani P.,University Romulo Gallegos
Livestock Research for Rural Development | Year: 2013

The objective was to evaluate the effect particle size of supplement and two non proteic nitrogen (NPN) sources on in vitro gas production and apparent degradation of Cynodon dactylon (6.3% PC, 36.6% FC, 0.37% Ca and 0.79% P). A complete randomized design with a 3×2 factorial arrangement, three particles size (PS: 0.5, 1 and 2 mm Ø) of rice grain and two NPN sources with different rate of release: urea and protected urea, was used. Protected urea was a commercial product consisting of granulated urea covered with a slowly biodegradable polymers film. The rice grain was equivalent to 20% fibrous resource, including urea or protected urea in respect to 8.7 g NPN/kg diet. Gas production at 3, 6, 9, 12 and 24 h, and apparent degradation of dry and organic matter at 24 h were measured. Independently of the NPN source used, and after 12 h of fermentation, 0.5 mm PS increased (P= 0.03) the gas production in 32.7%, and the dry and organic matter degradation (P<0.01) in 14.5 and 14.1%, respectively. No effects (P>0.05) were observed of the others evaluated factors in the rest of the fermentation period. The present study showed that protected urea didn't have effects on the parameters of in vitro ruminal fermentation, and the supplement particle size could be considered a tool to increase the fibrous resources used by ruminants. Source

Manrique A.J.,Federacion Bolivariana de Apicultores de Venezuela FEBOAPIVE | Colmenares O.,University Romulo Gallegos
Zootecnia Tropical | Year: 2014

The present research was carried out from february 2009 to february 2012, in Experimental Station “Jaime Henao Jaramillo”, Universidad Central de Venezuela, located in Guaicaipuro municipality, Miranda state, Venezuela. Some colonies of bees (Apis mellífera) produce more propolis than others, and this characteristic is genetically controlled; usually these propolis are produced by scraping, doubt to in certain areas the nets are full of beeswax and not with propolis. The objectives were to select and improve (genetically) propolis collector bees, and to determine seasonality in propolis production, using collector plastic screen. Base population were 50 colonies of Africanized honey bees, being evaluated 25. The best colony was selected as parent of the next generation, evaluating 11 selected colonies (S1) versus 13 non selected colonies (NS1) the first year, and 11 selected colonies (S2) versus 13 non selected colonies (NS2) thesecond year. Obtained results indicated higher values of propolis production in S1 andS2, statistically differents (P<0.05) to NS1and NS2, with averages of 623.36; 684.45; 365.61 y 420.61 g of propolis/colony/year, respectively. The propolis production was superior during December, January and February. Determined the bees respond to selection to improve the propolis production, there was seasonality collection propolis and the used nets were useful to collect them, in the evaluated conditions. © 2014, Instituto Nacional de Investigaciones Agricolas (INIA). All rights reserved. Source

Schargel W.E.,University of Texas at Arlington | Rivas G.A.,University of Zulia | Makowsky R.,University of Alabama at Birmingham | Senaris J.C.,Museo de Historia Natural la Salle | And 4 more authors.
Systematics and Biodiversity | Year: 2010

The phylogenetic relationships and species boundaries of the diurnal geckos of the genus Gonatodes in the Guayana region are examined. Seven species of Gonatodes are recognized for the region, six of which are endemic to this region and form a monophyletic group together with G. hasemani from the southern part of the Amazon Basin. Two of the six species in this group are new to science, one of which is endemic to Venezuela and it is described here. Taxonomic accounts are provided for all the Venezuelan species of Gonatodes that are endemic to the Guayana region. The phylogenetic relationships of Gonatodes suggest that the diversity of this genus in the Guayana region has resulted mostly from in situ diversification rather than multiple colonization events by different lineages. The phylogenetic analyses also support that G. antillensis, the only nocturnal species in the genus, is indeed nested within Gonatodes, indicating re-evolution of some traits associated with nocturnal life. Finally, we comment on a recently proposed framework of temporal diversification in Gonatodes and suggest that we are still a long way from attaining a complete understanding about the systematics of this genus. © 2010 The Natural History Museum. Source

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