Time filter

Source Type

Velasquez A.,Area de Produccion Animal | Velasquez A.,Catholic University of Temuco | Marnet P.-G.,Agrocampus Ouest | Arias R.,Austral University of Chile
Ciencia e Investigacion Agraria | Year: 2015

In afirst experiment, the effect of in vitro incubation with Aspergillus niger (An) on the chemicalcomposition of different fibrous substrates was studied. In a second experiment, the effectof incubation time (0, 72 and 144 h) on in vitro digestion with An of dry matter (IVDMD), neutral detergent fiber (DVNDF) and acid detergent fiber (DVADF) was evaluated for differentsubstrates. Wheat straw, WS; barley straw, BS; oat hulls, OH; dehydrated alfalfa, DA; anddehydrated ryegrass, DB substrates were evaluated. In both experiments, incubations wereperformed in 250 mL Erlenmeyer flasks; 2 g of substrate was added to a culture medium (pH= 6), and incubated at 28 °C with constant ventilation. The An dose consisted of 3 mL of asolution of 5.3 × 106 spores mL-1 per flask. Incubation time for the first experiment was 144h. After incubation, the contents of the flasks were homogenized in a blender for one minute.Subsequently, bromatological analysis was conducted without separating the An biomass. Nointeraction effects among any studied variables were observed. An incubation effected cell wall(NDF) and lignocellulose (ADF) content. An increase in true protein (TP) and soluble nitrogen(SN) was observed for all substrates tested, but responses differed depending on the type ofsubstrate. The largest increases in TP were observed in DA and DB substrates (0.55 and 0.63%DM, respectively). IVDMD, DVNDF and DVADF were affected by the type of substrate andincubation time. The highest value of IVDMD144 was observed in the DAAn treatment (49.47%DM), followed by the DBAn treatment, with a value of 45.51% DM. OHAn showed thelowest value of IVDMD144 (29.38% DM). The results suggest that An possesses fibrolytic andmetabolic potential for improving the nutritional value of fibrous foods through of the digestionof structural carbohydrates and the liberation of nitrogenous fractions embedded in cell walls, producing a change in the chemical composition and the potential digestibility of treated foods. © 2015, Ciencia e Investigacion Agraria. All right reserved.

Gonzalez-Martin M.I.,National Autonomous University of Mexico | Hernandez-Hierro J.M.,National Autonomous University of Mexico | Revilla I.,Area de Tecnologia de Los Alimentos | Vivar-Quintana A.,Area de Tecnologia de Los Alimentos | And 4 more authors.
Talanta | Year: 2011

Two independent methodologies were investigated to achieve the differentiation of ewes' cheeses from different systems of production (organic and non-organic). Eighty cheeses (40 organic and 40 non-organic) from two systems of production, two different breeds of ewe, different sizes, seasons (summer and winter) and ripening times up to 9 months were elaborated. Their mineral composition or the information provided by their spectra in the near infrared zone (NIR) coupled to chemometric tools were used in order to differentiate between organic and non-organic cheeses. Main mineral composition (Ca, K, Mg, Na and P) of cheeses and stepwise lineal discriminant analysis were used to develop a discriminant model. The results from canonical standardised coefficients indicated that the most important mineral was Mg (1.725) followed by P (0.764) and K (0.742). The percentage of correctly classified samples was 88% in internal validation and 90% in external validation, selecting Mg, K and P as variables.Spectral information in the NIR zone was used coupled to a discriminant analysis based on a regression by partial least squares in order to obtain a model which allowed a rate of samples correctly classified of 97% in internal validation and 85% in external validation. © 2011 Elsevier B.V. All rights reserved.

Mata J.,Area de Produccion Animal | Bermejo L.A.,Area de Produccion Animal | de Nascimento L.,Area de Produccion Animal | Camacho A.,Area de Produccion Animal
Small Ruminant Research | Year: 2010

The concept of grazing in general and goat grazing in particular, as the cause of the deterioration of ecosystems in all conditions, has profound roots in society and in the scientific community, mainly ecologists and environmentalists. Many authors have considered goats as destructive animals by nature, and grazing by these animals is considered one of the main reasons for desertification, habitat degradation or loss, extinction and deterioration of native vegetation, sometimes leading to legislative procedures for control and eradication of goat grazing. These aspects are of special interest in arid, semiarid or climatic non-equilibrated areas, where ecosystems are more sensitive to biotic and abiotic disturbances, and where stability and sustainability of vegetation resources is a complex equation. In this paper different methodologies and impact indicators are analysed to improve the management of goat grazed areas, by discussing different points of view which go from analytical procedures to new indicators and methodologies integrated into a dynamic monitoring scheme in accordance with the complexity of the ecosystems. These methodologies can be able to incorporate trend and condition measurements in the ecosystems, and also be able to detect grazing effects, as well as longer-term trends. The importance of local knowledge is also taken into consideration as a key element to achieve the sustainability of goat grazing systems. © 2009 Elsevier B.V. All rights reserved.

Loading Area de Produccion Animal collaborators
Loading Area de Produccion Animal collaborators