Universidad Nacional Agraria La Molina. Escuela de Posgrado. Maestría en Nutrición

The evaluation of the mean fibre diameter (MFD) and the incidence of representative medullation of alpaca fleeces in 10 g samples of fibres from the mid-rib area is usually carried out to identify fine animals in genetic improvement programmes. Subsamples are usually taken from each sample to determine the MFD with some type of measuring instruments; however, due to the great variability of the diameter between staples, between fibres and along the same fibre, there is no consensus on the number of subsamples to use to achieve a representative result for the sample. In the present study, results from a range of subsamples were evaluated against the result of the total subsamples for MFD measurements and for measurements of the following additional variables of interest in alpaca fleeces: total percentage of medullated fibres (PMedT), percentage of fibres with fragmented medulation (PMedF...

The aim of this study was to determine the effect of two ages of the long-spine acacia tree (Acacia macracantha) on the physical and chemical characteristics of the soil in a silvopastoral system with Guinea grass (Panicum maximum Jacq). The study was conducted in the Bellavista district, Cajamarca, Peru. The mechanical resistance, apparent density, humidity and temperature of the soil, as well as the content of organic matter, phosphorus (P2O5) and potassium (K2O) were evaluated in three soil locations: under the canopy of young (BCAj) and medium trees (BCAm) and outside the tree canopy (FCA), in two seasons of the year (dry and rainy). A complete randomized design with factorial arrangement 3 (location) x 2 (seasons) was used. Under the canopy of the medium trees, a lower soil temperature (27.96 °C) and higher soil humidity (15.23%) were found, in addition to improving soil fertility....