The aim of this study was to determine the growth rate and nutritional quality of Guinea grass (Panicum maximum Jacq) under a silvopastoral system with the faique tree (Acacia macracantha). The evaluation included two seasons (rainy and dry) and three treatments: (1) under the canopy of the young tree, (2) under the canopy of the medium-size tree, and (3) outside the canopy of the tree. The trees were classified according to the diameter at chest height. The growth and quality of the grass were measured by the method of cutting and separation and subsequent laboratory analysis. The growth rate ranged from 71.09 to 51.15 kg DM/ha/d, outside and inside the tree canopy, respectively, in the rainy season. Crude protein varied from 10.58, 12.79 and 13.88% (rainy season) and 8.93, 10.26 and 11.99% (dry season) outside the tree canopy, under the young tree canopy and under the middle tree canop...

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....

The value of a forage plant depends not only on its productivity but also on its acceptance and preference of the animals. The aim of this study was to evaluate the forage yield, chemical composition, acceptance and preference of three forage legumes (Arachis pintoi, Stylosanthes guianensis and Centrocema macrocarpum) in Girolando female calves under tropical conditions. Experiment 1: Production (KgMS/h) and Nutritional Value (%) of the species from quarterly cuts and for one year after the growth phase has ended. Experiment 2: Acceptability was determined by the intake rate (g/min) of each species in six calves without experience in their consumption, when they were offered individually to the animals for 5 min daily for three consecutive days. Experiment 3: Preference was estimated from the relative intake (%) in individual pens when the three species were offered for 10 min daily for ...

The aim of this study was to determine the growth rate and nutritional quality of Guinea grass (Panicum maximum Jacq) under a silvopastoral system with the faique tree (Acacia macracantha). The evaluation included two seasons (rainy and dry) and three treatments: (1) under the canopy of the young tree, (2) under the canopy of the medium-size tree, and (3) outside the canopy of the tree. The trees were classified according to the diameter at chest height. The growth and quality of the grass were measured by the method of cutting and separation and subsequent laboratory analysis. The growth rate ranged from 71.09 to 51.15 kg DM/ha/d, outside and inside the tree canopy, respectively, in the rainy season. Crude protein varied from 10.58, 12.79 and 13.88% (rainy season) and 8.93, 10.26 and 11.99% (dry season) outside the tree canopy, under the young tree canopy and under the middle tree canop...

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

Universidad Nacional Agraria La Molina. Escuela de Posgrado. Doctorado en Ciencia Animal

The models of growth and allometry of grasslands allow to know growth and development phenomena. Consequently, the aim of this study was to develop a multi-species allometric model to estimate biomass in three grasses in the High Andean Zone of Jauja, Peru, at an altitude of 3600 m above sea level. The native grasses were Festuca dolichophylla (J. Presl) tall (50-90 cm), Festuca humilior (Nees & Meyen) medium (20-35 cm) and Calamagrostis vicugnarum (Weddell) Pilger short (5- 25 cm). The measured variables were biomass (g, YB), basal diameter (cm, XD), canopy diameter (cm, XC) and height (cm, XH). The potential regression was used by choosing the strength of the models by the Akaike criterion (IAC) and the adjusted coefficient of determination (adjusted R2). The multispecies allometric model was Y = 1,238 * XD2,231, due to its lower IAC (383.795) and higher adjusted R2 (85.4%). C. vic...

The models of growth and allometry of grasslands allow to know growth and development phenomena. Consequently, the aim of this study was to develop a multi-species allometric model to estimate biomass in three grasses in the High Andean Zone of Jauja, Peru, at an altitude of 3600 m above sea level. The native grasses were Festuca dolichophylla (J. Presl) tall (50-90 cm), Festuca humilior (Nees & Meyen) medium (20-35 cm) and Calamagrostis vicugnarum (Weddell) Pilger short (5- 25 cm). The measured variables were biomass (g, YB), basal diameter (cm, XD), canopy diameter (cm, XC) and height (cm, XH). The potential regression was used by choosing the strength of the models by the Akaike criterion (IAC) and the adjusted coefficient of determination (adjusted R2). The multispecies allometric model was Y = 1,238 * XD2,231, due to its lower IAC (383.795) and higher adjusted R2 (85.4%). C. vic...

The objective of this study was to determine the enteric methane (CH4) emission factor (EF) at the national level for Peruvian dairy cattle following the IPCC Tier II (2006, 2019) methodology. Data were collected from seven regions of Peru and classified according to the type of feeding as intensive, semi-intensive or extensive. It included farm information (geolocation) and livestock information for two seasons of the year. At the national level, lactating cows obtained the highest EF with 117 kg CH4/head/year, followed by heifers from 15 to 24 months of age (91 kg), non-lactating cows (74 kg), heifers from 12 to 15 months of age (67 kg), calves (62 kg) and pre-weaned calves (16 kg). Additionally, the highest EF was reported for lactating cows in the intensive system (151.8 kg CH4/head), which is 46.8 kg CH4/head more per year than that reported in the semi-intensive and extensive syste...