Gustavo Jaurena

Gustavo Jaurena
University of Buenos Aires - School of Agriculture · Animal Production

Ing. Agr. (UBA); MSc. (Pontificia Univ. Católica de Chile); PhD. (Univ. of Wales)

About

118
Publications
16,279
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Citations
Introduction
Animal nutrition scientist. Major fields of interest: - Ruminant Nutrition, - Animal Feeds Quality Assessment - Forage Conservation (hay and silage), - Prediction of Methane emission by livestock. Present topics of work: - in vitro systems to assess feeds quality, - Mitigation strategies of methane emissions by livestock - Improvement of silage conservation, - Interactions between animal production systems and environmental impacts.
Additional affiliations
March 2008 - present
Universidad de Buenos Aires, Facultad de Agronomía
Position
  • Professor (Associate)
Description
  • Animal Nutrition for Students in Agriculture
March 1983 - present
University of Buenos Aires
Position
  • Professor (Associate)
Education
July 1999 - July 2003
University of Wales
Field of study
  • Animal Science
March 1994 - July 1996
Pontifical Catholic University of Chile
Field of study
  • Animal Science
March 1980 - July 1985
University of Buenos Aires
Field of study
  • Animal Production

Publications

Publications (118)
Article
Corn-derived starch and rumen-degradable protein (RDP) available for rumen microbial fermentation vary significantly with corn hybrid and environmental conditions. Identifying corn physicochemical traits potentially correlated with ruminal DM digestibility would facilitate the prediction of its nutritional value compared with more time-consuming de...
Article
Enteric methane (CH4) emissions from sheep contribute to global greenhouse gas emissions from livestock. However, as already available for dairy and beef cattle, empirical models are needed to predict CH4 emissions from sheep for accounting purposes. The objectives of this study were to: 1) collate an intercontinental database of enteric CH4 emissi...
Article
Full-text available
Increased dietary inclusion of rapidly-fermentable carbohydrates and a great proportion of corn-derived CP may result in increased rumen degradable protein (RDP) microbial requirements and reduced RDP supply, respectively. An experiment was conducted to evaluate the effect of processing and moisture content of corn grain in finishing diets concurre...
Article
Full-text available
Livestock systems based on subtropical and tropical pastures are characterized by the low productivity of livestock due to the poor nutritional value of the forage (low nitrogen concentration and digestibility, and high fiber and lignin concentrations). These conditions lead to low productivity and, consequently, high absolute emissions of methane...
Conference Paper
Full-text available
Measurement of enteric methane is expensive and not practical in most farms. Reliable prediction models have been developed recently for dairy and beef cattle based on intercontinental databases; however, equivalent sheep models are not yet available. This study aimed to: 1) collate an intercontinental database from individual sheep; 2) identify th...
Article
Full-text available
The objective of this work was to analyze the effect of the addition of condensed tannins (CT) in the efficiency of digestion, methanogenic potential and energy distribution between the fermentation products of two forages. An assay was carried out using the in vitro gas production technique in which extracts of Quebracho (Schinopsis balansae) and...
Article
Full-text available
BACKGROUND The in vitro gas production technique has been used to evaluate forage fermentation kinetics. However, individual and animal species variation can change fermentation patterns due to differences in ruminal environment and microbiota. The aim was to verify whether rumen inoculum (RI) of llama had superior intrinsic digestion capacity and...
Article
Full-text available
Latin America and Caribbean (LAC) is a developing region characterized for its importance for global food security, producing 23 and 11% of the global beef and milk production, respectively. The region's ruminant livestock sector however, is under scrutiny on environmental grounds due to its large contribution to enteric methane (CH4) emissions and...
Article
Lotus tenuis is a glycophytic forage legume (Fabaceae) used in feeding ruminants that can grow under salinity and waterlogging stresses. Plants obtained in controlled conditions were affected negatively in their growth by the effect of salt. Results from sequential extraction of plant cell wall polysaccharides and chemical characterization were rel...
Article
Full-text available
Implications ● Cattle production systems are facing dramatic changes due to increased social demands for cheap, safe and high quality products with less environmental impacts. ● Social demands are boosted by a not well educated perception of agricultural productive systems and legitimate concerns about environmental and animal welfare issues. ● Fut...
Article
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In vitro gas production techniques represent a valuable tool to describe the kinetics of ruminal degradation of food. However, the ruminal liquor used as a microbial inoculum has been a great source of variation and error. A standardization of this factor should contribute to assure the independence of food fermentation parameters from those of the...
Article
Full-text available
Los subproductos provenientes de la agroindustria suelen presentar una alta variabilidad en su calidad nutricional. Esto resulta problemático al momento de utilizarlos en dietas destinadas a producción animal. En el presente trabajo se analizó mediante ensayos químicos, in sacco y encuestas el perfil nutricional y la variabilidad de expellers y har...
Chapter
Full-text available
La disponibilidad de técnicas objetivas para medir o predecir las emisiones de gases de efecto invernadero (GEI) es fundamental para el desarrollo de trabajos de investigación y de gestión de las emisiones de GEI en los sistemas agropecuarios. Existe una variada disponibilidad de técnicas e instrumentos que permiten abordar estudios a nivel ruminal...
Chapter
Full-text available
Introducción Los productos de origen animal, y en especial la carne, son y serán en el futuro mediato objeto de una creciente demanda. Así lo han señalado distintos analistas macroeconómicos e instituciones de carácter nacional e internacional-e.g. la FAO (Organización para la Cooperación y el Desarrollo Económico, OCDE), USDA (Departamento de Agri...
Article
Full-text available
Background The use of agroindustrial by-products in ruminant nutrition to be an interesting alternative in order to reduce production costs and environmental impacts arising from the inadequate destination of residues. The initial step of beer production yields a large volume of wet brewer’s grains all year around, which is available at a low cost...
Article
The objective of this study was to assess the ruminal microbial population and fermentation of sheep and llamas fed low quality forages. Two llamas and three sheep with permanent ruminal cannula were fed ad libitum with a low quality fescue hay (Festuca arundinacea Schreb). The animals were adapted to forage feeding for 21 days, followed by one day...
Article
Full-text available
Ruminants are capable of degrading and fermenting the forage cell wall components. In reticulo-rumen, the microbial fermentation partition gross energy of the substrate into volatile fatty acids, microbial biomass (MB) and waste gases (e.g. methane, CH4). These gases are eliminated and they represent, not only environmental pollution due to its gre...
Article
Previous results have shown that during late gestation even under conditions of live weight (LW) gain, maternal body protein can be in negative balance due to the highly demanding gravid uterus and udder. It has also been claimed that current feeding standards underpredict dry cow nitrogen (N) requirement. Considering that it is not possible to mea...
Article
Energy and protein supply during the dry period can affect subsequent milk production and composition (Moorby et al. , 1996). Grass silage is a common ingredient of dry cow diets, but although it is usually adequate in crude protein concentration (CP), a high proportion is frequently in non-protein forms. Red clover silage has shown interesting cha...
Article
Despite many promising characteristics as a low-input home-grown protein source, red clover (Cv) silage supplies deficient amounts of rumen available carbohydrates to allow an efficient use of the available forms of soluble N. An in vitro experiment was designed in order to determine the optimum rate of inclusion of a rumen degradable carbohydrate...
Research
Full-text available
Presentado en el Congreso Argentino de Producción Animal 2015 RAPA Vol. 35 Supl. 1: 259-322
Article
An experiment was designed to study the effect of precalving supplementation with protein (Pr) 29 and rumen-inert fat (F) on body composition, and subsequent milk production and composition. Forty 30 Holstein-Friesian dairy cows were allocated to one of four dietary treatments in the dry period (DP) 31 based on a first cut ryegrass silage, with 6 M...
Article
Full-text available
Las emisiones de metano por parte de los sistemas de ganadería bovina son motivo de creciente preocupación por parte de amplios sectores de la población. La raíz nutricional de la generación de metano entérico, así como la rápida respuesta asociada a los cambios en la alimentación, ha contribuido a que el manejo nutricional esté entre las estrategi...
Article
Full-text available
The objective was to assess the impact of application of two enzyme mixtures on the in vitro dry matter digestibility, neutral detergent fibre digestibility, net cumulative gas production and methane production after 24 h of incubation of Milium coloratum (formely Panicum coloratum) and a Patagonian meadow grassland. A protease (Protex 6-L) and a f...
Article
Methane emission factor (Ym) is directly involved to calculate the worldwide livestock methane inventories, hence it is important to refine the estimation of this parameter for different livesctock production systems. The purpose of this work was to generate refined mathematical models to predict CH4 emissions from an extensive compilated database...
Article
Full-text available
In plants, compensatory growth takes place when the positive effects of defoliation compensate the negative ones, and defoliated plants show a similar or increased production in relation to non-defoliated plants. Our objective was to evaluate the ability to compensate defoliation of Poa spicifbrmis, a forage perennial tussock grass in southern Pata...
Conference Paper
Full-text available
COMUNICACIÓN El componente ambiental en la formación profesional en producción agropecuaria. Jaurena, G.*(1), Herrero M.A.(2), Ayala Torales A.(1), Gil, S.(2). (1)Facultad de Agronomía UBA, (2)Facultad de Ciencias Veterinarias UBA. *gjaurena@agro.uba.ar Environmental contents in undergraduate programs of agronomy related sciences. En el ámbito...
Article
Full-text available
Control of dry matter losses (DML) is a major concern of forage conservation systems. Measuring DML during hay and silage storage is difficult and time-consuming, so it is usually limited to experimental conditions. The lack of a practical way of measuring DML to monitor forage conservation efficiency has contributed to the poor adoption of good pr...
Article
Full-text available
The evaluation of animal feeds is a crucial link for the normal development of commercial and scientific activities related to Animal Production. The "Programme for the Improvement of Forage and Feedstuffs Assessment" (PROMEFA) is carried out within the "Animal Nutrition Research and Services Center" (CISNA), at School of Agriculture of the Univers...
Conference Paper
La formulación de raciones requiere de la valoración energética de todos los ingredientes, sin embargo existen escasos modelos para predecir la digestibilidad in vitro de la materia seca (ivDMS) para concentrados proteicos basados en resultados de química húmeda. El objetivo fue desarrollar modelos de predicción de la ivDMS de concentrados proteico...
Conference Paper
La producción de metano de los forrajes al ser digeridos por los rumiantes puede estar influida por su composición (e.g. presencia de compuestos antinutricionales como saponinas o taninos). La técnica de producción de gas (PG) in vitro permite medir la digestibilidad de la materia seca, estimar la degradabilidad y la producción de metano (PCH4). El...
Conference Paper
El metano generado durante el proceso de digestión de los rumiantes, constituye una pérdida de energía, y contribuye al efecto invernadero. Las diferencias en la capacidad metanogénicas de diferentes forrajeras son previsibles, pero las dificultades técnicas han dificultado su uso para las evaluaciones de calidad. La técnica de producción de gas (P...
Article
Full-text available
Livestock activity in the Argentinian «Tierra del Fuego» island is based on highly variable natural grasslands (NG). The conservation of fodder, despite the unfavorable environment, is restricted to hay; conservation as silage could be constrained by fodder quality and low temperatures. The objective was to assess the quality of NG silages fermente...
Article
Relatively low ruminal pH values have been frequently registered in dairy cows grazing alfalfa, which can be involved in reducing feed digestion. An in vitro experiment was carried out to study the effect of ruminal pH (6.4, 6.1, 5.8 and 5.5) on the digestion of fresh alfalfa. Decreasing the pH, in vitro gas production (ivGP) decreased (P < 0.05)....
Article
Las perdidas de materia seca (PMS) y de nutrientes durante la conservación de forrajes pueden ser cuantiosas y determinan la eficiencia del sistema de conservación elegido. Lamentablemente el control de las PMS es difícil y costoso, y la falta de una forma práctica y sencilla de medición dificulta su control parte de productores, extensionistas y c...
Conference Paper
Full-text available
En Patagonia Austral, la producción ovina depende casi exclusivamente de los recursos forrajeros naturales y está severamente limitada por la baja calidad del pastizal natural y las condiciones climáticas adversas. Muy frecuentemente no se logran cubrir los requerimientos nutricionales de los animales con las consecuentes perdidas en productividad....
Article
Bacterial protein supply from the rumen is frequently low in animals fed on silage-based diets, partially because of the lack of rumen available sources of energy. An in vitro experiment was designed to determine the optimum rate of inclusion of rolled barley to optimise rumen efficiency of bacterial protein synthesis (EBPS) of diets comprising a t...
Article
La actividad ganadera en Tierra del Fuego se caracteriza por la explotación extensiva de ovinos doble propósito (Corriedale) y bovinos para carne sobre recursos forrajeros de oferta variable a lo largo del año (cuanti-cualitativamente). Aunque escasamente empleados, los rollos de heno dispuestos a la intemperie constituyen la principal forma de con...
Article
En la técnica de producción de gas in vitro el gas indirecto es producto del desplazamiento del buffer carbonato/bicarbonato (CB) tradicional y es una fuente de variación que no proviene de la fermentación del alimento. Por el contrario, el buffer fosfato/citrato (FC) no contiene compuestos en equilibrio con la fase gaseosa y en consecuencia no apo...
Article
The lactation cycle of the dairy cow induces large changes in body fat and protein pools, which can be monitored through loin backfat (BF) and longissimus dorsi (LD) measurements. Data from two experiments (exp) using Holstein-Friesian dairy cows (no. = 40 and 32 respectively) were used to study the association of body weight (BW), BF and LD depth...
Article
Bacterial protein supply from the rumen is frequently low in animals fed on silage-based diets, partially because of the lack of rumen available sources of energy. An in vitro experiment was designed to determine the optimum rate of inclusion of rolled barley to optimise rumen efficiency of bacterial protein synthesis (EBPS) of diets comprising a t...
Article
The association among feeding, body fat reserves, plasma leptin concentration and intake has been indicated in many reports, however the characteristics of these associations in late pregnant ruminants is not yet completely clear. As part of a larger experiment concerned with nutrition during the dry period (DP), a study was undertaken to identify...
Article
Nutritional regime during the dry period (DP) has been shown to affect lactational performance in dairy cows. These responses could be mediated by a variety of mechanisms ( e.g. increased labile body proteins, function of the mammary gland or the liver, or modifying endocrine status), which are likely to exert an overlapping function.This study ana...
Article
Full-text available
The low content of water soluble carbohydrates (WSC) and the high buffering capacity usually constrains lucerne (Medicago sativa) ensilability. However, there are other sources of readily fermentable substrate and positive effects of adding cereal grains to wet silages have been reported. An experiment was carried out to study the contribution of h...