Evaluación del residuo del cultivo de agaricus bisporus como alimento de vacas lecheras en lactancia media / evaluation of the agaricus bisporus spent compost as feed of dairy cows in mid lactation

Resumen. Se evaluó el potencial del residuo del cultivo de la seta Agaricus bisporus como materia prima para la alimentación de vacas lecheras en segundo tercio de lactancia. Para esto, se sustituyó 10% del concentrado comercial por el residuo (sin turba) y se evaluó su efecto en la producción, el balance nutricional de las vacas y el costo final del concentrado. El diseño experimental fue un cross-over o de intercambio con medidas repetidas en eltiempo. Cada periodo experimental tuvo una duración de 14 días. Se utilizaron dos grupos de animales, uno con 4 vacas Holstein y otro con 4 vacas cruzadas Holstein x BON. En promedio, las vacas tenían 117 ± 18,6 días en leche, 2,6 ± 0,9 partos, 529,5 ± 52,9 kg peso vivo y una producción de leche/día de 15,42 ± 2,6 L. El tratamiento experimental redujo los nutrientes digeribles totales de la dieta total en 2%. No hubo diferencias estadísticas en el balance nutricional de las vacas a causa del tratamiento experimental. Tampoco hubo diferencia estadística en cuanto a la producción de leche (14,4 L) y calidad composicional (% de grasa:3,86; % de proteína: 3,5; relación grasa: proteína: 1,11). El análisis de costos mostró que al incluirse en el concentrado un 10% del residuo de A. bisporus (Champiñosa) se obtenía una reducción en los costos de alimentación de $403 pesos colombianos/vaca/día. / Abstract. This study evaluated the potential of the growth bed of the mushroom Agaricus bisporus as a feed for mid lactation dairy cows. We replaced 10$403 colombian pesos/cow/day

Limitaciones físicas y químicas de la digestibilidad de pastos tropicales y estrategias para aumentarla

The high fiber content in tropical forages, and its limited digestion by ruminants, is one of the greatest limitations to adequate animal productivity in the tropics. The discussion in this paper focuses in two areas: The first relates to voluntary intake by grazing rumi­nants, the factors that affect it and practical methods to increase intake in grazing or high-fiber consuming ruminants. For the value of discussion, it must be recognized that although assessment of voluntary intake of confined animals is not complicated, estimations of intake by grazing animals have been traditionally difficult and often imprecise. The implementation of pasture renovation strategies, the use of mixed (grass – legume) swards and of strategic supple­mentation, have often been reported as suc­cessful methods to increase voluntary intake by grazing ruminants. The second area of discussion relates to fiber digestibility in ruminants and includes comments on practi­cal ways to increase rumen fiber degrad­ability. Both areas are highly related with each other, and adequate understanding and management of factors that affect these two processes is needed to ensure the economic and environmental sustainability of cattle production in the tropics.El alto contenido de fibra en forrajes tropicales y su reducida digestibilidad por los rumiantes, es uno de los más grandes limitantes para la productividad animal en el trópico. En este artículo la discusión se centra en dos grandes áreas. La primera tiene que ver con el consumo voluntario de rumiantes en pastoreo, factores que lo afectan y estrategias exitosas para incrementarlo. Debe reconocerse que, aunque de fácil determinación en animales estabulados, la estimación de este parámetro bajo condi­ciones de pastoreo ha sido tradicionalmente difícil e imprecisa. Estrategias como la renovación de praderas, el establecimiento de asociaciones gramínea – leguminosa y la suplementación estratégica, han sido utilizadas exitosamente para aumentar el consumo voluntario de rumiantes en pastoreo. La segunda área de discusión describe los factores que afectan la digestibilidad de la fibra en rumiantes y plantea estrategias para aumentar la degradabilidad de la fibra en el rúmen. Ambas áreas están muy relacionadas entre sí, pues del adecuado entendimiento y optimización de ambos procesos, depende gran parte de la sostenibilidad económica y ambiental de la gana­dería del trópico

In Vitro Degradability Kinetics of Maralfalfa (Pennisetum sp.) Silage with Different Levels of Inclusion and Concentration of Sugar Cane (Saccharum Officinarum) Vinasse

RESUMEN: El uso de aditivos promueve cambios en las características químicas y estructurales del forraje durante el periodo de ensilado. Recientes estudios han mostrado que la vinaza de caña puede aprovecharse como aditivo y servir como una fuente importante de sustratos que faciliten la hidrólisis de los componentes estructurales de la pared celular vegetal, aumentando la degradabilidad de la MS. El objetivo del presente estudio fue evaluar la cinética de la degradabilidad in vitro del ensilaje de Maralfalfa elaborado con diferentes niveles de inclusión (3%, 6% y 9% por kg/FV) y concentración (20%, 30% y 40% de MS, respectivamente) de vinaza de caña. La degradabilidad de la MS, se determinó mediante la técnica in vitro de producción de gases. Los datos fueron analizados utilizando un diseño completamente al azar en un arreglo factorial 3 x 3 + 1 con 5 repeticiones. La inclusión de vinaza aumentó la degradabilidad in vitro de la MS con respecto al control (59,1% versus 51,8% a las 72 h, respectivamente; p<0,05). Asimismo, con la inclusión de vinaza se aumentó la fracción soluble (A; 14,62% versus 3,68%) y la degradabilidad efectiva (48,4% versus 47,4%) con respecto al control, respectivamente (p<0,05). Se concluye que la vinaza de caña es un aditivo que mejora la degradabilidad in vitro y el valor nutricional de ensilajes elaborados a partir de materias primas de baja calidad nutricional.ABSTRACT: The use of additives promote changes in the chemical and structural characteristics of fodders during the silage process. Recent studies have shown that sugar cane vinasse can be utilized as an additive and serve as an important source of substrates which facilitate hydrolysis of the structural components of plant cell wall, increasing DM degradability. The aim of this study was to evaluate the in vitro kinetics of Maralfalfa silage degradability under different levels of inclusion (3, 6, and 9% per kg/FV) and concentration (20, 30, and 40% DM, respectively) of sugar cane vinasse. The DM degradability was determined by the in vitro gas production technique. Data were analyzed using a completely randomized design in a 3 x 3 + 1 factorial arrangement with 5 repetitions. Vinasse inclusion increased in vitro DM degradability compared to the control (59.1 vs. 51.8% after 72 h, respectively; p<0.05). Furthermore, vinasse increased the soluble fraction (A; 14.62% versus 3.68%) and the effective degradability (48.4 versus 47.4%), respectively (p<0.05). We conclude that cane vinasse enhances the in vitro degradability and the nutritional value of silage made from raw materials of low nutritional quality.RESUMO: O uso de aditivos promove mudanças nas características químicas e estruturais da forragem durante o período de ensilagem. Recentes estudos têm mostrado que a vinhaça de canha pode ser aproveitada como aditivo e server como uma fonte importante de substratos que facilitem a hidrolise dos componentes estruturais da parede celular vegetal, aumentando a degradabilidade da matéria seca (MS). O objetivo do presente estudo foi avaliar a cinética da degradabilidade in vitro da ensilagem de Maralfalfa elaborado com diferentes níveis de inclusão (3%, 6% e 9% por kg/FV) e concentração (20%, 30% e 40% de MS, respectivamente) de vinhaça de canha. A degradabilidade da MS, determinou-se mediante a técnica in vitro de produção de gases. Os dados foram analisados utilizando um desenho inteiramente ao acaso em um desenho fatorial 3 x 3 + 1 com 5 repetições. A inclusão da vinhaça aumentou a degradabilidade in vitro da MS comparada com o controle (59,1% versus 51,8% às 72 h, respectivamente; p<0,05). Do mesmo jeito, com a inclusão da vinhaça aumentou-se a fracção solúvel (A; 14,62% versus 3,68%) e a degradabilidade efetiva (48,4% versus 47,4%) com respeito ao controle, respectivamente (p<0,05). Conclui-se que a vinhaça de canha é um aditivo que melhora a degradabilidade in vitro e o valor nutricional de ensilagem elaborado a partir de matérias primas de baixa qualidade nutricional

Tick loads in Bos taurus cattle grazing in two contrasting production systems

Objectives. To relate the effect of biotic and abiotic factors on Rhipicephalus (Boophilus) microplus tick loads on cows grazing either in intensive silvopastoral systems (ISS) (Lucerna) or in grass pastures associated with sugarcane plantations (La Isabela). Materials and methods. Tick counts were performed on 27 Lucerne breed animals that were in different physiological states, six of which were grazing on forage grass paddocks associated with commercial sugarcane plantations and the remaining animals grazed in an ISS based on Leucaena leucocephala and Cynodon plectostachyus. The tick counts were made every 15 days. The data of temperature, humidity, and radiation were taken from a weather station that was inside the ISS. Results. There was a weak relationship between saturation deficit and tick load (R2=0.34) and another between UV radiation and tick load (R2=0.205) for animals grazing in ISS. There were differences in tick counts when comparing animals of similar productivity from both systems evaluated: in La Isabela (sugarcane grass paddocks) average counts were 311 ticks perceptible to the touch (TPT) and in Lucerna (ISS farm) average counts were 206 TPT (p= 0.02). Additionally, there were greater tick counts in high productivity cows compared to low productivity cows. Conclusions. The abiotic and biotic factors of the ecosystem and animal productivity can affect the TPT counts. In ISS systems, tick counts can be lower than those observed in monoculture grazing systems. Objetivos. Relacionar el efecto de algunos factores bioticos y abioticos sobre las cargas de la garrapata Rhipicephalus (Boophilus) microplus en hembras bovinas que pastorean en sistemas silvopastoriles intensivos (SSPi)(Lucerna) y en monocultivos asociados a cañaduzales (La Isabela). Materiales y métodos. Se realizaron conteos en 27 animales de raza Lucerna en diferentes estados fisiológicos, seis de los cuales se encontraban pastoreando en lotes de gramíneas forrajeras asociados con plantaciones de caña comerciales y los animales restantes pastoreaban en SSPi basados en Leucaena leucocephala y Cynodon plectostachyus. El conteo de garrapatas se efectuó cada 15 días. Los datos de temperatura, humedad y radiación se tomaron de una estación meteorológica que se encontraba en el interior del SSPi. Resultados. Se encontró una relación débil entre el déficit de saturación y los conteos de garrapatas (R2=0.34) y entre la radiación UV y los conteos de garrapatas (R2=0.205) para los bovinos pastoreando en SSPi. Hubo diferencia entre los conteos en animales con similar productividad en ambos sistemas evaluados; siendo el promedio total de garrapatas perceptibles al tacto (GPT) de 311 para La Isabela y de 206 GPT para Lucerna (p=0.02). Hubo mayor número de GPT en hembras con mayor productividad en comparación con las de baja productividad (p<0.05). Conclusiones. Los factores bióticos y abióticos del ecosistema pueden influir en el promedio de GPT, al igual que el nivel de productividad de los animales. En SSPi, la carga de garrapatas puede ser inferior a la de sistemas de pastoreo en monocultivo

Estimation of greenhouse gas emissions from agricultural activities in the Aburra valley Metropolitan Area - Colombia

The aim of this study was to estimate emissions of greenhouse gases (GHG) generated by the agricultural activities carried out in the Metropolitan Area of the Aburrá Valley (AMVA), located in Medellin - Colombia. A TIER 1 approach of the methodology of the Intergovernmental Panel on Climate Change, IPCC was followed. Emissions of GHG from cropland, aggregate sources and non-CO2 emissions from land were estimated and analysis of the uncertainty of activity data and emission factors were made. The estimated total emission was 63.1 and 66 Gg CO2 eq for 2009 and 2011, respectively. The greatest contribution to greenhouse gases in agricultural production was the application of nitrogen to soils in the form of synthetic and organic fertilizers, which was associated with direct and indirect N2O emissions. The main sources of uncertainty were those derived from the activity data

Evaluation of in vitro energy distribution and methanogenic potential of two forages with the addition of condensed tannins

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 Lotus corniculatus were evaluated with fermentation patterns of derived products from Ryegrass (RG, Lolium perenne) and a tropical forage, Megathyrsus maximus (MM). Tannins were added to the substrate at a concentration of 30 mg g-1. MM presented higher and delayed gas production (GP), and in vitro dry matter, organic matter and fiber digestibilities (ivDMD, ivOMD and NDFD, respectively) were relatively high but lower than RG. In addition, MM presented higher CH4 production (CH4p) than RG in 24 and 48h. Even though CT of Quebracho induced a decrease in the NDFD, contrary to what was expected, CH4p was greater, although this effect could not be attributed to the presence of CT. The stoichiometric evaluation indicated that while the highest CH4p in Quebracho treatments were associated with acetogenic profiles, CH4p with Lotus did not show any relationship with the volatile fatty acids (VFA) profile, but it did show a relationship with the highest total VFA production and the highest GP.Fil: Cantet, Juan Manuel. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Animal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Unidad Ejecutora de Investigaciones en Producción Animal. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias. Unidad Ejecutora de Investigaciones en Producción Animal; ArgentinaFil: Colombatto, Dario. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Animal; ArgentinaFil: Martinez, Rocío Soledad. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Animal; ArgentinaFil: Barahona Rosales, Rolando. Universidad Nacional de Colombia. Sede Medellin; ColombiaFil: Molina Botero, Isabel Cristina. Universidad Nacional de Colombia. Sede Medellin; ColombiaFil: Jaurena, Gustavo. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Animal; Argentin

Enteric methane emissions of zebu steers fed with tropical forages of contrasting nutritional value

Methane (CH4) emissions from livestock contribute significantly to climate change and diet plays a fundamental role in the emissions generated. Research in animal nutrition should aim at identifying ways to increase production efficiency with the least possible environmental impact and manipulation of diet quality becomes one of the most viable options to both mitigate emissions and increase animal productivity