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38 resultados encontrados para: AUTOR: Ku Vera, Juan Carlos
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1.
- Artículo con arbitraje
Resumen en: Inglés |
Resumen en inglés

The main task was to evaluate the effect of tree foliage species supplemented in cattle balanced diets on the in vitro fermentation and digestibility, synthesis of microbial biomass and methane (CH4) production. The experimental diets were isoenergetic and isoproteic balanced and formulated to meet the requirements of growing cattle (250 kg BW). Seven treatments were tested: control treatment (CT1) with the grass Pennisetum purpureum and six additional treatments substituting P. purpureum (30% of DM) with foliage of Neomillspaughia emarginata (NE2), Tabernaemontana amygdalifolia (TA3), Caesalpinia gaumeri (CG4), Piscidia piscipula (PP5), Leucaena leucocephala (LL6) and Havardia albicans (HA7). A randomised complete block design with blocks repeated over time was implemented. The highest gas production (P < 0.05) was found in CT1 and TA3 (244.10 and 235.13 mL g−¹, respectively). The highest in vitro dry matter digestibility (IVDMD) and in vitro organic matter digestibility (IVOMD) (P < 0.05) were in CT1, TA3 and LL6 (IVDMD = 56.33%, 56.85% and 56.08%; IVOMD = 62.41%, 66.86% and 64.38%, respectively). Synthesis of microbial biomass and volatile fatty acid concentration was similar among tree foliage supplementation and CT1, and the lowest CH4 production (P < 0.05) was found in LL6 (35.94 L kg−¹ of digested dry matter). It is concluded that the supplementation with T. amygdalifolia, P. piscipula and L. leucocephala at 30% in balanced diets could be used without affect negatively the organic matter digestibility of the diets, the synthesis of microbial biomass and the volatile fatty acid concentration. Additionally, the supplementation with L. leucocephala reduces CH4 production in the rumen by 12.78%.


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Resumen en: Español | Inglés |
Resumen en español

El objetivo del trabajo fue evaluar el efecto de la incorporación de diferentes fuentes de saponinas sobre la producción total de gas in vitro (GT) y la producción de metano ruminal (CH4), la cinética de fermentación, la digestibilidad de materia seca (DIVMS) y digestibilidad de la materia orgánica (DIVMO). Los tratamientos evauados fueron la interacción de tres concentraciones (3.5, 7.0 y 14.0 mg/g de materia seca) de saponinas de Yucca schidigera (YS), Gliricidia sepium (GS), Enterolobium cyclocarpum (EC) y un control (Pennisetum purpureum [PP] solo). Se incubó una muestra de 1,0 g de cada tratamiento in vitro en un diseño completamente al azar con arreglo factorial con tres repeticiones por tratamiento. GT de PP no se vio afectado (P> 0.05) por la inclusión de saponinas de YS, GS y EC. La producción de metano no fue afectada (P> 0.05) por ningún nivel de inclusión de saponinas de YS. Cuando las saponinas de GS y EC se incorporaron a concentraciones de 7.0 y 14.0 mg/g de MS, la producción de metano se incrementó (P <0,05). DIVMS y DIVMO aumentaron significativamente (P <0.05) con todas las fuentes de saponinas, excepto con las de YS a una concentración de 14 mg/g de MS cuando la DIVMO se redujo (P <0.05). Se concluye que las saponinas de las diferentes plantas tropicales no redujeron la producción de metano en condiciones in vitro.

Resumen en inglés

The aim of the work was to assess the effect of incorporation of different sources of saponins on the in vitro total gas (TG) and ruminal methane (CH4) productions, kinetics of fermentation, digestibility of dry matter (IVDDM) and organic matter (IVDOM). Treatments were interaction of three concentrations (3.5, 7.0 and 14.0 mg/g dry matter) of saponins from Yucca schidigera (YS), Gliricidia sepium (GS), Enterolobium cyclocarpum (EC) and a control (Pennisetum purpureum [PP] alone). A sample of 1.0 g of each treatment was incubated in vitro in a complete randomized design with factorial arrangement with three replicates per treatment. TG from PP was unaffected (P>0.05) by the inclusion of saponins from YS, GS and EC. Methane production was not affected (P>0.05) by any saponins from YS at any level of inclusion. When saponins from GS and EC were incorporated at concentrations of 7.0 and 14.0 mg/g DM, methane production was increased (P<0.05). IVDDM and IVDOM were significantly increased (P<0.05) with all sources of saponins, except with those from YS at concentration of 14.0 mg/g DM when IVDOM was reduced (P<0.05). It is concluded that saponins from different tropical plants did not reduce methane production under in vitro conditions.


3.
- Artículo con arbitraje
Resumen en: Inglés |
Resumen en inglés

The objective of this study was to evaluate the influence of tree foliage species supplemented in ruminant diets based on Pennisetum purpureum on the in vitro digestibility and fermentation, microbial biomass synthesis and enteric methane production. Seven experimental diets were evaluated, including a control treatment based on P. purpureum (PT) grass, and six additional treatments supplemented with 30.0% foliage from Neomillspaughia emargiata (NE), Tabernaemontana amygdalifolia (TA), Caesalpinia gaumeri (CG), Piscidia piscipula (PP), Leucaena leucocephala (LL) and Havardia albicans (HA). A randomised complete block design repeated in two periods (block) was used. The highest gas production (P < 0.05) was recorded in treatments TA and PT (237 and 228 mL g−¹, respectively). The highest in vitro digestibility of dry matter (IVDMD) and organic matter (IVOMD) (P < 0.05) was recorded in the control treatment PT (57.9% and 66.1%, respectively). Treatments LL, NE, TA and PP promoted greater microbial biomass synthesis (290, 223, 220 and 213 mg g−¹, respectively) (P < 0.05). The proportion of propionic acid also increased in these latter treatments and in treatments CG and HA (P < 0.05). Additionally, treatments LL, PP, NE and TA decreased methane production (25.8, 29.5, 30.6 and 31.8 L kg−¹ of digested dry matter, respectively). In conclusion, supplementation with L. leucocephala, P. piscipula, N. emargiata and T. amygdalifolia in ruminant diets based on P. purpureum is one feed alternative that can promote greater efficiency and synthesis of microbial biomass, increase the proportions of propionic and butyric acid and decrease the production of enteric methane by 15.6 to 31.6%.


4.
- Artículo con arbitraje
Resumen en: Inglés |
Resumen en inglés

Incorporation of foliage and pods of tropical legumes in ruminant rations is an alternative to mitigate enteric methane emissions. The objective of this research was to evaluate the effect of adding increasing levels of ground pods of Enterolobium cyclocarpum (Jacq.) Griseb. mixed with foliage of Gliricidia sepium (Jacq.) Steud. on emissions of ruminal methane (CH4), volatile fatty acid proportions, rumen pH and microbial population in cattle. Four heifers (218 ± 18 kg LW) were fed (13 days) 0, 15, 30, and 45% of pods of E. cyclocarpum mixed with foliage of G. sepium, which were supplemented to a basal ration of Brachiaria brizantha (Hochst. ex A. Rich.) Stapf. Data were analyzed as a 4×4 Latin square. After three days of CH4 measurements in opencircuit respiration chambers, rumen fluid was collected to determine volatile fatty acid (VFA) molar proportions and quantify the microbial population. Samples of ration ingredients, refusals and feces were collected to evaluate nutrient composition. Foliage and pods of legumes provided crude protein (CP), condensed tannins (CT) and saponins, while grass was characterized by higher concentrations of neutral detergent fiber (NDF). Dry matter intake (DMI) was 5.35 kg/day on average (P=0.272). Apparent fiber digestibility was reduced (81 g/kg) and digestible CP intake (13 g/kg) increased when E. cyclocarpum mixed with G. sepium in rations were given (P < 0.05). Incorporation of legume foliage and pods had a linear effect on molar proportions of butyric acid and acetic to propionic acid ratio (P < 0.05).

Incorporation of legume foliage and pods had a linear effect on molar proportions of butyric acid and acetic to propionic acid ratio (P < 0.05). Methane production, expressed on basis to digestible dry matter intake (DDMI), ranged between 43.22 and 49.94 g/kg DDMI (P=0.131) and when CH4 was related to digestible CP (347 vs. 413 g CH4 /kg DCP) or annual weight gains (0.30 vs. 0.38 kg CH4/kg weight gain, P < 0.001) there were differences between the E. cyclocarpum mixed with G. sepium rations compared to the control treatment, respectively. Rumen population of total bacteria, methanogenic archaea, and total protozoa was not affected by the increasing levels of condensed tannins and saponins in rations (P > 0.05). Substitution of 15 and 30% of pods of E. cyclocarpum mixed with foliage of G. sepium in the ration, decreases annual methane emissions per unit product, without affecting dry matter intake or rumen microbial population, on the contrary, digestible CP intake and animal productivity increased due to supply of CP, CT and saponins.


5.
Artículo
PDF
Resumen en: Inglés |
Resumen en inglés

Livestock production is a main source of anthropogenic greenhouse gases (GHG). The main gases are CHч with a global warming potential (GWP) 25 times and nitrous oxide (N2O) with a GWP 298 times, that of carbon dioxide (CO2) arising from enteric fermentation or from manure management, respectively. In fact, CHч is the second most important GHG emitted globally. This current scenario has increased the concerns about global warming and encouraged the development of intensive research on different natural compounds to be used as feed additives in ruminant rations and modify the rumen ecosystem, fermentation pattern, and mitigate enteric CHч. The compounds most studied are the secondary metabolites of plants, which include a vast array of chemical substances like polyphenols and saponins that are present in plant tissues of different species, but the results are not consistent, and the extraction cost has constrained their utilization in practical animal feeding. Other new compounds of interest include polysaccharide biopolymers such as chitosan, mainly obtained as a marine co-product. As with other compounds, the effect of chitosan on the rumen microbial population depends on the source, purity, dose, process of extraction, and storage. In addition, it is important to identify compounds without adverse effects on rumen fermentation. The present review is aimed at providing information about chitosan for dietary manipulation to be considered for future studies to mitigate enteric methane and reduce the environmental impact of GHGs arising from livestock production systems. Chitosan is a promising agent with methane mitigating effects, but further research is required with in vivo models to establish effective daily doses without any detrimental effect to the animal and consider its addition in practical rations as well as the economic cost of methane mitigation.


Resumen en: Inglés |
Resumen en inglés

The objective of this study was to determine methane (CH4) yield by crossbred cattle fed tropical grasses. A total of 66 individual determinations of dry matter intake (DMI) and 42 determinations of organic matter intake (OMI) in relation to the production of enteric CH4 were carried out. Methane measurements in heifers were performed in open-circuit respiration chambers. Heifers (Bos indicus×B. taurus) with an average live weight of 288.5 ± 55.7 kg fed tropical grasses as basal ration were used. An average intake of 8.22 and 7.80 kg of DM and OM per day were recorded. An average enteric CH4 production of 88.0 g/heifer/day was determined. It was found that DMI and OMI in relation to CH4 production have a coefficient of determination (R²) of 0.73 and 0.70 respectively, to predict CH4 emissions. It is concluded that the methane yield (18.07 g CH4/kg DM intake) predicted by regressing DM intake against methane production represents a reliable value to be used for the estimation of enteric CH4 inventories for cattle grazing in the tropical regions of Mexico.


7.
- Capítulo de libro con arbitraje
*Solicítelo con su bibliotecario/a
Efecto de la inclusión de taninos condensados de quebracho sobre el patrón de fermentación y producción de metano en novillas alimentadas con Pennisetum purpureum
Piñeiro Vázquez, Ángel Trinidad ; Chay Canul, Alfonso Juventino (coaut.) ; Casanova Lugo, Fernando (coaut.) ; Sanginés García, José Roberto (coaut.) ; Aguilar Urquizo, Edgar (coaut.) ; Canul Solís, Jorge Rodolfo (coaut.) ; Jiménez Ferrer, Guillermo (coaut.) ; Ku Vera, Juan Carlos (coaut.) ;
Contenido en: Avances de la investigación sobre producción animal y seguridad alimentaria en México Morelia, Michoacán, México : Universidad Michoacana de San Nicolás de Hidalgo, 2018 p. 725-730
Nota: Solicítelo con su bibliotecario/a
Resumen en español

El objetivo del trabajo fue evaluar el efecto de los taninos condensados de quebracho (TCQ) sobre el consumo de alimento, la digestibilidad de la materia seca (MS) y las emisiones de metano (CH4) en novillas alimentadas con pasto Pennisetum purpureum de baja calidad. Cinco vaquillas (Bos taurus × Bos indicus) con un peso vivo promedio (PV) de 295 ± 19 kg se asignaron a cinco tratamientos (0, 1, 2, 3 y 4% TCQ/kg DM) en un diseño en cuadrado latino de 5 x 5. El consumo, la digestibilidad y las emisiones de metano (L/día) se registraron durante períodos de 23 h, cuando se encontraban dentro de las cámaras de respiración de circuito abierto. El consumo de materia seca (CMS); consumo de materia orgánica (CMO); la digestibilidad de la materia seca (DMS); y la digestibilidad de la materia orgánica (DMO) fue diferente entre tratamientos con 0 y 4% de TCQ/kg de MS (P <0.05). La proporción molar de propionato aumentó linealmente (P<0.01) para tratamientos con TCQ de 3 y 4%. disminuyó linealmente (P<0.01) cuando TCQ aumentó en la dieta, particularmente con en concentración de 3 y 4%. Se concluye que la adición de TCQ en 2 o 3% en la ración puede disminuir la producción de metano de 29 a 41% respectivamente, sin comprometer significativamente el consumo de alimento y la digestibilidad de los nutrientes.

Resumen en inglés

The aim of the work was to evaluate the effect of quebracho tannins condensed (QTC) on feed intake, dry matter (DM) digestibility and methane (CH4) emissions in cattle fed low-quality Pennisetum purpureum grass. Five heifers (Bos taurus × Bos indicus) with an average live weight (LW) of 295 ± 19 kg were allotted to five treatments (0, 1, 2, 3 and 4 % QTC /kg DM) in a 5 x 5 Latin square design. Intake, digestibility and methane emissions (L/day) were recorded for periods of 23 h when cattle were housed in open-circuit respiration chambers. Dry matter intake (DMI); organic matter intake (OMI); dry matter digestibility (DMD); and organic matter digestibility (OMD) was different between treatments with 0 and 4% of QTC /kg DM (P<0.05). The molar proportion of propionate increased linearly (P<0.01) for treatments with 3 and 4 % QTC. Total CH4 production decreased linearly (P<0.01) as QTC increased in the diet, particularly with 3 and 4 % concentration. It is concluded that the addition of QTC in 2 or 3% in the ration can decrease the production of methane from 29 to 41% respectively, without significantly compromising the intake of food and the digestibility of nutrients.


8.
Tesis - Doctorado
*En proceso técnico. Solicítelo con el bibliotecario de SIBE-Campeche
Efecto de las especies arbóreas tropicales sobre la microbiología ruminal y la producción de metano en rumiantes / Samuel Albores Moreno
Albores Moreno, Samuel ; Alayón Gamboa, José Armando (director) ; Ku Vera, Juan Carlos (asesor) ; Cobos Peralta, Mario Antonio (asesor) ; Jiménez Ferrer, Guillermo (asesor) ;
Lerma, Campeche, México : El Colegio de la Frontera Sur , 2018
Clasificación: TE/577.18097264 / A4
Bibliotecas: Campeche
Cerrar
SIBE Campeche
ECO040006896 (Disponible)
Disponibles para prestamo: 1
Nota: En proceso técnico. Solicítelo con el bibliotecario de SIBE-Campeche
PDF
Índice | Resumen en: Español |
Resumen en español

Los objetivos de esta investigación fueron: (1) evaluar la influencia de la composición y diversidad de la vegetación secundaria sobre la selección y el consumo voluntario de plantas por el ganado en el trópico; (2) evaluar la composición nutricional, degradación in vitro y potencial de fermentación de especies arbóreas consumidas por rumiantes en vegetación secundaria (acahual) de selva baja caducifolia; y (3 y 4) evaluar la suplementación con follajes arbóreos en dietas para rumiantes a base de Pennisetum purpureum y en dietas balanceadas, sobre la digestibilidad y los patrones de fermentación in vitro, la producción de metano y la síntesis de biomasa microbial. En el primer estudio, se seleccionó una unidad de producción representativa con manejo de acahual para alimentación de bovinos, ubicada en el municipio de Tenabo, Campeche, México. Se realizó un inventario florístico en 20 parcelas y se monitoreo la selección de las especies vegetales consumidas por los bovinos durante siete semanas, con el fin de conocer la preferencia y el consumo voluntario (CV) de las distintas especies vegetales; y que posteriormente serían colectadas en otras unidades de producción. En el segundo estudio se llevó a cabo un experimento a partir de las colectas de material vegetal realizado en el 20% (14 ranchos) del total de las unidades de producción ubicados en el municipio de Tenabo. Se utilizaron follajes de 18 especies arbóreas que fueron sometidas a fermentación in vitro y análisis bromatológico. En el experimento dos se probaron siete dietas, usando como testigo un tratamiento a base de pasto P. purpureum (PT); y la suplementación con 30% del follaje de Neomillspaughia emargiata (NE), Tabernaemontana amygdalifolia (TA), Caesalpinia gaumeri (CG), Piscidia piscipula (PP), Luecaena leucocephala (LL), y Havardia albicans (HA). En el último experimento, se probaron el efecto de los follajes en dietas balanceadas en energía y proteína.

Las dietas fueron un tratamiento control (CT1) que consistió en pasto P. purpureum (60%) y suplemento alimenticio (40%); y la sustitución de P. purpureum (30% de la MS) por el follaje de las mismas especies utilizadas en el experimento dos (NE2, TA3, CG4, PP5, LL6, y HA7). Todos los experimentos se llevaron a cabo en condiciones de laboratorio usando la técnica de gas in vitro y se utilizó un diseño experimental de bloques repetidos en el tiempo. La vegetación del acahual estuvo compuesta de 26 especies, 17 familias botánicas, y se encontró un índice de diversidad de Shannon de 2.45. Las especies con mayor índice de valor de importancia (IVI) fueron N. emarginata, G. floribundum, H. albicans, C. gaumeri, Lysiloma latisiliquum, Diospyros anisandra y Bursera simaruba. Independientemente de la época del año, se observó un mayor índice de preferencia, frecuencia de bocados y CV en G. floribundum, N. emarginata, Mimosa bahamensis, D. anisandra, Randia obcordata y herbáceas. Se observó un mayor (P<0.05) CV en la época de lluvia respecto a la época seca (12.48 y 10.26 kg de MS/animal/día), y se encontró que la cobertura y densidad de las especies en el acahual determinan el CV en la época seca y de lluvia, respectivamente. El contenido de PC, FDN, FDA y TC del follaje de las especies consumidas fluctuó de 109 a 262, 391 a 641, 322 a 579 y 1.73 a 233 g kg-¹ MS, respectivamente. Las especies G. floribundum, M. lindeniana, V. gaumeri, H. barvensis, T. amygdalifolia y C. gaumeri tuvieron los mayores (P<0.05) parámetros de fermentación y digestibilidad. Con la inclusión del 30% del follaje en las dietas a base de P. purpureum, se encontró que la mayor (P<0.05) producción de gas (Vm) ocurrió en TA y PT. Los tratamientos NE, TA, CG, PP, LL y HA afectaron la digestibilidad de la materia seca (DIVMS) y materia orgánica (DIVMO) (P<0.05).

Asimismo, los tratamientos PP, TA, NE y LL promovieron una mayor (P<0.05) síntesis de biomasa microbiana (213 a 290 mg g-¹) y disminuyeron la producción de metano de 31.6% a 15.6%. Mientras que la suplementación con el 30% del follaje de las arbóreas en dietas balanceadas, se encontró que los mayores (P<0.05) Vm se observaron en CT1, TA3 y CG4. Los tratamientos TA3 y LL6 tuvieron mayor DIVMS y DIVMO (P<0.05), y junto con los tratamientos HA7, y NE2 incrementaron (P<0.05) la síntesis de biomasa microbiana (325 a 379 mg g-¹). También se observó que el tratamiento LL6 ocasionó una disminución (P<0.05) en la producción de CH4 (35.94 L kg-¹ de MS digerida). Se concluye que el acahual, que se forma a partir de la perturbación de la selva baja caducifolia, representa un recurso con alto potencial alimenticio y que la producción animal usando este recurso detiene el impacto ambiental, el cual ha sido poco considerado en los esquemas de ganadería extensiva para adaptarse al cambio climático y mitigar sus efectos.

Índice

Dedicatoria
Agradecimientos
Resumen
Capítulo I. Introducción general
1.1 Referencias
Capítulo II. Influence of the composition and diversity of secondary vegetation on the selection and voluntary intake of plants by cattle in the tropics
2.1 Abstract
2.1.1 Keywords
2.2 Introduction
2.3 Materials and methods
2.3.1 Study area
2.3.2 Composition, structure and diversity of the acahual
2.3.3 Management and preparation of animals
2.3.4 Monitoring and recording of animal intake
2.3.5 Estimation of the selection and voluntary intake of plants
2.3.6 Statistical analysis
2.4. Results
2.4.1 Composition, structure, diversity and importance of acahual vegetation
2.4.2 Bite frequency, botanical composition of diet and plant preferences of cattle
2.4.3 Chemical composition of the cattle diet
2.4.4 Voluntary intake by cattle
2.4.5 Effect of acahual composition and structure on voluntary intake by cattle
2.5 Discussion
2.5.1 Composition, structure and diversity of the acahual
2.5.2 Bite frequency, botanical composition of the diet and plant preferences of cattle
2.5.3 Chemical composition of the diets of cattle grazing the acahual vegetation
2.5.4 Voluntary intake of cattle grazing the acahual vegetation
2.6 Conclusion
2.7 Acknowledgments
2.8 References
Capítulo III. Nutritional composition, in vitro degradation and potential fermentation of tree species grazed by ruminants in secondary vegetation (acahual) of deciduous forest
3.1 Abstract
3.1.1 Keywords
3.2 Introduction
3.3 Materials and methods
3.3.1 Plant selection
3.3.2 Nutrient Analysis
3.3.2.1 Chemical analysis
3.3.3 In vitro gas production
3.3.4 In vitro gas fermentation kinetics and fermentable fractions
3.3.5 In vitro digestibility of dry matter (IVDMD) and organic matter (IVOMD)
3.3.6 Soluble fraction (SolFrac)
3.3.7 Statistical design and analysis
3.4 Results
3.4.1 Chemical composition

3.4.2 In vitro gas fermentation kinetics
3.4.3 Fermentable fractions, digestibility and potential fermented gas emission index
3.4.4 Relationship among nutrient composition and kinetics of in vitro gas production
3.5 Discussion
3.5.1 Chemical composition
3.5.2 In vitro fermentation kinetics
3.5.3 Fermentable fraction, digestibility and potential fermented gas emission index
3.6 Acknowledgments
3.7 References
Capítulo IV. Effect of tree foliage supplementation of tropical grass diet on in vitro digestibility and fermentation, microbial biomass synthesis and enteric methane production in ruminants
4.1 Abstract
4.1.1 Keywords
4.2 Introduction
4.3 Materials and methods
4.3.1 Study area
4.3.2 Treatments
4.3.3 Nutrient analysis
4.3.4. In vitro gas production
4.3.5 In vitro gas fermentation kinetics and fermentable fractions
4.3.6 In vitro digestibility of dry matter and organic matter
4.3.7 Synthesis of microbial biomass
4.3.8 Determination of methane and carbon dioxide
4.3.9 Determination of volatile fatty acids (VFAs)
4.3.10 Determination of ammonia concentration
4.3.11 Experimental design and statistical analysis
4.4 Results
4.4.1 Chemical composition
4.4.2 In vitro gas fermentation kinetics
4.4.3 Fermentable fractions and digestibility
4.4.4 Synthesis of microbial biomass and ammonia concentration
4.4.5 Fermentation pattern and enteric methane production
4.5 Discussion
4.5.1 Chemical composition
4.5.2 In vitro gas fermentation kinetics
4.5.3 Fermentable fractions and digestibility
4.5.4 Effect on nitrogen metabolism
4.5.5 Fermentation pattern and enteric methane production
4.6 Acknowledgments
4.7 References
Capítulo V. Effect of supplementation with tree foliage on in vitro digestibility and fermentation, synthesis of microbial biomass and methane production of cattle diets
5.1 Abstract
5.1.1 Keywords
5.2 Introduction

5.3 Materials and methods
5.3.1 Study area and foliage collection
5.3.2 Treatments
5.3.3 Nutrient analysis
5.3.4 In vitro gas production
5.3.5 In vitro fermentation kinetics
5.3.6 In vitro digestibility of dry matter and organic matter
5.3.7 Synthesis of microbial biomass
5.3.8 Methane and carbon dioxide determination
5.3.9 Determination of volatile fatty acids
5.3.10 Determination of ammonia and lactic acid concentration
5.3.11 Statistical analysis and experimental design
5.4 Results
5.4.1 In vitro fermentation kinetics
5.4.2 Fermentation and digestibility
5.4.3 Synthesis of microbial biomass and fermentation pattern
5.4.4 Enteric methane and carbon dioxide production
5.5 Discussion
5.5.1 In vitro fermentation kinetics
5.5.2 Fermentation and digestibility
5.5.3 Synthesis of microbial biomass and fermentation pattern
5.5.4 Enteric methane and carbon dioxide production
5.6 Conclusion
5.7 Acknowledgments
5.8 References
Capítulo VI. Conclusiones Generales
Capítulo VII Anexos


PDF
Resumen en: Inglés |
Resumen en inglés

Objective: The aim of the experiment was to assess the effect of increasing amounts of Leucaena leucocephala forage on dry matter intake (DMI), organic matter intake (OMI), enteric methane production, rumen fermentation pattern and protozoa population in cattle fed Pennisetum purpureum and housed in respiration chambers. Methods: Five crossbred heifers (Bos taurus×Bos indicus) (BW: 295±6 kg) were fed chopped P. purpureum grass and increasing levels of L. leucocephala (0%, 20%, 40%, 60%, and 80% of dry matter [DM]) in a 5×5 Latin square design. Results: The voluntary intake and methane production were measured for 23 h per day in respiration chambers; molar proportions of volatile fatty acids (VFAs) were determined at 6 h postprandial period. Molar concentration of VFAs in rumen liquor were similar (p>0.05) between treatments. However, methane production decreased linearly (p<0.005), recording a maximum reduction of up to ∼61% with 80% of DM incorporation of L. leucocephala in the ration and no changes (p>0.05) in rumen protozoa population were found. Conclusion: Inclusion of 80% of L. leucocephala in the diet of heifers fed low-quality tropical forages has the capacity to reduce up to 61.3% enteric methane emission without affecting DMI, OMI, and protozoa population in rumen liquor.


10.
- Artículo con arbitraje
Resumen en: Inglés |
Resumen en inglés

The aim of this work was to evaluate the effect of quebracho tannins extract (QTE) on feed intake, dry matter (DM) digestibility, and methane (CH4) emissions in cattle fed low-quality Pennisetum purpureum grass. Five heifers (Bos taurus × Bos indicus) with an average live weight (LW) of 295 ± 19 kg were allotted to five treatments (0, 1, 2, 3, and 4% QTE/kg DM) in a 5 × 5 Latin square design. Intake, digestibility, and total methane emissions (L/day) were recorded for periods of 23 h when cattle were housed in open-circuit respiration chambers. Dry matter intake (DMI), organic matter intake (OMI), dry matter digestibility (DMD), and organic matter digestibility (OMD) were different between treatments with 0 and 4% of QTE/kg DM (P < 0.05). Total volatile fatty acid and the molar proportion of acetate in the rumen was not affected (P < 0.05); however, the molar proportion of propionate increased linearly (P < 0.01) for treatments with 3 and 4% QTE. Total CH4 production decreased linearly (P < 0.01) as QTE increased in the diet, particularly with 3 and 4% concentration. When expressed as DMI and OMI by CH4, production (L/kg) was different between treatments with 0 vs 3 and 4% QTE (P < 0.05). It is concluded that the addition of QTE at 2 or 3% of dry matter ration can decrease methane production up to 29 and 41%, respectively, without significantly compromising feed intake and nutrients digestibility.