Abstract:

BACKGROUND: The present study combines morphological and anatomical studies, cell wall chemical composition analysis, as well as assessment of the nutritional value of Guadua chacoensis foliage leaves. RESULTS: Foliage leaves of G. chacoensis are a promising source of forage because: (a) as a native woody bamboo, it is adapted to and helps maintain environmental conditions in America; (b) leaf anatomical studies exhibit discontinuous sclerenchyma, scarcely developed, while pilose indumentum, silica cells, prickles and hooks are also scarce; (c) it has a high protein content, similar to that of Medicago sativa, while other nutritional parameters are similar to those of common forages; and (d) glucuronoarabinoxylan, the major extracted polysaccharide, has one-third of the 4-linked β-d-xylopyranosyl units of the backbone substituted mainly with α-l-arabinofuranose as single stubs or non-reducing end of short chains, but also 5-linked α-l-arabinofuranose units, terminal β-d-xylopyranose and d-galactopyranose units, as well as α-d-glucuronic acid residues and small amounts of its 4-O-methylated derivative. CONCLUSION: These results constitute the first report on this species, and as culms are utilized in constructions and crafts, the remaining leaves, when used as forage, constitute a byproduct that allows an additional income opportunity. © 2016 Society of Chemical Industry.

Author affiliation: Panizzo, Cecilia C.. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Recursos Naturales y Ambiente; Argentina

Author affiliation: Fernández, Paula Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones en Hidratos de Carbono. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones en Hidratos de Carbono; Argentina. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Biología Aplicada y Alimentos; Argentina

Author affiliation: Colombatto, Dario. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Animal; Argentina

Author affiliation: Ciancia, Marina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones en Hidratos de Carbono. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones en Hidratos de Carbono; Argentina. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Biología Aplicada y Alimentos; Argentina

Author affiliation: Vega, Andrea Susana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Recursos Naturales y Ambiente; Argentina

Abstract:

This study was conducted to evaluate the effects of preservation type on chemical composition and in vitro ruminal degradation of warm-season grasses (WSG). Treatments consisted of two factors (6×2): the first factor was tropical grasses: Cenchrus ciliaris (cv. Biloela, and cv. Molopo), Chloris gayana (cv. Callide and cv. Finecut), Panicum maximum, and Brachiaria bryzanta; and the second factor was preservation type (hay vs. silage). Cell wall, hemicellulose, cellulose, and water-soluble carbohydrate (P<0.05) concentrations were different among WSG. In general, hay or silage altered fiber content compared with fresh. For instance, hemicellulose and cellulose contents were lower in silage than in hay and fresh grass (P<0.05). Gas production rates were higher in silage from 0 to 24 h of fermentation, except at 4 h of incubation. After 24 h, gas production (GP) rate was similar for both preservation types, whilst potential GP was similar between preservation types. However, silage had decreased lag time compared with hay (P<0.01). Silage had greater dry matter disappearance than hay (P<0.05), and gas production yield was similar for grass species and preservation type. Our results indicate that WSG conserved as silage showed beneficial changes in chemical composition and dry matter degradation compared with hay.

Author affiliation: Arroquy, Jose Ignacio. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Tucuman-santiago del Estero. Estación Experimental Agropecuaria Santiago del Estero; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia de Santiago del Estero. Universidad Nacional de Santiago del Estero. Centro de Investigaciones y Transferencia de Santiago del Estero; Argentina

Author affiliation: Cornacchione, M. V.. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Tucuman-santiago del Estero. Estación Experimental Agropecuaria Santiago del Estero; Argentina. Universidad de Buenos Aires. Facultad de Agronomia; Argentina

Author affiliation: Colombatto, Dario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia de Santiago del Estero. Universidad Nacional de Santiago del Estero. Centro de Investigaciones y Transferencia de Santiago del Estero; Argentina

Author affiliation: Kunst, C.. Universidad Nacional de Santiago del Estero. Facultad de Agronomia y Agroindustrias; Argentina

Abstract:

This study was conducted to evaluate the effects of preservation type on chemical composition and in vitro ruminal degradation of warm-season grasses (WSG). Treatments consisted of two factors (6 2): the first factor was tropical grasses: Cenchrus ciliaris (cv. Biloela, and cv. Molopo), Chloris gayana (cv. Callide and cv. Finecut), Panicum maximum, and Brachiaria bryzanta; and the second factor was preservation type (hay vs. silage). Cell wall, hemicellulose, cellulose, and water-soluble carbohydrate (PB0.05) concentrations were different among WSG. In general, hay or silage altered fiber content compared with fresh. For instance, hemicellulose and cellulose contents were lower in silage than in hay and fresh grass (PB0.05). Gas production rates were higher in silage from 0 to 24 h of fermentation, except at 4 h of incubation. After 24 h, gas production (GP) rate was similar for both preservation types, whilst potential GP was similar between preservation types. However, silage had decreased lag time compared with hay (PB0.01). Silage had greater dry matter disappearance than hay (PB0.05), and gas production yield was similar for grass species and preservation type. Our results indicate that WSG conserved as silage showed beneficial changes in chemical composition and dry matter degradation compared with hay.

Cette e´tude a e´te´ effectue´e pour e´valuer les effets du type de conservation sur la composition chimique et la de´gradation ruminale in vitro des herbes tropicales de la saison chaude (WSG « warm-season grasses »). Les traitements consistent de deux facteurs (6 2) : le premier facteur est l’herbe tropicale : Cenchrus ciliaris (cv. Biloela et cv. Molopo), Chloris gayana (cv. Callide et cv. Finecut), Panicum maximum, et Brachiaria bryzanta; le deuxie`me facteur est le type de conservation (foin c. ensilage). Les concentrations de parois cellulaires, d’he´micellulose, de cellulose et d’hydrates de carbone hydrosolubles (WSC « watersoluble carbohydrates ») e´taient diffe´rentes (PB0,05) parmi les WSG. De fac¸on ge´ne´rale, le foin ou l’ensilage avaient un contenu en fibres alte´re´ par rapport aux herbes fraıˆches. Par exemple, les contenus en he´micellulose et en cellulose e´taient plus faibles dans l’ensilage que dans le foin et les herbes fraıˆches (PB0,05). Les taux de production de gaz e´taient plus e´leve´ s dans l’ensilage de 0 a` 24 h de fermentation, sauf au temps 4 h d’incubation. Apre`s 24 h, le taux de production de gaz (GP « gas production ») e´ tait similaire pour les deux types de conservation, tandis que la GP potentielle e´ tait similaire entre les types de conservation. Par contre, l’ensilage avait un de´calage re´duit par rapport au foin (PB0,01). L’ensilage avait une plus grande disparition de matie`res se`ches (DMD « dry matter disappearance ») que le foin (PB0,05), et le rendement en production de gaz (RGY « gas production yield ») e´ tait similaire entre les espe`ces et les types de conservation. Nos re´sultats indiquent que les WSG conserve´es sous forme d’ensilage de´montrent des changements be´ne´fiques dans la composition chimique et la de´composition des matie`res se`ches par rapport a` la conservation sous forme de foin.

EEA Santiago del Estero

Author affiliation: Arroquy, Jose Ignacio. INTA. Estación Experimental Agropecuaria Santiago del Estero; Argentina. Universidad Nacional de Santiago del Estero. Facultad de Agronomía y Agroindustrias; Argentina

Author affiliation: Cornacchione, Monica. INTA. Estación Experimental Agropecuaria Santiago del Estero; Argentina

Author affiliation: Colombatto, Dario. Universidad de Buenos Aires. Facultad de Agronomia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Author affiliation: Kunst, Carlos Roberto. INTA. Estación Experimental Agropecuaria Santiago del Estero; Argentina Universidad Nacional de Santiago del Estero. Facultad de Agronomía y Agroindustrias; Argentina

Abstract:

Forty crossbred steers (Baladi×Friesian, average BW 153±5.14kg) were used to evaluate the effects of exogenous enzyme (ENZ) addition on nutrient intake, digestion, ruminal fermentation and feed conversion in beef steers. Steers were randomly assigned to two groups of 20 animals and fed individually a total mixed ration (TMR) without (CTRL) or with addition of 40g/hd/d of an enzyme mixture (ZADO®). The ENZ mixture was added for 220 days and in vivo apparent digestibility was measured on days 210-220. Enzyme addition did not affect (P=0.1) DM intake, whereas it increased (P<0.05) total tract apparent digestibility of all nutrients. The magnitude of improvement in digestibility varied among nutrients, with the highest improvement occurring in digestibility of NDF and ADF (21.8% and 26.7%, respectively). Addition of ENZ also increased (P<0.05) concentrations of rumen ammonia N and total short chain fatty acids (SCFA) before and 3h post-feeding. Allantoin concentration total purine derivates were increased (P=0.04) with enzyme addition while uric acid was not affected (P=0.05). Live-weight gain was also higher (P<0.01) in steers supplemented with ENZ. In conclusion, adding the exogenous enzyme product increased live-weight gain by 16% due to increased nutrient digestibility.

Author affiliation: Salem, A. Z. M.. Universidad Autónoma del Estado de México; México. Alexandria University; Egipto

Author affiliation: Gado, H. M.. Ain Shams University; Egipto

Author affiliation: Colombatto, Dario. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Animal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Author affiliation: Elghandour, M. M. Y.. Universidad Autónoma del Estado de México; México

Abstract:

Sixty multiparous, lactating Holstein cows (57 ± 23.1 d in milk at the start of the experiment) were used in a completely randomized design to examine effects of adding incremental levels of dietary essential oil compounds (EO; 0, 200, 400 and 600 mg/d) on milk production and composition. Cows were allowed to graze on winter oats for 8 h/d with a daily herbage allowance of 15 kg dry matter (DM)/cow, and then received supplemental corn silage and sunflower meal in confinement for the remainder of the day. The EO were fed individually at milking times (0600 and 1600 h), mixed with 0.86 kg DM of dry rolled corn grain. In addition, 4 ruminally cannulated lactating Holstein cows in mid lactation were used in a 4×4 Latin Square design with 14 d periods to study effects of EO on ruminal fermentation characteristics and ruminal in sacco DM, crude protein (CP), and neutral detergent fiber (aNDF) degradability. Milk production, which ranged from 18.8 to 20.2 kg/d, and milk composition were not affected by EO. In general, ruminal fermentation characteristics were not affected by EO addition at any level, except for a 13% increase in butyrate concentrations with all EO levels compared to the control. Ruminal ammonia N concentration was high in all treatments (51.5 ± 5.75 mg/100 ml) and tended (P=0.09) to increase when 200 and 400 mg/d of EO were added. In addition, 200 mg/d of EO marginally decreased the potentially ruminally degradable fraction of the CP of the complete ration. Results using dairy cows in mid lactation that grazed 8 h/d on lush pasture showed limited effects of this EO complex on ruminal fermentation, milk production and milk composition.

Author affiliation: Flores, Angela Jorgelina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Corrientes. Estación Experimental Agropecuaria Mercedes; Argentina

Author affiliation: Garciarena, Alberto D.. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce; Argentina

Author affiliation: Hernández Vieyra, Juan M.. Argent Export; Argentina

Author affiliation: Beauchemin, Karen A.. Agriculture and Agri-Food Canada; Canadá

Author affiliation: Colombatto, Dario. Universidad de Buenos Aires. Facultad de Agronomia. Departamento de Producción Animal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Abstract:

The objective of this work was to evaluate the efficiency and stability of cow–calf, fattening and whole cycle beef cattle agro-ecosystems from the subtropical region of Argentina. For this purpose, an agroecosystem model consisting of a production and a management system was developed. Flexible management rules were incorporated. This simulation-based study compared potential trends of different agro-ecosystems under different animal body sizes and several management options traditionally applied in the region. The experiment aimed at estimating productive, energetic and economic efficiency and stability. The results showed that whole cycle and cow–calf systems were more stable but less productive than fattening systems. Within each agro-ecosystem, as body size increased, energetic and economic efficiency and stability decreased. Systems dynamics and multi-criteria approaches allowed recognizing tradeoffs among indicators, and main differences between agro-ecosystems. Further investigation is required to generalize these findings to other system structures, particularly when economic aspects are taken into account in decision making processes.

Author affiliation: Nasca, J. A. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Instituto de Investigación Animal del Chaco Semiarido; Argentina

Author affiliation: Feldkamp, C. R.. Universidad de Buenos Aires. Facultad de Agronomia; Argentina. Asociación Argentina de Consorcios Regionales de Experimentación Agrícola; Argentina. Universidad de Concepción del Uruguay. Facultad de Ciencias Agrarias; Argentina

Author affiliation: Arroquy, Jose Ignacio. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Tucuman-Santiago del Estero; Argentina. Universidad Nacional de Santiago del Estero. Facultad de Agronomia y Agroindustrias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Author affiliation: Colombatto, Dario. Universidad de Buenos Aires. Facultad de Agronomia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Abstract:

The objective of this work was to evaluate the efficiency and stability of cow–calf, fattening and whole cycle beef cattle agro-ecosystems from the subtropical region of Argentina. For this purpose, an agro-ecosystem model consisting of a production and a management system was developed. Flexible management rules were incorporated. This simulation-based study compared potential trends of different agro-ecosystems under different animal body sizes and several management options traditionally applied in the region. The experiment aimed at estimating productive, energetic and economic efficiency and stability. The results showed that whole cycle and cow–calf systems were more stable but less productive than fattening systems. Within each agro-ecosystem, as body size increased, energetic and economic efficiency and stability decreased. Systems dynamics and multi-criteria approaches allowed recognizing tradeoffs among indicators, and main differences between agro-ecosystems. Further investigation is required to generalize these findings to other system structures, particularly when economic aspects are taken into account in decision making processes.

Instituto de Investigación Animal del Chaco Semiárido

Author affiliation: Nasca, Jose Andres. INTA. Instituto de Investigación Animal del Chaco Semiárido; Argentina

Author affiliation: Feldkamp, C.R. Universidad de Buenos Aires. Facultad de Agronomía; Argentina. Asociación Argentina de Consorcios Regionales de Experimentación Agrícola; Argentina. Universidad de Concepción del Uruguay. Facultad de Ciencias Agrarias; Argentina

Author affiliation: Arroquy, Jose Ignacio. INTA. Estación Experimental Agropecuaria Santiago del Estero; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Santiago del Estero.Facultad de Agronomía y Agroindustrias; Argentina

Author affiliation: Colombatto, Dario. Universidad de Buenos Aires. Facultad de Agronomia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Abstract:

The aim of this study was to evaluate the effect of Argentinean essential oils (EO) on methane production during in vitro fermentation compared to EO with proven effects as rumen fermentation modifiers. A complete randomized block design was used and the treatments included EO from Aloysia gratissima (50, 100, 150 and 300 mg/L), Eucalyptus globulus (5, 50, 150 and 300 mg/L), Lippia turbinata (30, 60, 120 and 240 mg/L), Mentha x piperita var. vulgaris (50, 100, 200 and 400 mg/L), Origanum vulgare ssp. hirtum cv. Compacto (0.5, 5, 50 and 250 mg/L) and cv. Mendocino (50, 150, 250 and 350 mg/L), Rosmarinus officinalis (100, 300, 500 and 700 mg/L), Schinus molle (75, 150, 300 and 600 mg/L), Tagetes minuta (5, 50, 125 and 250 mg/L), and Thymus vulgaris (5, 50, 150 and 300 mg/L). Two controls were included: control (not containing EO) and monensin (1.87 mg/L). Variables measured were: digestibility of neutral detergent fiber, gas and methane production. Compared to the control, monensin reduced methane production by 44%, but with a 15% reduction in fiber digestibility. Except for E. globulus and L. turbinata, each variable measured was significantly reduced with the higher level of inclusion compared to the control, representing that overall microbial activity was affected. L. turbinata (60.8% limonene) reduced methane by half compared to control, and by 35 to 85% when compared to monensin, without affecting digestibility of the fiber. Some essential oils from native Argentinean plants exhibited great potential to reduce enteric methane production without affecting digestibility, of which L. turbinata was the most promising alternative.

El objetivo de este estudio fue evaluar el efecto de aceites esenciales (AE) de plantas nativas de Argentina en la producción de metano durante la fermentación in vitro, en comparación con AE con efectos comprobados como modificadores de la fermentación ruminal. Se realizó un diseño en bloque completos al azar y los AE y dosis evaluados fueron: Aloysia gratissima (0,5, 5, 50 y 250 mg/L) , Eucalyptus globulus (5, 50, 150 y 300 mg/L), Lippia turbinata (30, 60, 120 y 240 mg/L), Mentha x piperita var. vulgaris (50, 100, 200 y 400 mg/L), Origanum vulgare ssp. hirtum cv. Compacto (0,5, 5, 50 y 250 mg/L) y cv. Mendocino (50, 150, 250 y 350 mg/L), Rosmarinus officinalis (100, 300, 500 y 700 mg/L), Schinus molle (75, 150, 300 y 600 mg/L), Tagetes minuta (5, 50, 125 y 250 mg/L), y Thymus vulgaris (5, 50, 150 y 300 mg/L). Se incluyeron dos controles: control (sin AE) y monensina (1,87 mg/L). Las variables evaluadas fueron: digestibilidad in vitro de la fibra en detergente neutro, producción de gas y metano. En comparación al control, la monensina redujo la producción de metano en un 44%, pero con una reducción de un 15% en la digestibilidad de la fibra. Con excepción a E. globulus y L. turbinata, todas las variables fueron reducidas significativamente con el mayor nivel de inclusión comparado con el control, lo cual representa que la actividad microbiana se vio afectada. L. turbinata (60,8% limoneno) redujo la producción de metano a la mitad comparado al control, y entre un 35 y 85% en comparación a la monensina, sin que la digestibilidad de la fibra se vea afectada. Algunos aceites esenciales de plantas nativas de Argentina demostraron gran potencial para reducir la producción de metano entérico sin afectar la digestibilidad, de los cuales L. turbinata fue la alternativa más promisoria.

EEA Manfredi

Author affiliation: García, F. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias; Argentina

Author affiliation: Brunetti, Maria Alejandra. INTA. Estación Experimental Agropecuaria Manfredi; Argentina

Author affiliation: Lucini, Enrique I. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias,; Argentina

Author affiliation: Scorcione Turcato, M.C. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Author affiliation: Moreno, Maria Valeria. INTA. Estación Experimental Agropecuaria Manfredi; Argentina

Author affiliation: Frossasco, Georgina. INTA. Estación Experimental Agropecuaria Manfredi; Argentina

Author affiliation: Colombatto, Dario. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Agronomia; Argentina.

Author affiliation: Martinez, Maria Jose. INTA. Estación Experimental Agropecuaria Manfredi; Argentina

Author affiliation: Martinez Ferrer, Jorge. INTA. Estación Experimental Agropecuaria Manfredi; Argentina

Abstract:

The use of phytogenic dietary additives is being evaluated as a means to improve animal productivity. The effect of tannins seems to be the influence not only directly on the digestive process through binding of dietary proteins but also indirectly over their effects on gastrointestinal microbiota. High-throughput sequencing of 16S rRNA gene was used to analyze the impact of dietary supplementation with a blend of chestnut and quebracho tannins on the rumen microbiota of Holstein steers. Bacterial richness was lower in tannins treated animals, while the overall population structure of rumen microbiota was not significantly disturbed by tannins. The ratio of the phyla Firmicutes and Bacteroidetes, a parameter associated with energy harvesting function, was increased in tannins supplemented animals, essentially due to the selective growth of Ruminococcaceae over members of genus Prevotella. Fibrolytic, amylolytic, and ureolytic bacterial communities in the rumen were altered by tannins, while methanogenic archaea were reduced. Furthermore, ruminal pH was significantly higher in animals supplemented with tannins than in the control group, while urease activity exhibited the opposite pattern. Further work is necessary to assess the relation between tannins impact on rumen microbiota and alteration of rumen fermentation parameters associated with bovine performance.

Author affiliation: Díaz Carrasco, Juan María. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Patobiología; Argentina

Author affiliation: Cabral, Claudio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Author affiliation: Redondo, Leandro Martin. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Patobiología; Argentina

Author affiliation: Pin Viso, Natalia Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires; Argentina

Author affiliation: Colombatto, Dario. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Animal; Argentina

Author affiliation: Farber, Marisa Diana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires; Argentina

Author affiliation: Fernandez Miyakawa, Mariano Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Patobiología; Argentina

Abstract:

The use of phytogenic dietary additives is being evaluated as a means to improve animal productivity. The effect of tannins seems to be the influence not only directly on the digestive process through binding of dietary proteins but also indirectly over their effects on gastrointestinal microbiota. High-throughput sequencing of 16S rRNA gene was used to analyze the impact of dietary supplementation with a blend of chestnut and quebracho tannins on the rumen microbiota of Holstein steers. Bacterial richness was lower in tannins treated animals, while the overall population structure of rumen microbiota was not significantly disturbed by tannins. The ratio of the phyla Firmicutes and Bacteroidetes, a parameter associated with energy harvesting function, was increased in tannins supplemented animals, essentially due to the selective growth of Ruminococcaceae over members of genus Prevotella. Fibrolytic, amylolytic, and ureolytic bacterial communities in the rumen were altered by tannins, while methanogenic archaea were reduced. Furthermore, ruminal pH was significantly higher in animals supplemented with tannins than in the control group, while urease activity exhibited the opposite pattern. Further work is necessary to assess the relation between tannins impact on rumen microbiota and alteration of rumen fermentation parameters associated with bovine performance.

Instituto de Patobiología

Author affiliation: Diaz Carrasco, Juan María. INTA. Instituto de Patobiología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Author affiliation: Cabral, Claudio. Animal Nutrition, Silvateam, Indunor; Argentina

Author affiliation: Redondo, Leandro Martín. INTA. Instituto de Patobiología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Author affiliation: Pin Viso, Natalia Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. INTA. Instituto de Biotecnología; Argentina

Author affiliation: Colombatto, Darío. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Animal; Argentina

Author affiliation: Farber, Marisa Diana. INTA. Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Author affiliation: Fernandez Miyakawa, Mariano Enrique. INTA. Instituto de Patobiología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina