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The objective of this study was to evaluate the effect of the addition of a phytogenic compound blend (PHA) containing hydrolyzable tannins, carvacrol, and cinnamaldehyde oil to mineral salt or energy supplementation on the rumen microbiota and nitrogen metabolism of grazing Nellore cattle. Eight castrated Nellore steers were distributed in a double-Latin-square 4 × 4 design, with a 2 × 2 factorial arrangement (two types of supplements with or without the addition of the PHA), as follows: energy supplement without the PHA addition (EW); energy supplement with the PHA addition (EPHA); mineral supplement without the addition of the PHA (MW); mineral supplement with the PHA addition (MPHA). Steers that received supplements with the PHA have a lower ruminal proportion of valerate (with the PHA, 1.06%; without the PHA, 1.15%), a lower ruminal abundance of Verrucomicrobia, and a tendency for lower DM digestibility (with the PHA, 62.8%; without the PHA, 64.8%). Energy supplements allowed for higher ammonia concentrations (+2.28 mg of NH3-N/dL), increased the propionate proportion (+0.29% of total VFA), and had a higher ruminal abundance of Proteobacteria and Spirochaetae phyla in the rumen. The PHA addition in the supplement did not improve nitrogen retention, reduced the ruminal proportion of valerate, and had a negative impact on both the total dry-matter digestibility and the abundance of several ruminal bacterial groups belonging to the Firmicutes and Verrucomicrobia phyla.

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Abstract Background: Digestibility of fiber in the rumen is not due to enzymatic activity of individual bacteria, but rather to their interaction, which complements their enzymatic functioning. Thus, efficiency of fiber digestion depends on the diversity and density of cellulolytic bacteria. Objective: To estimate in vitro production of biogas, methane, and fermentative characteristics of cobra grass (Brachiaria hibrido) inoculated with ruminal bacteria (RB) in coculture with isolated cellulolytic bacteria (ICB) from bovine (ICBbov) or water buffalo (ICBbuf). Methods: ICBbov and ICBbuf were isolated from ruminal cellulolytic bacteria consortia using specific culture media for cellulolytic bacteria. Both were morphologically characterized and a Gram stain was performed. In the in vitro gas production test, the substrate was cobra grass and the inocula were ruminal bacteria (RB), ICBbov, ICBbuf, Coculturebov (RB + ICBbov) and Coculturebuf (RB + ICBbuf). Biogas and methane (CH4) production, as well as dry matter degradation (DMD) and neutral detergent fiber degradation (NDFD) were measured. A completely randomized design was used. Results: The ICB obtained were Gram positive cocci. Accumulated biogas production at 72 h from ICBbov and ICBbuf was on average 42.11% of that produced by RB. The Coculturebov produced 14.24% more biogas than RB. The CH4 production was lower in ICBbov and ICBbuf than in RB, Coculturebov and Coculturebuf. The DMD and NDFD were not different among RB, Coculturebov and Coculturebuf. The ICBbov degraded 37.10 and 96.34% more DMD and NDFD than ICBbuf (p<0.05). Conclusion: The use of ICB from bovine or water buffalo in coculture with RB does not improve in vitro production of biogas, DMD or NDFD with respect to RB alone.

Resumen Antecedentes: La digestibilidad ruminal de la fibra no se debe a la actividad enzimática individual de las bacterias sino a su interacción para complementar su funcionamiento enzimático. Así, la eficiencia de digestión de la fibra depende de la diversidad y la densidad de las bacterias celulolíticas. Objetivo: Estimar la producción de biogás, metano, y las características fermentativas in vitro del pasto cobra (Brachiaria hibrido) inoculado con bacterias ruminales (BR) en cocultivo con bacterias celulolíticas aisladas (BCA) de bovino (BCAbov) o búfalo de agua (BCAbuf). Métodos: BCAbov y BCAbuf se aislaron de consorcios bacterianos celulolíticos ruminales usando medios de cultivo específicos para bacterias celulolíticas. Ambas se caracterizaron morfológicamente y realizó tinción de Gram. En la prueba de producción de gas in vitro, el sustrato fue pasto cobra y los inóculos fueron bacterias ruminales (BR), BCAbov, BCAbuf, Cocultivobov (BR + BCAbov) y Cocultivobuf (BR + BCAbuf). Se midió la producción de biogás y metano (CH4), así como la degradación de la materia seca (DMS) y de la fibra detergente neutro (DFDN). El análisis estadístico se basó en un diseño completamente al azar. Resultados: Las BCA resultantes se identificaron como cocos Gram positivos. La producción de biogás acumulada a las 72 h por BCAbov y BCAbuf fue en promedio 42,11% del producido por BR. El cocultivobov produjo 14,24% más biogás que BR. La producción de CH4 fue menor en BCAbov y BCAbuf que en BR, cocultivobov y cocultivobuf. Las DMS y DFDN no mostraron diferencias entre BR, cocultivobov y cocultivobuf. La BCAbov degradó 37,10 y 96,34% más DMS y DFDN que BCAbuf (p<0,05). Conclusión: El uso de BCA de bovino o búfalo de agua en cocultivo con BR no mejora la producción de biogás, DMS o DFDN in vitro respecto a BR.

Resumo Antecedentes: A digestibilidade da fibra no rúmen não se deve à atividade enzimática individual das bactérias, mas sim à sua interação para complementar o seu funcionamento enzimático. Assim, a eficiência da digestão das fibras depende da diversidade e densidade das bactérias celulolíticas. Objetivo: Estimar a produção in vitro de biogás, metano e características fermentativas da gramínea de cobra (Brachiaria hibrido) inoculada com bactéria ruminal (BR) em cocultura com bactérias celulolíticas isoladas (BCI) de bovino (BCIbov) ou búfalo de água (BCIbuf). Métodos: BCIbov e BCIbuf foram isolados a partir de consórcios de bactérias celulolíticas ruminais utilizando meios de cultura específicos para bactérias celulolíticas. Ambos foram caracterizados morfologicamente, e foi realizada uma coloração de Gram. No teste de produção de gás in vitro, o substrato era erva de cobra e os inóculos eram bactérias ruminais (BR), BCIbov, BCIbuf, Cocultivobov (BR + BCIbov) e cocultivobuf (BR + BCIbuf). Foram medidas a produção de biogás e metano (CH4), bem como a degradação da matéria seca (DMS) e a degradação da fibra em detergente neutro (DFDN). Foi utilizado um desenho completamente aleatório. Resultados: BCIs eram cocos Gram positivos. A produção acumulada de biogás a 72 h de BCIbov e BCIbuf foi em média 42,11% da produzida por BR. O cocultivobov produziu 14,24% mais biogás do que o BR. A produção de CH4 foi menor em BCIbov e BCIbuf do que BR, cocultivobov e cocultivobuf. DMS e DFDN não eram diferentes entre BR, cocultivobov e cocultivobuf. O BCIbov degradou 37,10 e 96,34% mais DMS e DFDN do que o BCIbuf (p<0,05). Conclusão: A utilização de BCI de bovino ou búfalo de água em cocultura com BR não melhora a produção in vitro de biogás, DMS ou DFDN no que diz respeito a BR.

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Our objective was to evaluate the effects of unprotected choline chloride (Cho) on the ruminal microbiome at 2 dietary neutral detergent fiber (NDF) concentrations. We hypothesized that the effects of Cho on ruminal bacterial populations would depend on NDF. Eight dual-flow continuous-culture fermentors were arranged in a duplicated 4 × 4 Latin square as a 2 × 2 factorial with the following treatments: (1) 30% NDF-control (30% NDF diet, no supplemental choline); (2) 30% NDF-Cho (30% NDF diet plus 1.9 g of choline ion per kg of dry matter); (3) 40% NDF-control (40% NDF diet, no supplemental choline); and (4) 40% NDF-Cho (40% NDF diet plus 1.9 g of choline ion per kg of dry matter). We did 4 fermentation periods of 10 d each and used the last 3 d for collection of samples of solid and liquid digesta effluents for DNA extraction. Overall, 32 solid and 32 liquid samples were analyzed by amplification of the V4 variable region of bacterial 16S rRNA. Data were analyzed with R (R Project for Statistical Computing) and SAS (SAS Institute Inc.) to determine effects of Cho, NDF, and NDF × Cho on taxa relative abundance. The correlation of propionate molar proportion with taxa relative abundance was also analyzed. At the phylum level, relative abundance of Firmicutes in the liquid fraction tended to be greater when Cho was supplemented with a 30% NDF diet. At the order level, Cho increased Coriobacteriales in solid fraction and decreased Fibrobacterales in liquid fraction. Moreover, Cho decreased abundance of Clostridiales and increased Selenomonadales in the solid fraction, only with the 30% NDF diet. For genera, lower abundance of Pseudobutyrivibrio resulted from Cho in solid and liquid fractions. Greater abundance of Succinivibrio in solid and Selenomonas and Selenomonas 1 in liquid resulted from Cho with the 30% NDF diet. Propionate molar proportion was positively correlated with relative abundance of order Selenomonadales in solid and liquid fractions, and with genus Succinivibrio in solid and genera Selenomonas and Selenomonas 1 in liquid. Our results indicate that Cho primarily decreases abundance of bacteria involved in fiber degradation and increases abundance of bacteria mainly involved in nonstructural carbohydrate degradation and synthesis of propionate, particularly when a diet with 30% NDF is provided.

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Abstract Background: Rumen microorganisms have developed a series of complex interactions, representing one of the best examples of symbiosis between microorganisms in nature. Conventional taxonomic methods based on culture techniques are being replaced by molecular techniques that are faster and more accurate. Objective: To characterize rumen bacterial diversity of Nellore steers grazing on tropical pastures by sequencing the 16S rRNA gene using Illumina sequencing. Methods: Three rumen-cannulated Nellore steers were used. The liquid and solid fractions of the rumen contents were processed to extract metagenomic DNA, and the V1 and V2 hypervariable regions of the 16S rRNA gene were sequenced using Illumina sequencing. Results: A total of 11,407,000 reads of adequate quality were generated, and 812 operational taxonomic units (OTUs) were found at the species level. Twenty-seven phyla were identified, and the predominant phyla were Firmicutes (23%), Bacteroidetes (14%), Proteobacteria (10%), Spirochaetes (9%), Fibrobacteres (7%), Tenericutes (5%), and Actinobacteria (2%), which represented 70% of the total phyla identified in the rumen content. Conclusion: Rumen environment in grazing Nellore steers showed high bacterial diversity, with Firmicutes, Bacteroidetes, Proteobacteria, Spirochaetes, and Fibrobacteres as the predominant phyla.

Resumen Antecedentes: Los microorganismos ruminales han desarrollado una serie de interacciones complejas que representan uno de los mejores ejemplos de simbiosis entre microorganismos en la naturaleza. Los métodos taxonómicos tradicionales basados en técnicas de cultivo están siendo reemplazados por técnicas moleculares debido a su mayor velocidad y precisión. Objetivo: Caracterizar la diversidad bacteriana ruminal de novillos Nelore mantenidos en pasturas tropicales mediante la secuenciación del gen 16S RNA utilizando la plataforma de secuenciación Illumina. Métodos: Se utilizaron tres novillos Nelore fistulados en el rumen. Las fracciones líquida y sólida del contenido ruminal fueron procesadas para la extracción del DNA meta genómico y las regiones hipervariables V1 y V2 del gen 16S rRNA fueron secuenciadas usando la plataforma Illumina. Resultados: En total, se generaron 11.407.000 lecturas de calidad adecuada, y en el nivel de especie se encontraron 812 unidades taxonómicas operacionales (OTUs). Se identificaron veintisiete filos, predominantemente Firmicutes (23%), Bacteroidetes (14%), Proteobacteria (10%), Spirochaetes (9%), Fibrobacteres (7%), Tenericutes (5%) y Actinobacteria (2%), los cuales representaron el 70% de los filos identificados en el contenido ruminal. Conclusión: El ambiente ruminal de novillos Nelore en pastoreo presenta una alta diversidad de bacterias, con dominancia de los filos Firmicutes, Bacteroidetes, Proteobacteria, Spirochaetes y Fibrobacteres .

Resumo Antecedentes: Os microrganismos ruminais têm desenvolvido uma serie de complexas interações que representam um dos melhores exemplos de simbiose entre microrganismos na natureza. Os métodos taxonômicos tradicionais baseados em métodos de cultura vêm sendo substituídos por técnicas moleculares que apresentam maior velocidade a acurácia. Objetivo: Caracterizar a diversidade bacteriana ruminal em novilhos Nelore mantidos em pastagens tropicais mediante o sequenciamento do gene 16S rRNA utilizando a plataforma de sequenciamento Illumina. Métodos: Foram utilizados três novilhos Nelore fistulados no rúmen. A fração liquida e solida do conteúdo ruminal foram processadas para extrair o DNA metagenômico, e as regiões hipervariáveis V1 e V2 do gene 16S rRNA foram sequenciadas na plataforma Illumina. Resultados: No total foram geradas 11.407.000 leituras de qualidade adequada, e 812 unidades taxonomicas operacionais (OTUs) foram identificadas no nível de espécie. Foram identificados 27 filos, e houve predominância de Firmicutes (23%), Bacteroidetes (14%), Proteobacteria (10%), Spirochaetes (9%), Fibrobacteres (7%), Tenericutes (5%) e Actinobacteria (2 %), os quais representaram 70% dos filos identificados a partir do rúmen bovino. Conclusão: O ambiente ruminal em novilhos Nelore em pastejo apresentou alta diversidade bacteriana, com Firmicutes, Bacteroidetes, Proteobacteria, Spirochaetes e Fibrobacteres como filos predominantes.

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BACKGROUND: Copper (Cu) is an essential microelement to the health and proper functioning of metabolic processes in animals, but the particular function of Cu in fermentation processes and the formation of methane (CH4 ) in the rumen have been poorly analyzed. The innovative aspect of this study was to investigate the effects of high doses of Cu as copper sulfate on in vitro ruminal degradation, fermentation patterns, and CH4 production. RESULTS: There was a decrease (P < 0.04) on in vitro dry matter (DM) and organic matter degradability from 60 to 100 µg Cu/g DM. Ammonia concentration decreased drastically with increasing Cu levels (linear effect, P < 0.01). Total bacteria and volatile fatty acids (quadratic effect, P < 0.02) were reduced with 80 and 100 µg Cu/g DM. Methane production (milliliters per gram digestible organic matter) was decreased when dosages of Cu were increased (linear effect, P < 0.003). CONCLUSION: Overall, the addition of increasing levels of Cu to 40 µg Cu/g DM did not have an adverse impact on ruminal bacteria growth and decreased CH4 production, without affecting the ruminal kinetics. © 2018 Society of Chemical Industry.

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ABSTRACT Objective. To measure the in vitro fermentation variables of a cellulolytic bacteria consortium (CBC) isolated from a water buffalo rumen in coculture with total ruminal bacteria (TRB) on two fibrous substrates. Materials and methods. A CBC was isolated from the ruminal fluid of a female water buffalo in selective cellulolytic media. The experimental design was completely random with a 3x2 factorial arrangement; factors were treatments [TRB, CBC, and coculture (TRB + CBC)] and substrates (cobra grass and corn stover). Total gas and methane (CH4) production were measured at different time intervals. At 72 h, measurements were taken of pH, ammoniacal nitrogen (NH3-N), dry matter degradation (DMD), neutral detergent fiber degradation (NDFD) and total bacteria population. Results. Gas production with both substrates was highest (p≤0.05) in the coculture at 3, 6 and 24 h. At 48 and 72 h, gas production in the cobra grass was highest (p≤0.05) in the coculture. The coculture and TRB did not differ (p>0.05) in terms of CH4, DMD and NDFD values at 48 and 72 h. With the cobra grass, NH3-N concentration was higher (p≤0.05) in the coculture than in the TRB. Conclusions. The gas production and dry matter degradation values of the water buffalo rumen cellulolytic bacteria consortia indicate them to be a promising alternative for improving cobra grass structural carbohydrates degradation when in coculture with bovine ruminal bacteria.

RESUMEN Objetivo. Determinar las variables fermentativas in vitro de un consorcio bacteriano celulolítico (CBC) aislado de una búfala de agua en cocultivo con bacterias ruminales totales (BRT) en sustratos fibrosos. Materiales y métodos. Un CBC se aisló de fluido ruminal de una búfala de agua en medios selectivos celulolíticos. El diseño experimental fue un diseño completamente al azar con arreglo factorial 3x2, los factores fueron tratamientos [BRT, CBC y un cocultivo (BRT + CBC)] y sustratos (pasto pangola y rastrojo de maíz). La producción de gas total y metano (CH4) se midieron a diferentes intervalos de tiempo. Además, se estimó pH, nitrógeno amoniacal (N-NH3), degradación de materia seca (DMS) y de fibra detergente neutro (DFDN), y la población de bacterias totales a 72 h de incubación. Resultados. El cocultivo produjo mayor (p≤0.05) cantidad de gas a las 3, 6 y 24 h en ambos sustratos. A las 48 y 72 h, el cocultivo produjo mayor (p≤0.05) gas en pasto cobra. El cocultivo y las BRT no presentaron diferencias (p>0.05) en la producción de CH4 a 48 y 72 h, y en DMS y DFDN (p>0.05). En el pasto cobra, la concentración de N-NH3 con el cocultivo fue mayor (p≤0.05) que con BRT. Conclusiones. La producción de gas y degradación de materia seca de los consorcios bacterianos celulolíticos procedentes del rumen de una búfala de agua muestran que son una alternativa para mejorar la fermentación de carbohidratos estructurales del pasto cobra cuando se cocultivan con bacterias ruminales bovinas.

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The objective of this study was to evaluate whether providing chitosan (CHI) to cows fed diets supplemented with whole raw soybeans (WRS) would affect the nutrient intake and digestibility, ruminal fermentation and bacterial populations, microbial protein synthesis, N utilization, blood metabolites, and milk yield and composition of dairy cows. Twenty-four multiparous Holstein cows (141 ± 37.1 d in milk, 38.8 ± 6.42 kg/d of milk yield; mean ± SD) were enrolled to a 4 × 4 Latin square design experiment with 23-d periods. Cows were blocked within Latin squares according to milk yield, days in milk, body weight, and rumen cannula (n = 8). A 2 × 2 factorial treatment arrangement was randomly assigned to cows within blocks. Treatments were composed of diets with 2 inclusion rates of WRS (0 or 14% diet dry matter) and 2 doses of CHI (0 or 4 g/kg of dry matter, Polymar Ciência e Nutrição, Fortaleza, Brazil). In general, CHI+WRS negatively affected nutrient intake and digestibility of cows, decreasing milk yield and solids production. The CHI increased ruminal pH and decreased acetate to propionate ratio, and WRS reduced NH3-N concentration and acetate to propionate in the rumen. The CHI reduced the relative bacterial population of Butyrivibrio group, whereas WRS decreased the relative bacterial population of Butyrivibrio group, and Fibrobacter succinogenes, and increased the relative bacterial population of Streptococcus bovis. No interaction effects between CHI and WRS were observed on ruminal fermentation and bacterial populations. The CHI+WRS decreased N intake, microbial N synthesis, and N secreted in milk of cows. The WRS increased N excreted in feces and consequently decreased the N excreted in urine. The CHI had no effects on blood metabolites, but WRS decreased blood concentrations of glucose and increased blood cholesterol concentration. The CHI and WRS improved efficiency of milk yield of cows in terms of fat-corrected milk, energy-corrected milk, and net energy of lactation. The CHI increased milk concentration [g/100 g of fatty acids (FA)] of 18:1 trans-11, 18:2 cis-9,cis-12, 18:3 cis-9,cis-12,cis-15, 18:1 cis-9,trans-11, total monounsaturated FA, and total polyunsaturated FA. The WRS increased total monounsaturated FA, polyunsaturated FA, and 18:0 to unsaturated FA ratio in milk of cows. Evidence indicates that supplementing diets with unsaturated fat sources along with CHI negatively affects nutrient intake and digestibility of cows, resulting in less milk production. Diet supplementation with CHI or WRS can improve feed efficiency and increases unsaturated FA concentration in milk of dairy cows.

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In ruminants, urea recycling is considered an evolutionary advantage. The amount of urea recycled mainly depends of the nitrogen (N) intake and the amount of organic matter (OM) digested in the rumen. Because recycled N contributes to meeting microbial N requirements, accurate estimates of urea recycling can improve the understanding of efficiency of N utilization and N losses to the environment. The objective of this study was to evaluate urea kinetics and microbial usage of recycled urea N in ruminants using a meta-analytical approach. Treatment mean values were compiled from 25 studies with ruminants (beef cattle, dairy cows and sheep) which were published from 2001 to 2016, totalling 107 treatment means. The data set was analyzed according to meta-analysis techniques using linear or non-linear mixed models, taking into account the random variations among experiments. Urea N synthesized in the liver (UER) and urea N recycled to the gut (GER) linearly increased (P<0.001) as N intake (g/BW0.75) increased, with increases corresponding to 71.5% and 35.2% of N intake, respectively. The UER was positively associated (P<0.05) with dietary CP concentration and the ratio of CP to digestible OM (CP:DOM). Maximum curvature analyses identified 17% dietary CP as the point where there was a prominent increase in hepatic synthesis of urea N, likely due to an excess of dietary N leading to greater ammonia absorption. The GER:UER decreased with increasing dietary CP concentration (P<0.05). At dietary CP⩾19%, GER:UER reached near minimal values. The fraction of UER eliminated as urinary urea N and the contribution of urea N to total urinary N were positively associated with dietary CP (P<0.05), both reaching values near the plateau when dietary CP was 17%. The fractions of GER excreted in the feces and utilized for anabolism decreased, whereas the fraction of GER returned to the ornithine cycle increased with dietary CP concentration (P<0.05). Recycled urea N assimilated by ruminal microbes (as a fraction of GER) decreased as dietary CP and CP:DOM increased (P<0.05). The efficiency of microbial assimilation of recycled urea N was near plateau values at 194 g CP/kg DOM. The models obtained in this study contribute to the knowledge on N utilization, and they could be used in feeding models to predict urea recycling and thus to improve formulation of diets to reduce N losses that contribute to air and water pollution.

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Seis ovinos machos, não castrados, da raça Santa Inês, com média de peso de 30kg, fistulados no rúmen, foram distribuídos em delineamento de quadrado-latino duplo (3x3). Três períodos e três dietas, uma controle, sem inclusão de fonte de lipídio, e duas com inclusão de grãos de girassol ou gordura protegida, foram testados quanto aos parâmetros ruminais. Foram verificadas diferenças (P<0,05) entre as dietas quanto à concentração ruminal de amônia (18mg/dL), mas não houve efeito sobre o pH (6,1), a produção total de ácidos graxos de cadeia curta (98mM), a proporção de acetato (66,4 por cento), de propionato (20 por cento) e de butirato (13 por cento) e sobre a razão acetato:propionato (3,2:1). As bactérias sólido-aderidas isoladas do conteúdo ruminal dos animais recebendo a dieta-controle apresentaram maior teor de nitrogênio (10,7 por cento) que as das dietas com gordura protegida (9,8 por cento) ou com grãos de girassol (9,1 por cento). A produção de nitrogênio pelas bactérias sólido-aderidas da dieta-controle (170mg/g) não diferiu da dieta com grãos de girassol (153mg/kg) ou com gordura protegida (160mg/kg). A inclusão de grãos de girassol ou gordura protegida na dieta com alto concentrado para ovinos propiciou ambiente adequado para fermentação ruminal.

Six not castrated Santa Inês breed male sheep, weighing 30kg, fistulated in the rumen, were randomly alloted in a double Latin-Square design (3x3). Three periods and three diets, a control without addition of the lipid source, and two with addition of sunflower seeds or protected fat, were tested on the ruminal fermentation. Differences (P<0.05) between diets for ruminal ammonia concentration (18mg/dL) were observed. However, effects were not detected on pH (6.1); the total production of short-chain fatty acids (98mM); proportions of acetate (66.4 percent), propionate (20 percent), and butyrate (13 percent); and acetate:propionate ratio (3.2:1). The solid-adherent bacteria isolated from the rumen content of animals fed control diet had higher nitrogen content (10.7 percent) than those fed protected fat diet (9.8 percent) or sunflower seeds diet (9.1 percent). The production of nitrogen by bacteria attached to solid-control diet (170mg/kg) did not differ from sunflower seeds (153mg/kg) or protected fat diets (160mg/kg). The inclusion of sunflower seeds or protected fat in diets with high concentrate for sheep provided suitable environment for rumen fermentation.

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Seis ovinos machos, não castrados, da raça Santa Inês, com média de peso de 30kg, fistulados no rúmen, foram distribuídos em delineamento de quadrado-latino duplo (3x3). Três períodos e três dietas, uma controle, sem inclusão de fonte de lipídio, e duas com inclusão de grãos de girassol ou gordura protegida, foram testados quanto aos parâmetros ruminais. Foram verificadas diferenças (P<0,05) entre as dietas quanto à concentração ruminal de amônia (18mg/dL), mas não houve efeito sobre o pH (6,1), a produção total de ácidos graxos de cadeia curta (98mM), a proporção de acetato (66,4 por cento), de propionato (20 por cento) e de butirato (13 por cento) e sobre a razão acetato:propionato (3,2:1). As bactérias sólido-aderidas isoladas do conteúdo ruminal dos animais recebendo a dieta-controle apresentaram maior teor de nitrogênio (10,7 por cento) que as das dietas com gordura protegida (9,8 por cento) ou com grãos de girassol (9,1 por cento). A produção de nitrogênio pelas bactérias sólido-aderidas da dieta-controle (170mg/g) não diferiu da dieta com grãos de girassol (153mg/kg) ou com gordura protegida (160mg/kg). A inclusão de grãos de girassol ou gordura protegida na dieta com alto concentrado para ovinos propiciou ambiente adequado para fermentação ruminal.(AU)

Six not castrated Santa Inês breed male sheep, weighing 30kg, fistulated in the rumen, were randomly alloted in a double Latin-Square design (3x3). Three periods and three diets, a control without addition of the lipid source, and two with addition of sunflower seeds or protected fat, were tested on the ruminal fermentation. Differences (P<0.05) between diets for ruminal ammonia concentration (18mg/dL) were observed. However, effects were not detected on pH (6.1); the total production of short-chain fatty acids (98mM); proportions of acetate (66.4 percent), propionate (20 percent), and butyrate (13 percent); and acetate:propionate ratio (3.2:1). The solid-adherent bacteria isolated from the rumen content of animals fed control diet had higher nitrogen content (10.7 percent) than those fed protected fat diet (9.8 percent) or sunflower seeds diet (9.1 percent). The production of nitrogen by bacteria attached to solid-control diet (170mg/kg) did not differ from sunflower seeds (153mg/kg) or protected fat diets (160mg/kg). The inclusion of sunflower seeds or protected fat in diets with high concentrate for sheep provided suitable environment for rumen fermentation.(AU)

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Avaliaram-se o crescimento da população, a atividade in vitro da enzima 1,4-b-endoglucanase e a taxa de digestão de celulose em culturas de Ruminococcus flavefaciens FD1 na presença de 50, 100, 200 e 400µg/ml de taninos purificado das leguminosas Mimosa hostilis (Jurema Preta), Mimosa caesalpinifolia (Sabiá) e Bauhinia cheilantha (Mororó). O crescimento bacteriano, a atividade da endoglucanase e a digestão de celulose foram fortemente inibidos pela presença dos taninos condensados purificados das três espécies, entretanto, a intensidade da inibição foi variável em função da espécie da leguminosa e da concentração de tanino.(AU)

The effects of tannin levels in three Brazilian browse legumes Mimosa hostilis (Jurema Preta), Mimosa caesalpinifolia (Sabiá) e Bauhinia cheilantha (Mororó) on growth and endoglucanase activity of Ruminococcus flavefaciens FD1 were evaluated. Isolated cultures of Ruminococcus flavefaciens FD1 were used to assess cellular growth, 1, 4-b-endoglucanase activity, and cellulose digestion in the presence of 50, 100, 200 and 400µg/ml of purified tannins from the three legume species. Growth of FD1, 1, 4-b-endoglucanase activity and cellulose digestion were highly inhibited by the presence of purified tannins of the three legume species. However, the intensity of inhibition varied in according to the legume species and tannin concentration.(AU)

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