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This study was carried out to evaluate the use of tannin extract from Acacia mearnsii as a strategy to reduce methane (CH

The objective was to assess the effects short-term use of monensin and Acacia mearnsii tannins as feed additives on nutrient intake, digestibility, and CH4 production in cattle. Six rumen-cannulated Holstein cows were distributed in two 3×3 Latin square experimental design, and each experimental period lasted 21 days. The basal diet was composed of corn silage and concentrate in a 50:50 dry matter (DM) basis proportion. Treatments were control, monensin (18 mg kg?1 of DM), and tannin-rich extract from Acacia mearnsii (total tannins equivalent to 6 g kg?1 of DM). Nutrient intake and apparent digestibility coefficients were not affected by the addition of monensin or tannins to diets. However, tannins showed a tendency to reduce crude protein digestibility. Monensin decreased CH4 emission by 25.6% (g kg?1 of body weight) compared with the control treatment. Monensin is more effective than Acacia mearnsii tannins in reducing CH4 emissions in the short term, considering a diet of the same roughage:concentrate proportion for cattle. Made available in DSpace on 2020-12-09T09:04:13Z (GMT). No. of bitstreams: 1 ShortTermUse.pdf: 298771 bytes, checksum: cf85d3a864d3ff48a8fdea9a90f2098f (MD5) Previous issue date: 2020

Aimed to evaluate the association between essential oils (Next Enhance 300®), exogenous enzymes (Allzyme SSF®), and monensin for the rumen fermentation manipulation, especially reduction of rumen methane in Nellore cattle. Eight cows weighing 480 ± 55 kg and cannulated in the rumen were used in two 4x4 Latin squares, into a 2x2x2 factorial arrangement, which one of the factors being analyzed by the squared effect. The animals fed the same basal diet using a corn silage: concentrate ratio of 60:40. The factors used were: 300 mg/animal/d, 10 g/animal/d, 300 mg/animal/d for essential oils, exogenous enzyme, and monensin, respectively. Each experimental period lasted 26 days. Sixteen days were used for adaptation to the experimental diets, while from D16 to D21 for evaluation of DMI and D22 to evaluate rumen fermentation (0, 3, 6, 9, and 12h after feeding) through the ex situ technique, which consists of incubating ruminal content in conditions similar to those of the rumen allowing the measurement of rumen production (SCFA and methane). Differences were considered significant when P-value was below 0,05 through analysis of variance using mixed procedure. No significant difference (P > 0.05) was observed for DMI Monensin decreased (P < 0.05) the concentration of acetic, butyric and total SCFA. However, the production of acetic acid, propionic acid, total SCFA and acetate:propionate ratio was not altered (P > 0,05). Significant interaction (P < 0.05) between enzyme and monensin was observed for butyric acid production, indicating the enzyme used alone did not alter the production of these acid, but when associated with monensin, a reduction was observed. The enzyme reduced (P < 0.05) methane concentration, and when associated with monensin this reduction was increased. However methane production was not affected (P > 0.05). The feed additives evaluated do not reduce the rumen production of methane, but reduced butyric acid production.

The objective of this experiment was to evaluate the association between different feed additives on ruminal fermentation parameters especially ruminal methane on cannulated beef cattle. Five Nellore cows, 480 ± 55 kg, ruminally cannulated were used. The experimental was a 5 x 5 Latin square design and the experimental unit was the animal within each period (n = 25 experimental units). The diets offered differed only by the inclusion or not of monensin, calcium nitrate or tannin, totaling five treatments: Control (without addition of additives), Monensin (30 ppm in the diet), Nitrate (3.0% of DM), Tannin (1.5% of DM) and Pool (combination of the three additives), being supplied in a basal diet with a concentrate: roughage (corn silage) ratio of 60:40. The study was divided into five periods, each one with 26 days. Sixteen days were used for adaptation to the experimental diets; ruminal fluid samples were collected at 0, 3, 6, 9 and 12h after feeding at 22nd day. To evaluate CH4 production and ammoniacal nitrogen balance, samples were incubated ex situ on equality ruminal conditions and then analyzed by gas chromatography and UV spectrophotometric, respectively. Data were analyzed using PROC MIXED of SAS and differences were declared significant at 5%. There was interaction between sampling time and treatment (P < 0001) and all the additives were efficient in decreasing the methane production in mol/g/hour (P < 0001), mol/kg/day (P < 0001) and g/kg/day (P < 0001). Comparing to the Control all additives decreased CH4 production, and decreases were 9.5% for monensin, 18.75% for tannin, 19.8% for calcium nitrate and 28.8% for the Pool (monensin, nitrate and tannin). Concentration and balance of rumen NH3-N was not affected by any treatments. It was possible to conclude that association of additives of different mechanism of action presented a partial additive effect.

High lipid concentration in ruminant diets often harms nutrient digestibility and feed intake; thus, a protected lipid and antioxidant source can be considered as an alternative for improving diet energy without putting animal production at a disadvantage. The aim of this study was to evaluate the dry matter intake (DMI), nutrient digestibility and feeding behavior of cattle fed cottonseed and vitamin E. Six cannulated cows, non-pregnant, non-lactating were distributed in a replicated 3 × 3 Latin Square design. Feed was offered ad libitum twice daily. Treatments were: 1) Control, 2) CS: 30 % cottonseed included; and 3) CSVitE: 30 % cottonseed plus 500 IU VitE included. Data were analyzed by SAS (Statistical Analysis System, v.9.3) and the significance was declared at p < 0.05. Diets with cottonseed had 22 % greater digestibility of ether extract and 9 % lower digestibility of non-fiber-carbohydrates compared to the control. Treatments with cottonseed had 13 % higher time eating, 48 % more ruminating, 34 % more chewing and 17 % lower time idling compared to the control. Molar proportion of propionate was 36 % higher and the butyrate and acetate:propionate ratio were 27 % and 30 % lower, respectively, for the cottonseed treatments compared to the control. Including cottonseed up to 30 % can be used to increase diet energy density leading to improvements in feeding behavior and ruminal parameters. The inclusion of Vitamin E did not result in benefits to cattle when it was combined with cottonseed. Further studies should be undertaken to evaluate vitamin E levels in association with different amounts and lipid sources.

Made available in DSpace on 2020-12-12T01:46:42Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-01-01 The effect of a polyclonal antibody preparation (PAP) against Streptococcus bovis and Fusobacterium necrophorum on ruminal fermentation and digestion in ruminally cannulated cows was investigated in two 3 × 3 Latin squares in factorial arrangement of treatments 3 × 2 regarding two feed additives (PAP in powder (PAPP) and in liquid (PAPL) presentation) plus control (CON) and two managements of diets (with or without adaptation to highly fermentable carbohydrate diets). Adapted group had greater DMI (p < 0.0001) and DM (p < 0.0001), NDF (p = 0.03) and total carbohydrates (p < 0.0001) apparent digestibility when compared to non-adapted group. PAPL had greater DM (p = 0.02), NDF (p = 0.03) and total carbohydrates apparent digestibility when compared to PAPP or CON. Adapted animals had lower (p < 0.0001) rumen pH when compared to non-adapted animals. Moreover, PAPL group had greater (p = 0.04) rumen pH values when compared to PAPP and CON. PAPL showed potential effect as an additive by increasing apparent digestibility of DM, NDF and total carbohydrates and also for being more efficient to prevent the drop in rumen pH during the peak of fermentation. Department of Animal Nutrition and Production University of Sao Paulo–FMVZ/USP Embrapa Beef Cattle Mato Grosso State Agricultural and Extension Service Brazilian Institute of Geography and Statistics–IBGE College of Technology and Agricultural Sciences Sao Paulo State University–UNESP Department of Animal Breeding and Nutrition Sao Paulo State University–FMVZ/UNESP College of Technology and Agricultural Sciences Sao Paulo State University–UNESP Department of Animal Breeding and Nutrition Sao Paulo State University–FMVZ/UNESP

Embora algumas estratégias alimentares tenham sido propostas para diminuir a emissão de metano (CH4) provenientes de ruminantes, poucas têm mostrado diminuição persistente, principalmente in vivo. O objetivo do presente estudo foi avaliar o uso de diferentes níveis de taninos como aditivo alimentar para ruminantes como mitigador das emissões de CH4 ruminal e dos dejetos. Utilizou-se o delineamento experimental quadrado latino 4x4 duplicado (4 períodos de 28 dias cada), em arranjo fatorial 2x4, sendo testados dois grupos distintos de bovinos (taurinos ou zebuínos) e quatro níveis de inclusão de taninos (extrato comercial de Acacia mearnsii, contendo 82,3% de taninos totais - equivalente em ácido tânico e 32,3% de taninos condensados - equivalente em leucocianidina) na dieta (0; 0,5; 1,0 e 1,5% da MS da dieta). Para avaliar a produção de CH4 dos dejetos utilizaram-se biodigestores anaeróbios experimentais do tipo batelada, em delineamento inteiramente casualizado. Os níveis utilizados do aditivo promoveram mudanças no comportamento de ruminação dos animais e apesar de causarem redução linear da digestibilidade dos nutrientes, mantiveram o equilíbrio entre a síntese e consumo de N-NH3 ruminal, reduziram linearmente a síntese de proteína microbiana e a produção de CH4 ruminal sem, contudo, reduzir a eficiência microbiana e a produção de ácidos graxos de cadeia curta (AGCC), demonstrando que estes taninos interferem diretamente e indiretamente sobre as archeas metanogênicas. Através do modelo Broken-line encontrou-se o limiar de 0,72% de taninos na dieta como ponto de inflexão para iniciar a diminuição da produção de CH4 ruminal. O processo de biodigestão dos dejetos não foi modificado pelo uso dos taninos, no entanto, as velocidades das produções de CH4 e CO2 foram influenciadas pela composição dos dejetos dos diferentes grupos de bovinos avaliados, sendo mais acentuada para os taurinos, podendo ser um fator positivo para redução do tempo de biodigestão. A utilização de extrato de Acacia mearnsii até níveis de 1,5% da MS da dieta demonstrou ser uma opção segura como aditivo alimentar para bovinos de grupos distintos, com potencial para mitigação de CH4 ruminal sem afetar a eficiência de conversão nos processos de tratamento de resíduos, com potencial para minimização dos volumes de dejetos. Although some dietary strategies have been proposed to reduce the emission of methane (CH4) from ruminants, few have shown persistent decline, mainly in vivo. The objective of the present study was to evaluate the use of different levels of tannins as feed additive for ruminants as a mitigator of ruminal CH4 and waste emissions. A double 4x4 Latin square experimental design (4 periods of 28 days each) was used in a 2x4 factorial arrangement, with two different groups of cattle (taurine or zebu) and four levels of tannins inclusion (commercial extract of Acacia mearnsii, containing 82.3% of total tannins - tannic acid equivalent, 32.3% of condensed tannins - leucocianidine equivalent) in the diet (0, 0.5, 1.0 and 1.5% of dietary DM). To evaluate the CH4 production of the wastes, anaerobic experimental batch biodigesters were used in a completely randomized design. The used additive levels promoted changes in rumination behavior of the animals and, although they caused linear reduction of nutrient digestibility, they maintained the balance between the synthesis and consumption of ruminal NH3-N, linearly reduced protein microbial synthesis and the ruminal CH4 production without, however, reducing the microbial efficiency and the short chain fatty acids production (SCFA), demonstrating that these tannins interfered directly and indirectly on the methanogenic archeas. Through the Broken-line model, the threshold of 0.72% of tannins in the diet was found as inflection point to initiate a decrease in ruminal CH4 production. The biodigestion process of the waste was not modified by the tannins use, however, the velocities of CH4 and CO2 production were influenced by the composition of the different bovines group evaluated, being more accentuated for the taurine, which can be a positive factor to reduce biodigestion time. The use of Acacia mearnsii extract up to 1.5% dietary DM levels proved to be a safe option as a feed additive for cattle of different groups, with potential for rumen CH4 mitigation without affecting conversion efficiency in waste treatment processes, with potential to minimize waste volumes.

The aimed of this study was to evaluate the individually and combine use of monensin, tannins of Acacia mearnsii extract and calcium nitrate on ruminal fermentation parameters (ex-situ technique), rumen microbiome as well as on anaerobic biodigestion of waste. The dissertation was structured in two studies. In study 1, five cannulated Nellore cows, non-pregnant and non-lactating, with a mean body weight of 530±75 kg, were distributed into a 5 x 5 Latin square. The animals were fed with a basal diet, concentrate:roughage (corn silage) ratio of 60:40, through which the additives were supplied totaling five treatments: control (without addition of additives), monensin (300 mg in the diet), tannin (1.5% of DM), nitrate (3.0% of DM), and Pool (combination of the doses of the three additives). Data were analyzed using PROC MIXED of SAS and differences were declared significant at 5%. Cows fed with tannins had an increase of 23% on dry matter and gross energy intake. A reduced CH4 production was observed when the control treatment was compared to the individual or combined use of all additives, being 9.5% related to monensin treatment, 18.75% in tannin, 19.8% in calcium nitrate and a reduction of 28.8% when cows were fed with the pool (monensin, nitrate and tannin). Regarding the ruminal microbiota, no effects were found on the total protozoan count when cows were fed with the pool in comparison to the control. Furthermore, the structure of members using PCoA of the bacterial community of the rumen of cows fed with the pool had differences when compared to cows fed with monensin and tannin, but the bacterial community observed in the pool group was similar to those of cows fed with nitrate. Overall, significant decreases in rumen methane emissions can be achieved without drastic effects on either the rumen microbial population or its function. In study 2, biodigesters were arranged in a completely randomized design of 5 treatments with 5 replicates, totaling 25 experimental units (feces were the main variable from cows fed with the individual or combined use of all additives). The data were analyzed by using the Statistical Analysis System (SAS 9.3, Institute Inc., 2013). The biodigesters supplied with waste from cattle fed tannins increased in 91% of CH4 production and 52% of CO2 production per gram of volatile solids. The pool treatment increased the biofertilizer nutrient compounds in 12.6% of Total C and 35% of Total N, monensin presented an increase of 7.5% of Total N, and K was increased in 35% to tannins and 22% to nitrate. The monensin did not present the potential for CH4 production in relation to the waste in the environment. Interestingly, the tannins showed significant results through anaerobic digestion, being its use recommended with the attempt to reduce the impacts of untreated manure on the environment. More studies are necessary to understand how nitrate acts on biodigesters. O objetivo deste trabalho foi avaliar individualmente e de forma combinada o uso de monensina, taninos do extrato de Acacia mearnsii e nitrato de cálcio sobre os parâmetros de fermentação ruminal (técnica ex situ), microbioma ruminal e a biodigestão anaeróbia de resíduos. Para tanto, foram desenvolvidos dois estudos. No estudo 1, cinco vacas Nelore canuladas, não gestantes e não lactantes, com peso corporal médio de 530 ± 75 kg, foram distribuídas em quadrado latino 5 x 5. Os animais foram alimentados com dieta basal, relação concentrado:volumoso de 60:40 (silagem de milho), por meio do qual foram fornecidos os aditivos; totalizando cinco tratamentos: controle (sem adição de aditivos), monensina (300 mg na dieta), tanino (1,5% da MS), nitrato (3,0% da MS) e \'pool\' (combinação das doses dos três aditivos supracitados). Os dados foram analisados usando PROC MIXED do SAS e as diferenças foram consideradas significativas quando o valor de P

Dois experimentos foram conduzidos para avaliar os efeitos de aditivos alimentares e fontes de volumoso no desempenho, características de carcaça, qualidade da carne e digestibilidade aparente do trato total de terminação de touros. In Exp. 1, 88 touros Nelore foram utilizados em delineamento em blocos casualizados em arranjo fatorial 2 × 2, para avaliar os efeitos da alimentação com monensina sódica (MON; 26 mg / kg MS) ou da combinação de uma mistura de óleos essenciais + α exógeno -amilase (BEO + AM; 90 e 560 mg / kg de MS, respectivamente de produto comercial) associada à silagem de milho (SM) ou cana-de-açúcar bagaço (BC) no desempenho, carcaça e qualidade da carne de bovinos em terminação. Touros alimentados com dieta baseada em SM tiveram maior ingestão de matéria seca (CMS; P

A erva-mate (Ilex paraguariensis, St. Hilaire) é uma árvore da família das Aquifoliáceas, nativa da região subtropical da América do Sul, caraterizada por apresentar propriedades diuréticas e anti-inflamatórias. O extrato de erva-mate já foi testado em frangos para melhorar a estabilidade da carne (0,5% do extrato aquoso de erva-mate). Entretanto, até o momento não existem relatos destacando o papel dessa erva na metanogênese ruminal. Assim, o objetivo do presente estudo foi avaliar o efeito da adição de extrato de erva-mate sobre a metanogênese, parâmetros ruminais, consumo de nutrientes e digestibilidade da dieta de bovinos Nelore canulados no rúmen. Foram utilizados oito bovinos machos, castrados, com peso vivo médio de 401,6 ± 32,3 kg, idade média de 2 anos e distribuídos em delineamento quadrado latino 4x4 com dois quadrados contemporâneos. Os animais foram alojados em baias individuais e divididos em quatro tratamentos com quatro níveis de inclusão (0, 0,5, 1 e 2%) de extrato de erva-mate na MS da dieta. O período experimental teve duração de 21 dias, sendo 14 dias de adaptação e 7 dias de coletas, onde foram coletadas amostras de gás metano, fezes, dieta e sobras, conteúdo ruminal para determinação de parâmetros ruminais e cinética fermentativa. A análise estatística dos resultados foi realizada através do procedimento MIXED do programa SAS 9.3. O efeito de nível foi avaliado pelo uso de polinômios ortogonais, separando-se os efeitos em linear e quadrático. Foi definida a probabilidade de 5% para efeito significativo. O extrato de erva-mate elevou o peso final e ganho médio diário (P0,05). Não foram encontradas diferenças nas emissões de metano ruminal, digestibilidade e consumo de nutrientes (P>0,05). O aditivo não alterou o pH ruminal, mas afetou o N-NH3 que reduziu linearmente à medida que o nível de extrato aumentou na dieta (P0,05). Yerba mate (Ilex paraguariensis, St. Hilaire) is a tree of the Aquifoliaceae family, native to the subtropical region of South America, characterized by its diuretic and anti-inflammatory properties. Yerba mate extract has already been tested on chickens to improve meat stability (0.5% of the yerba mate aqueous extract). However, to date there are no reports highlighting the role of this herb in rumen methanogenesis. Thus, the objective of the present study was to evaluate the effect of the addition of yerba mate extract on methanogenesis, ruminal parameters, nutrient intake and diet digestibility of fistulated Nellore cattle. Eight male castrated cattle with average live weight of 401.6 ± 32.3 kg, average age of 2 years were used and distributed in a 4x4 Latin square design with two contemporary squares. The animals were housed in individual pens and divided into four treatments with four levels of inclusion (0, 0.5, 1 and 2%) of yerba mate extract in the diet DM. The experimental period lasted 21 days, being 14 days of adaptation and 7 days of collection, where collected samples of methane gas, feces, diet and leftovers, ruminal content for determination of ruminal parameters and fermentative kinetics. The analysis of the results was performed using the SAS 9.3 MIXED procedure. The level effect was evaluated by the use of orthogonal polynomials, separating the effects into linear and quadratic. The probability of 5% was set for significant effect. Yerba mate extract increased final weight and average daily gain (P 0.05). No differences were found in rumen methane emissions, digestibility and nutrient intake (P> 0.05). The additive did not alter ruminal pH, but affected N-NH3 which decreased linearly as the extract level increased in the diet (P 0.05).

O presente estudo trata da investigação sobre o uso de um produto inovador, classificado como substâncias húmicas, as quais têm sido estudadas como aditivo alternativo na dieta de bovinos de corte. Assim, o objetivo deste estudo foi avaliar o uso de substâncias húmicas como aditivo na dieta de bovinos Nelore e sua influência no metabolismo ruminal e na síntese de proteína microbiana. Utilizou-se 8 machos canulados e castrados, alocados em baias individuais, com peso vivo de 549 kg (± 45 kg). Os animais foram divididos aleatoriamente em delineamento quadrado latino 4x4 replicado, recebendo tratamentos com níveis crescentes de substâncias húmicas na MS da dieta (0%, 0,45%, 0,9% e 1,35%). Avaliou-se o consumo de matéria seca, pH ruminal, ácidos graxos de cadeia curta, nitrogênio amoniacal, contagem de protozoários, síntese de proteína microbiana e níveis de ureia plasmática no sangue. Não houve efeito (p > 0,05) entre os tratamentos para o consumo de matéria seca, pH ruminal, nitrogênio amoniacal, população de protozoários e níveis de ureia plasmática no sangue. Quanto aos ácidos graxos de cadeia curta, ocorreu efeito linear decrescente nas concentrações de isobutírico e valérico e não houve efeito de tratamento para ácido acético, propiônico, butírico e isovalérico. Obteve-se efeito quadrático na excreção urinária de alantoína, purinas microbianas absorvidas e nos compostos nitrogenados microbianos. A adição de substâncias húmicas até o nível de 1,35% na matéria seca não influenciou os parâmetros ruminais dos animais recebendo uma dieta com 50% de concentrado. Estudos adicionais sobre o uso do produto em maior quantidade na dieta, com maior proporção de concentrados, influência de raças, idade e categoria animal podem contribuir para elucidar os efeitos desse produto como aditivo alimentar. The present study explore the use of an innovative product, classified as humic substance, which has been studied as an alternative additive for beef cattle diet. Therefore, the objective of this study was to evaluate the use of humic substances as an additive in the diet of Nellore cattle and their influence on ruminal metabolism. Eight cannulated and castrated males were used in individual pens with a live weight of 549 kg (± 45 kg). The animals were randomly allotted into a replicated 4x4 latin square design, receiving treatments with increasing levels of humic substances in the diet (0%, 0.45%, 0.9% e 1.35%). The dry matter intake, ruminal pH, short chain fatty acids, ammoniacal nitrogen, protozoan count, microbial protein synthesis and blood urea levels were evaluated. There was no effect (p> 0.05) between treatments for dry matter intake, ruminal pH, ammoniacal nitrogen, protozoan population and plasma urea levels in the blood. As for short chain fatty acids, there was no treatment effect for acetic, propionic, butyric and isovaleric acid, but it was observed linear decreasing effects on isobutyric and valeric concentrations. There was a quadratic effect on urinary excretion of allantoin, absorbed microbial purines and microbial nitrogen compounds. The addition of humic substances up to the level of 1.35% in DM did not influence the ruminal parameters of the animals receiving diet with 50% of concentrate. Additional studies on the product use considering more challenging ration, with a greater concentrated:forage ratios, animal age and other variations can contribute to clarify the effects of this product as additive.

As técnicas in vitro de produção de gases são usualmente empregadas em pesquisas na nutrição de ruminantes com a finalidade de simular a fermentação ruminal, possuindo diversas vantagens como facilidade de adoção, repetibilidade, uso minimizado de animais e baixo custo. Para tanto, é necessário a coleta de conteúdo ruminal, a qual geralmente é obtida com o uso de animais fistulados no rúmen, no entanto este tipo de cirurgia esta cada vez mais contestada. Frente a esse duelo, há um crescente interesse científico por pesquisas que forneçam alternativas ao inóculo ruminal. Sendo assim, o objetivo deste trabalho foi avaliar o uso de inóculo fecal submetidos à pré-incubações em substituição ao inóculo ruminal de bovinos na técnica in vitro de produção de gases em bioensaio de metanogênese (24 h) e de cinética fermentativa (72 h). Como doadores de inóculos ruminal e fecal foram utilizadas quatro novilhas Nelore portadoras de cânulas ruminal. O delineamento experimental utilizado foi o de blocos casualizados, com cinco tratamentos e quatro blocos com duas réplicas analíticas para cada repetição. Sendo os tratamentos os inóculos: conteúdo ruminal (CR), fezes sem pré-incubação (F0), e fezes com 12, 24 e 36 h de pré-incubação (F12, F24 e F36, respectivamente). Foram avaliados os efeitos da pré-incubação das fezes quando utilizado como inóculo fecal sobre a estimativa da degradabilidade ruminal, produção de metano e parâmetros de fermentabilidade. Os dados foram analisados pelo programa estatístico SAS 9.3 verificando a normalidade dos resíduos e a homogeneidade das variâncias, em seguida foram realizadas as comparações das médias pelo teste de Tukey. Em ambos os bioensaios (24 e 72 horas), os inóculos fecais pré-incubados por 24 ou 36 horas mostraram-se bom substituto ao inóculo ruminal para análises de degradabilidade in vitro da matéria seca e orgânica. Para as variáveis produção de total de ácidos graxos, perfil de ácidos graxo de cadeia curta, relação acético:propiônico e nitrogênio amoniacal, o inóculo sem pré-incubação (FE0) foi o que mais se aproximou do inóculo referência. Para as produções de gases, produção de metano e fator de partição da matéria seca e matéria orgânica as fezes não foram eficientes. The in vitro techniques of gas production are usually used in ruminant nutrition research with the purpose of simulating ruminal fermentation. This technique has several advantages such as ease of adoption, repeatability, minimized use of animals and low cost. Therefore, is necessary the collection of ruminal content, which is usually obtained with the use of fistulated animals in the rumen, however this type of surgery is increasingly challenged. Faced with this duel, there is a great scientific interest in research that provides alternatives to the ruminal inoculum. The objective of this research was to evaluate the use of fecal inoculum submitted to preincubation to replace rumen inoculum of Nelore in the in vitro technique of gas production in bioassay of methanogenesis (24 h) and fermentative kinetics (72 h). Four Nellore carrying ruminal cannula were donors of ruminal content and feces. The experimental design was a randomized block, with five treatments and four blocks with two analytical replicates for each replicate. The treatments were the inocula: ruminal contents (RC), faeces without preincubation (F0), and faeces with 12, 24 and 36 hours of preincubation (F12, F24 and F36, respectively). Estimates of ruminal degradability, methane production and ruminal fermentability were evaluated. The data were analyzed by the statistical program SAS 9.3 verifying the normality of the residues and the homogeneity of the variances, the averages were compared by the Tukey test. In the two bioassays (24 and 72 hours), the fecal inocula preincubated for 24 or 36 hours were good substitute for the ruminal inoculum in analyzes of in vitro degradability of dry and organic matter. For the variables production of total fatty acids, short chain fatty acid profile, acetic: propionic and ammoniacal nitrogen, the inoculum without pre-incubation (FE0) approached the reference inoculum. For gas production, methane production and partitioning factor of dry matter and organic matter were not efficient.