In the beef cattle industry, sustainable beef production is a primary focus, as it has direct effects on environmental stewardship, farm profitability, and public concerns. Research has been and is continually being conducted to evaluate alternative forages such as Brown Midrib Corn Silage (BMRCS) as a major component in growing beef cattle diets, to improve animal performance, ruminal fermentation, and economic returns. The objective of this study was to determine growth performance, ruminal fermentation characteristics, and economic returns of growing beef steers when fed a brown midrib corn silage-based TMR (BMRT) compared with a conventional corn silage-based TMR (CCST). This growing beef study was performed in a completely randomized design with 24 Angus crossbred steers (initial body weight (BW) = 258 ± 23.2 kg) to test 2 treatments: CCST vs. BMRT. All animals were placed in individual pens, and 12 animals allocated to each treatment (n = 12). All steers were adapted to the CCST for a 2-wk period prior to start of the trial. The CCST contained 48.1% CCS whereas the BMRT consisted of 49.0% BMRCS on a dry matter (DM) basis. All steers were fed once per day, and feed bunks assesed each afternoon and prior to morning feeding, which was used to determine the amount of feed to deliver to each pen the following day. The experiment lasted 84 d. For all steers, BW and ruminal fermentation characteristics were measured on wk 4, 8, and 12. Intake of DM averaged 9.54 kg/d across the treatments and was similar between the treatments. Steers fed the BMRT tended to increase average daily gain (ADG) compared to those fed the CCST (1.54 vs. 1.42 kg/d; P = 0.09). In addition, feeding the BMRT tended to increase G:F compared with the CCST (0.165 vs. 0.146; P = 0.07). Feeding the BMRT decreased ruminal pH (6.42 vs. 6.67; P < 0.01), whereas it increased total VFA concentration (P = 0.01) compared with the CCST. Feeding the BMRT decreased molar proportion of acetate (P < 0.01), but increased propionate proportion (P = 0.01), resulting in decreased acetate-to-propionate ratio compared with the CCST (P < 0.02). Steers fed BMRT increased feed margin (P = 0.05) and net return (P = 0.02) compared to those fed CCST throughout the trial. Overall data in this study indicate that feeding the BMRT to growing beef steers enhanced ruminal fermentation and beneficially shifted VFA profiles, which contributed to improved growth performance and economic performance of steers fed the BMRT.

Orientador: Flávio Dutra de Resende / Resumo: O objetivo desse estudo foi avaliar o efeito da suplementação de extrato de taninos (ET) e a inclusão de diferentes níveis de ureia na alimentação de bovinos Nelores na fase de crescimento durante o período da seca. A área de pastejo era formada por forrageira Urochloa brizantha cv. Marandu (PB = 5,9% e FDN = 74,8%). Os suplementos proteico energéticos eram ofertados, diariamente, na quantidade de 3 g/kg PC (PB = 26%). O arranjo dos tratamentos foi em fatorial 2 × 2: Fator 1 - baixa (3%) e alta (5%) de inclusão de ureia; Fator 2 - inclusão ou não de ET (0,7 g/kg MS de suplemento; SilvaFeed ByPro®). No primeiro experimento (n = 8, 293 kg ± 5,6 duplo quadrado latino), foi observada tendência de aumento da digestibilidade da PB com a inclusão de ET (P = 0,06). A alta ureia no suplemento promoveu uma tendência de aumento da ureia sérica nas primeiras horas após a suplementação (P = 0,08). Além disso, o tratamento com ureia interagiu com o tempo para N-NH3 no rúmen (P < 0,01), sendo maior às 6 horas pós-suplementação para alta ureia. O ET aumentou a riqueza e reduziu a diversidade bacteriana. A análise de componentes principais indicou que a variação da microbiota ocorreu principalmente em função das diferentes inclusões de ureia nos suplementos. No segundo experimento, [n = 64, 294 kg ± 15,2, delineamento em blocos casualizados, blocagem por peso corporal (PC)], verificou-se que o desempenho não foi influenciado pelos tratamentos (P ≥ 0,21). Em conclusão, o desempenho e os parâme... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The aim of this study was to evaluate the effect of tannins extracts (ET) supplementation and different levels of urea inclusion in Nellore cattle feed in the growing phase during the dry season. The grazing area was constituted by Urochloa brizantha cv. Marandu (CP = 5.9% and NDF = 74.8%). The energy protein supplements were offered daily in the amount of 3 g/kg BW (CP = 26%). The treatment arrangement was in factorial 2 × 2: Factor 1 - low (3%) and high (5%) inclusion of urea; Factor 2 – With or without inclusion of ET (0.7 g / kg MS of supplement, SilvaFeed ByPro®). In the first experiment (n = 8, 293 kg ± 5.6 double latin square), a trend of increased digestibility of PB was observed with the inclusion of ET (P = 0.06). High supplemental urea promoted a tendency for serum urea to increase in the first hours after supplementation (P = 0.08). In addition, treatment with urea interacted with time for N-NH3 in the rumen (P <0.01), being greater at 6 hours post-supplementation for high urea. ET increased richness and reduced bacterial diversity. Principal component analysis indicated that microbiota variation occurred mainly due to the different urea inclusions in the supplements. In the second experiment, [n = 64, 294 kg ± 15.2, randomized block design, blocking by body weight (PC)], it was found that performance was not influenced by treatments (P ≥ 0.21). In conclusion, performance and digestive parameters were not affected by higher urea inclusion in the dry period and ET ... (Complete abstract click electronic access below) / Mestre

Two trials were conducted to evaluate effects of grain adaptation protocol on subacute acidosis, feeding behaviour and ADG of cattle. In trial one, 12 crossbred heifers (384 ¡À 25 kg) were stepped from 40% to 90% dietary concentrate by either rapid adaptation (RA; one step-up diet fed for 3 d) or by gradual adaptation (GA; five step-up diets fed for 3 d each). Mean daily ruminal pH variables did not differ (P > 0.10) between treatments but variances of a number of ruminal pH variables were greater (P < 0.05) for RA than GA during adaptation to 65% and 90% concentrate. Mean hourly pH did not differ over the first 24 h of adaptation to 65% concentrate, but variance of hourly pH tended (P < 0.10) to be greater for RA than GA for eight of the first 24 h of adaptation to 90% concentrate. Increased variance in ruminal pH parameters was associated with detection of acidosis in certain individuals. On d 1 of 90% concentrate, ruminal pH tended (P = 0.07) to be lower at 11 and 12 h post-feeding with RA than with GA. Ruminal volatile fatty acids (VFA) and osmolality were similar between treatments. In trial two, 120 crossbred heifers (366 ¡À 23 kg) were adapted from 40% to 90% concentrate. A protocol identical to trial one was used with the addition of moderate adaptation (MA; three step-up diets fed for 3 d each). The increase to 65% concentrate caused reduced daily bunk attendance and increased maximum intermeal interval for RA compared to MA and GA cattle but the increase to 90% did not. ADG was reduced for RA compared to MA or GA during adaptation but over day 1 to 69 ADG did not differ between treatments (P ¡Ý 0.41). Current management strategies for preventing acidosis in pens of cattle are based on responses of the most susceptible individuals. Improved understanding of individual responses to acidotic challenge may allow development of more effective acidosis prevention practices.

El sistema de producción de carne de vacuno en España es muy específico. Es un sistema totalmente desligado de la tierra, con animales sacrificados jóvenes y alimentados durante todo el engorde a base de piensos concentrados ricos en cereales, produciendo la característica carne rosada. En los últimos años, ha cobrado interés la inclusión de leguminosas grano en estas dietas, con el problema de que estos suplementos están relativamente poco caracterizados en estas condiciones alimentarias, ya que la degradabilidad de suplementos proteicos puede reducirse en dietas concentradas. Por otra parte, la cebada y el maíz son los cereales más utilizados y aunque tienen diferentes velocidades de degradación ruminal del almidón, se han realizado pocos esfuerzos para sincronizar su degradación con fuentes proteicas de similares características y así maximizar la eficiencia de la fermentación ruminal. En el marco de la falta de información sobre la fermentación ruminal de terneros jóvenes alimentados con dietas concentradas nos planteamos los siguientes objetivos:a) Caracterizar la fermentación ruminal y la degradabilidad de la proteína de suplementos vegetales durante todo el engorde.b) Estudiar los efectos de la sincronización de la degradabilidad ruminal del almidón de la cebada y el maíz con dos fuentes proteicas, sobre la fermentación ruminal y sobre los parámetros productivos y el comportamiento de ingestión. En el primer experimento con un diseño de medidas repetidas estudiamos como evolucionaba la fermentación ruminal y la degradación de la proteína de 4 suplementos vegetales (dos leguminosas y dos subproductos de la extracción de aceite) en 6 terneras en crecimiento entre los 80 y los 250 kg alimentadas con dietas concentradas con distinta proporción de fibra. Una dieta contenía un 12% de paja de cebada y la otra un 30% de alfalfa deshidratada, y ambas eran isoenergéticas e isoproteicas. Observamos que aunque en ambas dietas la actividad celulolítica, estimada a través de la degradación ruminal de la FND de una muestra de heno de alfalfa incubada in situ, era muy baja, fue ligeramente superior en la dieta que tenía mayor proporción de forraje. La dieta con un 30% de alfalfa deshidratada también presentó mayor degradabilidad ruminal de las dos leguminosas grano (guisante y altramuz) incubadas in situ. Con la edad aumentó la ingestión total de carbohidratos no fibrosos y la fermentación se volvió más amilolítica y proteolítica, aumentando la concentración de AGV totales, la proporción de propionato y la degradabilidad efectiva de la proteína de los suplementos incubados, a excepción de la harina de soja. Estas mismas dietas se administraron en el segundo experimento a 4 terneras de 300 kg de peso vivo, asignadas a un diseño de cross-over para estudiar el efecto del nivel de fibra de la dieta sobre la fermentación ruminal y la degradación proteica de 7 suplementos proteicos de origen vegetal en la última fase de engorde. El perfil de fermentación ruminal no se vio afectado por el nivel de fibra de la dieta, siendo un perfil básicamente amilolítico. La degradación de la FND del heno de alfalfa también fue muy baja (25,5%) y la degradación de las leguminosas grano fue más baja que los valores aportados por los sistemas de referencia, siendo los valores obtenidos más adecuados para estas condiciones de producción. Los valores de degradación de la harina de soja y la harina de girasol fueron similares a los aportados por las tablas de referencia, sin verse afectados por el nivel de fibra de la dieta. Para el estudio de la sincronización de la degradabilidad ruminal entre fuentes de energía y de proteína, combinamos la cebada y el maíz con dos fuentes proteicas, harina de soja y harina de girasol, que demostraron tener diferente velocidad de degradación ruminal en los experimentos 1 y 2. De estas combinaciones resultó una dieta sincronizada para una fermentación rápida (cebada-girasol); una dieta sincronizada para una fermentación lenta (maíz-soja) y dos dietas desincronizadas con un componente de fermentación rápida y uno de fermentación lenta (cebada-soja y maíz-girasol). Las 4 dietas eran isoproteicas e isoenergéticas y con una relación forraje:concentrado cercana a 10:90. In vitro, con el sistema de fermentadores de doble flujo continuo observamos una potenciación de la fermentación ruminal por efecto de la sincronización, sin que se viera afectada por el pH ruminal que se mantuvo constante a 6,2 o fluctuante, 12 h a 5,8 y 12 h a 6,4, simulando una acidosis crónica, frecuente en este tipo de dietas. In vivo, estas dietas fueron asignadas a 4 terneras de 132 kg en un diseño de cuadrado latino 4 x 4, sin observar ningún efecto de la sincronización sobre la fermentación ruminal ni sobre la digestibilidad de todo el tracto. El tipo de carbohidrato afectó a la ingestión, siendo mayor en los tratamientos que contenían maíz. Los animales que recibían la dieta sincronizada para una fermentación rápida (cebada-girasol) redujeron su ingestión y rumiaron durante más tiempo el forraje sin que sufrieran problemas de acidosis ruminal. / Beef production in Spain is very specific. The production system is completely detached from the land and calves are fed high concentrate diets based on cereals from weaning to slaughtering at a young age, producing a tender and pink meat. The use of legume seeds in these high concentrate diets is increasing, although these protein supplements are poorly characterized in these feeding conditions and protein degradation can be reduced in such diets. Moreover, barley and corn are the main cereal grains used in high concentrate beef cattle diets. These cereals differ in their starch content and in their fermentation rate and extent of rumen degradation, but few efforts have been made to synchronize their degradation with protein supplements of similar degradation characteristics and maximize the efficiency of ruminal fermentation. Due to the lack of information about ruminal fermentation in young beef cattle fed high concentrate diets, the following objectives were proposed:a) To characterize ruminal fermentation and estimate ruminal nitrogen degradability of plant protein supplements during the fattening period. b) To study the effects of synchrony of ruminal degradability of corn and barley starch with protein sources of different rates and extents of degradation, on ruminal fermentation, animal performance and feeding behavior. In the first experiment, six Holstein heifers growing from 80 to 250 kg were used in a repeated measures trial to study the changes in ruminal fermentation and protein degradation of four plant protein supplements (two legume seeds and two by products from the oil industry). Heifers were fed two isoenergetic and isonitrogenous high concentrate diets with different fiber content. One diet contained 12% barley straw and the other 30% dehydrated alfalfa as forage source. Cellulolytic activity, estimated as NDF degradation of alfalfa hay incubated in situ, was very low in both diets, but it was slightly higher in the diet with 30% dehydrated alfalfa. In situ nitrogen degradability of legume seeds (peas and lupin seeds) was also higher in the diet with a higher proportion of forage. With age, gross nonstructural carbohydrate intake increased and ruminal fermentation became more amilolytic and proteolitic, increasing total VFA concentration, propionate proportion and nitrogen effective degradability of protein supplements, except for soybean meal. These two diets were assigned in the second experiment to four 300-kg growing heifers in a cross-over design to study the effect of dietary fiber level on ruminal fermentation and in situ nitrogen degradability of seven protein supplements (5 legume seeds) at the end of the fattening period. The ruminal fermentation pattern was basically amilolytic in both diets, and was not affected by dietary fiber content. Neutral detergent fiber degradation of alfalfa hay was also very low (25.5%) and values of effective degradation on legume seeds were lower than values reported by reference feeding systems, the values obtained in the present experiment being more adequate for beef cattle fed high concentrate diets. Effective degradation of soybean meal and sunflower meal were similar to values reported by feeding systems and not affected by NDF content of diets.To study the effects of synchrony of rumen degradability between energy and protein sources, barley and corn and two protein sources, soybean meal, SBM, and sunflower meal, SFM, differing in their rate and extent of rumen degradation were combined. This resulted in a synchronized rapid fermentation diet (barley-SFM), a synchronized slow fermentation diet (corn-SBM) and two unsynchronized diets with a rapidly and slowly fermenting component (barley-SBM and corn-SFM). All diets were isoenergetic and isonitrogenous with a forage to concentrate ratio close to 10:90. In vitro, with a dual flow continuous culture system, ruminal fermentation was enhanced in synchronized diets (Barley-SFM and corn-SBM). No effect of ruminal pH, which was held constant at 6.2 or fluctuant 12 h at 5.8 and 12 h at 6.4, simulating subclinical acidosis frequently associated with these diets, was observed. In vivo, these diets were fed to four 132-kg heifers assigned to a 4 x 4 Latin square design, but synchronization had no effect on ruminal fermentation or on apparent total tract digestibility. The type of carbohydrate affected intake, being higher for corn than barley based diets. Heifers fed the rapid synchronized diet (barley-SFM) reduced intake and increased time spent chewing per unit of forage intake, avoiding problems of ruminal acidosis.

Two trials were conducted to evaluate effects of grain adaptation protocol on subacute acidosis, feeding behaviour and ADG of cattle. In trial one, 12 crossbred heifers (384 ¡À 25 kg) were stepped from 40% to 90% dietary concentrate by either rapid adaptation (RA; one step-up diet fed for 3 d) or by gradual adaptation (GA; five step-up diets fed for 3 d each). Mean daily ruminal pH variables did not differ (P > 0.10) between treatments but variances of a number of ruminal pH variables were greater (P < 0.05) for RA than GA during adaptation to 65% and 90% concentrate. Mean hourly pH did not differ over the first 24 h of adaptation to 65% concentrate, but variance of hourly pH tended (P < 0.10) to be greater for RA than GA for eight of the first 24 h of adaptation to 90% concentrate. Increased variance in ruminal pH parameters was associated with detection of acidosis in certain individuals. On d 1 of 90% concentrate, ruminal pH tended (P = 0.07) to be lower at 11 and 12 h post-feeding with RA than with GA. Ruminal volatile fatty acids (VFA) and osmolality were similar between treatments. In trial two, 120 crossbred heifers (366 ¡À 23 kg) were adapted from 40% to 90% concentrate. A protocol identical to trial one was used with the addition of moderate adaptation (MA; three step-up diets fed for 3 d each). The increase to 65% concentrate caused reduced daily bunk attendance and increased maximum intermeal interval for RA compared to MA and GA cattle but the increase to 90% did not. ADG was reduced for RA compared to MA or GA during adaptation but over day 1 to 69 ADG did not differ between treatments (P ¡Ý 0.41). Current management strategies for preventing acidosis in pens of cattle are based on responses of the most susceptible individuals. Improved understanding of individual responses to acidotic challenge may allow development of more effective acidosis prevention practices.

This work helps to determine the extent of immune system involvement in the adaptive response to subacute ruminal acidosis (SARA) in three parts. The first (Chapter 2) uses non-lactating cows to study specific changes in inflammatory protein expression in which SARA is created. The second (Chapter 3), uses the same model as Chapter 2. However, in this case, lactating cows are used to help establish the time course for adaptation to acidosis. The third part (Chapter 4) delineates the genomic changes that occur in the rumen epithelium when a therapeutic intervention is introduced using exogenous supplemental butyrate. In the first experiment, the expression of the extracellular matrix (ECM) proteins type IV collagen and laminin β1 decreased, and the monocarboxylate transporter MCT1, increased during the acidotic challenge. Nuclear factor of activated T-cells, NFATc2, and tumour necrosis factor alpha (TNF-α) decreased while interleukin-1 beta (IL-1β) increased during the experimental treatment period. Chapter 3 measured lipopolysaccharide (LPS) and its carrier, LPS binding protein, LBP, which were found to be elevated due to SARA. Moreover, NFATc2 was reduced during this period. Exogenous butyrate resulted in increased plasma LBP, plasma beta hydroxyl butyrate (BHBA), and ruminal butyrate. Milk parameters (total protein and fat) were unaffected by treatment, as were rumen LPS, acetate, valerate, isovalerate, and isobutyrate. Moreover, exogenous butyrate increased gene transcription of genes involved in non-specific host defences (NHSD) such as mucin, and remodelling (RM), such as matrix metallopeptidase 16 (MMP16), and decreased the transcription of genes of the immune response (IR), such as nuclear factor kappa B2 (NFκB2). Together, these three experiments have demonstrated that although wound healing is mediated by the immune system in more severe models of epithelial damage, our model of SARA did not involve full-thickness, penetrating lesions and hence did not involve the systemic immune system to such a degree than was previously thought. In addition, we were able to demonstrate that the addition of butyrate to this model of grain-induced acidosis was beneficial, as it decreased the local inflammatory response and helped the epithelium adapt to its harsher environment. / Agriculture and Agri-Food Canada, the National Sciences and Engineering Council of Canada (NSERC), the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA), the Canadian Dairy Commission (CDC), and the Dairy Farmers of Ontario (DFO).

No description available.

Fenugreek (Trigonella foenum-graecum L.) is a single-cut, annual legume typically grown for seed. Fenugreek has potential as a forage because it maintains high quality throughout the growing season, and offers the benefits of a legume in a crop rotation. This work aimed to evaluate the growth of two fenugreek genotypes, AAFC F70 and CDC Quatro, in the central AB area over two growing seasons, and to evaluate fenugreek haylage degradation and digestion in dairy cows. In general, the two genotypes were similar in their growth patterns and fenugreek biomass yield was comparable to alfalfa in the same area. Plant quality was sufficient to be used for lactating dairy cows. The digestion studies revealed that while Quatro haylage was comparable to alfalfa haylage, F70 haylage was of lower quality and was not utilized to the same extent by dairy cows as the other two forage types. / Plant Science

Made available in DSpace on 2014-06-11T19:32:56Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-12-16Bitstream added on 2014-06-13T21:05:19Z : No. of bitstreams: 1 silva_zf_dr_jabo.pdf: 288941 bytes, checksum: c6a44e855aa5751be49544caeb8b11a1 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Fundação de Amparo à Pesquisa e ao Desenvolvimento Científico do Maranhão (FAPEMA) / Avaliou-se efeito da inclusão de 0, 15 e 30% de glicerina bruta (GB) na matéria seca (MS) de dietas em substituição ao milho grão moído sobre o consumo de MS, produção de leite (PL), fermentação ruminal e digestibilidade da MS (DMS) em vacas leiteiras. Foram utilizadas seis vacas multíparas, da raça Holandesa providas de cânula permanente de 4” no rúmen, estando no início do experimento com peso médio de 587 ± 39 kg, com 114 ± 29 dias em lactação e produzindo média de 20 ± 1,5 kg/leite em duas ordenhas diárias. As vacas foram distribuídas em dois quadrados latinos 3 x 3 com períodos de 21 dias, sendo 14 de adaptação. As dietas continham silagem de milho, milho grão, farelo de girassol, glúten de milho, uréia, vitaminas, minerais e GB (86% de glicerol, 95% MS, 6% sais e <100 g/kg de metanol) e foram oferecidas ad libitum, duas vezes ao dia, na forma de dieta total. A dieta controle - ausência de GB, continha 36% de milho; a dieta com 15% e 30% de GB continham, respectivamente, 19,3 e 2,8% de milho. A utilização da GB na dieta reduziu a PL (P=0,10), o consumo de MS (P=0,08), os tempos gastos com atividade mastigatória (P<0,03), a digestibilidade da FDN (P<0,04) e a produção de bactérias associadas à fase líquida do rúmen (P=0,04). Não foram observadas diferenças quanto a cinética de degradação e passagem. Porém, houve aumento na concentração de metano quando a GB foi incluída na dieta. A utilização de glicerina bruta (86% de glicerol) em 15% da matéria seca da dieta de vacas em lactação deprime produção de bactérias de fase líquida, digestibilidade da fibra e desempenho. A sua inclusão em até 10% parece ser o limite ótimo / The purpose of this work was to evaluate the effect of the inclusion of 0, 15 and 30% crude glycerin (CG) in the MS diet in replacement of corn grain (diet control) on the ground on the dry matter intake (DMI), milk production (MY), rumen fermentation and dry matter digestibility in dairy cows . We used six multiparous Holstein cows rumen cannulated, being at the experiment with 587±39 kg BW, 114±29 DIM and with average 20±1.5 kg/d MY in two daily milkings, distributed in two 3x3 Latin Square with 21-days periods. The diets contained corn silage (45% DM), corn grain, sunflower meal, corn gluten meal, urea, vitamins, minerals and CG (86% glycerol, 95% DM, salts 6% and <0.1ppm of methanol). Cows were individually fed on total mixed ration in twice daily. The control diet - no glycerin, containing 36% corn, the diet with 15% and 30% contained GB, respectively, 19.3 and 2.8% of the corn. The use of the CG in the diet reduced the MY (P=0.10), DMI (P=0.08), the time chewing activities (P<0.03), NDF digestibility (P=0.04) and the liquid-associated bacteria content (P=0,04). There were no differences in the kinetics of degradation and passage. However, increased methane output when GB was in the diet. The use of crude glycerin (86% glycerol) in 15% of the diet dry matter for lactating cows depresses production of bacteria in the liquid phase, fiber digestibility and performance. Inclusion in up to 10% seems to be the optimum limit

Made available in DSpace on 2014-06-11T19:32:57Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-07-27Bitstream added on 2014-06-13T19:03:44Z : No. of bitstreams: 1 ribeiro_ms_dr_botfmvz.pdf: 580098 bytes, checksum: d9ecebb398d17d8fec03f05fbe984a43 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Universidade Estadual Paulista (UNESP) / O objetivo deste trabalho foi avaliar a influência dos níveis de fibra em detergente neutro oriundo da forragem (FDNf) em dietas peletizadas, sobre o consumo e digestibilidade aparente da matéria seca (MS), proteína bruta (PB), fibra em detergente neutro (FDN) e carboidratos não fibrosos (CNF); e balanço de nitrogênio. Foram utilizadas cinco cabras fistuladas no rúmen dispostas em quadrado latino 5x5, sendo os níveis de FDNf de 15, 20, 25, 30 e 35% , as variáveis independentes. Os níveis de FDNf influenciaram de maneira quadrática os consumos de MS, PB, FDN e CNF expressos em % PV ou em unidade de peso metabólico (P<0,05). O maior consumo de MS foi encontrado no nível de 25,69% de FDNf e o valor médio de consumo de MS foi de 1,3% PV, inferior ao recomendado pelo NRC (1981) (1,46% PV), no entanto as exigências nutricionais foram atendidas em todas as dietas. Os coeficientes de digestibilidade aparente da MS, PB, e FDN foram influenciados de maneira quadrática pelos níveis de FDNf nas dietas, e foram maiores nos níveis de FDNf que apresentaram menor consumo de MS enquanto que o coeficiente de digestibilidade aparente dos CNF foi influenciado de maneira linear decrescente, diminuindo 0,66% para cada unidade de aumento dos níveis de FDNf nas dietas. Houve efeito quadrático dos níveis de FDNf nas dietas sobre o balanço de nitrogênio, o qual foi positivo em todos os níveis, mostrando eficiência das dietas quanto ao suprimento de proteína para os animais. / The purpose of this study was to evaluate the influence of the levels of neutral detergent fiber from forage (fNDF) in pelleted diets on the intake and digestibility of dry matter (DM), crude protein (CP), neutral detergent fiber (NDF) and on non-fibrous carbohydrates (NFC); and nitrogen balance. Five fistulated in the rumen goats were used, arranged in 5x5 Latin square, and the levels of fNDF 15, 20, 25, 30 and 35%, being the independent variables. Effect quadratic of the levels of fNDF on the intake of DM, CP, NDF and NFC expressed in % LW, or unit of metabolic weight (P<0,05). The higher consumption of DM was found in the level of 25.69% of fNDF and the average consumption of MS was 1.3% of LW, below that recommended by NRC (1981) (1.46% LW), however the nutritional requirements were met in all diets. The coefficients of apparent digestibility of DM, CP, and NDF were affected by the levels of fNDF of the diets in a quadratic behaviors and were higher on the levels of fNDF which had lower consumption of MS while the coefficient of digestibility of NFC has been so influenced linear decreasing, reducing 0.66% for each unit of increase in the fNDF of the diets. There was a quadratic effect of fNDF levels of the diets on the nitrogen balance, which was positive at all levels, showing efficiency of the diets on the supply of protein for the animals.