Resumen Este estudio tuvo como objetivo evaluar el efecto de la inoculación con L. buchneri liofilizado y/o activado sobre las poblaciones de bacterias de ácido láctico en ensilajes de maíz. Los tratamientos experimentales consistieron en ensilaje de maíz sin aditivo y ensilaje con los inoculantes L. buchneri 1 × 10 5 ufc/g, aplicados según las recomendaciones del fabricante (1 g/tonelada de forraje) en las formas de inoculante liofilizado e inoculante preactivado. Se identificaron aislados purificados de ensilajes de maíz con y sin inocu lación, y el 93% de los aislados correspondieron a bacterias de ácido láctico de la especie L. plantarum. Entre los aislados no se detectaron bacterias de la especie L. buchneri. La aplicación de L. buchneri liofilizado o activado en la masa ensilada promueve un aumento considerable de la población de bacterias de ácido lácticas en los ensilajes de maíz durante todo el período de fermentación.

Abstract This study aimed to evaluate the effect of inoculation with lyophilised and/or activated Lactobacillus buchneri on lactic acid bacteria populations in corn silage. Experimental treatments consisted of corn silage without additives or silage with the inoculants of L. buchneri (1 x 10 5 cfu/g) applied according to the manufacturer’s recommendations (1 g/tonne fodder) in the forms of the lyophilised inoculant and pre-activated inoculant. Purified isolates from corn silage with and without the inoculant were identified, and 93% of the isolates corresponded to the lactic acid bacteria of the species Lactobacillus plantarum. Among the isolates, no bacteria of the species L. buchneri were detected. The application of lyophilised or activated L. buchneri improved the microbiological profile and reduced ethanol production in corn silage, even without being identified among the isolates captured 70 days after ensilage.

Resumen: Este estudio tuvo como objetivo evaluar la ingesta, digestibilidad aparente, balance hídrico, balance de nitrógeno y rendimiento productivo en corderos alimentados con ensilaje de nopal asociado con forrajes tropicales. En el experimento se utilizaron 40 corderos machos cruzados intactos, con un peso corporal inicial de 18.85 ± 1.2 kg. El diseño experimental fue completamente al azar, con 5 tratamientos y 8 repeticiones. Los tratamientos consistieron en dietas con diferentes proporciones de pasto buffel y salvado de trigo como fuentes de fibra detergente neutro (FDN), en ensilaje de alimento total (EAT) a base de nopal: EAT1 - 279 g/kg de pasto buffel; EAT2 - 240 g/kg de pasto buffel y 17 g/kg de salvado de trigo; EAT3 - 198 g/kg de pasto buffel y 34 g/kg de salvado de trigo; EAT4 - 108 g/kg de pasto buffel y 74 g/kg de salvado de trigo; EAT5 - 118 g/kg de salvado de trigo. La ingesta más baja de FDN se encontró en corderos que consumieron EAT5 (402 g/día). La digestibilidad aparente de los carbohidratos no fibrosos fue mayor para EAT5, mientras que la digestibilidad aparente de FDN de EAT5 y EAT4 fue mayor que la de EAT1. Las dietas promovieron una ganancia diaria de peso promedio de 180.8 g/día. En condiciones experimentales, el uso de nopal forrajero y concentrado en forma de raciones mixtas totales de ensilaje conduce a una mayor ingesta de proteína cruda, carbohidratos no fibrosos, extracto etéreo y mayor digestibilidad de carbohidratos no fibrosos y fibra detergente neutro, sin embargo, todas las dietas fueron viables en la alimentación de ovinos confinados, proporcionando ganancias de hasta 198 g/d según la formulación de la dieta.

Abstract This study aimed was to evaluate the intake, apparent digestibility, water balance, nitrogen balance, and productive performance in lamb fed cactus pear silage associated with tropical forages. Forty male intact crossbred lambs, with an initial body weight of 18.85 ± 1.2 kg, were used in the experiment. The experimental design was completely randomized, with 5 treatments and 8 replications. The treatments consisted of diets with different proportions of buffelgrass and wheat bran as sources of neutral detergent fiber (NDF), in total feed silage (TFS) based on cactus pear: TFS1 - 279 g/kg of buffelgrass; TFS2 - 240 g/kg of buffelgrass and 17 g/kg of wheat bran; TFS3 - 198 g/kg of buffelgrass and 34 g/kg of wheat bran; TFS4 - 108 g/kg of buffelgrass and 74 g/kg of wheat bran; TFS5 - 118 g/kg of wheat bran. The lowest NDF intake was found in lambs that consumed TFS5 (402 g/d). The non-fibrous carbohydrates apparent digestibility was higher for TFS5, while the NDF apparent digestibility of TFS5 and TFS4 was higher than TFS1. Diets promoted an average daily weight gain of 180.8 g/d. Under experimental conditions, the use of forage cactus pear and concentrate in the form of total mixed rations silage leads to greater intake of crude protein, non-fibrous carbohydrates, ether extract and greater digestibility of non-fibrous carbohydrates and neutral detergent fiber, however, all diets were viable in the feed of confined sheep, providing gains of up to 198 g/d according with the formulation of the diet.

The objective of this study was to evaluate the morphogenetic and structural characteristics of Piatã grass under rotational stocking and nitrogen fertilization during the seasons. A randomized complete block design in a split-plot arrangement with three replications was used. The main plots were the applications of 0, 150, 300 and 450 kg per ha of N in the form of urea, and the subplots were seasons of the year: late summer/fall, winter, spring and summer. No interaction was detected between nitrogen fertilization and season for leaf appearance rate, leaf lifespan, number of live leaves and final length leaves. However, an interaction (P<0.05) of nitrogen fertilization and season influenced leaf elongation rate, phyllochron, leaf senescence rate and stem elongation rate. The leaf elongation rate and leaf appearance rate were linearly affected (P<0.05) by nitrogen fertilization. The seasons affected (P<0.05) the leaf lifespan and number of life leaves. The leaf lifespan decreased by 0.06 days for each kg of N applied. On the other hand, the number of live leaves increased by 0.0026 leaves/tiller for each kg of N. Fertilization with nitrogen positively affects morphogenetic and structural characteristics of Piatã grass under rotational stocking. This effect can be optimized during rainy periods in spring and late summer/autumn.

El objetivo de este estudio fue evaluar las características morfogenéticas y estructurales del pasto Piatã bajo pastoreo rotacional y fertilización nitrogenada durante las diferentes estaciones del año. Se utilizó un diseño de bloques completos al azar con un arreglo de parcelas divididas con tres repeticiones. Las parcelas principales fueron las aplicaciones de 0, 150, 300 y 450 kg/ha de N en forma de urea, y las subparcelas fueron las estaciones del año: finales de verano/otoño, invierno, primavera y verano. No se detectó interacción entre la fertilización nitrogenada y la estación para la tasa de aparición de hojas, la esperanza de vida de la hoja, el número de hojas vivas y longitud final de las hojas. Sin embargo, una interacción (P<0,05) de la fertilización nitrogenada y la temporada influyeron en la tasa de elongación de la hoja, filocrono, tasa de senescencia foliar y tasa de elongación del tallo. La tasa de elongación de la hoja y la tasa de aparición de la hoja se vieron afectadas linealmente (P<0,05) por la fertilización nitrogenada. Se observó un efecto (P<0,05) de las estaciones sobre la vida media foliar y el número de hojas vivas. La vida útil de la hoja disminuyó en 0,06 días por cada kg de N aplicado. Por otro lado, el número de hojas vivas aumentó en 0,0026 hoja/macollo por cada kg de N. La fertilización con nitrógeno influye positivamente en las características morfogenéticas y estructurales del pasto Piatã bajo pastoreo rotativo. Este efecto se puede optimizar durante los períodos de lluvia, en la primavera y al final del verano/otoño.

ABSTRACT. The cotton producers from southern Mato Grosso are currently experiencing control failure with the use of the use of insecticides against the cotton boll weevil Anthonomus grandis Boheman, the main pest species of this commodity. Therefore, the present study was designed to survey insecticide resistance and the associated likelihood of control failure among boll weevil populations in the region. Ten insect populations were sampled during the 2016/2017 season and subjected to time-mortality (contact) bioassays in glass vials impregnated with dried insecticide residues at their respective label rates. The three insecticides most frequently used in the region were surveyed: the organophosphate malathion and the pyrethroids beta-cyfluthrin and zeta-cypermethrin. The survival curves showed estimates of the respective median survival time (LT50) for each combination of insecticide and insect copulation. However, there were no significant differences in susceptibility among populations. The estimates of control failure likelihood for each compound at their respective label rates also indicated negligible risk of control failure with their use. These findings are consistent with time-mortality results indicating the lack of insecticide resistant populations at the surveyed sampling sites, suggesting that the reported field control failures result from other causes such as problems with insecticide application.

Abstract This study aimed to measure the carbohydrate and protein fractioning of silage of Brachiaria brizantha cv. Marandu (BBS). The experiment was a completely randomized design with five treatments and five repetitions to evaluate the inclusion of dehydrated brewery residue (DBR) to Marandu grass silage at levels of 0, 10, 20, 30 and 40% fresh matter basis. The DBR inclusion resulted in a linear reduction (P<0.05) of total carbohydrate content, which decreased 0.35% per unit of residue added. The content of fraction B2 decreased linearly as DBR was added (P<0.05). Nitrogen content increased linearly when residue was added to silage of Marandu grass (P<005). Fraction A, obtained from Marandu grass, presented a linear increasing behavior according to the inclusion of DBR. This inclusion promoted a linear decrease (P<0.05) of fraction B1+B2, which resulted in a 0.37% reduction for each 1% of byproduct added. Dehydrated brewery residue is a good source of additives for ensiling Marandu grass, by considerably improving fractions of proteins and carbohydrates. The level of addition of 40% is recommended for providing better nutritional value to silage.

Resumen Este estudio tuvo como objetivo medir el fraccionamiento de carbohidratos y proteínas del ensilaje de Brachiaria brizantha cv. Marandu (BBS). El experimento fue un diseño completamente al azar con cinco tratamientos y cinco repeticiones para evaluar la inclusión de residuos de cervezas deshidratadas (DBR) en ensilaje de hierba Marandu en niveles de 0, 10, 20, 30 y 40% de materia fresca. La inclusión de DBR resultó en una reducción lineal (P <0.05) del contenido total de carbohidratos, que disminuyó 0.35% por unidad de residuo agregado. El contenido de la fracción B2 disminuyó linealmente a medida que se agregaba DBR (P<0.05). El contenido de nitrógeno aumentó linealmente cuando se añadió residuo al ensilaje del pasto Marandu (P <005). La fracción A, obtenida del pasto Marandu, presentó un comportamiento de aumento lineal de acuerdo con la inclusión de DBR. Esta inclusión promovió una disminución lineal (P<0.05) de la fracción B1 + B2, que resultó en una reducción de 0.37% por cada 1% de subproducto agregado. Los residuos de cervecería deshidratada son una buena fuente de aditivos para ensilar el pasto Marandu, mejorando considerablemente las fracciones de proteínas y carbohidratos. Se recomienda un nivel de adición del 40% para proporcionar un mejor valor nutritivo al ensilaje.

RESUMO Objetivou-se avaliar os efeitos do farelo de arroz sobre as perdas por gases e efluente, o perfil fermentativo e a composição química das silagens de Brachiaria decumbens cv. Basilisk ensilado em silos de laboratório. Utilizou-se delineamento inteiramente casualizado, com cinco tratamentos: 0; 10; 20, 30 e 40g/kg de farelo de arroz, com base na matéria natural da gramínea. Os valores das perdas por gases e efluentes foram reduzidos linearmente em 0,11 e 0,39g/kg MS, enquanto a recuperação da matéria seca aumentou linearmente em 0,32g/kg MS. Houve comportamento quadrático nos valores de pH e, redução linear para os valores de N-amoniacal e poder tampão, estimados em 1,1 e 0,5g/kg MS. As concentrações de ácido acético, butírico e propiônico foram reduzidas linearmente em 0,1; 0,008 e 0,006g/kg MS, enquanto a de ácido láctico aumentou linearmente em 0,5g/kg MS. Cada unidade porcentual de farelo de arroz promoveu aumento linear de 4,3; 1,8; 7,1 e 7,0g/kg nos teores de matéria seca, proteína bruta, extrato etéreo e nutrientes digestíveis totais, e redução linear de 6,9; 4,3 e 2,6g/kg MS nos teores de fibra em detergente neutro, fibra em detergente ácido e hemicelulose. A inclusão de 10g/kg de farelo de arroz já assegura diminuição das perdas por gases e efluentes, aumento na recuperação de matéria seca, proporcionando melhorias no perfil fermentativo e na composição química das silagens.

SUMMARY The objective was to assess the effects of rice meal over losses by gas and effluent, the fermentative profile and the chemical composition of Brachiaria decumbens cv. Basilisk silage in laboratory bags. Entirely random lining was used, with five treatments: 0; 10; 20; 30 and 40g/kg rice meal, based on natural grass matter. The values of losses by gas and effluents were reduced linearly in 0.11 and 0.39g/kg DM, while recovery of dry matter increased linearly in 0.32g/kg DM. There was quadratic behavior for pH values and linear decrease for the values of N-ammoniacal and buffering power estimated in 1.1 and 5g/kg DM. Concentrations of acetic, butyric and propionic acids were reduced linearly in 0.1; 0.008 and 0.006g/kg DM, while lactic acid increased linearly in 0.5g/kg DM. Each 1g/kg rice meal promoted linear increase of 4.3; 1.8; 7.1 and 7.0g/kg dry matter levels, crude protein, ethereal extract and total digestible nutrients and linear decrease of 6.9; 4.3 and 2.6g/kg DM of fiber in neutral detergent, fiber in acidic detergent and hemicellulose levels. Inclusion of 10g/kg rice meal already ensures lowering losses by gas and effluents, increase in dry matter recovery, allowing improvements on the fermentative profile and the chemical composition of silage.

Resumo: O objetivo deste trabalho foi avaliar o efeito da alimentação suplementar de resíduos de feijão no desempenho produtivo e nos parâmetros sanguíneos de vacas leiteiras em pastejo. Foram utilizadas oito vacas mestiças, com peso médio de 500 kg, distribuídas em duplo quadrado latino 4×4, alimentadas com alimentação suplementar de 134, 240, 348 e 449 g kg-1 de resíduos de feijão na ração concentrada. Os animais receberam a suplementação após a ordenha no período da manhã e da tarde. A inclusão de resíduos de feijão não alterou os pesos corporais médios e os escores corporais; no entanto, reduziu a produção de leite. Os teores de gordura, proteína bruta, lactose e extrato seco total não foram alterados pela inclusão dos resíduos de feijão. A concentração sanguínea de glicose e colesterol não foi alterada pela adição do resíduo antes do fornecimento de ração concentrada e nem quatro e seis horas após essa alimentação. A inclusão dos resíduos de feijão na ração concentrada de vacas leiteiras em pastejo, com produção média diária de 13 kg, reduz a produção de leite. Todavia, a utilização desses resíduos pouco influencia a composição do leite e os parâmetros sanguíneos.

Abstract: The objective of this work was to evaluate the effect of dietary supplement bean residue on growth performance and blood parameters of dairy cows grazing. Eight crossbred cows weighing 500 kg were analyzed, distributed in 4×4 double Latin square, and fed with 134, 240, 348, and 449 g kg-1 of a supplementary diet of bean waste in the concentrated feed. The animals received the supplementation after milking in the morning and in the afternoon. The inclusion of bean residues did not change average body weights and body scores; however, it reduced the milk production. Fat, protein, lactose, and total solid contents (g kg-1) were not changed by bean waste inclusion. Blood glycose and cholesterol did not change before the offering of the concentrated feed diet, nor after four to six hours of feeding this diet. The inclusion of bean residues in the concentrated feed of dairy cows subjected to grazing, with a daily average production of 13 kg, reduces milk production. However, the use of these residues has little effect on milk composition and blood parameters.

The objective of this experiment was to evaluate the losses of nutrient through gases and effluents, the nutrient recovery, fermentation parameters and the chemical parameters of silages of Brachiaria decumbens with the addition of soybean hulls, testing five levels of inclusion: 0, 10, 20, 30 and 40% (as is), with five replications per treatment. After the standardization cut of the forage, performed at 5 cm from the soil level, the soil was fertilized with nitrogen and potassium in the form of ammonium sulfate and potassium chloride, respectively, at 60 kg/ha. After 60 days, the grass was cut at 10 cm from the soil and ensiled. Experimental silos with capacity of 10 liters with Bunsen valve were used. Silos had 3 kg of sand conditioned at the bottom for retention of the effluents. The results show that the contents of dry matter, crude protein, acid detergent insoluble fiber and total digestible nutrients presented positive linear behavior with the inclusion of soybean hulls. In the grass silages with addition of soybean hulls, there was greater recovery of dry matter in relation to the control silage, which is a reflection of the negative linear behavior for the values of losses of gases and effluent. There was quadratic behavior in the pH values and negative linear behavior for the ammonia N values and buffering capacity with the inclusion of the additive in the grass silage. Inclusion of soybean hulls is sufficient to improve the fermentation pattern and minimize the losses through gases and effluents, contributing to the nutrient recovery, in addition to promoting overall improvement of the nutritional value of Brachiaria grass silages.

This experiment was conducted to evaluate the protein and carbohydrate fractions, and to estimate the in situ rumen degradation kinetic parameters of Brachiaria decumbens grass silage with inclusion of rice bran. Five rice bran inclusion levels were tested: 0, 10, 20, 30 and 40% of the natural matter, distributed into a completely randomized design with five replications. The brachiaria grass was obtained at 60 days of regrowth by cutting the forage at 10 cm from the soil and ensiling it in 10-L experimental silo bags, which were opened after 40 days. The degradability profiles for DM, CP, NDF and of the feeds for each animal utilized made it possible to obtain the estimates of the parameters analyzed. The contents of total carbohydrates (TCH), fibrous carbohydrates and fraction A+B1 of the TCH decreased linearly as the rice bran levels were elevated. Fraction A of the protein was increased linearly by 0.64% for every 1% of rice bran added to the silage. For nitrogenous fractions B3 and C, there was a decrease of 0.11 and 0.40% for each 1% of rice bran added to the silage, respectively. For the rumen degradability parameters of the dry matter, fractions A and I had estimated increases of 0.54 and 0.04% for every 1% inclusion of rice bran. For the degradation rate of fraction B (c), treatments had no effect. Fractions A and I of the crude protein degradability parameters increased by 0.22 and 0.72%, respectively, with inclusion of 1% rice bran. Inclusion levels of rice bran had no effect on fraction D, on the degradation rate of fraction B (c) or lag time (L) estimated for neutral detergent fiber. Inclusion of 10 and 20% rice bran in the brachiaria grass silage improves protein and carbohydrate fractions and rumen degradation kinetic parameters of dry matter, crude protein and neutral detergent fiber.

This study was carried out to analyze the tillering profile of Guinea grass (Panicum maximum cv. Tanzania) pastures subjected to two grazing frequencies (time necessary to intercept 90 and 95% of the incoming light) and two post-grazing heights (30 and 50 cm) in the period from November 2005 to October 2006. The experimental design was of completely randomized blocks with three replications, in a 2 × 2 factorial arrangement. At the end of the spring, pastures managed with 90% light interception showed greater tiller appearance rates in relation to pastures managed with 95%, regardless of post-grazing height. In the summer and fall, pastures managed with post-grazing height of 30 cm showed higher tiller appearance rates in comparison with pastures managed at 50 cm, regardless of grazing frequency. Concerning the tiller mortality rates, in the summer, higher values were found for pastures managed at 90/50 and 95/30 (interception/height), intermediate values at 90/30 and lower values in those managed at 95/50. Pastures managed at 90/30, 95/30 and 95/50 in the fall presented greater tiller mortality rates than those managed at 90/50. These differences do not occur in the winter/beginning of spring. The stability index remained above 1 all through the experimental period. All management strategies evaluated are adequate for Guinea grass.

Esta pesquisa foi conduzida com o objetivo de avaliar as características estruturais e o acúmulo de forragem do capim-tanzânia (Panicum maximum cv. Tanzânia) sob pastejo rotativo e submetido às combinações de duas frequências de pastejo (tempo para o dossel atingir 90 ou 95% de interceptação da luz - IL) e duas alturas pós-pastejo (30 ou 50 cm). Adotou-se um arranjo fatorial 2 × 2 em delineamento de blocos completos casualizados com três repetições. As alturas pré-pastejo foram estáveis durante o período experimental (7/11/2005 a 12/10/2006) e corresponderam a 65 e 75 cm para metas de 90 e 95% de IL, respectivamente. Os pastos manejados com altura pós-pastejo de 50 cm e com 90% de IL apresentaram maior número de ciclos de pastejo em comparação àqueles submetidos à altura pós-pastejo de 30 cm e com 95% de IL. Padrão de resposta contrário ocorreu para o intervalo de pastejo. O acúmulo de lâmina foliar (LF) foi maior no verão, intermediário no final da primavera e menor no outono e no inverno e início da primavera. O acúmulo de FT e de LF foi maior nos pastos manejados com 30 cm de altura pós-pastejo em comparação àqueles com 50 cm. Por outro lado, os efeitos da condição pré-pastejo no acúmulo de FT dependeu do resíduo usado. Os níveis de IL (90 ou 95%) não influenciaram o acúmulo de lâminas foliares. As combinações de intensidades e frequências de pastejo resultaram em pouca variação na composição morfológica da forragem, exceto no outono, quando se observou maior percentual de material morto em pastos manejados com 50 cm de altura pós-pastejo em comparação àqueles sob 30 cm de resíduo. O pastejo rotativo do capim-tanzânia deve ser iniciado com 95% de IL pelo dossel e encerrado com 30 cm de altura pós-pastejo. Quando necessário, e para gerar flexibilidade no manejo do pastejo, o capim-tanzânia pode ser pastejado com 90% de IL pelo dossel.

The aim of this study was to evaluate the structural characteristics and herbage accumulation of tanzania guineagrass (Panicum maximum cv. Tanzania) under rotational grazing and subjected to combinations of two grazing frequencies (time for the canopy to intercept 90 or 95% of the incident light) and two post-grazing heights (30 or 50 cm). Treatments were assigned to experimental units according to a 2 × 2 factorial arrangement in a completely randomized design, with three replications. Sward heights at pre-grazing were consistent during the experimental period and were of around 65 and 75 cm, for 90% and 95% of light interception (LI), respectively. Pastures managed with post-grazing height of 50 cm and 90% of LI had higher number of grazing cycles when compared with those submitted to post-grazing height of 30 cm and 95% of LI. Herbage mass production was higher in summer, intermediate in late spring and lowest in fall and winter and early spring. Herbage mass and lamina leaves production were higher in pastures managed with post-grazing height of 30 cm when compared with post-grazing height of 50 cm. Nevertheless, the effects of frequency on herbage mass production were associated with the post-grazing height used. The LI levels (90 or 95%) did not affect leaf lamina production. The combinations of frequency and severity of grazing resulted in little variation in the morphological composition of forage, except in the autumn, when there was a higher percentage of dead material in pastures managed with post-grazing height of 50 cm when compared with those with post-grazing height of 30 cm. The rotational grazing of tanzania guineagrass should be initiated when canopy intercepts 95% of incident light until a post-grazing height of 30 cm. When necessary and in order to generate flexibility in grazing management, the tanzania guineagrass can be grazed with 90% of light interception.

Objetivou-se com este experimento avaliar os efeitos da adição de raspa de mandioca na ensilagem sobre as perdas por gases e efluentes, a recuperação da matéria seca, o pH, os teores de N-NH3, ácidos orgânicos e ácidos graxos voláteis e a composição bromatológica de silagens de capim-elefante. Utilizou-se um delineamento inteiramente casualizado, com quatro níveis de raspa de mandioca (0, 7, 15 ou 30% da matéria natural), cada um com quatro repetições. O capim foi cortado aos 50 dias de rebrota e ensilado em silos de 15 litros de capacidade, com válvula de bunsen para escape dos gases. A adição de raspa de mandioca ocasionou redução quadrática nas perdas por gases e redução linear nas perdas por efluente. A recuperação de matéria seca aumentou de forma quadrática com a adição de raspa de mandioca. O teor de matéria seca aumentou, enquanto os de proteína bruta, fibra em detergente neutro, fibra em detergente ácido (FDA) e hemicelulose diminuíram linearmente com a adição de raspa de mandioca. O valor de pH e o teor de ácido lático aumentaram de forma quadrática com a adição de raspa de mandioca. Os teores de N-NH3 e de ácido butírico diminuíram de forma quadrática com a adição de raspa de mandioca, enquanto o teor de ácido acético diminuiu linearmente. A inclusão de raspa de mandioca na ensilagem reduz as perdas por gases e efluentes e melhora o perfil fermentativo de silagens de capim-elefante e o nível de 7% da matéria natural é suficiente para assegurar essa melhora.

The objective of this experiment was to evaluate the effects of adding cassava scrapings on gas and effluent losses, dry matter recovery, pH, contents of N-NH3, organic acids and volatile fatty acids and the bromatological composition of elephant grass silages. It was used a randomized complete design, with four levels of cassava scrapings (0, 7, 15 or 30% natural matter) each one with four replications per level. The grass was cut at 50 days of regrowth and ensiled in 15-L silos, equipped with a Bunsen valve to allow gas outflow. The gas losses decreased quadratically with the addition of cassava scrapings, whereas effluent losses decreased linearly. Dry matter recovery increased quadratically with the addition of cassava scrapings. Dry matter (DM) concentration increased but crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF) and hemicellulose (HEM) decreased linearly with the addition of cassava scrapings. The pH value and lactic acid concentration increased quadratically with the addition of cassava scrapings. Contents of N-NH3 and butyric acid decreased quadratically with the addition of cassava scrapings, whereas acetic acid content decreased linearly. Addition of cassava scrapings reduced gas and effluent losses and improved the fermentation profile of elephant grass silages and the level of 7% already ensures this improvement.

Avaliaram-se as características morfogênicas e estruturais e o acúmulo de forragem do capim Panicum maximum, cv. Tanzânia, submetido a duas alturas de corte (25 e 50 cm) e três intervalos de corte (correspondentes ao surgimento de duas, três e quatro folhas por perfilho). Utilizou-se um arranjo fatorial 2 × 3 em delineamento de blocos completos casualizados, com três repetições. A taxa de aparecimento de folhas diminuiu e o filocrono aumentou com a redução da frequência de desfolhação. De modo geral, o comprimento final da folha foi menor na altura de corte 25 cm que na de 50 cm. A taxa de senescência de folhas e a taxa de alongamento de colmos tenderam a aumento quando o intervalo de corte variou de duas para três folhas por perfilho. A taxa de mortalidade de perfilhos aumentou ao longo do período de avaliação. As altas taxas de mortalidade e de aparecimento de perfilhos caracterizaram um padrão intenso de renovação (turnover) da população de perfilhos. A altura pré-desfolhação diminuiu com o aumento da frequência de corte, enquanto a massa de forragem tendeu a ser maior nas menores frequências de corte. O acúmulo de colmos só variou entre as alturas de corte no segundo corte e foi menor no intervalo de duas folhas em comparação aos de três e quatro folhas surgidas por perfilho, também no mesmo corte. O intervalo de cortes do capim-tanzânia não deve exceder o tempo necessário para o aparecimento de duas a três folhas por perfilho.

The morphogenetic and structural characteristics and herbage accumulation were assessed of Panicum maximum cv. Tanzania subjected to two cutting heights (25 and 50 cm) and three cutting intervals (corresponding to the appearance of two, three and four leaf per tiller). A 2 × 3 factorial arrangement was used in a randomized complete block design with three replications. Leaf appearance rate decreased and phyllochron increased with low cutting frequency. In general, the final leaf length was shorter for the 25 cm compared to the 50 cm cutting height. Rates of leaf senescence and stem elongation tended to increase as cutting interval increased from two to three new leaves produced per tiller. Tiller mortality rate increased throughout the experimental period, and the high rates of tiller appearance and death indicated an intense turnover in tiller population. The pre-defoliation hight decreased with increase in cutting frequency, while the herbage mass tended to be greater in hte smaller cutting frequencies. Stem accumulation differed between cutting heights only at the second cut and was smaller for the two leaf than for the three and four leaf per tiller cutting intervals for the same second cut. The cutting interval of Tanzania grass should not exceed the time necessary to ensure the appearance of two to three leaves per tiller.

O experimento foi realizado para avaliar a dinâmica do perfilhamento do capim-marandu submetido a duas alturas (15 e 30 cm) e três intervalos de corte (aparecimento de três, quatro e cinco folhas por perfilho). Utilizou-se delineamento de blocos completos casualizados com três repetições e arranjo fatorial 2 × 3. As avaliações consistiram do monitoramento mensal do aparecimento e morte de perfilhos em duas touceiras por parcela, sendo os novos perfilhos classificados em basilares e aéreos. A altura de corte de 15 cm promoveu maior aparecimento, 1,46 perfilhos/100 perfilhos.dia, e maior mortalidade de perfilhos, 0,368 perfilhos/100 perfilhos.dia. O intervalo de cortes de 5 folhas/perfilho resultou em menor taxa de aparecimento de perfilhos totais quando associado à altura de corte de 30 cm, 0,97 perfilhos/100 perfilhos.dia. Parcelas cortadas a 15 cm de altura apresentaram menor variação em densidade populacional de perfilhos, independentemente do intervalo de corte utilizado. A dinâmica de perfilhamento basilar, aéreo e total respondeu de forma diferenciada ao intervalo e à altura de corte, resultado do estádio fisiológico das plantas e das condições ambientais vigentes durante o experimento.

The study was conducted to evaluate the dynamics of the tillering process in marandu palisadegrass submitted to two cutting heights (15 and 30 cm), and three cutting intervals (leaf appearance intervals of three, four and five leaves per tiller). A complete randomized block design, with three replications and a 2 × 3 factorial arrangement was used. Evaluations consited of monthly measurements of tiller appearance and death in two tussocks per plot, with new tillers sorted into basal and aerial tillers. Cutting at 15 cm resulted in higher tiller appearance, 1.46 tiller/100 tiller.day, and death rates, 0.368 tiller/100 tiller.day. The five-leaf cutting interval resulted in the lowest tiller appearance rate when associated with the 30 cm cutting height, 0.97 tiller/100 tiller.day. Swards cut at 15 cm presented smaller variations in tiller population, regardless of the cutting frequency used. The dynamics of basal, aerial and total tillering responded differently to cutting frequency and intensity, consequence of the physiological state of plants and prevailing environmental conditions during the experiment.

Foi conduzido um experimento com o objetivo de avaliar o comportamento de bezerros em pastagens de Brachiaria brizantha e Brachiaria decumbens, no sistema de lotação contínua com taxa de lotação variável. O delineamento experimental foi o inteiramente casualizado, com dois pastos representando os tratamentos, cada um com cinco repetições. O período experimental foi de 30 dias, sendo 20 para adaptação dos animais e 10 para avaliações, que consistiram de três, com duração de 24h cada, em intervalos de cinco dias. Os bezerros pastejaram menos tempo no pasto de Brachiaria brizantha, com tempo de 9,75h, enquanto que o pastejo na Brachiaria decumbens foi de 11,3h. Comportamento diferente foi observado para o tempo de ruminação: 6,8 e 6,4 para os pastos de Brachiaria brizantha e Brachiaria decumbens, respectivamente. O número de bocados por minuto foi menor para a Brachiaria decumbens, 31,15, enquanto que, para a Brachiaria brizantha, os bezerros pastejaram com uma taxa de bocados de 34,91 bocados por minuto. Os bezerros tiveram um ganho de peso médio diário superior no pasto de Brachiaria brizantha (390g dia-1), enquanto que, para a Brachiaria decumbens, o ganho diário foi de 340g dia-1.

An experiment was carried out to evaluate the ingestive behavior of calves on Brachiaria brizantha and Brachiaria decumbens pastures, under continuous stocking with variable stocking rate. The experimental design was entirely randomized, with two treatments (two pastures), and five replicates per treatment. The experimental period lasted 30 days, consisting of days 20 for adaptation of animals and 10 for behavioral evaluations that consisted of three periods of 24:00h each, in intervals of five days. The calves spent less time grazing Brachiaria brizantha pasture (9,8h) than they did on the Brachiaria decumbens (11,3h). Different rumination times had been observed, 6,8 and 6,4 h for the animals grazing Brachiaria brizantha and Brachiaria decumbens, respectively. We suggested that the selective behavior of the calves on the Brachiaria decumbens made them to eat good quality grass, thus they spent a similar rumination time to that observed for Brachiaria brizantha. The number of bites per minute was inferior for the Brachiaria decumbens, 31,2h, when compared with Brachiaria brizantha (the mean bite rate was 34,9 bites per minute). The calves had a larger daily gain to Brachiaria brizantha (390g day-1) than they had to Brachiaria decumbens (340g day-1).