RESUMEN
The aim was to report cases and risk factors for hepatogenous photosensitization in lambs kept on Brachiaria spp. pastures and supplemented with levels of extruded urea (EU). The herd consisted of 69 Texel crossbred lambs with known parentage (fathers and mothers adapted to the consumption of forage of the genus Brachiaria), randomly divided into 5 groups and distributed in individual paddocks for each group. The animals were supplemented with increasing levels of EU (Amireia® 200S): 0, 6, 12, 18, and 24 g of EU per 100 kg-1 of body weight (BW). The concentration of protodioscin was estimated in the mixed pastures of Brachiaria spp. (cv. Marandu and cv. Basilisk), structural components (leaf, stem, and dead material), samples of each cultivar, and in the months of December (2018), February, and April (2019). The animals were examined daily, and when behavioral changes were identified, they underwent clinical examinations and anamnesis. Weighing was performed every 14 days, followed by necropsy and serum biochemical analysis, including gamma-glutamyltransferase (GGT). The highest concentrations of protodioscin (p < 0.0001) were found in the pastures used by animals supplemented without extruded urea (7.07 ± 0.56), in the Basilisk cultivar (11.35 ± 0.06), in the leaf blade components (2.08 ± 0.05), and thatch (2.20 ± 0.00), and in the month of April (7.34 ± 0.29) (the month with the lowest rainfall), respectively. Fourteen (20.29%) cases of photosensitization were observed in lambs, of which six recovered, and eight died. Serum GGT levels ranged from 42.2 to 225 IU/L; however, in animals that died, values ranged from 209.4 to 225 IU/L. The use of levels 12 g and 18 g per 100 kg-1 of body weight of extruded urea may contribute to the lower occurrence of photosensitization, as the animals selected pastures with lower protodioscin content, presenting a smaller number of cases.
Asunto(s)
Brachiaria , Diosgenina , Urea , Animales , Masculino , Alimentación Animal/análisis , Brasil , Suplementos Dietéticos , Diosgenina/análogos & derivados , gamma-Glutamiltransferasa/sangre , Trastornos por Fotosensibilidad/veterinaria , Saponinas , Ovinos , Enfermedades de las Ovejas , Urea/sangre , FemeninoRESUMEN
Protodioscin is a saponin present in grasses that can lead to losses in animal production. Our hypothesis was that mathematical models can accurately and precisely predict the protodioscin concentration in tropical grasses. We evaluated the ability of four mathematical models to describe the protodioscin concentration in Brachiaria and Panicum cultivars with different regrowth periods. Six cultivars of Panicum: Aruana, Massai, Mombaça, Tanzânia, Tamani, and Zuri; and five of Brachiaria-grass: Marandu, Paiaguás, Piatã, Xaraés and Basilisk. Protodioscin concentration evaluations were carried out at 51, 84, 110, and 111 days of age. Linear, Quadratic, Exponential, and Logarithmic models were evaluated, and the adequacy of the models was verified. The models were compared for accuracy and precision by pairwise mean squared error analysis and the delta Akaike information criterion. The models did not differ from each other in terms of accuracy and precision. The exponential model showed a high ability to explain the observed variability between protodioscin concentration and plant age for Brachiaria grasses. Panicum grasses have constant protodioscin concentration. Mathematical models are capable of predicting the protodioscin concentration in grasses of the genus Brachiaria based on plant age. We recommend Exponential model to predict the concentration of protodioscin in Brachiaria grasses.
Asunto(s)
Brachiaria , Diosgenina , Diosgenina/análogos & derivados , Panicum , Saponinas , Animales , Saponinas/análisis , Diosgenina/análisisRESUMEN
Our objectives were to evaluate the use of cottonseed cake in replacing corn silage in a diet without forage and to identify the model with higher precision and accuracy of adjustment of parameters of ruminal degradation kinetics. A diet containing corn silage and another with cottonseed cake as a fiber source were formulated. Gompertz, Dual-pool Logistic, Brody, and Ørskov models were evaluated for goodness of fit to gas production. There were significant differences in dry matter (DM), organic matter (OM), and neutral detergent fiber (NDF) in the in vitro digestibility for diets and fiber sources. The estimated values of the Gompertz (6.77), Brody (6.72), and Ørskov (6.73) models were similar to the observed mean of gas production in the corn silage diet (6.73 mL/100 mg DM). Similarly, the estimated values of the Brody (5.87) and Ørskov (5.89) models were similar to the observed mean of gas production in the cottonseed cake diet (5.87 mL/100 mg DM). The roughage-free diet containing cottonseed cake as a fiber source stimulated higher gas production. Brody and Ørskov models presented higher precision and accuracy in the fitting of kinetics of degradation independent of the fiber source in the diet.
RESUMEN
This research evaluated the effect of liming (with and without) and biochar (with and without) on sorghum cv. BRS Ponta Negra growth and Arenosol chemical properties in the Semiarid environment. The experimental design was in randomized blocks, with treatments in a 2x2 factorial scheme, corresponding to the application or not of lime (0 and 2.5 t ha-1) and biochar (0 and 12.5 t ha-1). Biochar was produced from cashew branches. The experiment was conducted in 16 m² plots where the forage sorghum cultivar BRS Ponta Negra was cultivated. The soil chemical characteristics, the production attributes, and the structural characteristics of the sorghum cultivar studied were evaluated. There was no interaction between factors. The use of biochar increased the pH and Ca and P contents in the soil and contributed to increasing the panicle mass (2.51 t ha-1 of DM). Lime application affected the soil Ca content as the dose of 2.5 t ha-1 resulted in higher values of culm diameter (15.25 mm), panicle mass, and culm mass (2.63 and 7.50 t ha-1 of DM, respectively). Therefore, these results allowed to outline strategies for the use of limestone and biochar for forage production in semiarid environments in sandy soils. Because, these materials improve some chemical attributes of the soil and the production of forage sorghum. It is noteworthy that edophoclimatic conditions can change the response patterns observed in this research. Therefore, research in other regions is essential.
Este trabalho teve como objetivo avaliar o efeito da calagem (com e sem) e do biocarvão (com e sem) sobre o crescimento e a produção de forragem do sorgo forrageiro cv. BRS Ponta Negra e nas propriedades químicas do Neossolo Quartzarênico no ambiente Semiárido. O delineamento experimental foi em blocos casualizados, com tratamentos em esquema fatorial 2x2, correspondendo a aplicação ou não do calcário (0 e 2,5 t ha-1) e do biocarvão (0 e 12,5 t ha-1). O biochar era produzido a partir de galhos de caju. O experimento foi conduzido em parcelas de 16 m² onde foi cultivada a cultivar de sorgo forrageiro BRS Ponta Negra. Foram avaliadas as características químicas do solo, os atributos de produção e as características estruturais da cultivar de sorgo estudada. Não houve interação entre os fatores. O uso do biochar aumentou o pH e os teores de Ca e P no solo e contribuiu para o aumento da massa da panícula (2,51 t ha-1 de MS). A aplicação de calcário afetou o teor de Ca no solo, assim a dose de 2,5 t ha-1 resultou em maiores valores de diâmetro do colmo (15,25 mm), massa da panícula e massa do colmo (2,63 e 7,50 t ha-1 de MS, respectivamente). Portanto, esses resultados permitem traçar estrategias de uso do calcário e biochar para produção forrageira em ambientes semiáridos com solos arenosos. Pois, esses materias melhoram alguns atributos quimicos do solo e a produção do sorgo forrageiro. Vale ressaltar que as condições edofoclimáticas podem alterar os padrões de resposta observados nesta pesquisa. Portanto, a pesquisa em outras regiões é essencial.
Asunto(s)
Química del Suelo , Suelos Calcáreos , Condición del Suelo , Sorghum , Brasil , Producción de Cultivos , Características del SueloRESUMEN
Our hypothesis was that extrusion of urea associated with corn may reduce N solubilization and increase the nutritional quality of this food for ruminants. We aimed to physically and chemically characterize a corn and urea mixture before and after the extrusion process. It was evaluated morphological differences by scanning electron microscopy, nitrogen solubilization, and compound mass loss by thermogravimetry. In scanning electron microscopy, extruded urea showed agglomerated and defined structures, with changes in the morphology of starch granules and urea crystals, differing from the arrangement of the corn and urea mixture. The extruded urea maintained a constant nitrogen release pattern for up to 360 min. In thermogravimetry, extruded urea presented a higher temperature to initiate mass loss, that is, the disappearance of the material with increasing temperature, but the mass loss was lower when compared to the first event of the corn and urea mixture. In conclusion the process of extrusion of urea with corn modifies the original structures of these ingredients and controls the release of nitrogen from the urea, maintaining in its formation an energy source optimizing the use of nitrogen by ruminal bacteria, because the more synchronized the release of starch (energy) and nitrogen, the better the use by ruminal microorganisms.
RESUMEN
The aim of this study was to predict carcass traits of Santa Inês lambs finished in tropical pastures by using biometric measurements. Data originated from two experiments involving 56 lambs (32 in experiment I and 24 in experiment II). In both experiments, the sheep were finished in that were finished in pastures of Panicum maximum and Brachiaria brizantha, experiment I being conducted in the rainy season and experiment II in the dry season. The following biometric measurements were recorded before slaughter: body length (BL), withers height (WH), rump height (RH), thorax width (TW), rump width (RW), chest width (CW), heart girth (HG), thigh circumference (TC), rump circumference (RC) and leg length (LL), in addition to live weight at slaughter (SW). After slaughter, hot carcass weight (HCW), cold carcass weight (CCW) and the weights of primal cuts (shoulder, neck, loin, leg and rib) were recorded. In the equations generated to predict SW, HCW and CCW, R2 ranged from 0.58 to 0.91 and the measurements of WH, TC, CW, HG and RW were the most relevant. In the equations developed to predict the weight of primal cuts, in turn, R2 ranged from 0.26 to 0.99. In these models, SW, BL, CW, TC, LL and HG explained most of the variation in the weight of primal cuts. Biometric measurements can be used to accurately and precisely predict HCW, CCW and the weight of primal cuts from the carcass of Santa Inês sheep finished in tropical pastures, since the equations presented R2 and correlation coefficient and agreement above 0.8.
RESUMEN
ABSTRACT: This study examined the use of the Gompertz, Groot, monomolecular, Richards and two-compartment-logistic mathematical models to investigate the kinetics of in vitro gas production of diets composed of combinations of Gliricidia hay or silage. In addition, the effects of Gliricidia hay or silage inclusion on the in vitro cumulative gas production of these diets were evaluated. Rumen fermentation kinetics were analyzed by the in vitro cumulative gas production methodology. The model parameters were estimated using the Gauss Newton method, with the exception of the Richards model, which was used by Marquardt's algorithm. Model fit was assessed using the determination coefficient, F test for parameters identity, concordance correlation coefficient, root mean square error of prediction, and decomposition of mean square error of prediction into mean error, systematic bias and random error. The models were compared for accuracy (pairwise mean square error of prediction) and precision (delta Akaike's information criterion). All model evaluation and comparison statistics were calculated using Model Evaluation System software version 3.2.2. The Groot and Richards models did not differ from each other (P>0.05) and were the most precise and accurate (P<0.05). Therefore, the Groot model was selected due to its better accuracy and precision and easier access to the parameters. The inclusion of Gliricidia silage in the diet resulted in an increase in the time to obtain the maximum rate of degradation and in the time after incubation when half of the asymptotic level was reached. The Groot model is recommended to estimate the average curve. Dietary inclusion of Gliricidia silage alters the gas production curve due to the longer time required for the diet to reach the maximum rate of degradation, this can increase the time the diet remains in rumen and promote a reduction in the consumption.
RESUMO: Objetivou-se avaliar os modelos matemáticos Gompertz, Groot, monomolecular, Richards e logístico bicompartimental para estudar a cinética de produção de gás in vitro de dietas compostas de combinações de feno ou silagem de Gliricídia. Além disso, avaliou-se os efeitos da inclusão de feno ou silagem de Gliricídia sobre a produção cumulativa de gás in vitro destas dietas. A cinética de fermentação ruminal foi avaliada pela metodologia de produção cumulativa de gás in vitro. Os parâmetros dos modelos foram estimados usando o método de Gauss Newton, com exceção do modelo de Richards, que foi usado algoritmo de Marquardt. O ajuste dos modelos foi avaliado por meio do coeficiente de determinação, teste F para a identidade dos parâmetros, coeficiente de correlação e concordância, raiz quadrada do quadrado médio do erro da predição e a decomposição do quadrado médio do erro da predição em erro médio, vício sistemático e erro aleatório. Os modelos foram comparados quanto à acurácia (quadrado médio da predição pareado) e quanto à sua precisão (critério de informação delta de Akaike). Todas as estatísticas de avaliação e comparação dos modelos foram calculadas usando o software Model Evaluation System versão 3.2.2. Os modelos de Groot e Richards não diferiram entre si (P>0.05) e foram os mais precisos e acurados (P<0.05). Portanto, modelo de Groot foi selecionado devido apresentar melhor acurácia e precisão e apresentar maior facilidade na obtenção dos parâmetros. A inclusão da silagem de Gliricídia na dieta, resultou em elevação no tempo para obtenção da máxima taxa de degradação e no tempo após a incubação em que metade do nível assintótico foi atingido. Recomenda-se a utilização do modelo de Groot para estimativa da curva média. A inclusão da silagem de Gliricídia altera a curva de produção de gás devido o maior tempo necessário para que a dieta atingisse a máxima taxa de degradação, isso pode elevar o tempo de permanência da dieta no rúmen e promover redução no consumo.
RESUMEN
ABSTRACT: There is little information about whether the increased secondary productivity observed in pastures fertilized with high nitrogen rates is attributable to fluctuations in the nutritional value or pasture structural characteristics, or both. This study aimed to identify a set of factors (structural and nutritional characteristics) that best explain the performance of beef steers grazing Mombasa grass pastures under residual effects of nitrogen fertilizer. The data were collected in Mombasa grass pastures fertilized with increasing rates of nitrogen (N) (100, 200 and 300 kg ha-1) from 2015 to 2017. In 2018, nitrogen fertilization was not used in order to characterize a residual effect of the nutrient. Variables related to pasture structural characteristics such as forage accumulation rate (FAR), canopy height, forage mass (FM) and morphological components were evaluated. The study also evaluated the nutritional value of leaf blades and the performance of beef steers based on average daily gain (ADG) and stocking rate. Principal component analysis was performed using the dataset available. Most of the variance (99.6%) was explained by only two principal components (PCs), of which 90.0% corresponded to PC1. The most influential parameters for PC1, in order of priority, were: FAR, FM, leaf blade and stem masses. These variables were positively associated with stocking rate. Conversely, ADG was not associated with any variable. ADG was the most relevant variable for the second PC; however, this PC explained less variance (9.6%). The structural characteristics of the pasture (FAR, FM and morphological components mass) better explain the fluctuations in the performance of cattle on pastures of Mombasa grass under residual effects of nitrogen fertilizer. The stocking rate is an efficient parameter to support decision-making in managed pastures with variable stocking.
RESUMO: Há pouca informação sobre se o aumento da produtividade secundária observada em pastagens fertilizadas com altas taxas de nitrogênio é atribuível a flutuações no valor nutricional ou nas características estruturais das pastagens, ou em ambas. Objetivou-se identificar grupos de caraterísticas (estruturais e nutricionais) que melhor explicassem o desempenho de novilhos de corte em pastos de capim-mombaça sob efeito residual de doses de nitrogênio. Os dados foram coletados em pastos de capim-mombaça que receberam três doses anuais de nitrogênio (N) (100, 200 e 300 kg ha-1) de 2015 a 2017. No ano de 2018 não foi utilizada adubação nitrogenada, para caracterizar o efeito residual do nutriente. As variáveis avaliadas foram relacionadas às características estruturais, taxa de acúmulo de forragem (TAF), altura do dossel, massa de forragem (MF) e dos componentes morfológicos. Também foi avaliado o valor nutritivo da lâmina foliar e o desempenho dos novilhos através do ganho médio diário (GMD) e da taxa de lotação. A partir do banco de dados foi realizada a análise de componentes principais. Os resultados demonstraram que 99,6% da variação no conjunto de dados foram explicados por apenas dois componentes principais (CPs), e 90,0% desse valor corresponde ao CP1. As características de maior magnitude para a diferenciação dos tratamentos no CP1, em ordem de prioridade foram: TAF, MF, massas de lâmina foliar e de colmo. Essas variáveis estiveram positivamente associadas com a taxa de lotação. Já o GMD não se relacionou com nenhuma variável. O GMD foi a variável de maior importância para o segundo CP, entretanto, esse CP teve pouca contribuição (9,6%) para a elucidação do resultados. As características estruturais (TAF e MF e compondes morfológicos) do pasto explicam melhor as oscilações em pastos de capim-mombaça sob efeito residual de doses de nitrogênio. A taxa de lotação é um parâmetro eficiente para apoiar a tomada de decisão em pastos manejados com lotação variável.
RESUMEN
The aim was to evaluate the impact of supplementation with different protein sources from agro-industrial production on the parasitological profile of ovine matrices and the development of their offspring. The protein sources used were: soybean bran, cotton pie, babassu pie, and coconut pie. A total of 60 ovine matrices were used, with confirmed pregnancy and supplemented in the final third of gestation at 0.5% of live weight in pastures of deferred Marandu grass. The evaluations occurred from the final third of gestation and in the lactation phase until weaning. The data collected in the matrices were: counting of eggs per gram of feces (EPG) and identification of infective larvae (Faecal test), evaluation of the degree of anemia by the FAMACHA© method, body weight (kg), and body condition score (BCS). In the lambs, the biometric measurements were taken from the 30 days of life until weaning. In Faecal test, the prevalence was 98% of Haemonchus spp. There was no effect of the protein sources for EPG (3476.0) and FAMACHA©. However, in the mats supplemented with coconut pie were observed the lowest body weights (36.9 kg) and lower BCS (2.7). Babassu, coconut and cotton cakes, and soybean meal used as a protein source in the supplementation of ovine matrices kept in deferred pastures of Marandu grass at the 0.5% level of live weight maintain the production indexes consistent with the physiology stage of the matrices even with a high endo-parasitic load.
O objetivo foi avaliar o impacto da suplementação com diferentes fontes proteicas da produção agroindustrial no perfil parasitológico das matrizes ovinas e no desenvolvimento de seus filhotes. As fontes de proteína utilizadas foram: farelo de soja, torta de algodão, torta de babaçu e torta de coco. Foram utilizadas 60 matrizes ovinas, com prenhez confirmada e suplementadas no terço final da gestação com 0,5% do peso vivo em pastagens de capim Marandu diferido. As avaliações ocorreram desde o terço final da gestação e na fase de lactação até o desmame. Os dados coletados nas matrizes foram: contagem de ovos por grama de fezes (OPG) e identificação de larvas infectantes (teste fecal), avaliação do grau de anemia pelo método FAMACHA ©, peso corporal (kg) e escore de condição corporal (ECC). Nos cordeiros, as medidas biométricas foram realizadas a partir dos 30 dias de vida até o desmame. No teste fecal, a prevalência foi de 98% de Haemonchus spp. Não houve efeito das fontes de proteína para OPG (3476,0) e FAMACHA ©. No entanto, nas matrizes suplementadas com torta de coco foram observados os menores pesos corporais (36,9 kg) e menorECC (2,7). Torta de Babaçu, coco, algodão e farelo de soja utilizados como fonte protéica na suplementação de matrizes ovinas mantidas em pastos diferidos de capim Marandu no nível de 0,5% de peso vivo mantêm os índices de produção consistentes com o estágio fisiológico das matrizes, mesmo com uma carga endo-parasitária alta.
Asunto(s)
Ovinos , Proteínas , HelmintosRESUMEN
The research submitted samples from stems and leaf blades from tree genotypes of Pennisetum purpureum called 93-32-02, 92-70-02, and 91-06-02 (EMBRAPA - Dairy cattle) and elephant grass cv. Napier (reference cultivar) to the chemical, anatomical evaluations, and in vitro dry matter digestibility (IVDMD) measurement. The anatomical characteristics of the stems and leaf blades, the chemical composition, and the IVDMD of these genotypes at 70 days of re-growth were correlated. Concerning IVDMD, the data highlighted differences, and the cultivar Napier presented the smallest value. Digital images obtained by light microscopy from cross-section reveal that all the stem and leaf blade have similar structural organization. Quantitative differences were verified mainly in the stem. The leaves displayed differences only in the mesophyll thickness. The genotypes showed higher potential in the rainy season since they had the largest IVDMD when compared to the cultivar Napier.
Asunto(s)
Pennisetum/anatomía & histología , Pennisetum/clasificación , Pennisetum/genética , Pennisetum/metabolismo , Valor NutritivoRESUMEN
The objective of this study was to evaluate the structural and productive features of Panicum maximum cultivars (Tanzânia, Mombaça, Massai, and Zuri) in three rest periods (30, 45 and 60 days), in the semiarid region of Brazil. The experiment was carried out in a completely randomized design with three replicates. The length of the leaf blade and the diameter of the stem increased as a function of the cut intervals. Leaf blade width and number of live leaves (3.86 leaves tiller-1) were not affected by cut intervals. The height of the canopy increased with the ages, with effect in the mass of forage, being the cv. Zuri the most productive with 148,75 cm e 18.297,49 kg ha-1 DM at 60 days. The highest masses of leaves and stems were obtained in the longest rest period, while the leaf/stem ratio decreased. In the cut-off interval of 45 days, the cultivars of Panicummaximum have shown satisfactory yield, and the smaller cut interval provides a reduction in canopy height and stem thickness.
Objetivou-se avaliar as características estruturais e produtivas de cultivares de Panicum maximum (Tanzânia, Mombaça, Massai e Zuri) em periodos de descanso (30, 45 e 60 dias) no semiárido brasileiro, sob irrigação. O experimento foi realizado em delineamento inteiramente ao acaso, com trêsrepetições. O comprimento da lâmina foliar e o diâmetro do colmo aumentaram em função dos intervalos de corte. A largura da lâmina foliar e o número de folhas vivas (3,86 folhas/perfilho) não foram afetados pelos intervalos de corte. A altura do dossel aumentou com as idades, com efeito na massa de forragem, sendo a cv. Zuri superior com 148,75 cm e 18.297,49 kg/ha de MS, aos 60 dias. As maiores massas de lâminas e colmos foram obtidas no maior período de rebrotação, enquanto que a relação folha/colmo diminuiu. No intervalo de corte de 45 dias, as cultivares de Panicum maximum apresentaram produção satisfatória, sendo que o menor intervalo de corte proporciona redução na altura do dossel e na espessura do colmo
Asunto(s)
Zona Semiárida , Riego Agrícola , PanicumRESUMEN
The objective of this study was to evaluate the biometry and carcass characteristics of finished Santa Inês crossbred sheep grazed on tropical grass pastures during the dry season. The study was carried out at the Grupo de Estudos em Forragicultura (GEFOR/UFRN), in Macaíba RN, Brazil. Four forage treatments were evaluated: Brachiaria brizantha cvs. Marandu e Piatã, Panicum maximum cvs. Aruana e Massai. The 2.88 ha-area used was divided in two blocks of 1.44 ha; each one was composed of four plots corresponding to each cultivar, and each plot was subdivided into six paddocks with an area of 0.06 ha. The pastures were managed under intermittent stocking with seven days of occupation and 35 days of rest, with variable stocking rate. No significant difference was observed in the biometric measurements evaluated in the animals, except for chest width in which animals kept in Marandu pastures obtained higher values than those in the Aruana cultivar. The lowest values of average daily gain, final weight and weight at slaughter values were observed in the animals kept in Aruana cultivars. Cut weights of the shoulder, the loins, short legs/shanks and ribs were higher in the animals kept in Marandu grass and lower in those kept in the Aruana grass; however, no differences were observed for the yield of the cuts and for the biometric measurements of the carcass. The evaluated pasture cultivars did not modify the finished sheep carcasses, however, the lower forage mass from Aruana grass pastures in the dry season affected animal performance and the sheep carcass composition.
Objetivou-se avaliar a biometria e as características da carcaça de ovinos mestiços de Santa Inês terminados em pastos de gramíneas tropicais na época seca. O trabalho foi realizado no Grupo de Estudos em Forragicultura (GEFOR/UFRN), em Macaíba RN, Brasil. Os tratamentos avaliados foram quatro forrageiras: Brachiaria brizantha cvs. Marandu e Piatã, Panicum maximum cvs. Aruana e Massai. A área utilizada foi de 2,88 ha dividida em dois blocos de 1,44 ha, onde cada um desses foi constituído de quatro parcelas correspondente a cada cultivar, e cada parcela subdivida em seis piquetes com área de 0,06 ha. Os pastos foram manejados sob lotação intermitente com sete dias de ocupação e 35 dias de descanso, com taxa de lotação variável. Não houve diferença significativa nas medidas biométricas avaliadas nos animais, exceto para a largura do peito, em que os animais mantidos nos pastos da cultivar Marandu obtiveram valores maiores que aqueles da cultivar Aruana. Os menores valores de ganho médio diário, peso final e peso ao abate foram observados nos animais mantidos na cultivar Aruana. Os pesos dos cortes paleta, lombo, pernil e costela foram maiores nos animais mantidos no capim-marandu e menores naqueles mantidos no capim-aruana, porém não foram observadas diferenças para o rendimento dos cortes e para as medidas biométricas na carcaça. As cultivares avaliadas não modificam as carcaças de ovinos terminados em pasto, porém a menor massa de forragem dos pastos da cultivar Aruana na época seca comprometem o desempenho animal e a composição das carcaça de ovinos.
Asunto(s)
Ovinos , Biometría , Brachiaria , PanicumRESUMEN
This study aimed to evaluate productive and structural parameters of Piatã and Marandu cultivars submitted to two grazing intensities. The experimental design was in randomized blocks with treatments in a 2 x 2 factorial arrangement (Marandu and Piatã palisadegrass x 25 and 30 cm residual heights). Intermittent stocking grazing method was used. Non-defined breed sheep were used as defoliation agents. Interaction between cultivars and height was not significant for any of the variables. In pastures managed at 25 cm post-grazing, a greater regrowth period was observed. Forage mass was on average 27% higher in Marandu palisadegrass in relation to Piatã palisadegrass, regardless of height. Dead material accumulation was higher in the Marandu cultivar. There was no difference in mass between the cultivars and heights for leaf blade or stem before and after grazing. The highest population density of tillers was observed in pastures lowered to 25 cm post-grazing height, with no difference between cultivars. In the third generation the appearance of tillers was higher in pastures managed at 25 cm. Post-grazing heights of 25 and 30 cm do not change pasture structure in Piatã and Marandu cultivars in pre-grazing; however, it is possible to obtain a shorter regrowth period if managed at 30 cm.
Objetivou-se avaliar parâmetros produtivos e estruturais das cultivares Piatã e Marandu submetidas a duas intensidades de pastejo. O delineamento experimental foi em blocos ao acaso, com os tratamentos em arranjo fatorial 2 x 2 (Marandu e Piatã x 25 e 30 cm de alturas de resíduo). O método de pastejo empregado foi o de lotação intermitente. Como agentes de desfolhação foram utilizados ovinos sem padrão racial definido. A interação entre cultivar e altura não foi significativa para nenhuma das variáveis. Nos pastos manejados a 25 cm de altura no pós-pastejo foi observado maior período de rebrotação. A massa de forragem foi em média, 27% maior no capim-Marandu em relação ao capim-piatã, independentemente da altura. O acúmulo de material morto foi maior na cultivar Marandu. Não houve diferença nas massas entre as cultivares e alturas para de lâmina foliar e colmo no pré e pós-pastejo. A maior densidade populacional de perfilhos foi observada em pastos rebaixados a 25 cm de altura pós-pastejo, sem diferença entre as cultivares. Na terceira geração o aparecimento de perfilhos foi superior nos pastos manejados a 25 cm. As alturas de pós-pastejo de 25 e 30 cm não modificam a estrutura dos pasto das cultivares de Piatã e Marandu no pré-pastejo, porém manejados a 30 cm é possível obter menor tempo de rebrotação.
Asunto(s)
Ovinos , Pastizales , BrachiariaRESUMEN
This paper aimed to evaluate the dynamics of tillering, tiller density and structural characteristics of Brachiaria brizantha, Panicum maximum and Cenchrus ciliaris under a cutting regime. The utilized design was randomized blocks with six treatments (cultivars) and three replications. The evaluations were conducted from May to September 2011, with the data grouped into two periods, rainy season and beginning of the dry season. The greatest tiller population density was observed in the Massai cultivar, averaging 1,019 tillers.m-2. The tiller mortality rate was higher for Mombaça and less for Piatã cultivars. The highest values for forage mass, percentage of leaf blades and relations between green mass:dead mass were observed in Brachiaria brizantha and Panicum maximum cultivars. Panicum and Brachiaria cultivars have shown to be promising for cultivation in the transition areas between the Atlantic Forest and Caatinga biomes in Northeastern Brazil. Cenchrus cultivars are less productive in environments without restriction of abiotic factors.
Objetivou-se avaliar a dinâmica de perfilhamento, a densidade populacional de perfilhos e as características estruturais de cultivares de Brachiaria brizantha, Panicum maximum e Cenchrus ciliaris em regime de corte. O delineamento utilizado foi em blocos ao acaso com seis tratamentos (cultivares) e três repetições. As avaliações foram realizadas de maio a setembro de 2011, sendo os dados agrupados em dois períodos, águas e início da seca. A maior densidade populacional de perfilhos foi observada na cultivar Massai com média de 1019 perfilhos/m2. A taxa de mortalidade de perfilhos foi maior na cultivar Mombaça e menor na Piatã. Os maiores valores para massa de forragem, percentual de lâminas foliares e relações entre massa verde:massa morta foram observados nas cultivares de Brachiaria brizantha e Panicum maximum. As cultivares de Panicum e Brachiaria se mostraram promissoras à utilização em áreas de transição entre os biomas de Mata Atlântica e Caatinga na Região Nordeste do Brasil. As cultivares de Cenchrus são menos produtivas em ambientes sem restrição de fatores abióticos.
Asunto(s)
Brachiaria , Cenchrus , Poaceae , PanicumRESUMEN
The ingestive behavior of sheep supplemented with concentrate in Brachiaria brizantha and Panicum maximum pastures were evaluated during the dry season. Twenty four male sheep of ½ Santa Inês x ½ undefined breed genotypes were used. The treatments were four feeds of cultivar grasses: B. brizantha cvs. Marandu and Piatã, P. maximum cvs. Massai and Aruana. The ingestive behavior of the animals was recorded during two periods of 24 hours. The grazing time, rumination, idleness (minutes day-1), bite rate (bites minute-1), and the frequency of the animals activities in relation to defecation, urination and search for water, concentrated and mineral salt were observed. There was interaction between time of the day and evaluated cultivars based on the grazing time and bite rate response. Sheep grazing on marandu-grass showed higher grazing time between 11 am to 4 pm (257 minutes), compared to animals grazing on aruana-grass (217 minutes). The bite rate was higher for sheep on massai-grass between 11 am to 4 pm (34.32 bits minute- 1). There was no grass effect for idleness and rumination, which can highlight the similarity of chemistry characterization and high percentage of structural components in evaluated pastures. The structural limitations and feed mass composition in the dry season caused effects on the ingestive behavior of idleness and bite rate of supplemented sheep in Brachiaria and Panicum pastures.
Avaliou-se o comportamento ingestivo de ovinos, suplementados com concentrado, em pastos de Brachiaria brizantha e Panicum maximum durante a época seca. Foram utilizados 24 animais, machos inteiros do genótipo ½Santa Inês x ½ sem padrão racial definido. Os tratamentos corresponderam a quatro cultivares de gramíneas forrageiras, sendo B. brizantha cultivares. Marandu e Piatã e P. maximum cultivares. Massai e Aruana. O comportamento ingestivo dos animais foi registrado durante dois períodos de 24 horas. Observou-se o tempo de pastejo, ruminação, ócio (minutos/dia), taxa de bocados (bocados/minuto) e a frequência dos animais em relação à defecação, micção e busca pela água, concentrado e suplemento mineral. Houve interação entre o período do dia e as cultivares avaliadas sobre as respostas de tempo de pastejo e taxa de bocado. Os animais sob pastejo no capim-marandu apresentaram maior tempo de pastejo no período de 11-16h (257 minutos) em relação aos animais do capim-aruana (217 minutos). A taxa de bocados foi maior para os animais do grupo do capim-massai no período 11-16h (34,32 bocados/minuto). Não houve efeito de tratamento para as variáveis de ócio e ruminação, o que pode evidenciar a semelhança da caracterização química e elevada porcentagem de constituintes estruturais nos pastos avaliados. As limitações estruturais, de composição e massa de forragem na época seca provocam efeitos sobre as variáveis de comportamento ingestivo de ovinos suplementados em pastos de Brachiaria e Panicum.
Asunto(s)
Ovinos , Pastizales , Brachiaria , Panicum , Fenómenos Fisiológicos Nutricionales del LactanteRESUMEN
Objetivou-se avaliar e as características morfogênicas e o acúmulo de forragem de três gêneros de gramíneas, Brachiaria, Panicum e Cenchrus em regime de corte. O delineamento utilizado foi em blocos ao acaso com parcelas subdivididas. Houve efeito de interação entre cultivar e época de avaliação para a taxa de aparecimento de folhas, alongamento de colmos, duração de vida das folhas e senescência de folhas. As cultivares Áridus e Biloela (Cenchrus) apresentaram os menores Filocronos, seguidos da cultivar Piatã (B. brizantha). A taxa de alongamento de folhas e seu comprimento final foram maiores no período das chuvas, para todas as cultivares. As cultivares Massai e Mombaça apresentaram os maiores comprimentos de folha, mas os menores números de folhas vivas por perfilho. As cultivares Áridus e Biloela as menores taxas de acúmulo de lâminas foliares em relação ás demais. O maior fluxo de tecidos observado no gênero Cenchrus, não foi suficiente para superar a maior de produtividade das cultivares dos gêneros Panicum e Brachiaria.
This study aimed to evaluate the accumulation of forage and the morphogenesis of three genera Brachiaria, Cenchrus and Panicum in cutting regime. The experimental design was a randomized block with three replicates and six treatments. After each cut were evaluated for forage production, appearance and elongation rates of leaves and stem final leaf length, number of green leaves, leaf life span, rate of senescence of leaves. For herbage accumulation rate was higher in the cv. Xaraes, which is more than double the cumulative cv. Aridus, the lowest rate among cultivars. As for leaf appearance rate and leaf elongation was higher in the rainy season only for cultivars Aridus Biloela and the other showed no difference between the evaluation periods. Cultivars Aridus, Biloela and Piata obtained the highest number of leaves per tiller, differing from Mombaça, Massai and Xaraes that showed the lowest values. The lower values of leaf life span were found in the rainy season to cultivate Aridus, Biloela and Mombaça. Except Aridus, which showed a higher rate of senescence of leaves in the rainy season, others grasses did not differ between the evaluation periods. We conclude that the highest rates of leaf appearance and number of green leaves found on the cultivars of the genus Cenchrus, were not enough to overcome the greatest potential for producing forage cultivars of the genera Panicum and Brachiaria. The grasses tested showed potential for use in the Northeast, but were influenced by seasons, mainly due to a decrease in rainfall.
Asunto(s)
Brachiaria , Cenchrus , Poaceae , PanicumRESUMEN
The purpose of this study was to evaluate the performance of sheep in different tropical forages and the structure of the canopy and chemical composition of pasture. The treatments consisted of two cultivars of Panicum, Massai and Aruana and two of Brachiaria, Marandu and Piatã under intermittent capacity and variable stocking rate, in the rainy season. Santa Inês intact male sheep were used. The greatest leaf blade mass and leaf blade:stem ratio for cv. Massai were observed in the pre- and post-grazing. The harvest efficiency of leaf blades and stem did not differ among cultivars. In both components of cvs. Marandu and Piatã showed the lowest NDF level. The highest crude protein value in stem and leaf blade were observed in Aruana and Marandu cultivars. Marandu also presented the highest in vitro dry matter digestibility of leaf blades. Animals kept in Aruana pastures had the highest average daily gain. The highest stocking rates and animal yield per area were observed in the pastures of cv. Massai and Marandu. The grasses are able to produce satisfactory results for sheep production on pasture under exclusive system in the northeastern Brazil during the rainy season.
Objetivou-se com esse estudo avaliar o desempenho de ovinos em diferentes forrageiras tropicais e a estrutura do dossel e composição química do pasto. Os tratamentos constituíram de duas cultivares de Panicum, Massai e Aruana e duas de Brachiaria, Marandu e Piatã, sob lotação intermitente e taxa de lotação variável, na época das águas. Foram utilizados ovinos machos não emasculados da raça Santa Inês. No pré e póspastejo foram observadas as maiores massas de lâminas foliares e relação lâmina foliar:colmo para a cv. Massai. As eficiências na colheita de lâminas foliares e colmos não deferiram entre as cultivares. Em ambos os componentes das cvs. Massai e Piatã foram obtidos os maiores teores de FDN. Os maiores teores de proteína bruta no colmo e na lâmina foliar foram observados nas cvs. Aruana e Marandu, esta também com a maior digestibilidade in vitro da matéria seca das lâminas foliares. Os animais mantidos nos pastos de aruana obtiveram os maiores ganhos médios diários. As maiores taxas de lotação e ganhos por área foram observadas nos pastos das cvs. Massai e Marandu. As gramíneas são capazes produzir resultados satisfatórios para ovinocultura sob sistema exclusivo em pasto na região Nordeste durante a época das águas.
Asunto(s)
Ovinos , Pastizales , Brachiaria , Industria Agropecuaria , PanicumRESUMEN
Objetivou-se com este estudo avaliar o acúmulo de forragem e as características estruturais do dossel de gramíneas forrageiras tropicais sob lotação intermitente na época das águas. Os tratamentos constituíram de quatro cultivares de gramíneas: Aruana, Marandu, Massai e Piatã pastejadas por ovinos sob lotação intermitente. Foram avaliadas as massas e os componentes da forragem no pré-pastejo em dois estratos, de 0-25 e de 25-50 cm, e no pós-pastejo; e o acúmulo de forragem. Não houve diferença entre os períodos de ocupação e de descanso entre as cultivares, para as variáveis avaliadas. A cv. Massai obteve a maior massa seca de forragem (MSF) nos dois estratos, além da maior densidade volumétrica (DV) e massa de material morto (MMM) no estrato 0 a 25 cm. No pós-pastejo dos pastos de Massai foram observadas as maiores MSF, DV e MMM. Os maiores acúmulos e taxa de acúmulo de lâminas foliares foram observados nos pasto de Massai. O pré-pastejo a 50 cm para as cultivares avaliadas, resulta em valores elevados para massa e proporção dos componentes de colmo e/ou material morto no dossel, além de excesso de forragens no pós-pastejo. As cultivares avaliadas são produtivas e adequadas para cultivo na região Nordeste, apresentando resultados de taxas de acúmulos de forragem e de lâminas foliares próximos a produção em outras regiões do Brasil.
The objective of this study was to evaluate the structural characteristics of canopy and herbage accumulation of tropical forage under intermittent stocking in the rainy season. Treatments consisted of four cultivars of grasses: Aruana, Marandu, Massai and Piata grazed by growing sheep. The masses and the grass components were evaluated on the pre-grazing in two layers, 0-25 and 25-50 cm, on the residual herbage; and forage accumulation. There was no difference between the periods of occupation and rest among cultivars. The cv. Maasai had the highest herbage dry matter (MSF) in two strata, the highest density (HD) and mass of dead material (MMM) in 0-25 cm. In the residual mass of Massai were observed the biggest MSF, DV and MMM. The highest accumulation rate and leaf accumulation was observed in Massai guineagrass. The pre-grazing height of 50 cm resulting in high mass components and proportions of stem and/or dead material in the canopy, and high forage mass in the residue. The cultivars are productive and suitable for cultivation in the Northeast region, showing good results for rates of accumulation of forage and leaf blades.