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The objective of this study was to evaluate the effects of different concentrate supplementation strategies to lactating F1 Holstein x Zebu cows managed on deferred signal grass pasture on milk yield, composition and body weight gain. Thirty-six F1 Holstein x Zebu cows with average days in milk of 102 ± 10 and body weight of 501 ± 19 kg were allotted to a 4 x 5 completely randomized factorial design, with four feeding strategies and five weeks of evaluation. The treatments consisted of four nutritional strategies: deferred pasture as a source of roughage + 700 grams of protein supplement (PDPI); deferred pasture as a source of roughage + 1,200 grams of protein supplement (PDPII); deferred pasture + 15 kilograms of corn silage (natural basis) + 1,200 grams of protein supplement (PDSP) and corn silage (ad libitum) + 700 grams of protein supplement (CSS). There was no interaction (P = 0.99) between supplementation strategies and test days on milk yield and chemical composition. The mean milk yield of cows managed on PDPI, PDPII and PDSP was 11.50 kg/day (P > 0.05), which was 14.30% lower than that of cows managed on CSS. Fat content (P < 0.01), protein (P < 0.01), lactose (P < 0.01), defatted dry extract (DDE) (P< 0 .01), total solids (P < 0.01) and milk casein (P < 0.01) were affected by different supplementation strategies. F1 Holstein x Zebu cows on deferred Urochloa decumbens cv. Basilisk pasture and supplemented with concentrate maintains milk production at 11.50 kg with normal composition, maintaining satisfactory body weight and condition score.

Objetivou-se com o presente estudo avaliar o desempenho produtivo e valor nutricional da forragem de cultivares de trigo e triticale em diferentes épocas de colheita no semiárido Mineiro. Foram avaliados oito cultivares de trigo e duas cultivares de triticale colhidas em três estádios de desenvolvimento das plantas: no Emborrachamento, grão no estádio de massa macia e maturação de colheita. O delineamento experimental adotado foi em blocos ao acaso em esquema fatorial 10×3, com três repetições sendo 10 cultivares e 3 estádios de desenvolvimento para colheita das plantas. Foram avaliadas as principais características agronômicas e o valor nutricional da forragem das cultivares em estudo. A pesquisa demonstrou o potencial do cultivo do trigo e triticale para forragem no semiárido de Minas Gerais. A produtividade média de matéria seca das cultivares de trigo foi de 5,90 t ha-1, 7,85 t ha-1 e 7,98 t ha-1 e triticale 6,47 t ha-1, 9,97 t ha-1 e 10,5 t ha-1 para os estádios de colheita de emborrachamento, grão no estádio de massa macia e maturação de colheita respectivamente. Para os teores médios de proteína bruta as cultivares de trigo apresentaram 15,07%, 9,13%, 10,60% e as cultivares de triticale 14,4%, 9,31% e 10,05% para os estádios de colheita de emborrachamento, grão no estádio de massa macia e maturação de colheita respectivamente. Ao se avaliar os teores médios de nutrientes digestíveis totais as cultivares de trigo e triticale apresentaram média de 48,90% e 48,67% no estádio de colheita de emborrachamento, 42,68% e 49,60% no grão no estádio de massa macia e 44,43% e 42,90% na maturação de colheita. A maior produtividade de matéria seca digestível foi observada com as cultivares colhidas no estádio de grão no estádio de massa macia. O Triticale IPR 111 e o Trigo IPR PANATY tiveram maior potencial produtivo e melhor qualidade nutricional para uso como forragem.

This trial aimed to analyze the replacement of forage sorghum silage (FS silage) with biomass sorghum silage (BRS 716 silage) in diets for heifers ¾ Holstein x ¼ Zebu on their nutrient intake and digestibility, nitrogen balance, microbial production, feeding behavior, and animal performance. Eight heifers with average age 18±4 months (mo) and average body weight (BW) 271 ± 57 kg were used. The experimental design was double-Latin square, 4×4, being four diets, four experimental periods and four animals. Four experimental diets with 0, 33, 67 and 100% substitution of forage sorghum silage with biomass sorghum silage were used. The roughage:concentrate ratio in the total dry matter (DM) of the diets was 75:25. The fraction “b” of DM was higher in the BRS 716 silage. There was no difference (p> 0.05) for dry matter intake (DMI; p = 0.45) and total digestible nutrients intake (p = 0.76). The dry matter digestibility (DMD), crude protein, ether extract and neutral detergent fiber increased linearly with the inclusion of BRS 716 silage. The feeding times, ruminating and idle have not been changed (p > 0.05). The replacement of FS silage with BRS 716 silage did not modify the average daily weight gain (ADG; p > 0.05; mean 1.30 ± 0.025 kg). Biomass sorghum silage can replace up to 100% forage sorghum silage in the diets of ¾ Holstein x ¼ Zebu heifers.

ABSTRACT The objective of this study was to evaluate the effects of wilting times and application of an enzymatic-bacterial inoculant on the fermentative profile and nutritional characteristics of BRS capiaçu grass silage in a semi-arid region. Four wilting times treatments (control, 6, 24, and 30 h), with or without the addition of an enzymatic-bacterial inoculant, were analyzed as a split-plot completely randomized design with eight replications. Parameters of the rumen degradability test were analyzed using a split-plot completely randomized block design with four replications. There was no interaction between wilting times and inoculant application on pH, ammoniacal nitrogen (NH3-N), and aerobic stability of BRS capiaçu silage. Aerobic stability was reduced by 1.2 h for every 1-h increase in wilting time. Inoculant application reduced the pH values by 2.59% and extended the aerobic stability of the silage by 19 h. There was a significant interaction of wilting times and inoculant application on the levels of malic, succinic, lactic, and acetic acids. Inoculant application increased the contents of dry matter, ash, crude protein, insoluble neutral detergent fiber, and total carbohydrates by 3.63, 6.13, 7.73, 6.39, and 9.97% compared with non-inoculated silages, respectively. Wilting times for up to 30 h and application of enzymatic-bacterial inoculant improves the fermentative profile and chemical composition and reduces dry matter losses of silage of BRS capiaçu grass harvested at 100 days of regrowth.

The objective of this study was to evaluate the effects of two grazing management strategies on structural, productive and nutritional parameters of Marandu grass (Urochloa brizantha cv. Marandu). A completely randomized block design with two pasture management strategies and eight replications (blocks) was used. The grazing management strategies were: (1) low intensity rotational grazing (LI), with a pre-grazing sward height of 40 cm and a post-grazing sward height of 24 cm, i.e., a defoliation intensity of 50%; (2) High intensity rotational grazing (HI), with a pre-grazing sward height of 40 cm and a post-grazing sward height of 10 cm (±70% defoliation intensity). Pastures were sampled before and after grazing for estimation of forage mass, forage accumulation rate, structural characteristics, nutritional value and dry matter intake. The LI strategy resulted in higher dry matter production than HI before (18.33%) and after grazing (49.06%), increasing pre-grazing forage density by 13.21% (P < 0.05). The production of potentially digestible dry matter was highest (P < 0.05) in LI strategy (21.3% before and 39.6% after grazing, respectively). Higher post-grazing green forage mass (45%) increased the residual crude protein in LI. The LI management strategy increased forage mass production and can be used in Marandu grass pastures.

The objective of this study was to evaluate the effect of bacterial-enzymatic inoculants with different concentrations of fibrolytic enzymes on the fermentation quality and nutritional value of the silage of BRS capiaçu grass. Two bacterial-enzymatic inoculants with different levels of enzyme complex were evaluated (Silotrato® (5%) and Biotrato® (8%)) and control silage (without additive) according to a completely randomized design with eight replicates. To evaluate the silage aerobic stability, a completely randomized split plot design was used with three treatments (plots) and seven times after opening (subplots). There was no interaction between treatments and times after opening on values of pH (P=0.79). Regarding bacterial-enzymatic inoculants, the silage pH was 21.66% and 16.16% higher in silage without additive (mean of 6.00) compared to silage with 5% and 8% enzyme complex (P < 0.01). There was no difference between treatments on pH (P = 0.08), lactic acid (p = 0.08) and acetic acid (p = 0.64), means of 3.11, 47.31 g dry matter (DM)-1 and 11.19 g DM-1, respectively. There was no difference between treatments for any of the chemical composition variables (P = 0.86). Mean values for DM, crude protein, neutral detergent fiber and total digestible nutrients were 22.31%, 6.65%, 71.15% and 42.07%, respectively. There was a higher concentration of butyric acid in the control silage compared to Silotrato® silage. The control silage and silage treated with Biotrato® presented effluent losses (P = 0.05) 13.99% higher than silage with Silotrato®. For ensiling BRS capiaçu grass, it is recommended to use lactic acid bacteria containing 5% fibrolytic enzymes.

Objetivou-se avaliar a produtividade, composição químico-bromatológica, degradabilidade ruminal da matéria seca e digestibilidade do Capim-Elefante-BRS capiaçu (Pennisetum purpureum Schum.) manejado em cinco idades de rebrota. Foi utilizado o delineamento inteiramente casualizado com dez repetições, na cultivar BRS capiaçu de capim-elefante submetida a cinco intervalos de corte (30, 60, 90, 120 e 150 dias) no verão, perfazendo um total de 50 parcelas com área útil de 4 x 2 m. Foram verificados incrementos diários na produção de matéria seca na ordem de 382 kg ha-1, sendo 49.859 kg ha-1 a produção aos 150 dias de rebrota. O teor de matéria seca e matéria orgânica aumentaram (P < 0,01) linearmente nas diferentes idades de rebrota. O teor de proteína bruta, digestibilidade in vitro da matéria seca e digestibilidade in vitro da fibra em detergente neutro reduziram (P < 0,01) linearmente de 0.037%, 0.196% e 0.256% por dia, respectivamente. A degradabilidade potencial da matéria seca reduziu de 68.9% aos 30 dias para 44.7% com 150 dias de rebrota (0.194 unidades percentuais por dia). A taxa de degradação da fração B ‘c’ não foi modificada (P=0.94), média de 1.46% hora-1. No cultivo do Capim-Elefante BRS capiaçu na estação verão, na região norte de Minas Gerais, recomenda-se a idade para colheita entre 90 e 120 dias de rebrota.

ABSTRACT The objective of this study was to evaluate the effect of quantitative feed restriction level on nutrient intake and digestibility, nitrogen balance, efficiency and feeding behavior, and productive performance of F1 Holstein × Zebu cows in late lactation. Sixty F1 Holstein × Zebu cows were used at the stage of late lactation (183.0±17.5 days of lactation) and with initial body weight (BW) of 499±30 kg. The experimental arrangement adopted was the completely randomized design, with five feed restriction levels (3.39, 2.75, 2.50, 2.25, and 2.00% of BW) and twelve cows as replicates for each treatment. The roughage:concentrate ratio was of 75:25 in the total dry matter of the diet. The restriction of dietary supply from 3.39 to 2.0% of BW linearly reduced dry matter intake by 51.74%. The restriction in diet supply linearly increased dry matter digestibility in 13.76%. For each 1% BW restriction in the diet supply for the animals, there was a linear reduction of 3 h in feeding time. Restriction in diet supply of crossbred cows from 3.39 to 2.0% of BW reduced milk production by 24.84%. For each 1% restriction on supply, 2.17 L of milk were not produced. Milk production corrected to 3.5% fat was not altered with the feed restriction. Final BW decreased 41 kg for each percentage unit of diet restriction. Feed efficiency increased 28.72% with feed restriction. For F1 Holstein × Zebu cows in the late lactation, the restriction of dietary supply up to 2.0% of body weight decreases nutrient intake, nitrogen balance, rumination time, and milk production; however, it improves nutrient digestibility and feed efficiency of the animals.

This study aimed to evaluate the structural, productive and nutritional characteristics of cactus pear (Nopalea cochenillifera Salm Dyck. cv. Miúda/Doce) under five nitrogen doses and two planting orientations. A randomized block design in a 5 x 2 factorial scheme was used in the scheme: five nitrogen doses (0, 150, 300, 450 and 600 kg of N ha-1), and two planting orientations (North/South and East/West), with three replicates. Except for the thickness of the secondary (p = 0.04) and tertiary cladodes (p = 0.02), the morphometric characteristics of the cactus pear were not influenced by the nitrogen doses (p > 0.05). The mean height was 120 cm, the areas of the primary, secondary and tertiary cladodium were 160.9; 208 and 158.4 cm², respectively. The application of nitrogen fertilizer, in the dry conditions and doses evaluated, did not affect the production of green matter (PGM, p = 0.56), dry matter (PDM, p = 0.74) and dry matter content (DM, p = 0.72), with averages of 276 t ha-1, 43.2 t ha-1 and 15.7%, respectively. The increase of the nitrogen doses does not improve the majority of the morphometric characteristics or the dry matter yield of the cactus pear cv. Miúda at 730 days after planting.

The objective of this study was to evaluate the yield, nutritional value and potential ruminal degradation of Tifton 85 hay (Cynodon spp.) harvested at four regrowth ages (28, 35, 42 and 49 days) and fertilized with two nitrogen doses (N; 100 and 300 kg N ha-1). The experimental design was a randomized block design, arranged in a 4 x 2 factorial scheme, with six replications each. Nitrogen fertilization increased (p < 0.05) dry matter yield and digestible dry matter production of hay and also lignin and crude protein contents. Nitrogen fertilization increased (p < 0.01) the dry matter yield and the digestible dry matter production of hay, as well as lignin (p = 0.01) and crude protein (p = 0.01). The neutral detergent fiber corrected for ash and protein (p = 0.01), acid detergent fiber (p = 0.01) and cellulose (p = 0.02) adjusted to the quadratic function regression model of the regrowth ages. For potential rumen degradability hay, it was observed quadratic effect (p = 0.01) with maximum value of 73.1% at 37 days of regrowth. Tifton 85 hay fertilized with 300 kg ha -1 of N and harvested up to 37 days of regrowth results in higher hay dry matter yield, higher crude protein content, and better dry matter rumen degradability.

The objective of this study was to evaluate grazing management strategies of Brachiaria decumbens cv. Basilisk managed with different heights under continuous grazing with cattle. Two grazing management strategies were evaluated: maintenance of pasture with an average height of 25 cm throughout the experimental period and maintenance of pasture on the average of 15 cm in height during winter, up to 25 cm from the beginning of spring. The split-plot scheme and the randomized block design with four replications were adopted. The grazing management strategies corresponded to the primary factor, while the seasons (winter, spring and summer) corresponded to secondary factor. The reduction of the average sward height to 15 cm in the winter resulted, when compared with pasture maintained at 25 cm, in overall higher growth rates (95 kg/ha.day DM) and leaf blade (66.1 kg/ha.day DM), as well as higher rates of total accumulation (81.5 kg/ha.day DM) and leaf blade (52.6 kg/ha.day DM). The accumulated forage production (from winter to summer) was higher in the pasture lowered to 15 cm in winter (25.6 t/ha DM) compared with that managed with an average height of 25 cm (22.2 t/ha DM). Regarding the seasons of the year, in the winter, there were lower rates of overall growth (6.4 kg/ha.day DM), leaf blade (5.6 kg/ha.day DM) and pseudostem (0.8 kg/ha.day DM), and also lower total (-6.6 kg/ha.day DM) and leaf blade (-7.5 kg/ha.day DM) accumulation rates. In the spring there was a higher rate of leaf senescence (22.4 kg/ha.day DM). The accumulation of forage is incremented when the pasture of B. decumbens is lowered to 15 cm during the winter, and in the spring and summer, its average height is increased to 25 cm.

This study was conducted to evaluate the defoliation patterns on B. decumbens cv. Basilisk (signalgrass) tiller as a function of influence of feces deposited naturally by cattle. The signalgrass was managed with an average height of 25 cm, under continuous stocking and variable stocking rate. Interval and intensity of defoliation, grazing efficiency and forage loss were evaluated in two sites on pasture - one close and the other distant from feces. The completely randomized block design with three replications was adopted. The defoliation rate of the pasture site close to feces was 40% lower than at that distant from feces. This response pattern was similar to defoliation intensity of leaf blade. The leaf blade of the tiller close to feces also achieved lower de foliation (1.64) than that in the tiller distant from feces (3.97). The relative number of grazed leaf per tiller in the tillers distant from feces was approximately 185% higher than those close to feces. The grazing efficiency was lower in the local close to feces compared with that distant, unlike forage loss. The natural deposition of feces by cattle modifies the grazing and use patterns of B. decumbens under continuous stocking.

Este trabalho foi realizado com o objetivo de identificar estratégias eficazes de manejo do pastejo de Brachiaria decumbens cv. Basilisk, sob lotação contínua, com base em avaliações das suas características morfogênicas e estruturais. Duas estratégias de manejo do pastejo foram estudadas: em uma, o pasto foi mantido com 25 cm de altura média durante todo o período experimental e, na outra, foi mantido em 15 cm de altura média durante o inverno, com aumento para 25 cm a partir do início da primavera. Adotou-se o delineamento de blocos casualizados em esquema de parcelas subdivididas com quatro repetições. Consideraram-se, como fator primário, as estratégias de manejo do pastejo, caracterizadas pelas alturas médias dos pastos durante as estações do ano (inverno, primavera e verão), e, como fator secundário, as estações. O rebaixamento do pasto para 15 cm no inverno resultou em maior taxa de aparecimento foliar (0,02 folha/perfilho.dia) e maior número de folhas vivas (4,5 folhas por perfilho) no inverno, mas provocou redução, no inverno, da duração de vida da folha (66 dias), da taxa de senescência foliar (0,22 cm/perfilho.dia) e dos comprimentos da lâmina foliar (11 cm) e pseudocolmo (15,2 cm) em relação ao pasto com 25 cm. Nesta estação, foram menores os valores observados para as taxas de aparecimento foliar (0,06 folha/perfilho.dia), alongamento foliar (0,110 cm/perfilho.dia) e alongamento de pseudocolmo (0,008 cm/perfilho.dia), número de folha viva (2,9 folhas por perfilho) e comprimentos da lâmina foliar (8,6 cm) e do pseudocolmo (13,5 cm). Por outro lado, a duração de vida da folha (139 dias) e o número de folhas mortas (2,0 folhas por perfilho) foram maiores. O maior valor de taxa de senescência foliar ocorreu na primavera (0,40 cm/perfilho.dia). O pasto de B. decumbens cv. Basilisk sob lotação contínua pode ser manejado de forma sazonal, com rebaixamento para 15 cm no início do inverno e posterior aumento para 25 cm no início da primavera.This study was conducted to identify effective strategies for grazing managing of Brachiaria decumbens cv. Basilisk, under continuous stocking, based on assessments of their morphogenetic and structural characteristics. Two strategies of grazing management were studied: in one, the grass was maintained with 25-cm mean height throughout the experimental period, and in the other, it was 15 cm during the winter, rising to 25 cm from the beginning of spring. The split-plot in randomized block design with four replications was adopted. The strategies of grazing management responded to primary factor, characterized by average heights of pastures during the seasons (winter, spring and summer). The seasons corresponded to secondary factor and consisted of measures over the experimental period. Pasture's lowering to 15 cm in the winter resulted in higher leaf appearance rate (0.02 leaves/tiller.day) and higher number of live leaves (4.5 leaves/tiller) in the winter. However, this management strategy lowered leaf lifespan (66 days), leaf senescence rate (0.22 cm/tiller.day), and length of leaf lamina (11 cm) and stem (15.2 cm) in winter months, in relation to pasture with 25 cm. During this season, rates of leaf appearance (0.06 leaves/tiller.day), leaf elongation (0.110 cm/tiller.day) stem elongation (0.008 cm/tiller.day), live leaves (2.9 leaves/tiller), length of leaf lamina (8.6 cm) and stem (13.5 cm) lowered. On the other hand, leaf lifespan (139 days) and number of dead leaves (2.0 leaves/tiller) were higher. The highest leaf senescence rate occurred in the spring (0.40 cm/tiller.day). The B. decumbens cv. Basilisk pasture under continuous stocking can be managed on a seasonal basis, with decrease to 15 cm in early winter, and further increase to 25 cm in early spring.

Objetivou-se estabelecer estratégias de manejo do pastejo, sob lotação contínua, que otimizem o padrão natural de perfilhamento da Brachiaria decumbens cv. Basilisk. Duas estratégias de manejo do pastejo foram estudadas: em uma, o pasto foi mantido com 25 cm de altura média durante todo o período experimental; e na outra foi mantido em 15 cm de altura média durante o inverno, com aumento para 25 cm a partir do início da primavera. Adotou-se o esquema de parcelas subdivididas em delineamento em blocos casualizados com quatro repetições. Consideraram-se como fator primário as estratégias de manejo do pastejo, caracterizadas pelas alturas médias em que os pastos foram mantidos durante as estações do ano (inverno, primavera e verão) e, como fator secundário, as medidas ao longo do período experimental. A taxa de aparecimento de perfilho (4,7%), a taxa de mortalidade (4,7%) e o índice de estabilidade (0,998) foram menores no inverno. Nesta estação, contudo, a taxa de sobrevivência de perfilho foi maior (95,3%). Em comparação aos pastos mantidos com 25 cm, aqueles manejados com 15 cm de altura média no inverno apresentaram maiores taxas de aparecimento de perfilho (34,2%) e índice de estabilidade (1,065). O florescimento do capim-braquiária ocorreu apenas no verão e com pouca intensidade (0,5%). A otimização da renovação de perfilhos no pasto de B. decumbens cv. Basilisk sob lotação contínua ocorre com seu rebaixamento para 15 cm no início do inverno e seu posterior aumento para 25 cm no início da primavera.The experiment was conducted to establish management strategies of grazing under continuous stocking that optimize the natural pattern of tillering of Brachiaria decumbens cv. Basilisk. Two strategies of grazing management were studied: in one, the grass was maintained with 25-cm mean height throughout the experimental period, and in the other, 15-cm mean height during the winter, rising to 25 cm from beginning of spring. The split-plot in randomized block design with four replications was adopted. The strategies of grazing management corresponded to primary factor, characterized by average heights of pastures during the seasons of the year (winter, spring and summer). The seasons corresponded to secondary factor and consisted of measures over experimental period. The rates of tillers appearance (4.7%), death (4.7%) and stability index (0.998) were lower in winter. During this season, however, the tiller survival rate was higher (95.3%). Compared with pastures maintained at 25 cm, those managed with 15 cm in winter had higher tiller appearance rate (34.2%) and stability index (1.065). The signalgrass flowering occurred only in the summer and with low intensity (0.5%). Optimization for renewal of tillers in B. decumbens cv. Basilisk pasture under continuous stocking occurs with its decrease to 15 cm at the beginning of winter and subsequent increase to 25 cm in early spring.

Objetivou-se avaliar as características morfogênicas e estruturais e o acúmulo de forragem em pastos de Brachiaria decumbens (capim-braquiária) de acordo com a localização das fezes de bovinos. Foram avaliadas duas áreas da pastagem: próxima e distante das fezes. O delineamento foi em blocos casualizados, com três repetições. Foram marcados perfilhos no pasto para avaliação do comprimento de folhas e colmos. O aparecimento e a morte de folhas também foram registrados. A taxa de alongamento de colmo foi 80% maior e a taxa de alongamento foliar 23% maior nos perfilhos das áreas próximas das fezes. O filocrono também foi maior nos perfilhos (8,5 dias) das áreas próximas às fezes em comparação àqueles de áreas distantes (7,7 dias). Não houve efeito da localização das fezes sobre a taxa de senescência foliar (0,39 cm/perfilho.dia) e a duração de vida da folha (38 dias). O comprimento final da lâmina foliar foi 25% maior nos perfilhos localizados próximos às fezes. O número de folhas com desfolhação (1,3 folhas) foi menor nas áreas próximas às fezes, contrariamente ao número de folhas mortas (2,8 folhas). O comprimento do pseudocolmo aumentou 73% com a proximidade das fezes. Os números de perfilhos vegetativos, mortos e total foram maiores nas áreas distantes das fezes. Maior taxa de crescimento total do capim-braquiária também ocorreu nas áreas próximas às fezes. A deposição de fezes bovinas modifica as características morfogênicas e a estrutura do pasto de B. decumbens. Nas regiões próximas às fezes, o fluxo de tecidos é mais intenso e o acúmulo de forragem é maior.The objective of this study is to evaluate morphogenetic and structural characteristics as well as forage accumulation on Brachiaria decumbens pastures according to the site of cattle feces. It was evaluated two grazing areas: near and far from the droppings. The design used was a random block design, with three replicates. Tillers were tagged on the pasture for evaluation of length of the leaves and stems. Leaf appearance and death were also recorded. Stem elongation rate was 80% higher and leaf elongation rate was 23% higher for the tillers near the dropping areas. Phyllochron was also higher for tillers (8.5 days) in sites close to the feces in comparison to those from the distant areas (7.7 days). There was no effect of dropping localization on leaf senescence rate (0.39 cm/tiller.day) and leaf life span (38 days). Final leaf blade length was 25% higher for tillers near the droppings. The number of defoliating leaves (1.3 leaf) was lower in areas near the droppings, contrary to the number of dead leaves (2.8 leaves). Pseudostem length increased 73% as it was closer to the droppings. Number of dead and total vegetative tiller was higher in areas far from the droppings. Higher total growth rate of B. decumbens also occurred in sites close to the droppings. Cattle droppings change the morphogenetic characteristics and structure of B. decumbens pasture. In areas close to the feces, the tissue flow is more intense and forage accumulation is higher.

The experiment was carried out aiming to classify and quantify tiller categories of Brachiaria decumbens cv. Basilisk from different heights found on the same pasture. Four different plant heights (10; 20; 30 and 40 cm) living at the same pasture were evaluated. Randomized block design with three replications was used. Tillers were classified according to their stage of development, growth origin, defoliation level and size. The number of vegetative tillers reduced linearly, while the number of reproductive tillers and dead tillers increased linearly according to the plant height. The number of aerial tillers showed a quadratic response in relation to the plant height. The pastures having grasses of 10, 20, 30 and 40 cm in height had respectively 292, 408, 496 and 344 aerial tillers/m2. The population density of defoliated tillers reduced linearly according to the plant height. The population density of tillers without the apical shoot showed quadratic response to the signal grass height, being the smallest values found for places having grasses of 10 cm (176 tillers/m2) and 40 cm (180 tillers/m2) in height. The number of tillers without defoliation quadratic responded to the plant height, being the highest values found for places having grasses extremely high. The areas with the highest grasses also showed the highest numbers of tallest tillers. There is indeed a spatial variability of the vegetation and a high morphological diversity of tillers on Brachiaria decumbens cv. Basilisk pastures managed under the continuous stocking system.

The experiment was carried out aiming to investigate the influence of natural deposition of cattle droppings on population density of several classes of tillers on the Brachiaria decumbens Stapf. cv. Basilisk pasture managed under continuous stocking. Two places on the same pasture were evaluated: one near (immediately adjacent) and one far, about 1.0 m, from the cattle droppings. Randomized block design with three repetitions was used. Tillers were classified according to the developmental stage, growth origin, defoliation rate and length. The number of vegetative tillers was higher (P

Thus study was conducted with the objective of evaluating production and forage characteristics of Signalgrass (Brachiaria decumbens cv. Basilisk) deferred at different initial heights and nitrogen doses. Three initial sward heights (low - 10 cm, medium - 20 cm and high - 30 cm), three nitrogen doses (40, 80 and 120 kg/ha) and a control treatment, of no fertilization were evaluated. The experimental design utilized was of completely randomized blocks with three replications, in a subdivided-plot arrangement. There was no interaction between sward initial height and nitrogen dose for the variables analyzed. The Signalgrass deferred at an elevated initial height presented greater masses of forage, live stem, dead stem and dead leaves; higher percentage of dead stem and falling rate; and lower number of vegetative tillers, percentage of live leaves and live leaf/live stem ratio. Elevation in the nitrogen dose increase along with the number of live and vegetative tillers; masses of forage, live stem, dead stem, dead leaves and live leaves; percentage of live stem; and live tissue/dead tissue ratio; and reduced the percentage of dead leaves and the live leaf/live stem ratio. Signalgrass can be deferred at low and medium initial heights and varied nitrogen doses, according to the objectives and possibilities of the farmer.

Tillering dynamics during regrowth in the spring (September to December 2009) on signal grass (Brachiaria decumbens cv. Basilisk) pastures deferred in the beginning of April 2009 is evaluated. Four pasture heights were evaluated at the beginning of deferment (10, 20, 30 and 40 cm). The experimental design consisted of completely randomized blocks with two replications. Rise in pasture height at the beginning of deferment decreased the appearance rate, increased the mortality rate and reduced the survival rate, the balance between appearance and mortality and the stability index of the tiller population at the beginning of the spring. Pastures deferred at initial height of 30 and 40 cm presented relatively stable tiller appearance rate between the beginning and end of spring. However, these pastures presented greater mortality rate, lower survival rate, lower balance between appearance and mortality and lower stability index of the tiller population at the beginning of spring when compared to rates at the end of spring. Pastures managed with shorter initial heights (10 and 20 cm) provided more tissue renewal in the subsequent growth season after their utilization in the winter.

Current experiment identified the height of signal grass {Urochloa decumbens (Stapf) R. D. Webster cv. Basilisk [syn. Brachiaria decumbens Stapf cv. Basilisk]} at the beginning of deferment that provided an appropriate pasture structure and potential selectivity by cattle on deferred pastures. Four pasture heights at the beginning of deferment (10, 20, 30 and 40 cm) and two forage samples (available on pasture and simulated grazing) were studied. The experimental design was set in completely randomized blocks, with two replications, in a split-plot arrangement. Higher percentage of live leaf blades and lower percentage of live stems and senescent forage were recorded in the forage sample from simulated grazing. The increase in pasture height increased the percentage of senescent forage and reduced the percentage of live leaf blades in forage samples. Pasture height at the beginning of deferment did not affect the potential selectivity index by cattle for the percentage of live leaf blade. The potential selectivity index varied quadratically for the percentage of live stems and increased linearly for the percentage of senescent forage with pasture height. A 10-to-20 cm reduction in pasture height at the beginning of deferment improved the structure of deferred signal grass and optimized selectivity by cattle.

Avaliou-se durante o período das águas no Norte de Minas Gerais o efeito de quatro doses de nitrogênio (100; 300; 500 e 700kg/ha/ano) e seis lâminas de água (0%; 20%; 40%; 80%; 100% e 120% da evapotranspiração de referência,ou ETo) sobre o rendimento forrageiro, densidade de perfilhos, relação folha/colmo, altura de plantas e teores de proteína bruta e fibra em detergente neutro do capim-elefante (Pennisetum purpureum, Schum). O delineamento experimental foi o de blocos casualizados em esquema fatorial 6x4 (seis níveis de lâminas de irrigação e quatro de adubação nitrogenada) com quatro repetições. As lâminas de água e as doses de nitrogênio aumentaram linearmente a produção de matéria seca e a densidade de perfilhos. Comportamento semelhante foi verificado para a altura das plantas frente a aplicação de lâminas de irrigação. Os teores de proteína bruta diminuiram linearmente com o aumento da lâmina de irrigação e aumentaram na proporção direta às doses de nitrogênio. Efeito quadrático foi proporcionado pela irrigação quanto aos teores de detergente neutro, com percentual máximo de 72,26%, quando foi aplicada lâmina de água de 96,25% da ETo. Já a adubação nitrogenada reduziu linearmente os teores de fibra em detergente neutro. Tanto a aplicação das lâminas de irrigação quanto a aplicação da adubação nitrogenada agindo isoladamente ou em interação, não afetaram o comportamento da relação folha/colmo, no período das águas. As lâminas de água associadas às doses de nitrogênio elevaram a produção de matéria seca, evidenciando assim a diminuição do efeito da estacionalidade de produção do capim-elefante “pioneiro” (lançamento da EMBRAPA–COOPAGRO) no Norte de Minas Gerais.Palavras-chave: estacionalidade, evapotranspiração, lâmina d’água, nitrogênioIt was evaluated during the rainy season in North of Minas Gerais the effect of four levels of nitrogen (100; 300; 500 and 700 kg/ha/year) and six water depths (0%; 20%; 40%; 80%, 100% and 120% of the reference evapotranspiration, or ETo) on the forage yield, tillers density, leaf/stem relationship, plants height and crude protein content and neutral detergent fiber of elephant grass (Pennisetum purpureum, Schum). The experimental design was in blocks at random with four replications. The water depths and doses of nitrogen increased lineally the dry matter production and the tillers density. The plants height presented a linear behavior proportionally to application of irrigation depths. The crude protein contents decreased linearly with the application of the irrigation depths and increased with the doses of nitrogen. Quadratic effect was provided by the irrigation to neutral detergent fiber content, with maximum percentage of 72,26%, when water depth of 96,25% of the ETo was applied. Nitrogen fertilization reduced the neutral detergent fiber content linearly. As much the application of the irrigation depths as the nitrogen fertilization one, acting separately or in interaction, did not affect the leaf/stem relation on the rainy season. The water depths associate to the doses of nitrogen raised the dry matter yield, thus evidencing the reduction of effect of production seasonality of the elephant grass “pioneiro” in the North of Minas Gerais.

O experimento foi conduzido com o objetivo de classificar e quantificar as categorias de perfilhos de Brachiaria decumbens cv. Basilisk existentes em locais com alturas variáveis em um mesmo pasto. Os tratamentos foram quatro alturas de plantas (10, 20, 30 e 40 cm) avaliadas dentro de uma mesma pastagem. O delineamento experimental foi em blocos casualizados, com três repetições. Os perfilhos foram classificados quanto ao estádio de desenvolvimento, à origem de crescimento, ao nível de desfolhação e ao tamanho. O número de perfilho vegetativo reduziu linearmente, enquanto que os números de perfilhos reprodutivos e mortos incrementaram linearmente com a altura da planta no mesmo. O número de perfilho aéreo apresentou padrão de resposta quadrático em função da altura da planta, sendo que os locais do pasto com 10, 20, 30 e 40 cm de altura possuíram, respectivamente, 292, 408, 496 e 344 perfilhos aéreos/m2. A densidade populacional de perfilhos desfolhados reduziu de forma linear com a altura da planta. A densidade populacional de perfilhos sem o meristema apical apresentou resposta quadrática à altura da planta de capim-braquiária, observando-se os menores valores nos locais com 10 cm (176 perfilhos/ m2) e com 40 cm (180 perfilhos/m2) de altura. O número de perfilhos sem desfolhação respondeu de forma quadrática à altura da planta, com maiores valores nos locais do pasto com as alturas extremas. Os locais mais altos do pasto possuíram maior participação de perfilhos mais compridos. Em pasto de Brachiaria decumbens cv. Basilisk manejada em lotação contínua existe variabilidade espacial da vegetação e grande diversidade morfológica de perfilhos.

O experimento foi conduzido objetivando-se investigar a influência da deposição natural das fezes pelos bovinos sobre a densidade populacional de diversas classes de perfilhos no pasto de Brachiaria decumbens Stapf. cv. Basilisk manejada sob lotação contínua. Os tratamentos foram dois locais, um próximo (imediatamente adjacente) e outro distante cerca de 1,0 m das fezes excretadas pelos bovinos, avaliados em blocos casualizados, com três repetições. Os perfilhos foram classificados quanto à origem de desenvolvimento, nível de desfolhação e ao comprimento. O número de perfilhos vegetativos foi maior no local distante (1851 perfilhos/m2) do que naquele próximo das fezes (848 perfilhos/m2). O número de perfilhos reprodutivos foi maior nos locais próximos das fezes. Não foi observado efeito da localização das fezes sobre a densidade populacional de perfilhos mortos. O número de perfilhos basais e aéreos foi superior no local distante, quando comparados ao do local próximo das fezes. Houve maiores densidades populacionais de perfilhos desfolhados e sem meristema apical nos locais distantes das fezes, enquanto que a densidade populacional de perfilhos não desfolhados foi maior nos locais próximos das fezes. Os perfilhos menores foram mais frequentes (P

A caracterização de perfilhos e de suas lâminas foliares quanto ao estádio de desenvolvimento permite realizar inferências sobre a estrutura do pasto, que determina as respostas das plantas forrageiras e dos animais em pastejo. Desse modo, o objetivo do estudo foi avaliar as características morfológicas de lâminas foliares e perfilhos com distintos estádios de desenvolvimento em pasto de Brachiaria decumbens Stapf. cv. Basilisk manejado sob lotação contínua com bovinos. No primeiro estudo, os tratamentos foram quatro níveis de desenvolvimento da lâmina foliar (níveis de inserção 1, 2, 3 e 4) e, no segundo, foram três tipos de perfilhos individuais com 2, 3 e 4 folhas completamente expandidas. O delineamento experimental foi de blocos completos casualizados, com três repetições. Foram avaliadas a altura de inserção da lâmina foliar (LF) no perfilho, a percentagem de LF pastejada, a área foliar, a massa, a área foliar específica e o comprimento da LF de acordo com o seu nível de inserção no perfilho. Os comprimentos e os percentuais do colmo e da LF, e o peso do perfilho também foram quantificados em função do seu número de folha expandida. Para cada nova folha completamente expandida surgida no perfilho, houve aumento de aproximadamente 2 cm na altura de inserção da LF. Não houve diferença na percentagem de LF pastejada nos diferentes níveis de inserção da folha no perfilho, que apresentou valor médio de 56,6%. A área foliar, a massa e o comprimento da LF aumentaram, enquanto que a área foliar específica diminuiu linearmente com o aumento do nível de inserção da folha no perfilho. O percentual de colmo diminuiu, mas os comprimentos do colmo e da LF, o percentual de LF e o peso do perfilho foram incrementados com o aumento do número de folhas expandidas por perfilho. Durante o desenvolvimento, as características morfológicas do perfilho e da lâmina foliar da B. decumbens são modificadas. O dossel de B. decumbens sob lotação contínua e com 25 cm de altura média possui perfilhos de duas até quatro folhas expandidas com adequadas características morfológicas.

A caracterização de perfilhos e de suas lâminas foliares quanto ao estádio de desenvolvimento permite realizar inferências sobre a estrutura do pasto, que determina as respostas das plantas forrageiras e dos animais em pastejo. Desse modo, o objetivo do estudo foi avaliar as características morfológicas de lâminas foliares e perfilhos com distintos estádios de desenvolvimento em pasto de Brachiaria decumbens Stapf. cv. Basilisk manejado sob lotação contínua com bovinos. No primeiro estudo, os tratamentos foram quatro níveis de desenvolvimento da lâmina foliar (níveis de inserção 1, 2, 3 e 4) e, no segundo, foram três tipos de perfilhos individuais com 2, 3 e 4 folhas completamente expandidas. O delineamento experimental foi de blocos completos casualizados, com três repetições. Foram avaliadas a altura de inserção da lâmina foliar (LF) no perfilho, a percentagem de LF pastejada, a área foliar, a massa, a área foliar específica e o comprimento da LF de acordo com o seu nível de inserção no perfilho. Os comprimentos e os percentuais do colmo e da LF, e o peso do perfilho também foram quantificados em função do seu número de folha expandida. Para cada nova folha completamente expandida surgida no perfilho, houve aumento de aproximadamente 2 cm na altura de inserção da LF. Não houve diferença na percentagem de LF pastejada nos diferentes níveis de inserção da folha no perfilho, que apresentou valor médio de 56,6%. A área foliar, a massa e o comprimento da LF aumentaram, enquanto que a área foliar específica diminuiu linearmente com o aumento do nível de inserção da folha no perfilho. O percentual de colmo diminuiu, mas os comprimentos do colmo e da LF, o percentual de LF e o peso do perfilho foram incrementados com o aumento do número de folhas expandidas por perfilho. Durante o desenvolvimento, as características morfológicas do perfilho e da lâmina foliar da B. decumbens são modificadas. O dossel de B. decumbens sob lotação contínua e com 25 cm de altura média possui perfilhos de duas até quatro folhas expandidas com adequadas características morfológicas.

The aim of this study was to evaluate different levels of feed restriction in the diet for F1 Holstein x Zebu cows during the winter on performance and economic viability. Data from Zootechnical book keeping, and from experiments conducted in the Experimental Field of Felixlândia, belonging to EPAMIG, were used. Total lactation of sixty F1 Holstein x Zebu cows receiving different diets was analyzed, by 2.00%, 2.25%, 2.50%, 2.75% body weight (BW), and a control group (3.4%; no feed restriction), allowing 5% leftovers in relation to the dry matter supplied, distributed in a completely randomized design. Data on milk production and feed cost were collected, evaluating the different periods that characterize the lactation of an animal. The highest milk production was found in the diet levels 3.4 %, and 2.75% BW, 3,636.00, and 3,271.50 kg, respectively. Lower milk production was observed at levels of 2.50%; 2.25%; 2.00% BW, respectively. The highest feed cost was verified without feed restriction followed by the levels of 2.75%, 2.50%, 2.25%, and 2.00% BW. The supply of the no feed restriction diet resulted in a performance superior to levels 2.75; 2.50; 2.25; 2.00% BW. The items profit, profitability were similar between all treatments, indicating that, when there is occasional feed shortage, a restriction in the diet supply of up to 2% BW provides economic security to the rural producer.