Warm-season grasses require N fertilization to achieve their full production potential; however, increased costs have limited the use of N by beef cattle (Bos spp.) producers. Th e objective of this study was to test the eff ects of two grazing frequencies (2 and 4 wk) on production, nutritive value, and persistence of 'Argentine' (tetraploid), 'Pensacola', 'Tift on 9', and 'UF Riata' (diploids) bahiagrass (Paspalum notatum Flügge) cultivars fertilized with 60 kg N ha -1 yr -1 . Th e study was conducted in Ona, FL, from January 2010 to December 2011. Treatments were eight factorial combinations of two grazing frequencies (2 and 4 wk) and four bahiagrass cultivars. Th e four cultivars were grazed by beef cows (505±30 kg) for approximately 8 h to a 7.5-cm stubble height at 2-or 4-wk intervals. Diploid cultivars had greater herbage accumulation (HA) in the spring; however, Argentine had greater annual HA in 2010 and 2011. Plots grazed at 4 wk had approximately 50% greater HA than 2-wk grazing frequency. Argentine and Pensacola had greater root and rhizome mass than Tift on 9 and UF Riata when grazed every 2 wk, while Argentine had greater cover than any of the diploids when grazed at the 2-wk frequency. Results show that Argentine is a productive and persistent bahiagrass for beef cattle producers using limited N fertilization and frequent grazing in Florida. Decreasing grazing frequency is an eff ective management practice to increase bahiagrass HA and persistence, particular the upright-growing Tift on 9 and UF Riata.

RESUMO -Objetivou-se, com este trabalho, avaliar a produção e a composição do leite de éguas Mangalarga Marchador e o ganho de peso dos potros lactentes. A produção de leite foi avaliada em oito éguas, pelo método da pesagem dos potros antes e depois das mamadas, em intervalos de duas horas, em doze observações diárias. A partir do somatório da quantidade de leite produzido nas observações, obteve-se a produção diária de leite. A produção de leite, analisado quanto aos teores de lactose, proteína, gordura e energia, foi avaliada aos 20, 40, 60, 80, 100, 120, 140 e 160 dias da lactação A produção média de leite variou de 9,95 kg/dia no 40 o dia a 7,48 kg/dia no final da lactação. A produção total de leite estimada foi igual a 1405,56 kg. A produção de leite, expressa em percentual do peso vivo (PV) das éguas, variou entre 2,3% do PV no 20 o dia e 1,8% do PV no final da lactação, sendo similar às quantidades de leite produzidas nos períodos diurno e noturno. Não foi observado efeito da idade das éguas na produção de leite. O ganho médio diário de peso dos potros ao longo do período de amamentação foi de 0,77 kg, com maiores valores nos meses iniciais do período de amamentação. O leite das éguas apresentou baixas concentrações de proteína, gordura e energia e altas de lactose, além de resposta quadrática decrescente, em função do período da lactação. Palavras-chave: lactação, eqüinos, exigências nutricionais Lactation in Mangalarga Marchador Mares: Yield production and Composition of Milk, and Weight Gain of Suckling FoalsABSTRACT -This work aims to evaluate yield production and composition of milk of Mangalarga Marchador mares and average weight gain of suckling foals. Milk yield was evaluated in eight mares by the weigh-suck-weigh method, at intervals of two hour, twelve times a day. Daily milk produced was estimated by summing of the twelve observations. Milk yield was performed at 20, 40, 60, 80, 100, 120, 140 and 160 days of lactation. The milk was analyzed for lactose, protein, fat and energy concentration. Daily milk production ranged from 9.95 kg at 40 th day to 7.48 kg no final da lactação (160 th day) Total estimate milk yield during the lactation was 1405.56 kg. Milk yield as a % LW of mares ranged from 2.3% LW at 20 th day to 1.8% LW at the end of lactation. Amounts of milk produced during daytime and nighttime was similar and mare age did not affect milk production. Average weight gain of foals during lactation period was 0.77 kg/day with higher values at first months of lactation period. Milk showed low concentration of protein, fat and energy, high levels of lactose, with a decreasing quadratic response in function of lactation period.

Neste estudo, foram realizados dois ensaios com os objetivos de avaliar o fracionamento dos carboidratos de alimentos volumosos e estimar a digestibilidade desses nutrientes em dois ensaios de digestão com eqüinos. No ensaio 1, foram utilizados cinco eqüinos em delineamento de blocos casualizados, com sete tratamentos - fenos de alfafa (Medicago sativa); amendoim forrageiro (Arachis pintoi); desmódio (Desmodium ovalifolium); guandu (Cajanus cajan); macrotiloma (Macrotyloma axillare); estilosantes (Stylosanthes guianensis); ou coastcross (Cynodon dactylon) - avaliados pela técnica de sacos de náilon móveis. No ensaio 2, foram utilizados quatro eqüinos em delineamento quadrado latino 4 × 4, alimentados com feno de coastcross em quatro tipos de moagem com o objetivo de avaliar se a redução do tamanho de partícula interfere na digestibilidade dos carboidratos. Os resultados comprovaram que os eqüinos possuem alta eficiência na digestão dos carboidratos não-fibrosos e de suas frações hidrolisáveis e rapidamente fermentáveis. Os fenos de amendoim forrageiro, estilosantess e macrotiloma apresentaram elevada digestibilidade dos carboidratos fibrosos e não-fibrosos, enquanto a digestibilidade de todos os nutrientes do amendoim forrageiro foi superior a 70%, o que indica potencial para uso desta leguminosa em dietas para eqüinos. O processamento do feno de coastcross não influenciou a digestibilidade das frações dos carboidratos fibrosos e não-fibrosos. A análise dos carboidratos fibrosos e não-fibrosos é um bom indicativo do valor nutricional dos alimentos e pode ser incluída na avaliação da qualidade de alimentos para eqüinos.

-The experiment was carried out on Cynodon spp cv. Tifton 85 pastures grazed by sheep under rotational stocking, with the objective of evaluating the structural characteristics as well as the forage mass of the pastures subjected to three grazing intensities in successive cycles. Treatments were composed of three residual leaf area indices (rLAI; 2.4; 1.6 and 0.8), allocated in completely randomized blocks with seven replications, totaling 21 experimental units. Tiller population density, pasture height, leaf area index, forage morphological composition and pasture forage mass were evaluated. The rLAI modified the tiller population density, which increased linearly with decrease in the rLAI of the pastures. Dry masses of leaf blade, stem and dead material were inferior when the rLAI imposed were lower, which resulted in differentiated forage production among the treatments. Tifton 85 pastures grazed by sheep in rotational stocking under tropical conditions with different rLAI show a modified sward structure over successive grazing cycles, mainly by alteration in the height and LAI of the plants at pre-grazing and by light interception post-grazing, which change the tiller population density. The residual leaf area index of 1.6 is the most suitable for pasture management for being equivalent to the heights of entrance and exit of animals on and from paddocks of 33 and 19 cm, respectively, which avoid great accumulation of dead material and excessive stem elongation, in addition to ensuring tillering in the sward.

RESUMOEstudaram-se os efeitos da adubação nitrogenada sobre o crescimento do capim Tifton 85 (Cynodon spp. cv. Tifton 85), em termos de ocorrência de plantas e altura do dossel, índice de área foliar e interceptação de radiação fotossinteticamente ativa. O estudo foi desenvolvido sobre um planossolo de ocorrência em campo experimental. Os tratamentos consistiram de níveis de N (0; 150; 300; 450 e 600kg/ha de N-ureia, aplicados em duas vezes), arranjados em um desenho experimental de blocos inteiramente ao acaso, com quatro repetições. As avaliações foram realizadas semanalmente, entre 10 e 40 dias após o corte. Tanto a ocorrência de plantas como a altura do dossel responderam à adubação nitrogenada, conforme um padrão de resposta que variou, sazonalmente, em função das doses de N em interação com as condições ambientais. A expansão da área foliar e a interceptação da radiação fotossinteticamente ativa associada, também foram controladas direta e proporcionalmente pelas doses de N aplicadas, sendo maximizadas a valores de índice de área foliar em torno de 4,0.Palavras-chave: Cynodon spp., altura de dossel, frequência de plantas, radiação fotossinteticamente ativa area. Treatments consisted of N levels (0; 150; 300; 450; split ABSTRACT The effects of nitrogen (N) fertilization levels on the growth patterns of the grass Tifton 85 (Cynodon spp. cv.Tifton 85) were studied in terms of occurrence of plants, sward height, leaf area index, and photosynthetically active radiation interception (PAR int ). The field trial was made in an experimental

Bermudagrass is the main warm-season grass species used for livestock production in the southeastern United States; however, when it is ensiled, the silage fermentation parameters are often less than desirable. The objective of this study was to investigate the effects of management practices on the nutritive value and fermentation characteristics of bermudagrass silage. In Exp. 1, treatments were the factorial combinations of 2 bermudagrass genotypes, 'Jiggs' () and 'Tifton 85' ( sp.), 4 additives, and 2 DM concentrations at ensiling. The additives were 1) untreated control (deionized water), 2) Ecosyl, 3) B500, or 4) sugarcane molasses. The 2 DM concentrations at ensiling were low DM (22% DM) or high DM (53% DM). Treatments were replicated 3 times in a completely randomized design. Silage treated with molasses had a lesser ( < 0.05) pH and greater ( < 0.01) lactate concentrations than the control, Ecosyl, and B500 in silage with low DM concentrations and greater ( < 0.01) in vitro true digestibility (IVTD) and lesser ( < 0.01) ADF concentrations than the other treatments at either DM concentration. Silage treated with B500 had the greatest ( < 0.01) aerobic stability, whereas that treated with molasses had the least aerobic stability. However, all treatments presented long aerobic stability (≥150 h). Jiggs had lesser ( < 0.01) ADF and NDF and NDF digestibility (NDFD) concentrations than Tifton 85 and Tifton 85 had greater ( < 0.01) IVTD than Jiggs in the silage with a high DM concentration. In Exp. 2, Jiggs silage treated with either molasses (20 g molasses [DM]/kg forage [as-fed basis]) or nothing (control, untreated silage) was fed to 16 beef heifers ( sp.) in individual drylot pens in a completely randomized design with 8 replicates for voluntary DMI, in vivo apparent DM digestibility, and NDFD evaluations. There were no differences ( = 0.36) among treatments in NDFD; however, there was a trend ( < 0.08) for greater in vivo apparent DM digestibility and DMI in heifers fed the molasses-treated silage. Microbial inoculants had decreased effects on Jiggs and Tifton 85 bermudagrass silage ensiled at a low DM concentration; however, adding molasses was an effective management practice to improve its nutritive value and fermentation characteristics.

ResumoO objetivo com este trabalho foi avaliar os efeitos de índices de área foliar residual (IAFr), anos de avaliação e ciclos de pastejo sobre as características morfogênicas e estruturais do capim-xaraés sob pastejo, em dois verões agrostológicos (anos de avaliação). O experimento foi conduzido na Universidade Estadual Paulista "Júlio de Mesquita Filho" -UNESP, Campus de Jaboticabal, São Paulo, Brasil e as intensidades de pastejos foram definidas por quatro IAFr: 0,8; 1,3; 1,8 e 2,3. Quando o dossel interceptou 95% da luz incidente, os animais foram colocados no piquete para o pastejo e permaneceram até que o IAFr alvo foi alcançado. Os pastejos foram realizados por vacas da raça Holandesa (Bos taurus taurus L.) não lactantes, utilizando-se a técnica de mob-stocking. As características morfogênicas e estruturais do capim-xaraés respondem de forma efetiva as mudanças nas condições climáticas. Observa-se variabilidade nas características morfogênicas e estruturais em respostas aos anos de avaliação e ciclos de pastejo dentro de ano. Palavras-chave: Brachiaria, índice de área foliar residual, interceptação de luz, Urochloa AbstractThe aim of this study was to evaluate the effects of residual leaf area index (rLAI), years of evaluation and grazing cycles on the morphogenetic and structural characteristics of xaraés palisadegrass subjected to grazing intensities in two summers (years of evaluation). The experiment was carried out at the Universidade Estadual Paulista "Júlio de Mesquita Filho" -UNESP, Campus de Jaboticabal, São Paulo, Brasil and the intensities of grazing were defined by four rLAI: 0.8, 1.3, 1.8 and 2.3. When the canopy intercepted 95% of incident light, the animals were placed on the pasture for grazing and kept until the rLAI target has been reached. Pastures were grazed by non-lactating Holstein cows (Bos Taurus Taurus L.), using the technique of mob-stocking. The morphogenetic and structural characteristics of xaraés palisadegrass respond effectively to weather conditions. There is variability in morphogenetic and structural characteristics in response to years and grazing cycles within years.

Overseeding warm‐season legumes into warm‐season perennial grass pastures is an option to improve forage quality and reduce the use of commercial N fertilizer. The objective of this study was to evaluate the effects of ‘Ubon’ stylo (Stylosanthes guianensis var. vulgaris × var. pauciflora) overseeded into bahiagrass (Paspalum notatum Flügge) pastures on forage production and nutritive value. Treatments were overseeding stylo into bahiagrass pastures, bahiagrass pastures fertilized with 60 kg N/ha/year, or control (bahiagrass pasture with no N fertilization or legume) arranged in a randomized incomplete block design with three replicates. All treatments were continuously stocked using a fixed stocking rate with two heifers (Bos spp.) per experimental unit. Forage evaluations were conducted every 28 days from July to October 2010 and 2011. Pastures fertilized with N had greater herbage mass (HM) and herbage allowance (HA) than overseeded or control treatments and there was no difference between overseeded and control treatments. Overseeded and N fertilized treatments had greater CP concentration than control. The proportion of Ubon stylo was constant in the overseeded pastures during the experiment (≈ 17%). The increased HM on N fertilized treatments may potentially allow greater stocking rates when compared to pastures overseeded with stylo.