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RESUMO -Objetivou-se com este trabalho avaliar o efeito do processo de digestão de bovinos sobre o poder germinativo de sementes de capim-annoni-2 (Eragrostis plana Ness) recuperadas nas fezes. As sementes (6 g, 27.273 sementes) foram colocadas no saco ventral do rúmem de oito novilhos fistulados, mantidos em gaiolas para ensaios metabólicos. Quarenta e três por cento das sementes fornecidas aos animais foram recuperadas nas fezes: aquelas recuperadas nos três primeiros dias corresponderam a 97,2% da quantidade de sementes fornecidas. Somente 7,2% das sementes recuperadas, equivalente a 3,1% da quantidade de sementes fornecidas, apresentaram viabilidade. O tempo de permanência no trato digestivo foi a principal causa do desaparecimento das sementes consumidas e da perda de seu poder germinativo. A ausência de sementes de capim-annoni-2 nas fezes ocorre a partir do oitavo dia após a ingestão, assim, bovinos devem permanecer em quarentena por sete dias em área livre de capim-annoni-2 para limpeza do trato digestivo.Palavras-chave: campo natural, dispersão de invasoras, ingestão de sementes, invasão biológica, transporte de sementes Germination of capim-annoni-2 (Eragrostis plana Ness) seeds recovered in bovine fecesABSTRACT -This work was carried out with the objective of evaluating the effect of the bovine digestion process on the germination capacity of the capim-annoni-2 (Eragrostis plana Ness) seeds recovered in feces. The seeds (6 g, 27,273 seeds) were placed in a ruminal ventral sack of eight fistulated steers kept in pen trial. Forthy-three percent of the offered seeds were recovered in the feces. Seeds recovered in the first three days corresponded to 97.2% of the offered seeds. Only 7.2% of the recovered seeds germinated and represented 3.1% of the offered seeds. The permanence time in the digestive trait was the main cause for the disappearance of consumed seeds and for the loss in their germination capacity. The absence of capim-annoni-2 seeds in the feces occurs in the eighth day after ingestion, then, bovines should be kept in quarantine for seven days in an area free of capim-annoni-2 seeds to clean their digestive trait.

-It was evaluated in this work, crop yield, fermentative quality and nutritional value of the silage of cultivars of white (Avena Sativa L.) and black (Avena Strigosa Schreb) oats cut at two development stages. It was used an experimental randomized block design in a 4 × 2 factorial scheme, consisting of four oat cultivars (two cultivars of black oats: Aveia Preta Comum and UTFP 971; and two cultivars of white oats: ER 91156-1-2-1 and SI 98105-b), with four replicates. The cultivars were ensiled at flowering and dough grain stages. Oat cut at dough grain stage, especially genotypes from white oat, allows the obtainment of a more productive and qualitative silage. Cultivar, genotype, and maturation stage affect protein fractioning and oat silage carbohydrates.

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Data from twenty-two digestibility trials were compiled to examine the relationship between faecal N concentration and organic matter (OM) digestibility (OMD), and between faecal N excretion and OM intake (OMI) by wethers fed tropical or temperate forages alone or with supplements. Data set was grouped by diet type as follows: only tropical grass (n = 204), only temperate grass (n = 160), tropical grass plus supplement (n = 216), temperate grass plus supplement (n = 48), tropical grass plus tropical legume (n = 60) and temperate grass with ruminal infusion of tannins (n = 16). Positive correlation between OMD and either total faecal N concentration (Nfc, % of OM) or metabolic faecal N concentration (Nmetfc, % of OM) was significant for most diet types. Exceptions were the diet that included a tropical legume, where both relationships were negative, and the diet that included tannin extract, where the correlation between OMD and Nfc was not significant. Pearson correlation and linear regressions between OM intake (OMI, g/day) and faecal N excretion (Nf, g/day) were significant for all diet types. When OMI was estimated from the OM faecal excretion and Nfc-based OMD values, the linear comparison between observed and estimated OMI values showed intercept different from 0 and slope different from 1. When OMI was estimated using the Nf-based linear regressions, the linear comparison between observed and estimated OMI values showed neither intercept different from 0 nor slope different from 1. Both linear comparisons showed similar R(2) values (i.e. 0.78 vs. 0.79). In conclusion, linear equations are suitable for directly estimating OM intake by wethers, fed only forage or forage plus supplements, from the amount of N excreted in faeces. The use of this approach in experiments with grazing wethers has the advantage of accounting for individual variations in diet selection and digestion processes and precludes the use of techniques to estimate forage digestibility.

Endozoochorous dispersal of seeds of weedy rice (Oryza sativa L.) and barnyardgrass (Echinochloa crus-galli L.) by cattle.Ciência Rural, v.48, n.8, 2018.

RESUMO Foi realizado um experimento com o objetivo de verificar o efeito da suplementação com uréia encapsulada ou normal sobre a utilização de volumoso de baixa qualidade em novilhos. Os tratamentos foram: Feno INTRODUÇÃOOs sistemas pastoris são extremamente dependentes de fatores climáticos, o que gera oscilações nos seus níveis produtivos durante o ano. Visando contornar certas adversidades, procuram-se sistemas que melhorem a utilização de recursos de baixo custo e já disponíveis na propriedade. No caso da suplementação de animais em pastejo, o foco é a diminuição dos efeitos deletérios da estacionalidade produtiva e qualitativa das plantas forrageiras de forma a melhorar a utilização destas. A utilização da suplementação nitrogenada pode ocorrer em situações em que a proteína bruta do volumoso é limitante, visto que o teor de proteína é o principal fator limitante no uso de pastagens de baixa qualidade (COCHRAN et al., 1998).Alguns estudos realizados no Brasil comprovaram a superioridade da suplementação

The current study evaluated the efficiency of mechanical, physical, chemical and cultural methods, used exclusively or integrated, to control tough lovegrass. The experimental design was completely randomized, with 15 treatments and four repetitions. Physical control of tough lovegrass was based on the application of fire, whereas mechanical controls consisted in mowing and harrowing/plowing procedures. The herbicide clethodim and different glyphosate salts were evaluated for chemical control. Glyphosate and soil fertility correction were applied as cultural and integrated methods, in addition to isopropylamine + potassium salts combination, soil fertility correction and implantation of one of the following forage plants: Elephant grass, Pangola grass, Forage peanut and Birdsfoot trefoil. The effect of treatments on the incidence of tough lovegrass and on its botanical composition was evaluated one year after their applications. Isolated control methods, except for glyphosate using, did not present efficient tough lovegrass control. Glyphosate salts could control tough lovegrass plants, but their association with improved soil fertility and Pangola grass implantation was the best strategy to control the invasive plant.