Ingestive behavior of calves on pastures of Brachiaria brizantha and Brachiaria decumbens RESUMO Foi conduzido um experimento com o objetivo de avaliar o comportamento de bezerros em pastagens de

Objetivou-se avaliar o efeito da inclusão de farelo de trigo sobre as perdas, recuperação da MS e qualidade de silagem de capim-mombaça, em um experimento inteiramente casualizado com quatro tratamentos: 0, 20, 40 e 60% de farelo de trigo, e quatro repetições por tratamento. Foram utilizados baldes com capacidade para 15 litros, dotados de válvula de bunsen, para escape dos gases e com 3 kg de areia adicionados no fundo para retenção dos efluentes. As variáveis avaliadas foram perdas por gases, perdas por efluentes, recuperação da matéria seca, pH, N-amoniacal, matéria seca (MS), proteína bruta (PB), fibra em detergente neutro (FDN), fibra em detergente ácido (FDA) e hemicelulose (HEM). A adição de farelo de trigo reduziu as perdas por gases e as perdas por efluentes. A recuperação da matéria seca foi menor para o tratamento sem farelo de trigo. Os valores de PB aumentaram com a adição de farelo de trigo. Os valores de FDN e FDA na silagem reduziram de forma linear em função da aplicação de farelo de trigo. Conclui-se que a inclusão de 20% de farelo de trigo é suficiente para atingir melhorias consideráveis na qualidade da silagem de capim-mombaça e, considerando-se o aspecto econômico, pode ser adotado.

No abstract

We evaluated the fractions of protein and carbohydrates in distillers dried grains with solubles (DDGS), corn grain (CG), soybean meal (SM), and corn silage (CS), as well as the in vitro digestibility (IVD) of DDGS, CG, SM, CS, rations containing 0.0, 8.0, 16.0, and 24.0% DDGS, and in vitro fermentation parameters after 24 h of incubation. DDGS were obtained following microbial fermentation for ethanol production from a sugar and alcohol distillery located in the state of Mato Grosso -Brazil. The Cornell Net Carbohydrate and Protein System (CNCPS) was used to determine the protein and carbohydrate fractions of experimental diets. For the in vitro nutrient digestion assay using the experimental foods and experimental diets, two sheep with an average body weight of 26 kg were used as inoculum donors. The in vitro digestibility of food and feed was assayed in three replicates. Fraction A of DDGS CP was 88, 71, and 37% lower in relation to fraction A of SM, CG, and CS, respectively. Fraction B2 of DDGS protein contained 21% CP, which represents 78.84% of DDGS protein in fraction B2, and is higher than the SM, which was 70.44%. The B3 fraction of CP, which is partly released during ruminal fermentation, was 18% lower for SM compared to DDGS, and is expressed in %CP. For carbohydrate fractionation, the DDGS presented 8.64% for the A + B1 fraction on a DM basis, which was 62, 86, and 74% lower compared to those obtained for SM, CG. and CS, respectively. The hemicellulose and cellulose contents of DDGS were higher than those of SM, as verified in fraction B2, with a value of 46.92%, expressed in DM. The in vitro digestibility coefficients (IVDC) of the DDGS nutrients did not differ (p > 0.05) in relation to those of the other experimental foods. The inclusion of DDGS in rations formulated for sheep did not change (p > 0.05) the IVDC of DM, OM, CP. NDF, or ADF, with mean values of 70.93, 70.64, 59.58, 52.83, and 43.40%, respectively. Therefore, DDGS comprise a proteinrich food containing more than 70% CP in fraction B2, with a large amount of carbohydrates bound to the cell wall. In addition, DDGS possess a similar digestibility coefficient to corn grain and soybean meal; however, up to 24% can be included in feed formulations for ruminants without changing the in vitro digestibility coefficient of nutrients. ResumoForam avaliadas as frações da proteína e dos carboidratos de grãos secos de destilaria com solúveis (GSDS), grão de milho (GM), farelo de soja (FS), e silagem de milho (SM), e a digestibilidade in vitro (CDIV) do GSDS, GM, FS, SM e de rações contendo a inclusão de 0,0%; 8,0%; 16,0% e 24,0% de GSDS, bem como os parâmetros de fermentação in vitro após 24 horas de incubação. O GSDS foi obtido após processo de fermentação microbiana para a produção do etanol, de uma destilaria de flex de açúcar e álcool localizada no estado de Mato Grosso -Brasil. Para determinação das frações proteicas e de carboidratos dos alimentos experimentais foi utilizado Cornell Net Carbohydrate and Protein System -CNCPS. Para o ...

Twenty crossbred lambs (21.6 ± 3.5 kg BW) were used in a completely randomised design to determine the effects of babassu mesocarp flour (BMF) on performance and ingestive behaviour. The treatments were defined by the increase in concentrations (0, 10, 20 or 30%, in DM basis) of BMF in the diet. When significant treatments effects were found, orthogonal polynomials for treatment responses were determined by linear and quadratic responses (p < .05). To determine the in situ ruminal degradability of the diets used in performance trial, one rumen-fistulated Santa Inês male sheep (63 kg BW) was used in a completely randomised design in a split splot arrangement with three replications (three periods of incubation) in times 3, 6, 24 and 72 h. Data from potential degradability (PD), dry matter (DM) and crude protein (CP) degradability for diets and the incubation time were compared by t-test (p < .05). Negative quadratic effect was observed upon nutrients intake, except for neutral detergent fiber (NDF) intake. The average daily gain, body condition score, feeding efficiency of DM and time spent in feeding decreased linearly with BMF addition. The BMF decreased the soluble fraction (a) potentially degradable fraction (b) PD, effective degradability of DM and CP and the NDF degradability. The addition of BMF in diets of sheep had negative effects on performance, feed efficiency of DM and degradability of DM, CP and NDF. However, the BMF can be used in diets, during the conventional grains off-season, at concentration up to 10.5% as alternative feed. HIGHLIGHTS The mesocarp produced from industrialization of the babassu coconut has a great content of fiber and lignin. The great content of fiber associated to decrease in degradation of fiber and potential degradability in DM and CP reduced the performance of lambs. Although the reduction of the performance, BMF can partially replace the corn in diets of lambs in periods that the price of this ingredient is great.

Inadequate management in recent times has been considered the main factor contributing to pasture degradation. A major reason for this is related to gross errors of grazing management as a consequence of the lack of knowledge of ecophysiological limits of forage. This review aimed to approach the importance of organic reserves for grasses under grazing. Therefore, the predominant effect of animal grazing is the reduction of leaf area which impacts on carbohydrate and nitrogen reserves and consequently the growth of tillers, leaves and roots. Grass growth after defoliation is related to organic reserves and rate of photosynthesis. The latter is affected by the level of canopy light interception of and by the reminiscent leaf area index. When grazing management is carried out with respect to the physiological limits of grass growth, the rate of dry matter accumulation will be quick and constant. In this aspect, grazing management consists of seeking an efficient balance between plant growth and consumption which will reflect on animal productivity. Therefore, a balance point among frequency and intensity of defoliation must be found to achieve greater animal production concerning the ecophysiological limits of the forage plants. So the challenge will be to find a balance between frequency and intensity of grazing to achieve greater production of animals respecting the eco-physiological limits of forage plants for each forage grass individually.

This study aimed to evaluate the effects of Streptococcus bovis on the fermentation characteristics and nutritive value of Tanzania grass silage. Tanzania grass was chopped and left untreated (U) or treated with Streptococcus bovis JB1 at 1 × 106 colony-forming units per gram (cfu/g) of fresh forage or Streptococcus bovis HC5 at 1 × 106 cfu/g of fresh forage and packed into sixtuplicate laboratory silos. The largest number of enterobacteria, molds and yeast (M&Y) occurred in untreated silages and the smallest populations of enterobacteria and M&Y and the largest numbers of lactic acid bacteria (LAB), at 9.81 and 9.87 log cfu/g, were observed in Streptococcus bovis JB1 and HC5, respectively (P < 0.05). Silages treated with JB1 and HC5 had lower (P < 0.05) silage pHs and concentrations of ammoniacal nitrogen (NH3-N) than untreated silages. The application of Streptococcus bovis JB1 and HC5 resulted in fewer losses through gases and effluents (P < 0.05), which resulted in greater dry matter recovery (DMR) and crude protein recovery (CPR) (P < 0.05). Streptococcus bovis JB1 and HC5 improved the fermentative profile and increased the concentration of crude protein and DMR and CPR in Tanzania grass silage.

SUMMARYThe objective of this study was to evaluate morphogenetic and structural characteristics of Guinea grass pastures subjected to two grazing frequencies (90 and 95% light interception) and two post-grazing heights (30 and 50 cm), during the rainy season and dry year. The leaf appearance rate varied only in the summer, the grazing pastures managed at 90/50 (light interception/post-grazing height) presented higher values in the leaf appearance rate (0.440 leaf/tiller.day), compared with those managed at 90/30 (0.275 leaf/tiller.day) and 95/50 (0.228 leaf/tiller.day), respectively. In the winter/beginning of the spring, pastures managed at 90/30 (0.03 cm/tiller.day) presented lower stem elongation rate in comparison with those managed at 90/50 (0.19 cm/tiller.day) and 95/30 (0.16 cm/tiller.day). Management strategies do not compromise the tissue flow in tillers and, consequently, can be utilized for the management of Guinea grass.