Valdir Botega Tavares

Teores críticos de fósforo em três solos para o estabelecimento de capim-Mombaça, capim-Marandu e capim-Andropogon em vasos

A pot trial was carried out in a greenhouse to evaluate the effect of phosphorus rates applied in two Oxisols (LVAd and LVd) (0, 110, 220, 330 and 560 mg dm-3 de P) and an Entisol (RQ) (0, 80, 160, 240 and 410 mg dm-3) on tillering and dry matter yield of shoot (SDM) and root (RDM) of Mombacagrass (Panicum maximum cv. Mombaca), Marandugrass (Brachiaria brizantha cv. Marandu) and Andropogongrass (Andropogon gayanus cv. Planaltina) to identify critical phosphorus rates for obtaining 90% of maximum production. Three experiments were set in complete randomized block design in a factorial scheme (five P rates x three species), with three replicates. The phosphorus rates, linearly increased the P available in soil extracted by Mehlich-1 and resin methods. The tillers number per pot and shoot dry matter changed in a quadratic form with phosphorus rates. Plants in the no P did not tiller and shoot dry matter was very low. The critical P doses, corresponding to 90% of maximum yield, for Mombacagrass, Marandugrass and Andropogongrass were respectively 236, 231 and 258 mg dm-3 in LVAd; 274, 305 e 253 mg dm-3 in LVd and 94, 171 and 163 mgdm-3 in RQ, with critical P concentration of 81, 79 and 90 mg dm-3 in the LVAd; 26, 29 e 23 mg dm-3 in the LVd e 53, 83 and 79 mg dm-3 in the RQ, respectively. Lower values for the critical P concentration occurred in LVd (soil with higher clay and silt concentrations) than in the others soils, whose concentrations corresponded to higher critical doses. In all soils P application resulted in higher yield of SDM than RDM.

Effects of different compaction degrees, inclusion of absorbent additive and wilting on the chemical composition of tanzania grass silages

The objective of this work was to evaluate the effects of different compaction degrees, inclusion of absorbent additive and wilting on the chemical composition of tanzania grass silages. The experiment was conducted using tanzania grass (Panicum maximum Jacq. cv. Tanzânia I) harvested at 60-65 days of growth. The forage was ensiled in experimental PVC silos fitted with Bunsen type valves, with capacity for about 4 and 8 kg each. The treatments consisted of three types of silages (control, 5% of citric pulp and pre-wilted) with five compaction degrees (400, 500, 600, 700 and 900 kg/m3). The experimental design was random blocks, with four replicates. Citric pulp and pre-wilting increased the dry matter content of tanzania grass silages. The increased density resulted into decreases in the pH values and amoniacal-N contents; the greatest densities resulted in pH values within the ideal range. The presence of citric pulp and the pre-wilting practice reduce the losses by effluent and gas relative to the control. As the density increased, the amount of effluent increased in the control silage and decreased in silages with citric pulp.

Effect of the addition of Lactobacillus sp. in sugarcane silages

Objetivou-se avaliar o efeito de aditivos microbianos com bacterias heterofermentativas ou homofermentativas sobre as caracteristicas de silagens de cana-de-acucar (Saccharum spp.). A cana-de-acucar foi inoculada com as bacterias Lactobacillus plantarum (LP), L. paracasei (LPARA), L. brevis (LBREVIS), L.buchneri (LB), isoladas da silagem de canade-acucar, e tres inoculantes comerciais, dois contendo L. buchneri (Pioneer 11A44TM-LBP e Lalsil Cana-LBLC) e um, L. plantarum (Biomax®-LPB), e avaliada em comparacao a uma silagem controle (sem inoculante). Todos os inoculantes foram aplicados com populacao de 105 ufc da bacteria por g de forragem. O delineamento utilizado foi o inteiramente casualizado com oito tratamentos e tres repeticoes. O efeito da inoculacao sobre as caracteristicas bromatologicas foi variavel. A silagem contendo a bacteria L. plantarum apresentou maior teor de MS (32,6%), enquanto, para os outros inoculantes, nao houve diferenca, com media de 28,4%. Os teores de proteina bruta variaram de 3,6 a 4,9% e os de FDN, de 60,0 a 66,7%. As porcentagens de FDA, hemicelulose e cinzas foram semelhantes em todas as silagens. O consumo de carboidratos soluveis foi superior a 85% durante a fermentacao, para todas as silagens, o que resultou em pH em torno de 3,5. Os valores de pH e nitrogenio amoniacal para todas as silagens estiveram no padrao aceitavel para silagens de boa qualidade. Os inoculantes retardaram o aumento da temperatura, em aerobiose, conferindo maior estabilidade aerobia. Os melhores resultados foram obtidos com os inoculantes LBLC, LB e LPB.

Perfil de fermentação das silagens de capim-tanzânia com aditivos teores de nitrogênio amoniacal e ph

Em geral, gramineas forrageiras colhidas em estadio de desenvolvimento mais jovem apresentam baixos teores de MS, o que, associado aos baixos teores de carboidratos soluveis, pode prejudicar o processo de fermentacao, comprometendo a qualidade final da silagem. Dessa forma, deve-se adotar procedimentos que modifiquem esse quadro, como a utilizacao de aditivos. Com este trabalho, objetivou-se avaliar a fermentacao das silagens do capim-tanzânia com aditivos em relacao aos teores de nitrogenio amoniacal e pH, e entre esses aditivos, determinar qual deles e em que dose conferem as melhores qualidades a silagem produzida. O experimento foi conduzido nas dependencias do Departamento de Zootecnia da UFLA, utilizando o capim-tanzânia (Panicum maximum Jacq. cv. Tanzânia I) estabelecido em um Latossolo Roxo Argiloso e colhido com 60-65 dias de crescimento. A forragem foi ensilada em silos experimentais de PVC, adaptados com valvula tipo Bunsen, com capacidade para aproximadamente 3 kg cada um. Os tratamentos constituiram-se de tres aditivos (polpa citrica, farelo de trigo e fuba de milho), em quatro doses (3, 6, 9 e 12%) mais uma testemunha, sem aditivos, e 8 tempos de abertura dos silos (0, 1, 2, 3, 7, 14, 28 e 56 dias). O delineamento experimental utilizado foi o de blocos ao acaso, constituindo um esquema fatorial com tratamento adicional [(3 x 4) + 1] x 8 com 3 repeticoes. As adicoes de polpa citrica, farelo de trigo ou fuba de milho melhoram as caracteristicas fermentativas das silagens de capim-tanzânia. As silagens sem aditivos tambem apresentaram valores de pH e nitrogenio amoniacal caracteristicos de uma silagem de qualidade satisfatoria; no entanto, os aditivos devem ser utilizados com o intuito de prevenir perdas.

Avaliação dos conteúdos de carboidratos solúveis do capim-tanzânia ensilado com aditivos

The aim of this study was to check on the effect of additive addition on the variations in the water soluble carbohydrate contents of the tanzaniagrass silage during the fermentation period, and to know the buffering capacity values and water soluble carbohydrate: buffering capacity ratio of this forage. Tanzaniagrass (Panicum maximum Jacq. cv. Tanzânia I) was established in a Clavey Red Dusk Latosol and harvested at 60-65 day of age. The forage was ensiled in experimental PVC silos, fitted with Type Bunsen valves, with a capacity of about 3 kg each. The treatments consisted of four doses (3, 6, 9 and 12%) of three additives (citrus pulp, wheat meal and corn meal), plus one check without additives and 8 times of silo opening (0, 1, 2, 3, 7, 14, 28 and 56 days) building up a factorial scheme with an additional treatment [(3 x 4) + 1] x 8 with 3 replicates. The experiment was run in a completely randomized block design. Water soluble carbohydrate content of tanzaniagrass at 60-65 days of age was low and all of it was consumed during the fermentation process, regardless of additive treatments. All three additives, mainly the citrus pulp, favored the water-soluble carbohydrate contents and buffering capacity of the silages. An increase of the water soluble-carbohydrate: buffering capacity ratio contributes to the yield of better quality silage by assisting in the fermentation process.

Produção e composição do efluente da silagem de capim-elefante com casca de café

The experiment was carried out to evaluate the effects of processing (whole or ground) and including coffee hulls in elephant grass silage on the effluent production and composition. A randomized complete design in a 2 × 5 factorial design with two processes (whole or ground) and five coffee hull levels (0; 6; 12; 18 and 24 %) each with three replications. A split-plot design was used to assess the effluent composition, where the main plot consisted of a 2 × 3 factorial with two processes and three coffee hull levels (0, 6, 12%) and the split-plot consisted of the effluent collection days, with three replications. The total effluent production was 243.1 L/t silage for silage without hulls, 196.8; 93.2; 30.8; 3.1 and 149.1; 52.3; 30.8; 0.0 L/t for the silages with whole and ground hulls at levels of 6, 12, 18 and 24%, respectively. The hull processing and inclusion levels had a quadratic effect, according to the days, on the total solids and total nitrogen contents. A quadratic effect of the processing and days and the hull levels and days, respectively, on the composition in calcium and magnesium. The hull levels and the coffee hull processing had a linear effect on the phosphorus content in the effluent. There were effects of processing, hull levels and of the days on the contents of chemical and biochemical demands for oxygen. Coffee hulls were efficient in reducing effluent production in the elephantgrass silage, especially when ground, because they had more effect than when whole. The effluent composition is influenced by the day of collection and inclusion and processing of coffee hull levels.

Efeitos da adição de batata na silagem de capim-elefante sobre o consumo e a produção em vacas leiteiras

ABSTRACT - The objective of this study was to evaluate production and composition of milk from cows fed silagescontaining potato. Twelve females were selected: nine between 50 and 70 months of age and three between 36 and 42 monthsof age, lactating, with approximate weight of 550 kg. The experimental design consisted of 12 cows in three 4 × 4 Latin Squares,with four experimental periods and four treatments: silages of corn (CS); elephant grass (ES); elephant grass activated with 7%potato residue (ES7%) and elephant grass activated with 14% potato residue (ES14%). The animals submitted to the diets withthe silages CS, ES 14% and ES 7% presented greater ingestions of DM than those that ingested diets based on silage of pure elephantgrass. Supply of diet of elephant grass silage with addition of 14% potato residue presented greater production of milk andmilk corrected for 3.5% fat, kg of fat, kg of protein, kg of total solids, kg of degreased dry extract and kg of lactose comparedwith the addition of 7% potato. The corn silage was superior to the others in production of milk, kg of protein, kg of degreaseddry extract (DDE) and kg of lactose. Elephant grass silage presented smaller production than the other silages for kg of DDEand lactose. There was no difference between treatments for fat contents, protein, total solids, DDE, lactose, or milk urea-N (mg/dL). The addition of 14% of potato residue in the elephant grass silage improves ingestion of DM and production of milk.Key Words: milk fat, milk production corrected for 3.5% fat, milk protein, total solids