Solidete de Fátima Paziani

Fermentation and epiphytic microflora dynamics in sugar cane silage

Silagens de cana-de-acucar caracterizam-se pela extensa atividade de leveduras, alto teor de alcool e grandes perdas de materia seca - MS. Conhecer melhor o processo fermentativo e fundamental para o desenvolvimento de tecnicas eficientes de ensilagem da cana. Este trabalho avalia a mudanca temporal na composicao quimica, nas perdas de MS e na microflora epifita nestas silagens. Cana-de-acucar (RB835486) foi colhida manualmente (12 meses de crescimento), picada em picadora estacionaria e ensilada em baldes de plastico de 20 L com valvulas para gases e aparato para colheita de efluentes. Os silos laboratoriais foram mantidos sob temperatura ambiente e amostrados apos ½, 1, 2, 3, 7, 15, 45, 90, 120 e 180 dias. Etanol atingiu 6,4% na MS no 15o dia apos ensilagem, seguido pelo desaparecimento de 71% dos carboidratos soluveis - CHOs. As perdas gasosas e a perda total de MS estabilizaram-se apos 45 dias (16% e 29% da MS). A contagem de leveduras foi maxima no segundo dia (5,05 log ufc g-1). O pH atingiu nivel abaixo de 4,0 no terceiro dia. A producao de efluentes foi insignificante (20,1 kg t-1). O teor de MS da forragem decresceu (35% para 26%) do dia 0 ao 45o dia. O padrao de variacao na concentracao de etanol foi inverso a concentracao de CHOs e a reducao da digestibilidade da silagem. O desenvolvimento de metodos de controle das leveduras, provavelmente com o uso de aditivos, melhorara a eficiencia no uso de silagens de cana-de-acucar pelos pecuaristas.

Efeito do tratamento com aditivos químicos e inoculantes bacterianos nas perdas e na qualidade de silagens de cana-de-açúcar

Objetivou-se avaliar a eficacia de aditivos quimicos e inoculantes bacterianos na inibicao da producao de etanol, na diminuicao das perdas de MS e na melhoria da digestibilidade in vitro de silagens de cana-de-acucar. Foram testados os seguintes tratamentos (doses com base na materia natural): sem aditivos - controle; UR - ureia (0,5; 1,0; 1,5%); NaOH - hidroxido de sodio (1,0; 2,0; 3,0%); PROP - propionato de calcio (0,05; 0,1; 0,2%); BENZ - benzoato de sodio (0,05; 0,1; 0,2%); SORB - sorbato de potassio (0,015; 0,03; 0,045%); PLA - Lactobacillus plantarum (1 x 106 ufc/g); BUCH - Lactobacillus buchneri (3,64 x 105 ufc/g); PLA/UR 0,5% - L. plantarum combinado com 0,5% de ureia; PLA/UR 1,0% - L. plantarum combinado com 1,0% de ureia. A ensilagem foi realizada em baldes plasticos de 20 L adaptados com valvulas para eliminacao de gases e dispositivo para coleta de efluentes. Os dados foram coletados aos 90 e aos 180 dias apos a ensilagem. Nenhum dos aditivos foi capaz de reduzir a concentracao de etanol nas silagens. Os tratamentos PROP 0,1% e PLA causaram aumento no teor de alcool em relacao a silagem controle (4,8 e 12,5% vs 3,8% da MS, respectivamente). Os tratamentos UR, NaOH, SORB-0,03%, BUCH, PLA/UR 0,5% e PLA/UR 1,0% reduziram a perda total de MS. As silagens tratadas com ureia, hidroxido de sodio, benzoato de sodio e sorbato de potassio 0,045% apresentaram maior digestibilidade in vitro da MS em comparacao a silagem controle.

Aditivos químicos e biológicos na ensilagem de cana-de-açúcar: 1. composição química das silagens, ingestão, digestibilidade e comportamento ingestivo

The effect of the addition of additives in the ensiling of sugar cane (Saccharum officinarum L.) on chemical composition of silages, ingestive behavior, voluntary feed intake and digestibility by beef steers. Five rumen-cannulated Nelore steers were allotted to a 5 x 5 latin square design. The steers were placed in metabolic cages and they were fed with diets with 65% forage (%DM). Five silages were evaluated (wet basis): Control sugar cane, no additives; Urea sugar cane + 0.5% of urea; Benzoate sugar cane + 0.1% of sodium benzoate; LP - sugar cane inoculated with Lactobacillus plantarum (1 x 106 cfu/g forage); LB sugar cane inoculated with L. buchneri (3.6 x 105 cfu/g forage). During 90 days, before the animal feeding, the forage was stocked in vertical silos. The chemical composition of sugar cane changed after the ensiling, as compared to fresh sugar cane, with reduction of water soluble carbohydrates and in vitro digestibility and relative increase in the NDF and ADF content. Ethanol (0.30% DM) and organic acids (0.99% of lactic and 2.31% of acetic acid) contents were low and similar among silages. The additives applied in the ensiling did not promote alterations in the voluntary intake and apparent digestibility of DM that showed average values of 7.2 kg/day and 63.6%, respectively. The ingestive behavior of the animals also was not altered, with average time spent in feeding, rumination and idleness were: 230.6, 519.6 and 672.8 minutes/day activities, respectively.So, the additives applied in the sugar cane forage resulted in slightly changes in most of the studied variables.

Fermentation, losses, and aerobic stability of sugarcane silages treated with chemical or bacterial additives

Utilization of sugarcane Saccharum officinarum L. silage is increasing in Brazil but intensive ethanol production during fermentation reduces forage quality. This experiment aimed to evaluate the effects of additives on fermentation and aerobic stability of sugarcane silages produced in minisilos. Treatments were (fresh basis): untreated silage (control), urea (5.0 g kg-1), sodium benzoate (1.0 g kg-1), potassium sorbate (0.3 g kg-1), Lactobacillus plantarum (1 x 106 cfu g-1), and Lactobacillus buchneri (3.64 x 105 cfu g-1). At the 94th day after ensilage, ethanol concentration was lower in urea, benzoate, sorbate and L. buchneri supplemented silages and higher in L. plantarum inoculated silage, as compared to control. Urea and benzoate treated silages showed the highest and L. plantarum treated silage the lowest in vitro dry matter digestibility. Effluent production was higher in the urea treated silage. Inoculation with L. buchneri reduced 50% ethanol production as compared to control. Urea and L. buchneri reduced yeast count. Aerobic stability was enhanced by L. buchneri and benzoate. Sodium benzoate and L. buchneri were the most promising additives, improving both silage fermentation and aerobic stability; inoculants containing L. plantarum can be deleterious to fermentation and conservation of sugarcane silages.

Características agronômicas e bromatológicas de híbridos de milho para produção de silagem

The objective of this work was to establish correlations between quantitative and qualitative variables and to evaluate their influence on the corn quality for ensilage production. Data from the Corn Hybrids for Silage Evaluation Program were used (IAC/APTA/ESALQ). Pearson correlations between the variables were calculated. The digestible dry matter (DM) production was affected not only by forage and grain productions, but also by the whole plant and stem digestibility. The digestible dry matter production presented the highest correlation coefficients with the total dry matter production (0.85) and with the grain production at ensiling (0.60) and maturity (0.68), production of fresh forage (0.47) and with the plant ears index (0.48). The correlation coefficients between the digestible DM production and the whole plant digestibility (0.44) and the stem fraction (0.38) were lower than those observed for the DM production. The whole plant digestibility depended mainly on the stem digestibility (0.60) and on parameters related to the grains. It may be concluded that when specific information on corn hybrids is not available, those with higher production of grains at maturity are selected due to their elevated correlation with DM production and digestible DM.

Avaliação da determinação da fibra em detergente neutro e da fibra em detergente ácido pelo sistema ANKOM

The ANKOM filter bag system was compared with the conventional filtration system (Van Soest) to determine acid detergent fiber (ADF) and neutral detergent fiber (NDF) in different materials. In the first experiment five feeds (sugar cane, Marandu grass - Brachiaria brizantha cv. Marandu, corn silage, citrus pulp and cattle feces) and four types of filter bags were compared. A completely randomized block design in a factorial scheme (5x4), with three replications, was used. The means obtained by the ANKOM system were compared with those obtained by the conventional filtration procedure. The sample amount effect (0.5; 0.8; 1.0 g) in each filter bag on ADF and NDF contents was studied in the second experiment, using three feeds and the ANKOM system. In this experiment, a completely randomized blocks design, in a factorial scheme (three feeds x three amount feed) and three replications, was used. The types of filter bag did not affect the NDF content of the different feeds, except for feces, which bags showed smaller NDF contents. There were no statistical differences among NDF or ADF values determined either by the ANKOM or by the conventional filtration procedures for most of the feeds used, except citrus pulp, which had lower ANKOM- ADF values than the conventional procedure. The sample amount did not affect the NDF of the feed determined by the ANKOM System.

Valor nutritivo de silagens de capim-marandu submetidas aos efeitos de umidade, inoculação bacteriana e estação do ano

The objectives of this work were to evaluate the effect of year season, dry matter concentration (DM), and bacterial inoculation on the nutritive value of palisadegrass silages. The trial was carried out in a complete randomized experimental design with four replications, in a factorial arrangement (2 × 3 × 3): two year seasons (summer and winter), three dry matter levels (with or without wilting or added with dried citrus pulp), and without microbial additive or with Lactobacillus plantarum or Lactobacillus buchneri, totalizing 18 treatments. Silages were stored in 20 L plastic buckets. After 90-d of fermentation, the silos were opened and the silages were evaluated. Wilting increased DM, neutral detergent fiber (NDF), and lignin (LIG), in both year seasons, and did not change in vitro true dry matter digestibility (IVTDMD). Addition of citrus pulp increased crude protein (CP) concentration and water soluble carbohydrates (WSC) and decreased the NDF concentration. As a result, this additive increased the IVTDMD in both year seasons. The use of microbial inoculants did not change fiber fractions and did not increase the IVTDMD in the silages. Summer-silages had higher CP level and lower cell wall concentrations, except for HEM, resulting in higher IVTDMD. The low nutritive value obtained for the winter silages was not in agreement with the literature, mainly due to the greater regrowth age of palisadegrass in this season. As a result, the overall analysis pointed out that summer season silages are a better option of roughage for animal nutrition, mainly when ensiled with dried and pelleted citrus pulp.

Relações biométricas entre o estádio de maturação e a produtividade de híbridos de milho para produção de silagem

This experiment evaluated the plant and stem dry matter (DM) content, plant, stem and grain DM productivity of corn cultivars harvested in different maturity stages. A randomized block design, with a 8 × 6 × 2 factorial scheme, composed of eight harvesting times, six corn cultivars and two evaluation harvests (2001/2002 and 2002/2003) was used. Cultivars CO 32, AG 5011, P 3041, DKB 333B, AG 1051 and Z 8550 were harvested when reaching 50% of male flowering, 15 days after this date and later, every week, totalizing eight harvesting times. Cultivar CO 32 showed the highest plant and stem DM content, and the lowest stem DM production, while cultivar P 3041 achieved the lowest plant and stem DM content. The maturity advance resulted in increased plant DM content, (from 14.5 to 46%), stem DM content (from 16.9 to 28%), plant DM production (from 9.6 to 20.9 t DM/ha) and grain production (from 0 to 9.3 t DM/ha). In the 2001/2002 harvest, the production was initially reduced and then increased, while in the 2002/2003 harvest, the production increased up to the 6th harvest and then reduced again. The plant DM content showed low correlations with plant DM production (r2 = 0.27), stem DM production (r2 = 0.13) and grain production (r2 = 0.40). The plant DM production showed high positive correlation with stem production (r2 = 0.83) and grain production (r2 = 0.72). The individual evaluation of the ideal plant harvesting time for a good silage production is fundamental, once the harvesting window for ensilage can be reduced in function of specific characteristics of each material.