Gustavo Rezende Siqueira

Bagaço de cana-de-açúcar tratado com hidróxido de sódio

The experiment was conducted with the objective of evaluating chemical composition and in vitro dry matter digestibility of sugar-cane bagasse containing 60% dry matter submited to increasing sodium hydroxide concentrations (0, 2.5, 5, and 7.5% NaOH on a dry matter basis). NaOH was applied as a 2:1 water:NaOH solution, over different treatment times (1, 3, 5, and 7 days). Plastic pails with 10 L capacity were utilized and stocked in climatic chamber at 25oC constant temperature. The experimental treatments had no effect on the crude protein content of the sugar cane bagasse which averaged 1.6% CP. The dry matter content of the bagasse increased over of the days of treatment, without any effect of the NaOH solution concentration. Mean values for the bagasse neutral detergent fiber, acid detergent fiber, cellulose, hemicellulose and lignin contents declined in response to NAOH solution concentration. NaOH treatment improved the in vitro dry matter digestibility (IVDMD) and sodium content of the bagasse. Time of treatment had no effect on these variables. The treatment of sugar cane bagasse with the NaOH solution improved its nutritive value in terms of its reduced cell wall constituents and increased IVDMD.

Avaliação da queima e da adição de milho desintegrado com palha e sabugo na ensilagem de cana-de-açúcar

This research aimed to evaluate the effects of burning and the use of dry additive on the sugar cane silage fermentative pattern. Six treatments were tested: natural or burned sugarcane, associated to three supplementation levels: 0, 50 or 100 g/kg of dehydrated corn grain, cob, and straw (CGCS) based on forage fresh mater. The following response variables were determined in the forage: DM, CP, acid detergent insoluble nitrogen (ADIN), NDF, ADF, cellulose, hemicellulose and lignin concentrations. Considering the fermentative traits, soluble carbohydrate levels, buffering capacity, pH, ammonia nitrogen and ethanol levels were measured. The CGCS inclusion increased DM concentration and slightly reduced ethanol and N-NH3 levels in silages, but did not affect pH or yeast growth. Burning reduced DM and N-NH3 concentration, as well as increased ethanol levels and yeast growth. Ethanol production in sugarcane silage was not controlled by using dry additive or burning.

Queima e aditivos químicos e bacterianos na ensilagem de cana-de-açúcar

Objetivou-se avaliar o efeito da queima e do uso de aditivos (ureia, benzoato de sodio, hidroxido de sodio (NaOH), Propionibacterium acidipropionici + Lactobacillus plantarum e Lactobacillus buchneri) na ensilagem de cana-de-acucar. Utilizou-se o delineamento inteiramente casualizado, em esquema fatorial 2 (cana-de-acucar crua e queimada) × 6 (cinco aditivos mais o grupo controle) com tres repeticoes. Determinaram-se as perdas durante o processo fermentativo nas formas de gases e de efluentes e a recuperacao de materia seca (MS). Maior recuperacao de MS foi observada nas silagens de cana-de-acucar queimada (77,3%) em relacao as silagens de cana crua (73,1%). As recuperacoes de MS observadas nas silagens tratadas com NaOH ou L. buchneri foram de 84%, enquanto das silagens controle, 69%. No periodo apos abertura, uma variavel importante e a inibicao da elevacao do pH, nesse caso, medida pela variacao do pH. Destacam-se como inibidores da variacao do pH o benzoato de sodio e o L. buchneri, que promoveram variacao do pH de 0,05 e 0,18 unidade de pH, respectivamente. A ensilagem da cana-de-acucar sem aditivos, crua ou queimada, e uma estrategia que resulta em grandes perdas quantitativas, que podem ser evitadas pelo uso de aditivos. Entre os aditivos avaliados, o L. buchneri e o que atua de forma mais satisfatoria nas fases de fermentacao e pos-abertura de silagens de cana-de-acucar crua ou queimada.

Effects of feeding corn silage inoculated with microbial additives on the ruminal fermentation, microbial protein yield, and growth performance of lambs

This study aimed to examine the effects of feeding corn silage inoculated without or with either Lactobacillus buchneri (LB) alone or a combination of LB and Lactobacillus plantarum (LBLP) on the apparent digestibility, ruminal fermentation, microbial protein synthesis, and growth performance of lambs. Thirty Santa Inês×Dorper crossbred intact males lambs weighing 20.4±3.8 kg were blocked by weight into 10 groups. Lambs in each group were randomly assigned to 1 of the following 3 dietary treatments: untreated (Control), LB, and LBLP silage. Lambs were fed experimental diets for 61 d. The apparent digestibility was indirectly estimated from indigestible NDF measured on d 57 to 59. Spot urine samples were collected from all animals on d 59 to estimate microbial protein synthesis. Lambs were slaughtered for carcass evaluation on d 61 when they weighed 32.4±5.2 kg. Six additional ruminally cannulated Santa Inês×Dorper crossbred wethers weighing 40.5±1.8 kg were used to examine dietary effects on ruminal fermentation. Average daily gain was increased when lambs were fed LBLP silage (P<0.05) but not LB silage. The LBLP silage had the highest (P<0.05) lactic acid concentration and both inoculated silages had greater acetic acid concentrations than the Control silage (P<0.05). Inoculation of corn silage increased intakes of DM, OM, CP, NDF, total carbohydrate (CHO), and GE by the lambs but decreased digestibility of DM, OM, CP, total and nonstructural carbohydrates, and concentration of GE and ME. (P<0.05). Nevertheless, lambs fed inoculated silages had greater microbial N supply than those on the Control treatment (P<0.05). The acetate to propionate ratio was lower in ruminal fluid of wethers in LBLP treatment than LB and Control treatment (P<0.05) and ruminal pH tended to be greater in LB lambs than in LBLP and Control wethers (P<0.10). Finally, the inoculation with both bacteria combined enhanced the silage fermentation. The intakes of DM, OM, CP, NDF, and GE were improved in the lambs fed corn silage inoculated with L. buchneri alone or combined with L. plantarum. The microbial N supply was enhanced in the lambs fed corn silage inoculated with L. buchneri. The inoculation of L. buchneri combined with L. plantarum reduced the acetate to propionate ratio in ruminal fluid and improved the ADG of lambs.

Características fermentativas e químicas de silagens de capim-marandu produzidas com quatro pressões de compactação

The objective of this experiment was to evaluate the fermentative and chemical parameters of four different bulk densities of marandugrass (Brachiaria brizantha) silages. The forage was harvested with 60 days of vegetative growth and 32% of DM. The bulk densities used were 100, 120, 140 and 160 kg DM/m3. Treatments were distributed in a completely randomized design with four replicates. Gas production data were analyzed by repeated measures model. The lower density silages showed greater gas production. Low effluent production was observed in all treatments due to the high forage DM during harvesting. Higher bulk density silos showed lower DM losses and also achieved a lower pH than lower density silos. Ammoniacal nitrogen concentration was not influenced by treatments and the observed values were satisfactory for tropical grasses silages. Bulk density increase provided a reduction in NIDN, B3 fraction, NDF and ADF concentration. Higher bulk densities also provided greater DM recovery and greater true in vitro DM digestibility.

Performance of Nellore young bulls on Marandu grass pasture with protein supplementation

The objective of this study was to verify the effect of low-intake supplementation on performance of Nellore young bulls kept on Marandu grass pasture. The experiment was divided in two periods: the dry and rainy seasons. Treatments during the dry period were composed of mineral salt with urea and mineral supplement enriched with true protein and additive. In the rainy period treatments were mineral salt and enriched mineral supplement only. Pastures were evaluated and animals were weighed in both evaluation phases. The variables studied were evaluated in a completely randomized design in a split-plot arrangement, where plots were treatments and subplots were the periods within each phase, considering the types of supplementation as treatments. During the dry season there was no effect of supplement type in the first and second periods of assessment on weight gain of animals, which was of 0.307 and 0.113 kg/day, respectively. In the third period of this phase there was effect of the type of supplementation on animal performance; animals which received enriched mineral supplement gained 0.600 kg/day vs. 0.517 kg/day for those which received mineral salt with urea. In the rainy season, animals receiving enriched mineral supplement gained more weight than animals receiving mineral supplement: 0.800 and 0.696 kg/day, respectively. Mineral supplementation with addition of protein and additives provides increases in the weight gains of animals kept at a grazing regime of 15%.

Degradabilidade ruminal da matéria seca, da fração fibrosa e da proteína bruta de forrageiras

Abstract – The objective of this work was to evaluate ruminal degradability of dry matter, neutral detergent fiber,acid detergent fiber and crude protein of alfalfa ( Medicago sativa ), black oat ( Avena strigosa ), leucaena ( Leucaenaleucocephala ) and pigeon pea ( Cajanus cajan ). Samples of 3 g of forages were incubated in the rumen of threesteers for 0, 6, 12, 24, 36, 48 and 72 hours periods. The dry matter effective degradabilities of alfalfa and oat, fora passage rate of 5%/hour, were high (over 60%). However, leucaena and pigeon pea showed lower values, 50.9and 56.0%, respectively. From 24-hour incubation period on, the oat presented the highest neutral detergent fiberand acid detergent fiber disappearance and showed the greatest effective degradation rates of these fractions.The oat was the forage with the highest dry matter, neutral detergent fiber, acid detergent fiber and crude proteinruminal degradability. Pigeon pea, however, was the forage that showed the worst degradation rates.Index terms: degradation, forage, roughage, rumen.

Degradabilidade ruminal da matéria seca, da proteína bruta e da fração fibrosa de silagens de milho, de sorgo e de Brachiaria brizantha

Avaliou-se a degradacao da materia seca (MS), da proteina bruta (PB), da fibra em detergente neutro (FDN), da fibra em detergente acido (FDA) e da hemicelulose das silagens de milho, de sorgo e de Brachiaria brizantha. Foram utilizados tres novilhos Nelore, machos, fistulados no rumen, com media de peso de 200kg. Em cada animal foram incubadas amostras das tres silagens nos tempos de 0, 6, 12, 24, 36, 48, 72 e 96 horas. Para as degradabilidades potencial e efetiva da MS (taxa de passagem no rumen de 5%/h), a silagem de milho foi a que apresentou valores mais altos, 80,1 e 56,7%, respectivamente, seguida da silagem de sorgo, 73,0 e 45,3%, e da silagem de Brachiaria, 60,8 e 33,7%. Para a PB, o maior valor de degradabilidade foi verificado para a silagem de milho, 87,0%, seguida das silagens de sorgo, 81,8%, e de Brachiaria, 75,2%. A degradabilidade da FDN foi maior para as silagens de milho e sorgo. Para FDA, a silagem de sorgo apresentou perfil de degradacao menor que a silagem de milho. Os resultados sugerem melhor qualidade da silagem de milho, seguida pela do sorgo e pela de Brachiaria.

Óxido de cálcio e Lactobacillus buchneri NCIMB 40788 na ensilagem de cana-de-açúcar in natura ou queimada

The objective of this trial was to evaluate the effects of the inclusion of calcium oxide (CaO) and/or L. buchneri (LB) on the losses and chemical composition changes of in natura and burned sugar cane silages. Silage treatments were: in natura sugar cane without additive (IS), with Lactobacillus buchneri (ISLB), with calcium oxide (ISCaO) equivalent to 1% of natural matter, and the combination of LB and CaO (ISLBCaO). Experimental design was completely randomized in a factorial scheme (2 × 4) considering status (burned or not) and additives (LB, CaO and LB+CaO) with three replications per treatment. Dry matter variation was lower for in natura and burned silages treated with CaO; regardless of the LB presence, the mean difference was 5.85 percentage units. In sugar cane silages without additives, higher dry matter recoveries were observed when the plant was ensiled with in natura silage (63.5%) compared with burned silage (46.8%). However, when additives (CaO and LB) were used, no significant differences occurred between the in natura and burned silage treatments. The presence of calcium oxide was the factor that provided the greatest discrimination among the data. Calcium oxide is effective in reducing losses and chemical changes on the in natura and burned silages. The L. buchneri acts effectively on burned sugar cane silages, and the latter are more susceptible to losses than those of in natura sugar cane.

Beef quality of young Angus × Nellore cattle supplemented with rumen-protected lipids during rearing and fatting periods

This work evaluated the beef quality parameters of 108 bulls randomly administered to three treatments during rearing in pastures and two treatments during fatting in feedlots, including mineral and rumen-protected lipids. Meat and fat color, cooking yield, shear force, sensorial traits and chemical and fatty acid compositions were evaluated. Generally, the beef quality parameters were not affected by the rumen protected lipids; however, supplementation with rumen-protected lipids during the rearing period yielded darker beef and brighter fat and increased beef tenderness in meat aged for 28days compared to the meat from animals that received only mineral supplementation. In addition, the percent of meat polyunsaturated fatty acids was negatively affected by the inclusion of protected lipids, yielding 5.58 and 3.72% in animals fed with and without rumen-protected lipids, respectively, during the fatting period.